Radiation therapy in the treatment of pituitary tumors

Abstract

<jats:p>✓ The treatment of pituitary tumors has progressed into a multidisciplinary approach that involves neurosurgeons, radiation oncologists, and endocrinologists. This has allowed improved outcomes in treatment of pituitary tumors due to a combination of surgical, medical, and radiation therapies. In this study, the authors review the role of radiation therapy in the treatment of pituitary adenomas.</jats:p>

Linear‐Accelerator‐Based Modified Radiosurgical Treatment of Pituitary Tumors in Cats: 11 Cases (1997–2008)

“…Surgical resection is the preferred treatment for many pituitary tumors in people, the exception being prolactin‐secreting tumors for which medical management is the preferred approach 21 . The success rate of surgery varies, with persistence or recurrence of clinical signs common.…”

“…Depending on the equipment available, this approach can give a 3 dimensional conformal dose at the isocenter of the treatment, with little dose to the surrounding tissues. Currently in human medicine, radiosurgery is performed using either a gamma knife, a radiation device incorporating multiple static 60 Cobalt beams intersecting at the center of the unit, proton therapy, or with linear accelerators, 21 where beam movement allows for treatment with multiple beam angles. Our limitations of time and technical support necessitated development of a treatment field that was not conformal to tumor, but defined a cylinder into which the tumor fit.…”

Errata

“…Regrowth has been reported in 38% to 95% of patients 4, 6, 12, 14, 17, 18. In these patients, current standard treatments include: 1) reoperation for patients with visual deterioration for opticochiasmatic decompression; 2) stereotactic radiosurgery , which is effective in patients with small adenoma remnants distant to the opticochiasmatic system31‐37; and 3) fractionated radiotherapy , which is reserved for the rare cases that are considered inoperable because of their fibrous consistency and unsuitable for radiosurgery because of large tumor size, location, and extension 14, 15, 31‐33, 38‐40. Although tumor control is achieved in up to 93% of patients,40 long‐term side effects of fractionated radiotherapy are common and include hypopituitarism, cerebrovascular disease, cognitive impairment, optic neuropathy, and the formation of secondary tumors as well as increased mortality 15, 31, 33, 38, 39, 41, 42…”

Update on the management of recurrent Cushing's disease

“…Accordingly, the recent literature reflects a greater focus on these treatment strategies as a means for achieving tumor control and disease remission in recurrent CD. 5,19,32,58 Such strategies are important for adjuvant or salvage therapy for patients in whom repeat resection was unsuccessful or who seek noninvasive treatments. They are also relevant for treating tumors that cannot be repeatedly resected because of cavernous sinus invasion or equivocal appearance on MRI scans.…”