Lower dose Radiotherapy for myxoid liposarcomas

All sarcoma patients who require radiotherapy will receive 25 radiation doses before their surgery. We know that myxoid liposarcomas are more sensitive to radiation. We are currently investigating whether these sarcoma types can be treated using only 18 sessions.

Explanation of image

Figure A shows an MRI scan of the leg of a patient with myxoid liposarcoma before their treatment. Number 1 is the sarcoma itself, number 2 is the regular muscles in the upper leg. Number 3 is the regular fatty tissue under the skin, and number 4 is the thigh bone (femur). There are 3 MRI images next to it (the top one is a small version of the larger image; the middle one is the tumor from the back and front, and the image below is the tumor seen from the side).

Figure B shows the same tumor under the microscope. The arrows point at the many blood vessels seen in the tumor. These vessels are filled with red content, the red blood cells. That means that this (not yet treated) tumor receives a good blood flow at the time of diagnosis. The purple dots are the nuclei of the living cancer cells.

Figure C shows the results of the lower radiation dose (36Gy) as part of the trial. (the standard dose for other types of sarcomas will remain 50Gy).

Figure D shows the same tumor after surgery and placed under the microscope. The purple dots, which mark the tumor cells, are (nearly) all gone. Central to this image is an enlarged blood vessel. The passage of this blood vessel is much narrower and the red blood cells are hard to see: the tumor is receiving a much smaller blood supply. The tumor has mostly been destroyed by the radiation with a lower dose.