title: Fractionated stereotactic radiotherapy to the post-operative cavity for radioresistant and radiosensitive brain metastases.
abstract: Following surgical resection for brain metastases, fractionated stereotactic radiotherapy (FSRT) has been used as an alternative to single dose treatment for large cavities and to reduce risks of late toxicity. The purpose of this study was to evaluate the outcomes of patients treated with FSRT to the post-operative bed for both radioresistant and radiosensitive brain metastases. Between December 2009 and May 2013 a total of 65 patients with newly diagnosed brain metastases were treated with resection followed by FSRT. Patients were treated to a total dose of 20-30 Gy in five fractions. Median planning target volume (PTV) was 16.88 cm(3) (range 4.87-128.43 cm(3)). The median follow-up for all patients was 8.5 months (range 1.1-28.6 months) with a median of 12.9 months for living patients. One and two year Kaplan-Meier estimates of local control were 87.0 and 70.0 %, respectively. Local control at 1 year was 85.6 and 88.0% for radioresistant and radiosensitive tumors, respectively (p = 0.44). A PTV ≥17 cm(3), was associated with local failure, HR 8.63 ((1.44-164.78); p = 0.02). One and two year distant control rates were 50.9 and 46.2%, respectively with six patients (9.2%) experiencing leptomeningeal disease. OS rates at 1 and 2 years were 65.2 and 47.5%, respectively. Survival was significantly associated with recursive partitioning analysis class (p = 0.001) and graded prognostic assessment score (p = 0.005). One case of radionecrosis was noted on follow-up imaging. FSRT in five fractions offers excellent local control in both radiosensitive and radioresistant tumors with minimal toxicity.
authors.affiliation: Departments of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Dr., Tampa, FL, 33612, USA.
authors.forename: Kamran A
authors.initials: KA
authors.lastname: Ahmed
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Freilich
authors.forename: Yazan
authors.initials: Y
authors.lastname: Abuodeh
authors.forename: Nicholas
authors.initials: N
authors.lastname: Figura
authors.forename: Neha
authors.initials: N
authors.lastname: Patel
authors.forename: Siriporn
authors.initials: S
authors.lastname: Sarangkasiri
authors.forename: Prakash
authors.initials: P
authors.lastname: Chinnaiyan
authors.forename: Hsiang-Hsuan Michael
authors.initials: HH
authors.lastname: Yu
authors.forename: Arnold B
authors.initials: AB
authors.lastname: Etame
authors.forename: Nikhil G
authors.initials: NG
authors.lastname: Rao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000473:pathology; D008875:Middle Aged; D011836:Radiation Tolerance; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D012509:Sarcoma / Q000473:pathology; D016019:Survival Analysis; D015996:Survival Rate; D055815:Young Adult