CNS Digital Poster

Radiosurgery for Brain Metastasis from Breast Cancer

Alessandra A. Gorgulho, MD; Nikita Bezrukiy, PHD; Jonathan Pieton, BS; Edward Mitchell, BS; Nzhde Agazaryan, PHD; John De Marco, PHD; Michael Selch, MD; Antonio A.F. De Salles, MD, PhD, Prof
University of California at Los Angeles

	Introduction
	One of every eight women suffer from breast cancer in her lifetime. Brain metastasis occur in about 10% of breast cancer.(1) As systemic therapy improves, brain metastasis become more frequent.(2) Brain metastasis from breast cancer are considered to be radiation sensitive.(3). Whole brain radiation therapy (WBRT) showed to improve survival and quality of life when compared with steroids alone, leading to a median survival time of 4-5 months.(2,4) However, a detailed analysis of specific lesion histological response to radiosurgery with or without whole brain radiation therapy (WBRT) is lacking. Radiosurgery (SRS) is an attractive option to treat single or multiple lesions. It can also be used as salvage therapy after WBRT failure.(2) There are studies showing that radiosurgery has a role in selected patients.(2,3,5) The time course of response of breast metastases to the brain after radiosurgery was analyzed.
	Methods
	From January 1992 to March 2005, 94 patients with 297 brain metastasis from breast were treated with SRS at UCLA. Mean age was 57.5 years-old, all female. Most common primary breast tumor was infiltrating ductal carcinoma (73%). There were 50 patients treated with WBRT prior to SRS. Only 30 (32.25%) patients had single metastasis. The average Karnofsky Performance Score (KPS) was 86% (40%-100%). The most frequent locations were frontal area (n = 66, 22.22%) with 18 lesions at the motor area and cerebellum (n = 63, 21.2%). A mean dose of 16.36 ± 2.3 Gy was prescribed to the mean 88% isodoseline (IDL). The mean lesion volume was 2.79cc (0.03-62.20cc). Radiation was mostly delivered via shaped beam with the mini multi-leaf collimator (mMLC), which was used on 154 lesions (52%). The circular collimator most often used was 10 mm in diameter(n = 36, 12%).

	Table 1
	Results
	- Excellent conformal tumor coverage with the 90% isodoseline was achieved in 257 (87%) lesions. - Twenty-one (7.07%) lesions required craniotomy due to SRS failure. Histology showed radiation necrosis associated with tumor cells in 19 (90.5%) cases, while only one patient had no viable tumor cells. Mean prescribed dose for these lesions was 15.4 ± 2.1 Gy. - Eleven (3.7%) lesions increased in size and were treated with repeated SRS. Six were located at the occipital-parietal area. - Complications consisted of 14 (4.71%) seizures in 5 patients, 8 patients experienced worsening in KPS, 4 (4.12%) post-SRS hospitalization and 1 (7%) bleeding. - The mean survival was 6.5 months.
	Conclusions
	Breast carcinoma responded to radiosurgery with tumor stabilization or decrease in more than 90% of the lesions treated. The very low intracranial failure rate observed during the follow up period suggests that the majority of the patients die of systemic disease.

	Case Example - Radiation Necrosis and Tumor Growth
	Bibliographic References
	DiStefanoA, Young Yap Y, Hortobagyi GN, Blumenshein GR. The natural history of breast cancer patients with brain metastases. Cancer 44;1913-1918,1979. Lin NU, Bellon JR, Winer EP. CNS Metastases in breast cancer. Journal of Clinical Oncology 22(17):3608-3617. Goyal S, Prasad D, Harrell F, Matsumoto J, Rich T, Steiner L. Gamma knife surgery for the treatment of intracranial metastases from breast cancer. J Neurosurg 103:218-223, 2005. Mahmoud-Ahmed AS, Suh JH, Lee S-Y et al. Results of whole brain radiotherapy in patients with brain metastases from breast cancer: a retrospective study. Int Radiat Oncol Biol Phys 54:810-817, 2002 Kondziolka D, Martin J, Flickinger JC, Friedland DM, Brusfsky AM, Baar J, Agarwala S, Kirkwood JM, Lunsford LD. Long term survivors after Gamma Knife radiosurgery for brain metastases. Cancer 104 (12): 2784-2791.