Immediate Side Effects of Cranial Stereotactic Radiosurgery and Radiotherapy (Single Institution Experience)

Purpose: To examine the incidence and nature of immediate side effects encountered during and within 2 weeks following stereotactic radiosurgery and radiotherapy. Patients and methods: Between December 1999 and August 2002, 163 patients with benign and malignant cranial lesions were treated by Linac-based stereotactic radiosurgery and radiotherapy (101 and 62 respectively). Inclusion criteria were an upper age limit of 70 years old, adequate performance status ≥ 50 and volume to be treated should not exceed 125 cc. Radiosurgical treatment consisted of a single therapy session of 10-20 Gy depending on lesion volume, while stereotactic radiotherapy treatment consisted of three sessions of 500 cGy each, delivered every other day. Immediate side effects were assessed during and within two weeks of therapy completion and graded according to RTOG system. Results: Fifty seven (34.9%) patients had developed (69) immediate side effects. Patients had tolerated treatment well without grade III or IV morbid events and no single patient showed deterioration of performance status. The most frequently encountered side effects were; headache in 23 (14%), nausea and vomiting in 39 (23.9%), convulsive fits in 2 (2.9%) and worsening of pretreatment manifestations in 5 patients (3.06%). No specific disease or therapy related factors could be considered to be associated with immediate side effects except for nausea and vomiting which were encountered in patients who received radiation doses greater than 2 Gy to area postrema.