Fractionated Stereotactic Radiation Therapy for Intracranial Malignant Tumor: Preliminary Results of Clinical Application

Kim, Dae Young; Ahn, Yong Chan; Huh, Seung Jae; Choi, Dong Rak; Lee, Jung Il; Kim, Jong Hyun; Shin, Hyung Jin; Lim, Do Hoon; Wu, Hong Gyun

Abstract

PURPOSE
Fractionated stereotactic radiation therapy(FSRT) is a new modality that combines the accurate focal dose delivery of stereotactic radiosurgery with the biological advantages of conventional radiotherapy. We report our early experience using FSRT for intracranial malignant tumor.
MATERIALS AND METHODS
Between October 1995 and December 1996, 16 patients(9 males and 7 females aged between 10~64 years) with central nerve system malignancy were treated using FSRT. Sixteen patients had the following diagnosis: 6 high-grade gliomas, 1 pineoblastoma, 4 germinomas, 2 medulloblastomas, and 3 solitary brain metastases. Using the Gill-Thomas-Cosman relocatable head frame and multiple non-coplanar therapy, the daily dose of 2 Gy(3 Gy in metastasis) was irradiated at 85~100% isodose surface.
RESULTS
Although the follow-up period is relatively short(range; 2~18 months), post- treatment clinical courses in 16 patients have been consistent with changes similar to those found after conventional radiation therapy. No significant adverse effects were observed in our neurological and radiological studies. Four out of 5 patients with high grade glioma died from progressive disease, surviving from 7 to 17 months(median 14 months), but patients with pineoblastoma, germinoma and medulloblastoma showed no evidence of recurrence. All patients with metastasis obtained a neurologic response, but two among them died with extracranial progression and one die from multiple intracranial metastasis.In overall patient setup with scalp measurements, reproducibility was found to have mean of 1.1+/-0.6 mm from the baseline reading.
CONCLUSION
FSRT and relocatable stereotactic head frames were well tolerated with minimal transient acute side effects. Subacute or late complications were not observed, because the follow-up period was short. We expect that FSRT might be a good indication for; recurrent disease with previous radiation therapy history, tumors of relatively large volume, lesions adjacent to radiosensitive organs, and as a boost, following conventional radiation therapy.