Feasibility and outcome of re-irradiation in the treatment of multiply recurrent pituitary adenomas.

Abstract

PURPOSE:

This study evaluates the toxicity and outcomes of re-irradiation to the sella for pituitary adenomas.

METHODS:

Patients diagnosed with a pituitary adenoma and treated with two or more courses of radiation treatment (RT) to the sella were retrospectively analyzed for: initial diagnosis, including histological type and functional status; RT modality, technique, dose, and fractionation; treatment with surgery, endocrine agents, and chemotherapy; toxicity of RT including radiation-induced optic neuropathy, radionecrosis, and radiation-induced neoplasms; and outcomes including local control, distant metastasis, biochemical control of functional tumors, and vital status at last follow-up.

RESULTS:

We identified 15 patients with non-functioning pituitary adenoma (n = 6), Cushing's disease (CD) (n = 5), acromegaly (n = 3), and prolactinoma (n = 1). Initial RT was delivered using opposed lateral fields in 8 (53%), intensity-modulated radiation therapy (IMRT) in 4 (27%), fractionated stereotactic radiation therapy (FSRT) in 1 (6.7%), and stereotactic radiosurgery (SRS) in 2. The median dose was 49.5 Gy for fractionated RT and 15-25 Gy for SRS. Re-irradiation was performed a median of 5.8 years after initial RT, and delivered using lateral opposed beams (n = 1), IMRT (n = 4), linear-accelerator based SRS (n = 3), FSRT (n = 3), gamma knife surgery (n = 2), and yttrium-90 brachytherapy (n = 1). The median dose of re-irradiation was 45 Gy (range 27.9-54 Gy) for fractionated RT and 18 Gy for SRS. Radiation-induced optic neuropathy (RION) was observed in 2 (13.3%) patients, 6 months and 14 years after re-irradiation; the 5-year rate of RION was 9 %. Temporal lobe necrosis (TLN) occurred in two patients (13.3%), both of whom had received SRS. The 2- and 5-year rates of TLN were 10 and 28%. Actuarial local control rates at 2 and 5 years were 80 and 58%, respectively. Biochemical remission occurred in one of three patients with CD. Four patients (27%) ultimately developed pituitary carcinoma.

CONCLUSIONS:

Re-irradiation is a feasible treatment option for local control in patients with recalcitrant pituitary adenomas, with acceptable rates of RION and TLN given the lack of options that may be available otherwise. Re-irradiation, however, did not control hormonal hypersecretion.

• Authors: Jonathan Verma, Ian E McCutcheon, Steven G Waguespack, Anita Mahajan
• Journal: Pituitary (Pituitary) Vol. 17 Issue 6 Pg. 539-45 (Dec 2014) ISSN: 1573-7403 [Electronic] United States
• PMID: 24272035 (Publication Type: Journal Article)

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Disease Progression
• Feasibility Studies
• Female
• Humans
• Male
• Middle Aged
• Necrosis
• Neoplasm Metastasis (pathology)
• Neoplasm Recurrence, Local (radiotherapy)
• Neoplasms, Radiation-Induced (epidemiology)
• Optic Nerve Diseases (etiology)
• Pituitary Function Tests
• Pituitary Neoplasms (radiotherapy)
• Radiotherapy (adverse effects, methods)
• Retrospective Studies
• Salvage Therapy
• Survival Analysis
• Treatment Outcome
• Young Adult