Dose verification of critical structures in Gamma Knife Radio surgery of Pituitary Adenoma

摘要

90-cases of pituitary adenoma were treated by Gamma Knife Radiosurgery (GK) from January 1997 to December 2008 at P.D. Hinduja National Hospital & Medical Research Centre, Mumbai. 40 cases were previously operated by Trans-sphenoidal route and the residual / recurrent tumour was treated by Gamma Knife. 10 cases were primarily treated by Gamma Knife Radiosurgery. The prescription to 40 - 50% Isodose was 25-35Gy in hormonally active adenomas and 10-15 Gy in hormonally inactive adenomas. 65 cases had hormonally inactive pituitary tumour and 25 had hormonally active pituitary adenoma, Acromegaly and Cushing's disease. 5 cases were simulated and dose to critical structures was measured in a specially designed and locally fabricated polystyrene phantom. Gafchromic MD-55-2 as well as Gafchromic EBT films; TLD-100 powder and MOSFET dosimeters were used to measure the dose to the critical organs. Results indicate that measured dose and calculated dose are within acceptable limit.