Medipolis Technique: immobilization for breast cancer radiotherapy

It is not always necessary to aim for great precision when the whole breast is irradiated after breast-conserving surgery but targeted proton beam therapy requires immobilization of the breast and this presents practical difficulties for clinicians. Further, there is no consensus on the best position of the patient at fixation because the shape of the breasts may change due to the effect of gravity. Irradiation of the breast with the patient in the supine (that is, face-up) position would lead to a greater damage to the lungs and heart compared with the prone (that is, face-down) position. However, it is difficult to obtain high geometric accuracy during irradiation in the prone position because the breast is not secured and it shifts with the movement of the thorax due to respiration. The Medipolis Technique utilizes a hybrid breast-immobilization system (HyBIS) that exploits the best aspects of the supine and prone positions.

Using HyBIS: overview

There are three phases to HyBIS: preparation, setup and treatment. In the preparation phase, the patient is secured (except for the affected breast) on a whole body immobilization system that allows for adjustments in position. The device incorporates a photo scanning system that generates a digital image of the breast from which a unique breast cup is created.

The breast cup is fitted to the breast and held in place with a specially designed retention apparatus.

With the patient and breast immobilized, the setup phase of simulation and planning treatment based on CT images can begin. These data provide the basis on which the treatment phase is implemented. Treatment ends with the removal of the breast cup and relaxation in a bathtub.

Novel technologies

MPTRC has incorporated novel technologies in the development of HyBIS. The whole body immobilization system was designed to hold the entire body of a patient in a polycarbonate case on a purpose-built aluminum stretcher, with vacuum cushions and belts.

Treatment Schedule

Treatment schedule will be decided by the oncology specialists and advisors.   Patients will be treated daily  at the time for 15 min to 40 min.   In the average treatments, lung and liver cancers needs two to three weeks of daily treatment during weekdays,and prostate and osteocartilaginous cancers need approximately 8 weeks.

Adverse Effects

Patients with proton therapy therapy do not show significant adverse effects such as hair loss, nausea, vomiting, and mental disturbance.