Dosimetry of 32P radiocolloid for treatment of cystic craniopharyngioma

In Tajrish Shohada Hospital, patients with either cystic craniopharyngiomas or cystic astrocytomas have been treated with 32P radiocolloid by stereotactic procedure. The total activity was prescribed for delivery dose between 200 and 300 Gy to the cyst wall thicknesses of 1-3 mm. In this project, MD-55-2 radiochromic film was utilized to determine the dose distribution around the source. The film dosimetry data were compared with Monte Carlo simulated values calculated with MCNP4C code. In addition, the clinical and dosimetric factors such as the cyst volume, and method of radiocolloid injection were evaluated. The required activity and distribution of radial dose in and out of cyst wall have been investigated.