| Abstract: | This investigation is to study red marrow dose measurement for the 60Co gamma-ray treatment of nasopharyngeal carcinoma with the aid of Rando phantom. The energy of scattered radiation in space and in tissue was investigated by means of half-value layers with thermoluminescent dosimeters. Other related factors such as field size, SSD, and orientation of primary beams were also investigated. In the non-metastases cases, the red marrow dose is 26 +/- 6 rads which is about 0.40% tumor dose excluding the marrow at the NPC site. For the metastases cases, the red marrow dose is still about 0.40% tumor dose. If the red marrow at the NPC site is included, the red marrow dose is about 14.5% tumor dose for both non-metastases and metastases cases. |
