Radiosurgical treatment of residual and recurrent pituitary adenomas

Abstract

Objective ‒ the treatment result estimation of subtotally removed and recurrent pituitary adenomas using different algorithms of radiotherapy and radiosurgery.
Materials and methods. The retrospective analysis of 21 cases of pituitary adenomas was performed. There were 11 women and 10 men included. The average age was 45 (from 18 to 72) years. All patients had relapse or residual tumor after incomplete surgical removal. The method of irradiation was chosen by a radiologist. Tumor size control was assessed by an independent radiologist in 3 months and 1 year after treatment. Endocrine function was estimated by an independent endocrinologist in 3 months and 1 year after treatment.
Results. Following transsphenoidal removal ‒ 13 patients (4 were operated twice), 5 after cranial surgery and 3 were operated sequentially transnasally and transcranially. Irradiation of 14 cases of residual tumor was performed no later than 6 months after surgery. The mean term of treatment start of recurrent adenomas was 12 months (8‒17) after surgery. VARIAN Novalis was applied in 16 cases, VARIAN Clinac iX in 4 cases and VARIAN TrueBeam STx was used once. Single and total radiation doses were determined individually. None of patients had visual impairment after treatment. The hypopituitarism deterioration was not noted as well.
Conclusions. Hypofractionated stereotactic radiosurgery allows to bring a high dose of radiation to the pituitary adenomas, minimizing damage to the visual pathways, the pituitary gland and infundibulum. As the sequence, it reduces the toxicity of the technique. The application of modern radiation technologies minimize the irradiation of healthy surrounding tissues and reduce the negative effects of treatment.