• IRSA. Stereotactic radiosurgery for patients with pituitary adenomas. Harrisburg (PA): IRSA; 2004 Apr. 12 p. (Practice Guideline Report; no. 3-04). [70 references]

This is the current release of the guideline.

Stereotactic radiosurgery is defined as a relatively high dose of focused radiation delivered precisely to the pituitary adenoma, under the direct supervision of a medical team (neurosurgeon, radiation oncologist, registered nurse, and medical physicist), in one surgical treatment session.

Patient Selection

• Patients with pituitary adenomas, defined by modern neurodiagnostic imaging (computed tomography [CT], magnetic resonance imaging [MRI] scan) constitute the study group. Such patients typically present with symptoms related to pituitary hormone imbalance (acromegaly, Cushing's disease, prolactinoma, etc.) in cases of functional adenomas, and symptoms of mass effect (headache, visual changes, and progressive neurological deficits) in cases of non-functional adenomas. Pituitary adenomas are considered suitable for multimodal management, including observation, surgical excision, fractionated radiation therapy, and stereotactic radiosurgery. Stereotactic radiosurgery is typically employed in combination with prior surgery but may be employed alone in particular circumstances. The selection of patients suitable for radiosurgery is dependent on the prior treatment history, the age of the patient, existing comorbidities, anatomic location of the tumor, and clinical history. Single session radiosurgery, a minimally invasive, single high-dose, closed skull treatment strategy, may be especially suitable for patients in advanced age groups, those with excessive medical comorbidity risk factors for surgical excision, and those with adenoma involving the cavernous sinus.

Treatment/Management

• The optimal dose range for volumetric conformal stereotactic pituitary radiosurgery has been largely established based on tumor anatomy (proximity to visual apparatus), hormonal secretory status, volume, estimated adverse radiation risks, pre-existing neurological conditions, and prior history of radiation therapy. Minimum doses to the margin of the non-functional pituitary adenomas typically range from 12 to 16 Gy in a single fraction. For secretory adenomas, minimal margin doses as high as 30 to 35 Gy are optimal if they can be administered safely given the anatomic relationship of the tumor edge to surrounding radiosensitive structures. Stereotactic volumetric imaging (high resolution) is usually necessary for precise conformal dose planning. MRI target imaging is preferred. Depending upon the technology used, the margin of the radiosurgery dose is usually 50 to 90% of the central target dose within the tumor. Sharp fall-off of the radiation dose outside of the target volume is required. Current radiation delivery technologies for volumetric stereotactic conformal single session radiosurgery include Gamma Knife®, proton beam using Bragg peak effect, and specially modified linear accelerators.
• Patients may receive a single stress dose of corticosteroids at the conclusion of the radiosurgery procedure. It is recommended that hormone suppression therapy (dopaminergic drugs for prolactinomas and octreotide for acromegaly) be discontinued at least 1 to 2 months prior to radiosurgery. Currently used long acting drugs (e.g., slow release octreotide) should be discontinued 3 to 4 months prior to radiosurgery. These medications can be restarted one week after the radiosurgery procedure. Patients can continue to take other medications as recommended by their physicians.
• Postradiosurgical clinical examinations and magnetic resonance (MR) studies are requested by referring physicians at six-month intervals for the first year and then annually to assess the effect of radiosurgery for 4 to 5 years. Visual field and acuity testing along with serum and urinary hormone screening are recommended at intervals coinciding with clinical and neuroimaging reevaluations. Tumors proven to be stable over five years can then be subsequently reassessed at 2 to 4 year intervals.
• For non-functional adenomas, estimated tumor control rates vary from 90 to 100%. Stereotactic radiosurgery should not be considered as the panacea for large volume pituitary adenomas, which are better managed initially by surgery. This is particularly true for patients who present with sudden symptomatic mass effect from pituitary apoplexy.
• Causes for failure of stereotactic radiosurgery include inadequate visualization of the tumor, lack of intraoperative stereotactic three-dimensional (3-D) (volumetric) imaging, and insufficient dose (due to proximity with optic apparatus) to achieve the growth control response.

The original guideline contains clinical algorithms for management choices for pituitary adenomas and pituitary adenoma surgical management.

Type I, II, and III evidence exists in support of stereotactic radiosurgery for pituitary adenomas. Refer to the "Rating Scheme for the Strength of the Evidence" field.

• IRSA. Stereotactic radiosurgery for patients with pituitary adenomas. Harrisburg (PA): IRSA; 2004 Apr. 12 p. (Practice Guideline Report; no. 3-04). [70 references]

Not applicable: The guideline was not adapted from another source.

2004 Apr

IRSA - Professional Association

IRSA (International RadioSurgery Association) is a non-profit entity dedicated to promoting the development of scientifically relevant practice guidelines for stereotactic radiosurgery. IRSA works to educate and provide support for physicians, hospitals, insurers, and patients.

IRSA (International RadioSurgery Association)

IRSA (International RadioSurgery Association) Physician Advisory Board Guidelines Committee and other professionals who provide radiosurgery

Committee Members: L. Dade Lunsford, MD, Neurosurgeon, (Chair); Ajay Niranjan, MBBS, MCh, Neurosurgeon; Tatsuya Kobayashi, MD, PhD, Neurosurgeon; Mark Linskey, MD, Neurosurgeon; Thomas Witt, MD, Neurosurgeon; Alex Landolt, MD, Neurosurgeon; Roman Liscak, MD, Neurosurgeon; Edward R. Laws, Jr., MD, Neurosurgeon; Mary Lee Vance, MD, Endocrinologist; John Buatti, MD, Radiation Oncologist; Jonathan Knisely, MD, Radiation Oncologist; Paul Sperduto, MD, Radiation Oncologist; Sammie Coy, PhD, Medical Physicist; Tonya K. Ledbetter, MS, MFS, Editor; Rebecca L. Emerick, MS, MBA, CPA, ex officio

Not stated

This is the current release of the guideline.

None available

This NGC summary was completed by ECRI on July 14, 2004.

This guideline is copyrighted by IRSA (International RadioSurgery Association) and may not be reproduced without the written permission of IRSA. IRSA reserves the right to revoke copyright authorization at any time without reason.