Stereotactic Radiotherapy for the Treatment of Pituitary Adenomas

Abstract

Purpose: The aim of this study was to retrospectively review local control and morbidity following stereotactic radiotherapy (SRT) for pituitary adenoma. Methods: Between 1997 and 2004, 39 patients with pituitary adenomas received SRT. Median age was 56 years (range: 13 to 90 years). Thirty-three patients underwent incomplete transsphenoidal surgery prior to SRT and six had unresectable tumors. The largest tumor dimension varied from 1.7 to 6 cm (median: 3 cm). Tumor volume varied from 1.2 to 56 mL (median 10.5 mL). Thirty-five tumors were ≤ 1 mm from the optic chiasm/nerve. Thirty-three tumors were non-functional. SRT was delivered by a dedicated linear accelerator (Novalis, Heimstetten, Germany). Beam collimation was achieved by a fixed circular collimator (five patients) or a micro-multileaf collimator (34 patients). Total dose varied from 4500 to 5040 cGy (median: 4860 cGy) and was prescribed at the 90 % isodose line. Results: After a median follow-up of 32 months (range: 12 to 94 months), the local control rate was 100 %. Tumor size was stable in 26 patients and decreased in 13 patients. Hormone normalization did not occur following SRT. New endocrine deficiency occurred in six patients. No patient developed cranial nerve injury or second malignancy following treatment. Conclusions: SRT achieves a high rate of local control and a low rate of treatment-induced morbidity. SRT is applicable to pituitary adenomas in close proximity to the optic apparatus and tumors in excess of three centimeters in the greatest dimension. Further follow-up is necessary to establish the long-term outcome following SRT for pituitary adenomas.

Key words

Stereotactic radiotherapy - pituitary adenoma

References

• 1 Ezzat S, Asa S L, Couldwell W T, Couldwell W T, Barr C E, Dodge W E, Vance M L, McCuthcheon I E. The prevalence of pituitary adenomas. A systematic review.  Cancer. 2004;  101 613-619
• 2 Ebersold M Y, Quast L M, Laws E R, Scheitauer B, Randall R V. Long-term results in transphenoidal removal of non-functioning pituitary adenomas.  J Neurosurg. 1986;  64 713-719
• 3 Leavens M E, McCutcheon I F, Samaan N A. Management of pituitary adenomas.  Oncology. 1992;  6 69-80
• 4 McGregor A M, Scanlon Hall K, Cook D B, Hall R. Reduction in size of a pituitary tumor by bromocriptine therapy.  N Engl J Med. 1979;  300 291-293
• 5 Thorner M O, Martin W H, Rogol A D, Morris J L, Perryman R L, Conway B P, Howards S S, Wolfman M G, MacLeod R M. Rapid regression of pituitary prolactinomas during bromocriptine treatment.  J Clin Endocrinol Metab. 1980;  51 438-445
• 6 Grigsby P W, Simpson J R, Emami B, Fineberg B B, Schwartz HG. Prognostic factors and results of surgery and postoperative irradiation in the management of pituitary adenomas.  Int J Radiation Oncol Biol Phys. 1989;  16 1411-1417
• 7 Tsang R W, Brierly J D, Panzarella T, Gospodarowicz M K, Sutcliffe S B, Simpson W J. Radiation therapy for pituitary adenoma: treatment outcome and prognostic factors.  Int J Radiation Oncol Biol Phys. 1994;  30 557-565
• 8 Zierhut D, Flentje M, Adolph J, Erdmann J, Raue F, Wannenmacher M. External radiotherapy of pituitary adenoma.  Int J Radiation Oncol Biol Phys. 1995;  33 307-314
• 9 Zaugg M, Adaman O, Pescia R, Landolt A M. External irradiation of macroinvasive pituitary adenomas with telecobalt: a retrospective study with long-term follow-up in patients irradiated with doses mostly of between 40 - 45 Gy.  Int J Radiation Oncol Biol Phys. 1995;  32 671-680
• 10 McCord M W, Buatti J M, Fennell E M, Mendenhall W M, Marcus R B, Rhoton A L, Grant M B, Freidman W A. Radiotherapy for pituitary adenoma: long-term outcome and sequelae.  Int J Radiation Oncol Biol Phys. 1997;  39 437-444
• 11 Al Mefty O, Kersh J E, Routh A, Smith R R. The long-term side effects of radiation therapy for benign brain tumors in adult.  J Neurosurg. 1990;  73 502-512
• 12 Leksell L. The stereotactic method and radiosurgery of the brain.  Acta Chirug Scan. 1951;  102 316-391
• 13 Sheehan J P, Niranjian A, Sheehan J M, Jane J A, Laws E R, Kondziolka D, Flickinger J, Landolt A M, Loeffler J S, Lunsford L D. Stereotactic radiosurgery for pituitary adenomas: an intermediate review of its safety, efficacy and role in the neurosurgical treatment armamentarium.  J Neurosurg. 2005;  102 678-691
• 14 Tome W A, Mehta M, Meeks S L, Buatti J M. Fractionated stereotactic radiotherapy: a short review.  Tech Cancer Res Treat. 2002;  1 153-172
• 15 Coke C, Andrews D W, Corn B W, Werner-Wasik M, Downes B, McCune C, Curran W J. Multiple fractionated stereotactic radiotherapy of residual pituitary macroadenomas: initial experience.  Stereotac Funct Neurosurg. 1997;  69 183-190
• 16 Mitsumori M, Shrieve D C, Alexander E, Kaiser U B, Richardson G E, Black P M, Loeffler J S. Initial clinical results of linac-based stereotactic radiosurgery and stereotactic radiotherapy for pituitary adenomas.  Int J Radiation Oncol Biol Phys. 1998;  42 573-580
• 17 Welsh J S, Wharam M D, Nauta H, Jackson J, Williams J A. Stereotactic radiotherapy for Cushing's disease and prolactinoma.  J Radiosurgery. 1999;  2 23-29
• 18 Jalali R, Brada M, Perks J R, Traish D, Burchell L, McNair H, Thomas D GT, Robinson S, Johnston D G. Stereotactic conformal radiotherapy for pituitary adenomas: technique and preliminary experience.  Clin Endocrinol. 2000;  52 695-702
• 19 Milker-Zabel S, Debus J, Thilmann C, Schlegel W, Wannenmacher M. Fractionated stereotactically guided radiotherapy and radiosurgery in the treatment of functional and nonfunctional adenomas of the pituitary gland.  Int J Radiation Oncol Biol Phys. 2001;  50 1279-1286
• 20 Milker-Zabel S, Zabel A, Huber P, Schlegel W, Wannenmacher M, Debus J. Stereotactic conformal radiotherapy in patients with growth hormone secreting pituitary adenoma.  Int J Radiation Oncol Biol Phys. 2004;  59 1088-1096
• 21 Paek S H, Downes M B, Bednarz G, Keane W M, Werner-Wasik M, Curran W J, Andrews D W. Integration of surgery and fractionated stereotactic radiotherapy for the treatment of nonfunctioning pituitary macroadenomas.  Int J Radiation Oncol Biol Phys. 2005;  61 795-808
• 22 Colin P, Jovenin N, Delemer B, Caron J, Grulet H, Hecart A C, Lukas C, Bazin A, Bernard M H, Scherpereel B, Peruzzi P, Nakib I, Reon C, Rousseaux P. Treatment of pituitary adenomas by fractionated stereotactic radiotherapy: a prospective study of 110 patients.  Int J Radiation Oncol Biol Phys. 2005;  62 333-341
• 23 Dunbar S F, Tarbell N J, Kooy H M, Alexander E, Black P M, Barnes P D, Goumnerova L, Scott R M, Pomeroy S L, La Vally B, Sallan S E, Loeffler J S. Stereotactic radiotherapy for pediatric and adult brain: preliminary report.  Int J Radiation Oncol Biol Phys. 1994;  30 551-559
• 24 Kooy H M, Dunbar S F, Tarbell N J, Mannarino E, Ferarro N, Shustermann S, Bellerive M, Finn L, McDonough C V, Loeffler J S. Adaptation and verification of the relocatable Gill-Thomas-Cosman frame in stereotactic radiotherapy.  Int J Radiation Oncol Biol Phys. 1994;  30 685-691
• 25 Erfurth E M, Bulow B, Nordstrom C H, Mikoczy Z, Hagmar L, Stromberg U. Doubled mortality rate in irradiated patients reoperated for regrowth of a macroadenoma of the pituitary gland.  Eur J Endocrinol. 2004;  150 497-502
• 26 Sohn J W, Dalzell J G, Suh J H, Tefft M, Schell M. Dose-volume histogram analysis of techniques for irradiating pituitary adenomas.  Int J Radiation Oncol Biol Phys. 1995;  32 831-837
• 27 Grigsby P W, Simpson J R, Fineberg B. Late regrowth of pituitary adenomas after irradiation and/or surgery. Hazard function analysis.  Cancer. 1989;  63 1308-1312
• 28 Landolt A M, Haller D, Lomax N, Schubiger O, Siegfried J, Wellis G. Stereotactic radiosurgery for recurrent surgically treated acromegaly: comparison with fractionated radiotherapy.  J Neurosurg. 1998;  88 1002-1008
• 29 Constine L S, Woolf P D, Cann D, Mick G, McCormick K, Raubertas R F, Rubin P. Hypothalamic-pituitary dysfunction after radiation for brain tumors.  N Engl J Med. 1993;  328 87-94
• 30 Trampe E A, Lundell G, Lax I, Werner S. External irradiation of growth hormone producing pituitary adenomas: prolactin as a marker of hypothalamic and pituitary effects.  Int J Radiation Oncol Biol Phys. 1991;  20 655-660
• 31 Rush S, Cooper P R. Symptom resolution, tumor control and side effects following postoperative radiotherapy for pituitary macroadenomas.  Int J Radiation Oncol Biol Phys. 1997;  37 1031-1034
• 32 McCollough W M, Marcus R B, Rhoton A, Ballinger W E, Million R R. Long-term follow-up of radiotherapy for pituitary adenoma: the absence of late recurrence after > 4500 cGy.  Int J Radiation Oncol Biol Phys. 1991;  21 607-614
• 33 Fiegl G C, Bonelli C M, Berghold A, Mokry M. Effects of gamma knife radiosurgery of pituitary adenomas on pituitary function.  J Neurosurg. 2002;  97 (Suppl 5) 415-421
• 34 Nedzi L A, Kooy H, Alexander E, Gelman R S, Loeffler J S. Variables associated with the development of complications from radiosurgery of intracranial tumors.  Int J Radiation Oncol Biol Phys. 1991;  21 591-599
• 35 Minniti G, Traish D, Ashley S, Gonsalves A, Brada M. Risk of second brain tumor after conservative surgery and radiotherapy for pituitary adenoma: update after an additional 10 years.  J Clin Endocrinol Metab. 2005;  90 800-804