The invention provides a chest
radiation-
oncology positioning device. The chest
radiation-
oncology positioning device comprises a
fixed frame and a positioning mechanism, a chest-belly positioning groove is formed in the
fixed frame, and multiple pressing mechanisms for pressing the positioning mechanism are also arranged at the portions, located on the two sides of the chest-belly positioning groove, on the
fixed frame; the positioning mechanism comprises a lower positioning film arranged in the chest-belly positioning groove and connected with the fixed frame, an upper positioning film located on the lower positioning film and connected with the fixed frame and vacuum pads arranged between the upper positioning film and the lower positioning film. According to the chest
radiation-
oncology positioning device, the lower positioning film is used for positioning the back after a patient lies, the lower positioning film can firmly fit the back of the patient, and the problem that as a gapexists between the back of the patient and the fixed frame, and the patient slightly moves, the
treatment effect is influenced is solved; the vacuum pad can also be spliced on the positioning face ofthe upper positioning film or the positioning face of the lower positioning film, the vacuum pads are vacuumized to be formed according to the
lying gesture of the patient, the gap between the upperpositioning film or the lower positioning film can be filled with the vacuum pads, and the positioning accuracy is further increased.