Urokinase-type plasminogen activator receptor (UPAR)-PET / CT in head and neck squamous cell carcinoma (HNSCC)

Abstract

The present invention relates to a positron emission imaging agent for use in predicting the prognosis of head and neck cancer (HNSCC) by PET imaging of the cancer in a subject, the imaging agent comprising a uPAR binding peptide bound to the radionuclide 68Ga or 64Cu via the chelating agent NOTA or DOTA.

Description

[Technical field]

[0001] The present invention relates to a positron-emitting nuclide-labeled peptide conjugate for use in predicting the prognosis of head and neck cancer (HNSCC) by PET imaging of a patient's tumor. In particular, the present invention relates to the use of the conjugate 68GA-NOTA-AE105 in predicting the prognosis of recurrence-free survival (RFS) using PET imaging of subjects suffering from head and neck cancer (HNSCC). [Background technology]

[0002] Traditionally, head and neck squamous cell carcinoma (HNSCC) has been attributed to alcohol and smoking, but in recent years, the rise in incidence of oropharyngeal carcinoma (OPSCC) has been linked to human papillomavirus (HPV) (1). Currently, HPV-positive tumors account for 63% of OPSCC cases in Western Europe and have a very good prognosis (2,3). HPV-positive and HPV-negative OPSCC show distinct molecular and clinical characteristics, and new staging guidelines downstage HPV-positive tumors based on p16 immunohistochemistry as a surrogate marker for HPV-induced carcinogenesis (3,4).

[0003] However, recent clinical trials investigating attenuated treatment regimens for low-risk HPV-positive OPSCC have resulted in poor survival in the attenuated group.(5-8) Currently, there are no reliable methods to identify candidates for attenuated treatment, and HPV-positive and -negative OPSCC are treated similarly.(3,9)

[0004] Primary tumor spread, regional lymph node and metastasis (TNM) stage, and HPV are the most important prognostic factors for HNSCC, but there are no other prognostic biomarkers available for clinical use. Published results regarding the prognostic value of 18F-FDG are inconsistent (9-11).

[0005] Urokinase-type plasminogen activator receptor (uPAR) promotes cancer cell invasion by degrading the extracellular matrix and promotes several carcinogenic processes, including proliferation and migration (12-14). High expression of uPAR has been reported in many types of cancer, including HNSCC, by non-PET techniques and has been associated with high disease grade, distant metastasis, and poor survival (14). uPAR is located on the cell surface, with limited expression in the surrounding tissues (13). 68Ga- and 64Cu-labeled AE105-radioligens have been used in uPAR-PET studies in patients with various cancer types (15-17), but no studies have been performed in HNSCC.

[0006] WO 2014 / 086364A1 discloses peptides labeled with positron-emitting nuclides, including 68Ga-NOTA-AE105, 68Ga-DOTA-AE105, 64Cu-NOTA-AE105 and 64Cu-DOTA-AE105, for use in uPAR PET imaging of human cancers. WO 2014 / 086364A1 does not mention HNSCC. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, it would be beneficial to improve methods for predicting the prognosis of patients with HNSCC. [Means for solving the problem]

[0008] The aim of this study was to investigate the prognostic value of uPAR-PET tracer (AE105) (68Ga-NOTA-AE105 as an example) in patients with HNSCC using PET / CT and to compare it with 18F-FDG-PET.

[0009] It was found that in HNSCC patients, high primary tumor uPAR-PET-tracer uptake was associated with poor recurrence-free survival (RFS), whereas low primary tumor uPAR-PET-tracer uptake was associated with good recurrence-free survival (RFS) in HNSCC patients. Surprisingly, low amounts of uPAR performed better than 18F-FDG-PET, especially when evaluating recurrence-free survival (RFS) (see, for example, Example 5, compare Figures 3A and 3C).

[0010] Therefore, uPAR-PET / CT represents a promising tool for clinicians to select low-risk HNSCC patients for attenuated treatment regimens to avoid unnecessary toxicity and for risk-stratified follow-up plans.

[0011] It is therefore an object of the present invention to provide improved prognostic tools for HNSCC patients.

[0012] In particular, it is an object of the present invention to provide improved prognostic tools for determining recurrence-free survival (RFS) in HNSCC patients.

[0013] Accordingly, an aspect of the present invention is a positron-emitting imaging agent for use in determining the prognosis of a patient with head and neck cancer (HNSCC) by PET imaging of the cancer, comprising: The imaging agent comprises a uPAR binding peptide bound to the radionuclide 68Ga or 64Cu via the chelator NOTA or DOTA; The objective of the present invention is to provide an imaging agent which is a uPAR-binding peptide which is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof.

[0014] Two uPAR-PET tracers, 64Cu-DOTA-AE105 and 68Ga-NOTA-AE105, share the same binding moiety, the peptide AE105. Moreover, both have been tested in both humans and animals (e.g., 15, 17 and WO 2014 / 086364 A1) and have been shown to be similarly taken up by breast, bladder and prostate cancers. Thus, without wishing to be bound by theory, - with 64Cu or 68Ga as radionuclides; - with DOTA or NOTA as chelating agents; - a uPAR binding peptide according to the invention; It is believed that PET tracers including may act in a similar manner in HNSCC patients.

[0015] Another aspect of the invention is a positron emitting imaging agent for use in determining the prognosis of a patient with head and neck cancer (HNSCC) by PET imaging of the cancer, comprising: the imaging agent comprises a uPAR binding peptide conjugated to the radionuclide 68Ga via the chelator NOTA; The uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) (AE105) or a uPAR-binding variant thereof.

[0016] A further aspect is a positron emitting imaging agent for use in determining the prognosis of recurrence free survival (RFS) and / or overall survival (OS) of a human patient with head and neck squamous cell carcinoma (HNSCC) by PET imaging of the cancer, comprising: the imaging agent comprises a uPAR binding peptide conjugated to the radionuclide 68Ga via the chelator NOTA; the uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof; This uPAR-binding variant is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Ser)-(Leu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Gln)-(Tyr)(Leu)-(Trp)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Thr)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (D-Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(β-2-naphthyl-L-alanine)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Leu)-(Leu)-(Trp)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(β-cyclohexyl-L-alanine)-(Leu)-(Trp)-(Ile), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(D-His); (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(3-indolylethyl)glycine)-(N-(2-methoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-benzylglycine)-(N-(2[beta]thoxyethyl)glycine), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(methylnaphthalyl)glycine)-(N-(2-methoxyethyl)glycine) and (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(2,3-dimethoxybenzyl)glycine)-(Ile); is selected from the group consisting of - Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate poor prognosis with respect to recurrence-free survival (RFS) and / or poor prognosis with respect to overall survival (OS); and - Quantified SUVmax and / or SUVmean values ​​below a threshold value indicate a favorable prognosis in terms of recurrence-free survival (RFS) and / or overall survival (OS), Concerning imaging agents.

[0017] A further aspect of the invention is a method of in vivo imaging by PET imaging to assess prognosis of head and neck cancer (HNSCC) in a patient, the method comprising: a) providing a subject that has been previously administered an imaging agent as defined according to the present invention; b) detecting radioactive emissions from the 68Ga radioisotope of the imaging agent administered in step a) by in vivo PET imaging; c) generating an image representative of the location and / or amount of said radioactive emissions; d) determining the distribution and extent of uPAR expression in said subject, said expression correlating with said signal emitted by said in vivo imaging agent; e) comparing the determined distribution and extent of uPAR expression to a threshold; Including, Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate poor prognosis with respect to recurrence-free survival (RFS) and / or poor prognosis with respect to overall survival (OS); and Quantified SUVmax and / or SUVmean values ​​below a threshold value indicate a favorable prognosis in terms of recurrence-free survival (RFS) and / or overall survival (OS), It concerns the method.

[0018] Yet another aspect of the present invention is the use of a positron emitting imaging agent according to the present invention in predicting the prognosis of a patient with head and neck cancer (HNSCC) by in vivo PET imaging of a tumor expressing uPAR, comprising: the imaging agent comprises a uPAR binding peptide conjugated to the radionuclide 68Ga via the chelator NOTA; The uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof. Regarding use. [Brief description of the drawings]

[0019] [Figure 1] CONSORT flow diagram of the inclusion procedure. [Diagram 2] Target tumor volumes are delineated for two discordant cases of 68Ga-uPAR-high / 18F-FDG-low (A) and 68Ga-uPAR-low / 18F-FDG-high (B) on uPAR-PET / CT using 68Ga-NOTA-AE105 and 18F-FDG-PET / CT. Both cases are stage 3 oropharyngeal cancer (T3N0M0). High and low refer to above or below the established cutoffs. [Figure 3A] (A) Kaplan-Meier plot of 68Ga-uPAR RFS stratified by corresponding 68Ga-uPAR-SUVmax cutoffs and 18F-FDG-SUVmax cutoffs. [Figure 3B] (B) Kaplan-Meier plot of OS by 68Ga-uPAR stratified by corresponding 68Ga-uPAR-SUVmax cutoffs and 18F-FDG-SUVmax cutoffs. [Figure 3C](C) Kaplan-Meier plot of 18F-FDG RFS stratified by corresponding 68Ga-uPAR-SUVmax cutoffs and 18F-FDG-SUVmax cutoffs. [Figure 3D] (D) Kaplan-Meier plot of OS by 18F-FDG stratified by corresponding 68Ga-uPAR-SUVmax cutoffs and 18F-FDG-SUVmax cutoffs. [Figure 4A] (A) Kaplan-Meier plot for recurrence-free survival (RFS) for the concordant and discordant groups; the group with low levels of both 68Ga-uPAR and 18F-FDG (curve with the top endpoint); the group with low levels of one and high levels of the other (curve with the middle endpoint); and the group with high levels of both (curve with the bottom endpoint). [Figure 4B] (B) Kaplan-Meier plot for overall survival (OS) for the concordant and discordant groups; the group with low 68Ga-uPAR and 18F-FDG levels (the curve with the top endpoint); the group with low levels of one and high levels of the other (the curve with the middle endpoint); and the group with high levels of both (the curve with the bottom endpoint).

[0020] The invention will now be described in more detail below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] definition Before describing the invention in further detail, the following terms and conventions will first be defined:

[0022] HNSCC Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of malignant tumors that are frequently attributable to alcohol and tobacco use, but the incidence of HNSCC due to persistent high-risk human papillomavirus (HPV) infection is also increasing.

[0023] In one embodiment, the HNSCC according to the invention is located in the pharynx, larynx or oral cavity.

[0024] 68Ga Gallium-68.

[0025] 64Cu Copper 64.

[0026] AE105 Ac-Asp-Cha-Phe-(D)Ser-(D)Arg-Tyr-Leu-Trp-Ser.

[0027] The peptides according to the invention can be synthesized, for example, by standard solid phase peptide chemistry.

[0028] NOTA NOTA: 2,2',2"-(1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid. NOTA can be bound to AE105 to form NOTA-AE105 (NOTA-Asp-Cha-Phe-Ser-Arg-Tyr-Leu-Trp-Ser), which can be represented by the following chemical structure:

[0029] In one embodiment, the imaging agent is 68Ga-NOTA-AE105.

[0030] [ka]

[0031] DOTA DOTA (also known as tetraxetane) is an organic compound with the formula (CH2CH2NCH2CO2H)4. The molecule consists of a central 12-membered tetraaza (i.e., containing four nitrogen atoms) ring. DOTA has been used as a complexing agent, particularly for lanthanide ions. The complexes have medical applications as an imaging agent and cancer treatment drug.

[0032] Preferred IUPAC Name for DOTA 2,2',2'',2'''-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid Further below is shown DOTA complexed with 68Ga and 64CU and bound to AE105.

[0033] Recurrence-free survival (RFS) The term "recurrence-free survival" (RFS) is defined as a clinical endpoint defined as the time from diagnosis to locoregional disease recurrence (TN site) and / or distant metastasis (M site). Death from other causes is recorded as censored. Disease-free survival (DFS) is defined as RFS including death from any cause as an event.

[0034] Local region control (LRC) The term "locoregional control" (LRC) was defined as the time from diagnosis to locoregional recurrence, with death and distant metastasis recorded as censored.

[0035] Overall survival (OS) The term "overall survival" (OS) is defined as the time from diagnosis to death from any cause. Follow-up time was calculated from the time radiotherapy was indicated until the first recurrence, death, or end of follow-up on January 1, 2021.

[0036] Threshold A "threshold", "reference value" or "cutoff" in the context of the present invention relates to a quantitative standard to which another value or feature can be compared.

[0037] In one embodiment of the present invention, the thresholds can be determined by examining uPAR levels from PET / CT of healthy subjects. One or more thresholds can be calculated by applying different statistical methods such as cutoff finding, multivariate analysis, etc.

[0038] See also Example 5 for determining the cutoff.

[0039] Based on these results, a cut-off can be obtained that indicates the relationship between the detected amount and a risk group, so that, for example, this cut-off can be used to determine the amount of uPAR that corresponds to an increased risk of, for example, poor RFS or poor OS.

[0040] Risk assessment The present inventors have succeeded in developing a novel method for predicting the prognosis, such as RFS and / or OS, of a subject with head and neck cancer (HNSCC). In order to determine whether a patient is at high risk of having a poor prognosis, a cutoff (reference value) needs to be set. This cutoff can be set by a laboratory, by a physician, or individually for each patient.

[0041] Cut-off values ​​can be set using several methods, including: multivariate statistical tests (e.g., partial least squares discriminant analysis (PLS-DA), random forests, support vector machines), percentiles, mean ± standard deviation; median; fold change.

[0042] Multivariate discriminant analysis and other risk assessments can be performed using free or commercially available computer-based statistical packages (SAS, SPSS, Matlab, R, etc.) or other statistical software packages or screening software known to those of skill in the art.

[0043] As will be apparent to one skilled in the art, in any of the above described embodiments, the results of the discriminant analysis for each subject may be altered by changing the risk cutoff value.

[0044] Statistics can be used to evaluate the significance of each value. Conventional statistical tests applied to data sets include t-tests, f-tests, or more advanced tests and methods for comparing data. Using such tests or methods, it can be determined whether two or more samples are significantly different.

[0045] Significance can be determined by standard statistical methodologies known to those of skill in the art.

[0046] The reference value selected may vary depending on the mammal / subject to which the test is applied.

[0047] Preferably, the subject according to the present invention is a human.

[0048] The selected reference value can be varied to obtain different specificities or sensitivities, as is known in the art, if desired. Sensitivity and specificity are widely used in statistics to describe and quantify the quality and reliability of a biomarker or diagnostic test. Sensitivity evaluates how good a biomarker or diagnostic test is at detecting disease, while specificity estimates how well it identifies an individual (i.e., a control, a patient without the disease) as not being at risk.

[0049] In conjunction with the description of sensitivity and specificity, several terms are used; true positive (TP), true negative (TN), false negative (FN) and false positive (FP). A diagnostic test result is considered a TP if it demonstrates the presence of a disease in an unwell patient. If an individual (i.e., a control, disease-free patient) does not have a disease and the absence of disease is confirmed by a diagnostic test, the test result is a TN. If a diagnostic test indicates the presence of such a disease in an unwell individual, the test result is an FP. And if a diagnostic test indicates the absence of disease in a diseased patient, the test result is an FN.

[0050] sensitivity Sensitivity, as used herein, refers to the proportion of actual positives that are correctly identified as positive, i.e., a measure of the percentage of subjects at higher risk of having a poor prognosis than normal that are identified as having a poor prognosis above normal.

[0051] The sensitivity of a test can usually be described as the proportion of true positives among the total number of people with the target disorder, i.e., those at higher than normal risk of a poor prognosis. The total number of patients with the target disorder is the sum of the true positives (TP) (detected) and false negatives (FN) (not detected).

[0052] specificity As used herein, specificity refers to the proportion of negatives that are correctly identified as negative, i.e., the percentage of mammals that are not at high risk of poor prognosis that are identified as not at higher than normal risk of poor prognosis.An ideal diagnostic test would have a specificity of 100%, i.e., detect only subjects that are at higher than normal risk of poor prognosis, thus giving no false positive results, and a sensitivity of 100%, i.e., detect all subjects that are at higher than normal risk of poor prognosis, thus giving no false negative results.

[0053] Typically, for any test, there is a trade-off between each measure. For example, in a setting where defects are tested during production, one might be willing to risk discarding functioning parts (low specificity) in order to increase the likelihood of identifying nearly all defective parts (high sensitivity). This trade-off can be represented graphically using an ROC curve.

[0054] The choice of specificity determines the proportion of false positive cases that can be tolerated in a given study / population and at a given institution: lowering the specificity increases the sensitivity.

[0055] As is generally understood by those skilled in the art, methods for screening prognosis are a decision-making process, and therefore the specificity and sensitivity selected will depend on what a given institution / clinician considers to be the optimal outcome.

[0056] SUVmax The term "SUVmax" in this context refers to the "normalized uptake value maximum" (SUVmax), which is widely used to measure uPAR and FDG uptake in malignant tissues. Higher uptake values ​​represent more tracer taken up or bound by cancer cells, which can be imaged and quantified using PET.

[0057] SUVmean The term "SUVmean" in the present context means the mean normalized uptake value.

[0058] Imaging agents for use in PET prognostic assessment of patients with head and neck cancer (HNSCC) Improving the prognosis of patients with head and neck cancer (HNSCC) is important, for example to allow clinicians to select attenuated treatment regimens to avoid unnecessary toxicity. Accordingly, an aspect of the present invention is a positron emitting imaging agent for use in prognosticating cancer in patients with head and neck cancer (HNSCC) by PET imaging, comprising: the imaging agent comprises a uPAR binding peptide conjugated to the radionuclide 68Ga via the chelator NOTA; The uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof. Concerning imaging agents.

[0059] Surprisingly, as outlined in the Examples section (Example 5), in a multivariate analysis model including uPAR-PET and conventional 18F-FDG-PET scans, TNM stage and p16 status, it was found that only uPAR-PET remained significant for prognosis expressed as RFS.

[0060] Various uPAR-binding variants of uPAR-binding peptides (including AE105) are disclosed in WO 2014 / 086364 A1. Thus, in one embodiment, the uPAR-binding variant is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Ser)-(Leu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Gln)-(Tyr)(Leu)-(Trp)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Thr)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (D-Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(β-2-naphthyl-L-alanine)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Leu)-(Leu)-(Trp)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(β-cyclohexyl-L-alanine)-(Leu)-(Trp)-(Ile), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(D-His); (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(3-indolylethyl)glycine)-(N-(2-methoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-benzylglycine)-(N-(2[beta]thoxyethyl)glycine), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(methylnaphthalyl)glycine)-(N-(2-methoxyethyl)glycine) and (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(2,3-dimethoxybenzyl)glycine)-(Ile); is selected from the group consisting of:

[0061] The uPAR binding portion of the imaging agent is preferably that known as AE 105. Thus, in one embodiment, the peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser).

[0062] In other embodiments, the C-terminus is a carboxylic acid or an amide.

[0063] In a further embodiment, the imaging agent has the formula:

[0064] [ka]

[0065] has. PET scanning may be combined with other types of scanning to further improve cancer localization. Thus, in one embodiment, prognosis involves PET / CT and / or PET / MR scanning. In the Examples section, PET / CT is used.

[0066] Prognosis can be further defined. Thus, in one embodiment, prognosis is recurrence-free survival (RFS) and / or overall survival (OS). In the Examples section, RFS and OS are evaluated.

[0067] In a preferred embodiment, the prognosis is recurrence-free survival (RFS). Again, for example, in Example 5, in a multivariate analysis model including uPAR-PET and conventional 18F-FDG-PET scan, TNM stage and p16 expression status, it was found that only uPAR-PET remained significant for prognosis expressed as RFS.

[0068] Different amounts (MBq) of imaging can be used. The time between administration of the imaging agent and scanning can also vary. Thus, in one embodiment, the imaging agent is administered at a dose of 20-500 MBq, for example 100-500 MBq, followed by PET scanning 10 minutes to 24 hours after administration of the imaging agent, and quantification by SUVmax and / or SUVmean.

[0069] In other embodiments, the imaging agent is administered at a dose of 20-400MBq, for example 50-400MBq, for example 70-300MBq, for example 100-300MBq or for example 100-300MBq, preferably at a dose of 150-250MBq, more preferably at a dose of 170-230MBq. Thus, in a preferred embodiment, the imaging agent is administered at a dose of 70-300MBq, preferably at a dose of 150-250MBq. In the examples section, about 200MBq was used, and PET imaging was performed using a Siemens Biographm CT 64 slice. However, other devices may be more sensitive, allowing for smaller amounts (MBq) of imaging agent.

[0070] In one embodiment, an imaging aging agent is administered in an amount sufficient to allow PET imaging with sufficient radioactivity for imaging.

[0071] Since the half-life of 68Ga is about 1 hour (68 minutes), a realistic time before PET scanning is 10 minutes to 5 hours, preferably 20 minutes to 3 hours. Since the half-life of 64Cu is about 12.7 hours, a realistic interval before PET scanning is 20 minutes to 24 hours.

[0072] Thus, in a related embodiment, PET scanning is performed 20 minutes to 10 hours after administration of the imaging agent, for example 20 minutes to 5 hours, such as 30 minutes to 3 hours after administration of the imaging agent.

[0073] In yet another embodiment, the imaging agent according to the present invention is comprised in a pharmaceutical composition comprising the imaging agent together with one or more pharma- ceutically acceptable adjuvants, excipients and / or diluents.

[0074] A threshold (cut-off / reference value) may be included to allow for prognosis. Thus, in one embodiment, the imaging agent for use according to the invention comprises: o Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate poor prognosis with respect to recurrence-free survival (RFS) and / or poor prognosis with respect to overall survival (OS); and Quantified SUVmax and / or SUVmean values ​​below the thresholds indicate a favorable prognosis for recurrence-free survival (RFS) and / or overall survival (OS).

[0075] In Example 5, a specific optimal threshold (cutoff) was calculated (see also Figures 3A to 3D).

[0076] As also outlined in Example 5, the imaging agent according to the present invention is particularly useful for the prognosis of recurrence-free survival (RFS). Thus, in one embodiment: Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate a poor prognosis with respect to recurrence-free survival (RFS); and Quantified SUVmax and / or SUVmean values ​​below the thresholds indicate a favorable prognosis for recurrence-free survival (RFS).

[0077] In a further embodiment, the SUVmax and / or SUVmean threshold is in the range of 1 to 4, such as in the range of 2 to 4, preferably in the range of 2 to 3, such as in the range of 2.4 to 2.8. The SUVmax and / or SUVmean threshold is calculated as in Example 5.

[0078] In a further embodiment, the threshold is determined by a method for finding a cutoff to obtain a cut-off point in a Kaplan-Meier plot (log-rank test) and the corresponding hazard ratio (HR).

[0079] In yet other embodiments, the human patient is indicated for radiation therapy with curative intent.

[0080] In further embodiments, the HNSCC is located in the pharynx, larynx, or oral cavity.

[0081] In one embodiment, the prognosis prediction further includes one or more of 18F-FDG-PET scan, TNM stage and p16 expression status. However, it is noted that it was surprisingly found that only uPAR-PET remained significant for the prognosis expressed as RFS.

[0082] In a preferred embodiment, the present invention provides a positron emission imaging agent for use in prognosticating recurrence-free survival (RFS) and / or overall survival (OS) in head and neck squamous cell carcinoma (HNSCC) by PET imaging of the cancer in a human patient, comprising: the imaging agent comprises a uPAR binding peptide conjugated to the radionuclide 68Ga via the chelator NOTA; the uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof; This uPAR-binding variant is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Ser)-(Leu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Gln)-(Tyr)(Leu)-(Trp)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Thr)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (D-Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(β-2-naphthyl-L-alanine)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Leu)-(Leu)-(Trp)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(β-cyclohexyl-L-alanine)-(Leu)-(Trp)-(Ile), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(D-His); (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(3-indolylethyl)glycine)-(N-(2-methoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-benzylglycine)-(N-(2[beta]thoxyethyl)glycine), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(methylnaphthalyl)glycine)-(N-(2-methoxyethyl)glycine) and (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(2,3-dimethoxybenzyl)glycine)-(Ile); is selected from the group consisting of - Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate poor prognosis with respect to recurrence-free survival (RFS) and / or poor prognosis with respect to overall survival (OS); and - for an imaging agent for which a quantified SUVmax and / or SUVmean value less than or equal to a threshold value is indicative of a favorable prognosis with respect to recurrence-free survival (RFS) and / or a favorable prognosis with respect to overall survival (OS).

[0083] In vivo imaging with PET to assess the prognosis of patients with head and neck cancer (HNSCC) Another aspect of the invention is a method of in vivo imaging by PET imaging to assess prognosis of head and neck cancer (HNSCC) in a patient, the method comprising: a) providing a subject that has been pre-administered with an imaging agent according to the present invention; b) detecting radioactive emissions from the radioisotope of the imaging agent administered in step a) by in vivo PET imaging; c) generating an image representative of the location and / or amount of said radioactive emissions; d) determining the distribution and extent of uPAR expression in said subject, said expression correlating with said signal emitted by said in vivo imaging agent; e) comparing the determined distribution and extent of uPAR expression to a threshold; Including, Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate poor prognosis with respect to recurrence-free survival (RFS) and / or poor prognosis with respect to overall survival (OS); and wherein a quantified SUVmax and / or SUVmean value equal to or less than a threshold value indicates a favorable prognosis in terms of recurrence-free survival (RFS) and / or a favorable prognosis in terms of overall survival (OS).

[0084] The prognosis according to the present invention can be used by clinicians to select a treatment protocol, such as curative radiation therapy, for a patient. That is, in one embodiment, if a favorable prognosis is indicated for recurrence-free survival (RFS), the subject may be scheduled for a reduced treatment regimen to avoid unnecessary toxicity and / or a risk-stratified follow-up plan. In one embodiment, the treatment is curative radiation therapy.

[0085] Attenuated treatment protocols in this context are those that are considered to be less toxic / harmful to patients compared to patients with a poorer prognosis in terms of recurrence-free survival (RFS).

[0086] In one embodiment, the attenuated therapy avoids or reduces radiation therapy.

[0087] Use of positron-emitting imaging agents in predicting prognosis in patients with head and neck cancer (HNSCC) by in vivo PET imaging A further aspect of the present invention is the use of a positron emitting imaging agent according to the present invention in predicting the prognosis of a patient with head and neck cancer (HNSCC) by in vivo PET imaging of uPAR expressing tumors, comprising: the imaging agent comprises a uPAR binding peptide conjugated to the radionuclide 68Ga via the chelator NOTA; The uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof. Regarding use.

[0088] In an alternative portion of this embodiment, the imaging agent comprises a uPAR binding peptide bound to the radionuclide 68Ga or 64Cu via the chelator NOTA or DOTA.

[0089] Similarly, in one embodiment, the uPAR binding variant is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Ser)-(Leu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Gln)-(Tyr)(Leu)-(Trp)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Thr)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (D-Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(β-2-naphthyl-L-alanine)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Leu)-(Leu)-(Trp)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(β-cyclohexyl-L-alanine)-(Leu)-(Trp)-(Ile), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(D-His); (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(3-indolylethyl)glycine)-(N-(2-methoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-benzylglycine)-(N-(2[beta]thoxyethyl)glycine), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(methylnaphthalyl)glycine)-(N-(2-methoxyethyl)glycine) and (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(2,3-dimethoxybenzyl)glycine)-(Ile); is selected from the group consisting of:

[0090] A further aspect of the invention is a positron emission imaging agent for use in prognostic assessment by PET imaging of cancer in a head and neck cancer (HNSCC) patient, comprising: The imaging agent comprises a uPAR binding peptide bound to the radionuclide 68Ga or 64Cu via the chelator NOTA or DOTA; The uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof.

[0091] Similarly, in one embodiment, the uPAR binding variant is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Ser)-(Leu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Gln)-(Tyr)(Leu)-(Trp)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Thr)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (D-Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(β-2-naphthyl-L-alanine)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Leu)-(Leu)-(Trp)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(β-cyclohexyl-L-alanine)-(Leu)-(Trp)-(Ile), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(D-His); (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(3-indolylethyl)glycine)-(N-(2-methoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-benzylglycine)-(2[beta]thoxyethyl)glycine), (Asp)-(β-Cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(methylnaphthalyl)glycine)-(N-(2-methoxyethyl)glycine) and (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(2,3-dimethoxybenzyl)glycine)-(Ile); is selected from the group consisting of:

[0092] In one embodiment, the imaging agent comprises 68Ga-NOTA and a uPAR binding peptide as outlined in the present invention.

[0093] In one embodiment, the imaging agent comprises 68Ga-DOTA and a uPAR binding peptide as outlined in the present invention. In one embodiment, the imaging agent has the formula:

[0094] [ka] has.

[0095] In one embodiment, the imaging agent comprises 64Cu-NOTA and a uPAR binding peptide as outlined in the present invention. In one embodiment, the imaging agent has the formula:

[0096] [ka] has.

[0097] In one embodiment, the imaging agent comprises 64Cu-DOTA and a uPAR binding peptide as outlined in the present invention. In one embodiment, the imaging agent has the formula:

[0098] [ka] has.

[0099] Various variations of radionuclide-chelator-uPAR binding peptides (including AE105) are also disclosed in WO 2014 / 086364 A1, the specification of which is incorporated herein by reference.

[0100] Two uPAR-PET tracers, 64Cu-DOTA-AE105 and 68Ga-NOTA-AE105, share the same binding moiety, namely, the peptide AE105. In addition, both have been tested in both humans and animals (e.g., 15, 17 and International Publication WO2014 / 086364A1) and have been shown to be similarly taken up by breast, bladder and prostate cancers. Therefore, without being bound by theory, it is believed that the two PET tracers will act in a similar manner in HNSCC patients.

[0101] It should be noted that embodiments and features described in relation to one of the aspects of the invention also apply to the other aspects of the invention.

[0102] All patent and non-patent references cited in this application are hereby incorporated by reference in their entirety.

[0103] The invention will now be described in further detail in the following non-limiting examples. EXAMPLES

[0104] Example 1 – Materials and Methods Patient population Inclusion criteria were patients with a biopsy-confirmed diagnosis of pharyngeal, laryngeal, or oral cavity cancer, for whom curative radiation therapy was indicated, who understood the information presented, were able to provide informed consent, and were aged 18 years or older.

[0105] Exclusion criteria were pregnancy, lactation / breastfeeding, age ≥85 years, obesity (weight ≥140 kg), small laryngeal cancer (1A, 1B), allergy to 68Ga-NOTA-AE105, metastasis on FDG-PET / CT, and previously known other cancers and claustrophobia. Eligible patients were included after informed consent was obtained. The diagnosis of HNSCC and p16 status were histologically confirmed before inclusion. Information on smoking, alcohol consumption, clinical examinations, treatment plan, laboratory and histological results, medical history, and follow-up examinations was collected from patient records. Disease stage was coded according to the Union for International Cancer Control (UICC) 8th edition.

[0106] Acquisition of 68Ga-uPAR-PET / CT According to current national guidelines for the treatment of HNSCC, radiotherapy should be initiated within 11 days of the decision to treat, and 18F-FDG-PET / CT and 68Ga-uPAR-PET / CT were both performed within this time frame as part of a prospective study. To minimize the risk of osteonecrosis after radiotherapy, patients underwent dental examinations, and in cases of tooth extraction, the start of radiotherapy was postponed until 2 weeks after the procedure. In such cases, 18F-FDG-PET / CT and 68Ga-uPAR-PET / CT were scheduled before or at least 4 days after the procedure.

[0107] All patients received an intravenous injection of approximately 200 MBq (median 191, range 158–209 MBq) of 68Ga-NOTA-AE105, and sequential whole-body PET / CT scans were started 20 min after injection. Whole-body 68Ga-NOTA-AE105 PET and diagnostic contrast-enhanced CT (skull base to proximal femur) were performed simultaneously using an integrated whole-body PET / CT (Siemens Biograph mCT 64 slice, Siemens, Erlangen, Germany). Ligand synthesis was performed as previously described (15).

[0108] The patient was fixed in supine position on a flat table with the arms in standard anatomical position and no head mask. CT scans were performed at 120 kV, 170 MAS, and pitch 0.8. PET data were reconstructed by iterative reconstruction with time-of-flight, point-spread-function, and attenuation corrections, with 2 iterations, 21 subsets, and a Gaussian filter of 2 mm.

[0109] Image analysis Image data from 68Ga-uPAR-PET / CT and 18F-FDG-PET / CT were analyzed by two certified nuclear medicine technologists. Readers were blinded to the regions of interest (VOI), the results of the other readers, and patient information. Regions of interest corresponding to the primary tumor site on 18F-FDG-PET / CT were visually outlined on 68Ga-uPAR-PET / CT. Uptake of 68Ga-uPAR ligand and 18F-FDG in the ROI was recorded for both tracers as variables, SUVmax on 68Ga-uPAR-PET / CT and 18F-FDG-PET / CT, and information on recurrence and survival was obtained.

[0110] If a patient had two synchronous primary HNSCCs, the tumor with the highest SUVmax was included in the statistical analysis. The mean SUVmax from two independent readers was included in the statistical analysis.

[0111] Treatment and follow-up All patients received intensity-modulated radiation therapy (IMRT) with or without chemotherapy according to national guidelines (18). All patients received a recommended dose of 66–68 Gy in 33–34 fractions given six times per week, and one patient received proton beam radiation. Patients with progressive disease received weekly cisplatin (40 mg / m2) if assessed as appropriate; all patients with normal liver and renal function tests and no central nervous system symptoms received a hypoxic radiosensitizer (Nimorazole) daily (1200 mg / m2). In accordance with national guidelines, all HNSCC patients participated in a 5-year follow-up program. During the study period, all patients participated in the follow-up program, and complications, consultations with other medical departments, and deaths were tracked using the Danish personal identification number.

[0112] statistical analysis With a statistical power of 70% (β: 30%), a significance level (α) of 5%, and a follow-up period of 2 years, the sample size required for the study to detect an HR of 2.5 was calculated to be 104. However, the COVID-19 pandemic caused delays in the implementation of clinical trials, which delayed the study, but the required number of events was reached by extending the follow-up period.

[0113] Clinical endpoints were recurrence-free survival (RFS), defined as the time from diagnosis to locoregional disease recurrence (TN site) and / or distant metastasis (M site), with death from other causes recorded as censored, and disease-free survival (DFS), defined as RFS including death from any cause as an event. Locoregional control (LRC) was defined as the time from diagnosis to locoregional recurrence, with death and distant metastasis recorded as censored. Overall survival (OS) was defined as the time from diagnosis to death from any cause. Follow-up time was calculated from the time radiation therapy was indicated to the first recurrence, death, or end of follow-up date on January 1, 2021.

[0114] Determination of optimal cut-offs (thresholds) for discriminating between good and bad prognosis was performed using Cut-off finder, an R package developed by Budczies et al. (19). Associations between biomarker expression lower or higher than the cut-offs and survival outcomes were visualized in Kaplan-Meier plots with log-rank tests to assess the significance of differences. Hazard ratios were estimated in univariate and multivariate Cox proportional hazards models, including PET variables as dichotomized variables according to the defined cut-offs for RFS and OS.

[0115] The number of events included in the survival analysis was: 17 events for the RFS analysis and 16 events for the OS analysis. Based on this number of events, four predictors was the maximum number of explanatory variables that could reasonably be included in the final multivariate Cox model. In addition to the aim to evaluate the prognostic value of 68Ga-uPAR SUVmax and compare it with 18F-FDG SUVmax, we also included in the multivariate analysis the most important non-imaging prognostic factors for HNSCC: TNM stage and p16 status (p16-positive OPSCC vs. all other tumors) (9). Model performance was estimated using Harrell's Concordance Index (C-index).

[0116] Interrater reliability of SUV measurements was assessed using intraclass correlation coefficients (ICC).

[0117] A p value of <0.05 was considered statistically significant. Statistical analyses were performed using IBM SPSS Statistics v.22 (IBM Corp. Armonk, NY) and R (http: / / www.Rproject.org).

[0118] Example 2 – Patients A total of 57 patients with recently diagnosed HNSCC of the pharynx, larynx, or oral cavity and indicated for radiation therapy with curative intent at Rigshospitalet and Naestved Hospital, Denmark, were consecutively enrolled in this prospective phase II study between December 2017 and November 2019 (Figure 1). No patients experienced any reactions or adverse events related to the administration of 68Ga-NOTA-AE105. One patient discontinued the 68Ga-NOTA-AE105-(uPAR)-PET / CT scan due to claustrophobia, and two patients were excluded from statistical analysis because they were diagnosed with unknown primary tumor (UPT) of the head and neck on lymph node biopsy. Patient characteristics are shown in Table 1. More than half of the patients (59.2%) had early stage disease (stages 1–2), and 38.9% did not have primary regional lymph node disease. Furthermore, 61.1% were located in the oropharynx, of which 78.7% were p16 positive. The median follow-up period was 33.8 months (range 2.30-47.2).

[0119] [Table 1]

[0120] Example 3 – Clinical follow-up Locoregional recurrence was histologically confirmed in 15 / 16 cases and was used to inform the study results. One case did not have locoregional recurrence histologically confirmed, but had active tumor at the primary site on 18F-FDG-PET / CT and histologically confirmed lung metastasis. Biological material was obtained by biopsy or surgery from all (3) patients with suspected distant metastasis. As a result, there were no missing data on recurrence, and 2 cases of tumor of unknown primary site (UPT) were excluded due to missing data on the primary tumor. No cases were lost to follow-up, and clinicopathological information was collected before inclusion.

[0121] Seventeen patients (31.5%) were diagnosed with recurrence, including 7 (13.0%) at the primary site (T site), 5 (9.3%) at the primary site and lymph nodes (TN site), 2 (3.7%) at lymph nodes (N site), and 3 (5.6%) with distant metastasis to the lung (M site). Two patients were classified as having residual tumor at 2-month follow-up. Of the 17 recurrences, 10 (58.8%) had p16-negative tumors and 7 (41.2%) had p16-positive tumors. Thirty percent (3 / 10) of locoregional recurrences were p16-positive, and all (3 / 3) distant metastases were confirmed as p16-positive. All 17 patients who experienced recurrences had completed all fractions of primary radiotherapy.

[0122] Sixteen patients (29.6%) died during follow-up, eight (14.8%) from HNSCC and eight (14.8%) from causes other than HNSCC; one (1.9%) died from sepsis 1 month after treatment, one from chronic obstructive pulmonary disease (COPD) exacerbation, one from pulmonary embolism (recurrence diagnosed before death and successfully operated on), one from infection after discontinuing routine HIV treatment, one from rectal cancer, two from lung cancer, and one for unknown cause of death, but no signs of recurrence at follow-up 2 months before death. None of the non-cancer deaths had signs of recurrence at the previous follow-up. One patient who died from sepsis 1 month after treatment and before the first routine follow-up was included in the statistical analysis as a non-event. No signs of recurrence were found on imaging studies performed during the acute phase of sepsis and COPD exacerbation. Of the six patients who died due to HNSCC, four (66.7%) were p16 negative and two (33.3%) were p16 positive.

[0123] Example 4 – 68Ga-uPAR- and 18F-FDG uptake The median SUVmax of the primary tumors was 2.98 (range 1.94–5.24) for 68Ga-uPAR uptake and 15.7 (range 4.24–45.5) for 18F-FDG uptake (Figure 2). The median time to 68Ga-uPAR- and 18F-FDG-PET / CT was 2.4 days (range 1–4).

[0124] Example 5 – Cut-off points and Kaplan-Meier curves Research Objective Determining cut-off points and Kaplan-Meier curves.

[0125] result The optimal cutoff point (threshold) determined as the most significant split point in the Kaplan-Meier plot (log-rank test) and the corresponding hazard ratio (HR) were calculated, including 95% confidence intervals (19).

[0126] The cut points for 68Ga-uPAR were 2.63 for RFS and 2.66 for OS; in the RFS analysis, patients were divided into 41 (75.6%) above the cutoff and 13 (24.1%) below the cutoff, and in the OS analysis, patients were divided into 40 (74.1%) above the cutoff and 14 (25.9%) below the cutoff.

[0127] The cut points for 18F-FDG-PET were 22.7 for RFS and 22.9 for OS; in the RFS analysis, patients were divided into 42 (77.8%) patients below the cutoff and 12 (22.2%) patients above the cutoff, and in the OS analysis, patients were divided into 43 (79.6%) patients below the cutoff and 11 (20.4%) patients above the cutoff.

[0128] conclusion Kaplan-Meier curves combined with log-rank analysis of differences showed significant associations between: a) between poor recurrence-free survival (RFS) (log-rank p=0.012) and 68Ga-uPAR SUVmax above the cutoff (Figure 3A); and b) Between poor overall survival (log-rank p=0.02) and 68Ga-uPAR SUVmax above the cutoff (Figure 3B).

[0129] Similarly, Kaplan-Meier curves combined with log-rank analysis of differences showed significant associations between: a) between shorter recurrence-free survival (RFS) (p=0.012) and 18F-FDG SUVmax above the cutoff (Figure 3C); and b) Between poor overall survival (OS) (p<0.001) and 18F-FDG SUVmax above the cutoff (Figure 3D).

[0130] Importantly, and surprisingly, 68Ga-uPAR SUVmax below the specified cutoff was a strong predictor of recurrence-free survival (RFS) and overall survival compared to 18F-FDG (see Figure 3). Even more surprising (and important), 68Ga-uPAR SUVmax below the specified cutoff was a very strong predictor of recurrence-free survival (RFS) compared to 18F-FDG (compare Figures 3A and 3C).

[0131] Thus, 68Ga-uPAR is a strong prognostic marker for RFS, allowing clinicians to decide on attenuated treatment regimens when 68Ga-uPAR levels are low.

[0132] In summary, in a multivariate model including uPAR-PET and conventional 18F-FDG-PET scans, TNM stage, and p16 status, only uPAR-PET remained significant with regard to prognosis expressed as RFS.

[0133] Example 6 –Survival Analysis Research Objective To perform survival analysis.

[0134] result Univariate and multivariate analyses using Cox proportional hazards models for RFS and OS are summarized in Tables 2 and 3, respectively.

[0135] [Table 2]

[0136] [Table 3]

[0137] In univariate analysis, high 68Ga-uPAR uptake in the primary tumor (above the cutoff) was significantly associated with shorter RFS (HR = 8.53, 95% confidence interval (CI) 1.12-64.7, p = 0.038) and borderline significant association with OS (HR = 7.44, 95% CI 0.981-56.44, p = 0.052). High 18F-FDG uptake was significantly associated with shorter RFS and OS (HR = 3.27, 95% CI 1.237-8.66, p = 0.017) and (HR = 7.10, 95% CI 2.60-19.4, p < 0.001). Higher TNM stage (S3-4) was significantly associated with both RFS (HR = 3.46 (95% CI 1.216-9.88), p = 0.020) and OS (HR = 6.72 (95% CI 2.12-21.4), p = 0.001).

[0138] In multivariate analysis including 68Ga-uPAR SUVmax, 18F-FDG SUVmax, TNM stage, and p16, only 68Ga-uPAR SUVmax remained significantly associated with RFS (HR 8.50 (95%CI 1.11-65.3), p=0.040), but not with OS (HR=4.58 (95%CI 0.583-36.0), p=0.148). For OS, higher 18F-FDG SUVmax (HR=4.986 (95%CI 1.658-14.990), p=0.004) and higher TNM stage (HR=3.856 (95%CI 1.114-13.343), p=0.033) remained significantly associated with RFS. The results of the DFS analysis reflected that DFS was a combination of RFS and OS events (data not shown). For LRC, there were too few events to be powered to draw any conclusions, but it showed the same trend as RFS.

[0139] In post hoc analyses, the inclusion of 68Ga-uPAR SUVmax in the multivariate Cox model improved the predictive ability of the RFS analysis (C-index: 0.74-0.78), as did the inclusion of 18F-FDG (C-index: 0.76-0.78). In the OS analysis, the inclusion of 68Ga-uPAR SUVmax improved the predictive ability (C-index: 0.81-0.84), as did the inclusion of 18F-FDG (C-index: 0.80-0.84). The C-index for the model including only TNM stage and p16 was 0.70 for RFS and 0.77 for OS.

[0140] Example 7 - Concordance of 68Ga-uPAR and 18F-FDG Research Objective To determine the concordance between 68Ga-uPAR and 18F-FDG.

[0141] result In a post-hoc analysis, 68Ga-uPAR-PET and 18F-FDG were combined and divided into groups according to established cutoffs: 1) low values ​​on both scans, 2) high values ​​on one scan / low values ​​on the other scan, and 3) high values ​​on both scans. The concordance rates for RFS and OS were close to 40%, and the discordance rates for RFS and OS were close to 60%.

[0142] The distribution of each group is shown in Table 4 and the Kaplan-Meier curves in Figures 4A-B.

[0143] [Table 4]

[0144] Overall, there were significant differences between groups in the RFS and OS analyses (log-rank p=0.001). Patients with high and concordant uptake had a significantly worse RFS and OS than patients with low and concordant uptake (p<0.0001). Patients with discordant uptake (one low / one high) had an intermediate prognosis, with a significantly better prognosis for both RFS and OS than patients with high uptake (p=0.006 and p<0.0001), but a worse prognosis than patients with low uptake (p=0.110 and p=0.069), although this did not reach significance.

[0145] conclusion Quite surprisingly, in a multivariate model that included, in addition to uPAR-PET, conventional 18F-FDG-PET scans, TNM stage, and p16 expression status, only uPAR-PET remained significant for prognosis, expressed as RFS.

[0146] Example 8 – Inter-rater reliability Interrater reliability for tumor SUVmax measurements was good, with an ICC of 0.835 (95% CI 0.713-0.905).

[0147] Data Consideration The main finding from this prospective study was that 68Ga-uPAR-PET / CT using 68Ga-NOTA-AE105 can predict RFS in patients with HNSCC for whom radiation therapy with curative intent is indicated.

[0148] In univariate analysis, 18F-FDG-SUVmax also predicted RFS, but in multivariate analysis including 68Ga-uPAR-SUVmax, 18F-FDG-SUVmax, TNM stage, and p16 immunohistochemistry, only 68Ga-uPAR-SUVmax remained significant.

[0149] Thus, we demonstrated that primary tumor 68Ga-uPAR-PET SUVmax cutoffs could be established to discriminate between high- and low-risk groups of HNSCC patients for whom curative-intent radiotherapy was indicated. The PET parameter SUVmax is easily obtained, the most widely reported in the literature, and the most reproducible measure of PET uptake (20).

[0150] The failure of 68Ga-uPAR-PET to predict OS may be explained by the large proportion of non-HNSCC-related deaths (8 / 16 (50%)) in our study. Many HNSCC patients have poor general health, and competing risks from smoking and alcohol consumption are known to increase non-HNSCC mortality (21). However, our study was not powered to evaluate 68Ga-uPAR-PET in predicting HNSCC-related mortality.

[0151] Since uPAR expression is involved in tumor invasion and metastatic processes (12,14), it is not surprising that high levels of uPAR-PET are associated with recurrence. In addition to a phase I clinical trial of 68Ga-uPAR-PET (16,17,22), we have also demonstrated in a series of preclinical studies (13,23-26) that uPAR expression can indeed be visualized by 68Ga-uPAR-PET.

[0152] 18F-FDG-PET SUVmax is the most common and well-characterized PET uptake index and has been proposed as a prognostic marker for various cancers. Therefore, in our study, we predefined 18F-FDG-PET SUVmax for comparison. Regarding HNSCC, several studies have concluded that 18F-FDG-PET SUVmax reliably carries prognostic information, but the results are inconsistent. Most of the studies were retrospective cohort studies, and their interest was simply in 18F-FDG being a surrogate marker for known clinical risk factors, especially tumor size (10, 11). On the other hand, our results support the evidence that both 68Ga-uPAR and 18F-FDG SUVmax are significant predictors of patient outcome in univariate analysis.

[0153] 18F-FDG is not tumor specific, and there are various pitfalls in image interpretation due to physiological uptake and the complex anatomy of the head and neck (27). We found that 18F-FDG-PET SUVmax could predict OS in a multivariate model, but not RFS. In a multivariate model, 68Ga-uPAR-PET remained significant for RFS, whereas 18F-FDG-PET was not, indicating that the prognostic information obtained with 68Ga-uPAR is different from 18F-FDG-PET. The two tracers can be used for different purposes and can complement each other in noninvasive detailed characterization of the entire tumor (28-30). Concordance between 68Ga-uPAR and 18F-FDG could provide additional information for risk stratification of low (both low), intermediate (one low / one high) and high-risk patients (both high) for personalized treatment and follow-up strategies in the future.

[0154] More recently, the 18F-FDG-PET uptake indices metabolic tumor volume (MTV) and total tumor metabolic load (TLG) have shown promising prognostic results, and it would be interesting to include such parameters in later phase studies in the future (31). Nevertheless, these parameters have some limitations, and no consensus has been established regarding volume segmentation and thresholds (31). Regarding prognostic assessment with 68Ga-uPAR-PET, we believe that SUVmax is a more suitable index than volumetric measurements to characterize the most aggressive phenotypes within tumors and as a prognostic predictor.

[0155] This is the first proof-of-concept study in a moderately sized study population. Future larger prospective (phase III) studies are needed to set the exact cut-off value, which may also depend on the exact composition of the population. Nevertheless, we used the current SUVmax cut-off point of 2.63 to identify 25% of patients with low risk of recurrence. As chemoradiotherapy is associated with significant toxicity, strategies to attenuate treatment in selected patients are being sought, and 68Ga-uPAR may help to identify such low-risk patients with high reliability (7).

[0156] Furthermore, surveillance strategies after treatment for head and neck cancer vary considerably. (32) Regular imaging is not standardized, and patients are often required to complete fewer follow-up visits. (33) If 68Ga-uPAR-PET results are validated, 68Ga-uPAR-PET may contribute to the development of risk-stratified follow-up plans.

[0157] For the past decades, research to optimize the treatment of patients with HNSCC has focused on the geometric precision of radiation therapy, but is beginning to shift to biological precision. The prognostic advantage of 68Ga-uPAR-PET is that it provides a quantitative readout rather than a visual contouring of tumor lesions, as some tumors may have low or even no uptake. Therefore, 68Ga-uPAR-PET will not replace 18F-FDG-PET as a diagnostic tool. In addition, 68Ga-uPAR-PET / CT may be an important companion diagnostic to select patients for uPAR-targeted optically guided surgery using uPAR-targeted optical probes or for uPAR-targeted radionuclide therapy, and to plan individualized uPAR-targeted external beam radiation therapy in IMRT for patients with high tumor uptake (23,34-37).

[0158] conclusion In the current phase II clinical trial evaluating the prognostic impact of 68Ga-uPAR-PET / CT with 68Ga-NOTA-AE105, 68Ga-uPAR-PET SUVmax was shown to be predictive of RFS in HNSCC patients for whom radiation therapy with curative intent was indicated. In a multivariate analysis including 68Ga-uPAR SUVmax, 18F-FDG SUVmax, TNM stage, and p16 status, only 68Ga-uPAR SUVmax remained significant for RFS. For OS, TNM stage and 18F-FDG SUVmax were significant.

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Claims

1. 1. A positron-emitting imaging agent for use in determining the prognosis of recurrence-free survival (RFS) and / or overall survival (OS) of head and neck squamous cell carcinoma (HNSCC) by PET imaging of the cancer in a human patient, comprising: The imaging agent comprises a uPAR-binding peptide bound to the radionuclide 68Ga or 64Cu via the chelator NOTA or DOTA; the uPAR-binding peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser) or a uPAR-binding variant thereof; The uPAR-binding variant is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Ser)-(Leu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Gln)-(Tyr)(Leu)-(Trp)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(Ser)-(D-Arg)-(Tyr)-Leu)-(Trp)-(Ser), (D-Thr)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(β-2-naphthyl-L-alanine)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Arg)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(Ser), (D-Glu)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(Tyr)-(Tyr)-(Leu)-(Trp)-(Ser), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Leu)-(Leu)-(Trp)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(β-cyclohexyl-L-alanine)-(Leu)-(Trp)-(Ile), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)(β-1-naphthyl-L-alanine)-(D-His), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(3-indolylethyl)glycine)-(N-(2-methoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-benzylglycine)-(2[beta]thoxyethyl)glycine), (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(methylnaphthalyl)glycine)-(N-(2-methoxyethyl)glycine) and (Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(N-(2,3-dimethoxybenzyl)glycine)-(D-Phe)-(N-(2,3-dimethoxybenzyl)glycine)-(Ile); is selected from the group consisting of - A quantified SUVmax and / or SUVmean value exceeding a threshold value indicates a poor prognosis for recurrence-free survival (RFS) and / or a poor prognosis for overall survival (OS); and - quantified SUVmax and / or SUVmean values ​​below a threshold value suggest a favorable prognosis for recurrence-free survival (RFS) and / or overall survival (OS); Imaging agents.

2. 2. The imaging agent for use according to claim 1, wherein the peptide is (D-Asp)-(β-cyclohexyl-L-alanine)-(Phe)-(D-Ser)-(D-Arg)-(Tyr)-(Leu)-(Trp)-(Ser).

3. 2. The imaging agent for use according to claim 1, having the formula: 【Chemistry 1】 1. An imaging agent comprising:

4. The imaging agent for use according to claim 1, comprising the formula: 【Chemistry 2】 1. An imaging agent comprising:

5. The imaging agent for use according to claim 1, comprising the formula: 【Transformation 3】 1. An imaging agent comprising:

6. 2. The imaging agent for use according to claim 1, wherein the prognosis is recurrence-free survival (RFS).

7. 2. The imaging agent for use according to claim 1, wherein the imaging agent is administered at a dose of 10 to 500 MBq, followed by PET scanning 10 minutes to 24 hours after administration of the imaging agent, and quantified by SUVmax and / or SUVmean.

8. 2. The imaging agent for use according to claim 1, wherein the imaging agent is administered at a dose of 20 to 400 MBq, such as 50 to 400 MBq, for example 70 to 300 MBq, such as 100 to 300 MBq or such as 100 to 300 MBq.

9. 2. The imaging agent for use according to claim 1, wherein the imaging agent is administered at a dose of 70 to 300 MBq.

10. 2. The imaging agent for use according to claim 1, Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate a poor prognosis for recurrence-free survival (RFS); and Quantified SUVmax and / or SUVmean values ​​below a threshold value suggest a favorable prognosis for recurrence-free survival (RFS), Imaging agents.

11. The imaging agent for use according to claim 1, comprising: Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate a poor prognosis for recurrence-free survival (RFS); and A quantified SUVmax and / or SUVmean value below a threshold value indicates a favorable prognosis for recurrence-free survival (RFS), The threshold value of the SUVmax and / or SUVmean is in the range of 1 to 4, for example in the range of 2 to 4, preferably in the range of 2 to 3, for example in the range of 2.4 to 2.8; Imaging agents.

12. The imaging agent for use according to claim 1, comprising: Quantified SUVmax and / or SUVmean values ​​exceeding a threshold value indicate a poor prognosis for recurrence-free survival (RFS); and A quantified SUVmax and / or SUVmean value below a threshold value indicates a favorable prognosis for recurrence-free survival (RFS), The threshold is determined by a method for finding a cutoff point in a Kaplan-Meier plot (log-rank test) and the corresponding hazard ratio (HR).

13. 10. The imaging agent for use according to claim 1, wherein the human patient is indicated for curative radiation therapy.

14. 2. The imaging agent for use according to claim 1, wherein the HNSCC is located in the pharynx, larynx or oral cavity.

Images