Treatment of pituitary adenomas using radiosurgery and radiotherapy: A single center experience and review of literature
ABSTRACT Fractionated radiotherapy (FRT) and gamma knife stereotactic radiosurgery (GKSRS) are used as adjuvant therapies to surgical resection for functional and non-functional pituitary adenomas, although their optimum role in the treatment algorithm, as well as long-term safety and efficacy, still awaits further study. We report a single center experience with 33 patients with non-functional (16 patients), ACTH- (five patients), GH- (four patients), or prolactin-secreting (eight patients) tumors treated with FRT or SRS. The median tumor diameter was 1.9 cm, and the median follow-up was 36 months. For GKSRS, the median dosage was 16 Gy for non-functional adenomas and 23 Gy for hormone-secreting tumors. The median total dose for FRT was 50.4 Gy over 28 fractions (median). Two patients (6%) demonstrated radiographic evidence of tumor progression, three patients (9%) demonstrated radiation-induced visual field deficits on neuro-ophthalmic evaluation, and two patients (6%) suffered from radiation-induced hypopituitarism. Biochemical control, defined as normalized hormone values in the absence of medical therapy, was achieved in five out of eight prolactinoma patients and two out of five patients with Cushing's disease, but none of the four patients with acromegaly. These results are presented with a review of the relevant literature on the differential characteristics of FRT versus SRS in the treatment of functional and non-functional pituitary adenomas and validate postoperative irradiation as a potentially safe and effective means for tumor control.
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ABSTRACT: To review physiology of prolactin (PRL), cause and managment of hyperprolactinemia, and discuss evolving diverse roles of PRL in men's health. Hyperprolactinemia can be physiologically found after sexual activities, exercise, lactation, during pregnancy, and after stressful venipuncture. Elevated PRL can be caused by medications use, renal failure, hypothyroidism, and by prolactinoma - PRL secreting tumors. Symptomatic hyperprolactinemia and prolactinomas should be treated to lower PRL levels, decrease tumor size, and restore gonadal function. Three modes of treatment are typically utilized: pharmacological, radiosurgery with gamma radiation, and external beam radiation. Pharmacological treatment of prolactinomas is mainly based on dopamine agonists. The most frequently used dopamine agonists are bromocriptine and cabergoline. Cabergoline becoming the preferred drug in the treatment of prolactinomas because of higher response rate and less side-effects. Bromocriptine has been recently approved to improve glycemic control in diabetes mellitus. PRL plays a diverse role in men's reproduction and health. Detecting and treating elevated PRL may not only improve infertility and hypogonadism but also have a positive effect on the metabolic profile of patient and control of glycemic control and metabolic profile - an important advantage considering dramatic and worldwide increase in obesity and diabetes.Current opinion in urology 09/2011; 21(6):527-34. DOI:10.1097/MOU.0b013e32834bdf01 · 2.12 Impact Factor
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ABSTRACT: Review the medical and surgical management of patients with prolactinomas and provide an in-depth appraisal of the role of radiotherapy in the treatment of prolactinomas. A thorough review of the pertinent literature was carried out and relevant topics were identified. Topics covered in this comprehensive review include: indications for the use of radiotherapy, choice between conventional radiotherapy and stereotactic radiosurgery, as well as the benefits and potential complications associated with each modality. Due to the excellent response rates with medical management, and rapid symptom relief afforded by resection or debulking surgery in patients who do not respond or tolerate medical therapy, radiotherapy is reserved for patients who do not respond to dopamine agonists and surgery. Both external beam radiotherapy and stereotactic radiosurgery retain important roles in the treatment of refractory or recurrent prolactinomas. Choosing the optimal approach is crucial in maximizing tumor control outcomes and minimizing the risks associated with treatment. The primary determinants of optimal radiation approach are proximity of the tumor to the optic apparatus and tumor size, with radiosurgery being our recommended treatment of choice unless the tumor is larger than 3-4 cm or within 3 mm of the optic nerves, chiasm or tracts. Optimal multidisciplinary management requires the identification of appropriate candidates for radiotherapy in order to take full advantage of treatment options available for each patient.Pituitary 09/2011; 15(2):135-45. DOI:10.1007/s11102-011-0348-6 · 2.22 Impact Factor
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ABSTRACT: BACKGROUND: The majority of prolactinomas respond to dopamine agonist therapy, but a proportion are resistant, requiring other treatments including surgery and/or radiotherapy. Temozolomide is an oral chemotherapy agent, which has been used as a salvage therapy to treat aggressive pituitary adenomas and carcinomas, including prolactinomas, unresponsive to all conventional treatment. CASE SERIES: We report three patients where temozolomide was used in the treatment of refractory prolactinomas. Case 1 describes a patient with a highly invasive prolactinoma, resistant to all conventional therapy, which responded dramatically to temozolomide used as a salvage treatment. In case 2, temozolomide was used after incomplete surgical resection to relieve chiasmal compression and avoid chiasm exposure to radiotherapy. In case 3, temozolomide enabled radiotherapy to be deferred in a 16-year old with a resistant prolactinoma. In all three cases, the tumours were negative by immunostaining for methylguanine methyltransferase (MGMT). LITERATURE REVIEW AND DISCUSSION: A review of the published literature reveals 51 reported cases of temozolomide treatment for pituitary tumours, including 20 prolactinomas. Fifteen of the 20 prolactinomas showed a good response to temozolomide. Our analysis demonstrates a strong association between MGMT-negative staining and a good response to temozolomide (OR 9.35, P = 0.0030). Current clinical practice is to use temozolomide as a salvage therapy after all conventional modalities of treatment have failed. We suggest that, in selected cases, consideration should be given to using temozolomide earlier in the treatment algorithm.Clinical Endocrinology 02/2012; 76(6):877-86. DOI:10.1111/j.1365-2265.2012.04373.x · 3.35 Impact Factor