Radiation is often used immediately after surgery (postOp
radiation) some studies are noted below:
Pituitary adenomas: long-term results for radiotherapy alone and post-operative radiotherapy.Hughes MN, Llamas KJ, Yelland ME, Tripcony LB Int J Radiat Oncol Biol Phys 1993 Dec 1;27(5):1035-43Queensland Radium Institute, Royal Brisbane Hospital, Brisbane, Australia. The study involved a retrospective review of outcome in a series of 268 patients with pituitary adenomas, treated at the Queensland Radium Institute from January 1962 to December 1986. The study population included 108 patients treated with radiotherapy alone and 160 patients treated by surgery and post-operative radiotherapy. For radiotherapy alone, the 10-year progression-free survival rate was 60%, and overall tumor control was obtained in 77%. Univariate analysis suggested that tumor type and radiotherapy field size were of prognostic significance. Multivariate analysis confirmed that Prolactinoma subtype and increasing radiotherapy field size were independently predictive of reduced progression-free survival. Long-term visual complications occurred in 1% of patients treated by radiotherapy alone. In patients treated by surgery and post-operative radiotherapy, the 10-year progression-free survival rate was 77%, and overall tumor control was achieved in 83%. Univariate analysis suggested that tumor type, completeness of surgical excision, and radiotherapy dose were predictive of outcome. However, on multivariate analysis, only the extent of surgical excision predicted prognosis independently. Long-term visual sequelae were noted in 3% of patients treated by surgery and post-operative radiotherapy. CONCLUSION: Both radiotherapy alone and post-operative radiotherapy are effective in long-term control of pituitary adenomas, and produce acceptably low complication rates. Postoperative radiation therapy for pituitary adenoma.Isobe K, Ohta M, Yasuda' S, Uno T, Hara R, Machida N, Saeki N, Yamaura A, Shigematsu N, Ito H J Neurooncol 2000 Jun;48(2):135-40Department of Radiology, Chiba University, School of Medicine, Japan. A total dose of 48-60 Gy (median: 50 Gy) was delivered with a conventional fractionation schedule after surgery. Of 75 patients, 55 (73%) were followed for more than 5 years and 27 (36%) were followed for more than 10 years with a median of 95 months. RESULTS: Five- and 10-year local control probabilities were 87.1% and 85.0%, respectively. Univariate analysis revealed that age (p = 0.007), tumor volume smaller than 30 cm3 (p = 0.018) and the absence of prolactin secretion (p = 0.003) were significantly favorable prognostic factors for local control probability. After multivariate analysis combining these 3 factors, tumor volume smaller than 30 cm3 (p = 0.017) and age (p = 0.039) were statistically significant. Patients with prolactinoma greater than 30 cm3 showed particularly poor local control rates. No significant improvement of the local control rate was detected with increasing total irradiation doses between 48 and 60 Gy (p = 0.29). The most common side effect was hypopituitarism, and there were no severe sequelae such as optic neuropathy or brain necrosis. CONCLUSION: Except with prolactinoma, the dose of postoperative RT for pituitary adenoma should not exceed 50 Gy. Large prolactinoma, however, was very difficult to control with the irradiation doses between 50 and 60 Gy, and would be good candidates for stereotactic radiosurgery or stereotactic radiation therapy. |