PURPOSE This study aimed to evaluate the preliminary treatment results of fractionated stereotactic radiotherapy (FSRT) for metastatic brain tumors. MATERIALS AND METHODS Between August 1997 and December 1998, frameless FSRT was performed in 11 patients with metastatic brain tumor (1S lesions).
Primary sites were lung in 7 patients, breast in 2, stomach in 1, and malignant melanoma in 1, All patients received 30-36 Gy/10-20 fx external beam irradiation to whole brain.
Eight patients received FSRT for 1 lesion, one for 2 lesions, and two for 4 lesions.
Fractionation schedule was 25 Gy/5 fx in 11 lesions, 18 Gy(1 fx in 3, 30 Gy/5 fx in 2, 15 Gy/5 fx in 1. Mean tumor volume was 7.0 cc (0.39~55.23 cc). Multiple-arc FSRT was delivered to 16 lesions and conformal FSRT through irregular ports shaped to tumor profile to 2 lesions. RESULTS No patient experienced any acute side reaction from FSRT. Follow-up radiologic evaluation was available in 9 patients. Six of nine patients achieved the complete response, but two showed the partial response and one showed no response on follow-up radiologic studies.
Among six patients with complete response, 5 patients survived from 5 to 15 months and showed no evidence of metastatic brain d#isease clinically and/or radiologically at last follow-up. Among two patients who did not have radiologic evaluation, one showed clinically complete response until death and the other died just after FSRT caused by intercurrent disease. One patient with no response radiologically survived 7 months and showed nearly complete disappearance of clinical symptom with stable status radiologically, CONCLUSION: Initial experience in this study suggests that the external beam irradiation to whole brain with 30 Gy/10 fx followed by FSRT with 20~30 Gy/5~6 fx could be the good treatment option to the patients with metastatic brain tumor. This study suggests that the fractionation schedule for FSRT should be determined in consideration of performance status, number of metastasis, tumor volume, location, presence of extracranial disease, and age.
PURPOSE To evaluate the clinical results of stereotactic radiosurgery (SRS) and frac- tionated stereotactic radiotherapy (FSRT) for metastatic brain tumors. MATERIALS AND METHODS Nineteen patients with brain metastases (34 lesions) were treated with LINAC-based SRS or FSRT with or without whole brain radiotherapy between October 1995 and February 1998. SRS was preferred to FSRT in cases with three or more lesions and poor performance status. FSRT was preferred to SRS in cases with lesions larger than 3 cm and lesions located near or at the eloquent areas such as thalamus, brain stem, and optic apparatus. Single isocenter was used both in SRS and FSRT, and the median peripheral dose in SRS was 15 Gy (range 13~20 Gy), while that in FSRT was 21 Gy (range 15~24 Gy) by 3 Gy per fraction. RESULTS Local control was achieved in 79% (27/34 treated lesions) and 1-year over- all survival rate was 58% with the median survival of 12 months. Lethal progressive brain metastases, both local and regional, were in four patients (27% of all deaths). No significant differences in local control and survival was observed with histology, age, sex, performance status, tumor volume, number of lesions, or treatment modality. Unacceptable acute or late complications did not occur. CONCLUSION Stereotactic radiotherapy including SRS and FSRT is effective, non-invasive therapy for brain metastases. This study suggests that stereotactic radiotherapy might be an alternative to surgical resection in selected patients of brain metastases.
Dae Yong Kim, Yong Chan Ahn, Jung Il Lee, Do Hyun Nam, Jeong Eun Lee, Do Hoon Lim, Inhwan J Yeo, Seung Jae Huh, Young Joo Noh, Hyung Jin Shin, Kwan Park, Jong Hyun Kim
PURPOSE To assess the radiologic response and cranial nerve morbidity in intracranial schwannoma patients treated with stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT). MATERIALS AND METHODS Twenty-six patients with intracranial schwannoma were treated with linear accelerator- based SRS or FSRT between February 1995 and October 1999.
The origin of schwannoma was acoustic nerve in twenty-one patients, facial nerve in two, trigeminal nerve in two, and glossopharyngeal nerve in one. SRS were performed with the median peripheral dose of 14 Gy (range 12-16), and FSRT were done with the median peripheral dose of 25 2 Gy (range 50-60). RESULTS With a median follow-up period of 33 months (range 12-67), the local control rate was 100%. Tumorregression was noted in eleven patients, and tumor stabilization was found in the remaining fifteen. Useful hearing preservation was achieved in two of three patients. Facial nerve neuropathy was shown in two patients and one patients developed trigeminal nerve neuropathy. CONCLUSION Stereotactic radiotherapy including SRS and FSRT provided excellent local control in intracranial schwannoma.
It shows the possibility of a high rate of hearing preservation and an acceptable neurotoxicity, although the number of patients are small and follow-up is relatively short.