Comparison of conventional external radiotherapy and stereotactic radiotherapy in the treatment of pituitary adenoma.

OBJECTIVE: To compare the results of pituitary adenoma treated with conventional external beam radiotherapy (EBRT) versus stereotactic radiosurgery and stereotactic radiotherapy (SRS/SRT). METHOD AND MATERIAL: Data of patients with pituitary adenoma treated at Radiotherapy and Oncology unit, Ramathibodi Hospital between 1990 from 2003 were retrospectively collected and analyzed. Twenty-two patients were treated with EBRT and 51 patients were treated with SRS/SRT. RESULTS: The 5-year overall survival and local control rates were not different between the EBRT and SRS/SRT group (91% vs 100%, p = 0.10; 95% vs 96%, p = 0.33). The 5-year freedom from newly initiated hormonal replacement was 50% in EBRT and 75% in SRS/SRT group (p = 0.38). CONCLUSION: At a similar outcome but with lower expense of resources, EBRT should be considered an acceptable radiation technique for patients with pituitary adenoma, especially in developing countries such as Thailand.

Stereotactic radiation therapy for optic nerve sheath meningioma; an experience at Ramathibodi Hospital.

OBJECTIVE: To evaluate results of stereotactic radiotherapy for the treatment of optic nerve sheath meningioma (OM) at Ramathibodi Hospital. MATERIAL AND METHOD: Twelve patients with primary OM were treated with stereotactic radiation between 1998 and 2005. Five patients underwent surgery and had no light perception before radiation. All patients except one were treated with fractionated stereotactic radiotherapy (FSRT). Mean average dose of FSRT was 55. 7 Gy; 180 cGy/fraction. One patient was treated with 15-Gy stereotactic radiosurgery. RESULTS: With a median follow-up of 34 months, there was no visual improvement in the five patients who were completely blind before radiation. Visual acuity improved in four patients and remained stable in two patients. Four of six patients had improved visual field, and five of six decreased in proptosis. Follow-up images were available in six patients, showing minimal tumor regression in five and stable in one. No serious acute side effect was observed. Vision became worse in one patient, who developed vitreous hemorrhage two years after FSRT. CONCLUSION: Stereotactic radiotherapy is an effective treatment for primary OM. It provides tumor control and visual preservation with low risk of complications. However more patients and further follow-up are needed for long-term outcomes.

Fractionated stereotactic radiotherapy for bilateral vestibular schwannomas associated with neurofibromatosis type 2: early experiences in Ramathibodi Hospital.

PURPOSE: To evaluate the rates of tumor control and useful hearing preservation in patients with bilateral vestibular schwannomas (VSs) associated with neurofibromatosis type 2 (NF-2) treated with fractionated stereotactic radiotherapy (FSRT). MATERIAL AND METHOD: From August 1998--December 2002 there were 5 patients with NF-2 who underwent FSRT (Linac-based system) for bilateral CP angle tumors. Median age was 28 (18-47) years. Median tumor volume was 5.4 (2.2-9.4) cc. Eight lesions received a marginal dose of 44.2-59.9 (median = 46.2) Gy in 25-33 fractions. The other 2 lesions received 4.4 and 4.9 Gy/fraction for 6 fractions in 3 and 2 weeks. Median follow-up was 19 (14-44) months. RESULTS : Radiographic and clinical tumor control rate was 90%. One lesion progressed at 7 months after FSRT and was completely resected Of the 5 lesions with Gardner-Robertson class I-II hearing before FSRT 2 (40%) retained useful hearing at the last follow-up. One patient had left facial spasm at 10 months after FSRT which gradually improved. No patient had facial palsy, facial numbness or pain. CONCLUSIONS : FSRT provided good tumor control and hearing preservation rate in NF-2 patients with minimal morbidity. However, a longer follow-up is needed to evaluate long term results.