ABSTRACT
PURPOSE: With the development of stereotactic immobilization systems capable of reliable serial repositioning, fractionated stereotactic radiation therapy (FSRT) offers the potential for an improved treatment outcome by excellent dose delivery, and dose distribution characteristics with the favorable radiobiological properties of fractionated irradiation. We describe our initial experience using FSRT for the treatment of intracranial benign tumor. MATERIALS AND METHODS: Between August 1995 and December 1996, 15 patients (7 males and 8 females aged 6-70 years) were treated with FSRT. The patients had the following diagnosis : pituitary adenoma (10) including one patient who previously had received radiotherapy, craniopharyngioma (2), acoustic neurinoma (1), meningioma (2). Using the Gill-Thomas-Cosman relocatable head frame and multiple non-coplanar therapy, the daily dose of 2Gy was irradiated at 90% to 100% isodose surface of the isocenter. The collimator sizes ranged from 26mm to 70mm. RESULTS: In all patients except one follow-up lost, disease was well- controlled. Acute complication was negligible and no patient experienced cranial nerve neuropathies and radiation necrosis. In overall patient setup with scalp measurements, reproducibility was found to have mean of 1.1+/-0.6mm from the baseline reading. CONCLUSION: Relocatable stereotactic system for FSRT is highly reproducible and comfortable. Although the follow-up period was relatively short, FSRT is considered to be a safe and effective radiation technique as the treatment of intracranial tumor. But the fractionation schedule (fraction size, overall treatment time and total dose) still remains to be solved by further clinical trials.
Subject(s)
Female , Humans , Male , Adenoma , Appointments and Schedules , Cranial Nerves , Craniopharyngioma , Diagnosis , Follow-Up Studies , Head , Immobilization , Meningioma , Necrosis , Neuroma, Acoustic , Pituitary Neoplasms , Radiotherapy , Scalp , Treatment OutcomeABSTRACT
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.
Subject(s)
Female , Humans , Male , Brain , Diagnosis , Follow-Up Studies , Germinoma , Glioma , Head , Medulloblastoma , Neoplasm Metastasis , Pinealoma , Radiosurgery , Radiotherapy , Recurrence , ScalpABSTRACT
PURPOSE: This study is to report experience with Fractionated Stereotactic Radiation Therapy (FSRT) for locally recurrent nasopharynx cancer after curative conventional radiation therapy. MATERIALS AND METHODS: Three patients with locally recurrent and symptomatic nasopharynx cancer were given FSRT as reirradiation method between the period of September of 1995 and August of 1996. For two patients, application of FSRT is their third radiation therapy directed to the nasopharynx. Two patients were given low dose chemotherapy as radiation sensitizer concurrently with FSRT. Authors used 3-dimensional coordinate system by individually made, relocatable Gill-Thomas-Cosman (GTC) stereotactic frame and multiple non-coplanar arc therapy dose planning was done using XKnife-3. Total of 45 Gy/18 fractions or 50 Gy/20 fractions were given. RESULTS: Authors observed satisfactory symptomatic improvement and remarkable objective tumor size decrease by follow-up MR images taken 1 month post-FSRT in all three patients, while no neurologic side effect attributable to reirradiation was noticed. Two died at 7 and 9 months with loco-regional and distant seeding outside FSRT field, while one patient is living for 4 month. CONCLUSION: Authors experienced satisfactory therapeutic effectiveness and safety of FSRT as reirradiation method for locally recurrent nasopharynx cancer. Development of more effective systemic chemotherapeutic regimen is desired for distant metastasis.