(fx) hfSRT in patients with intact brain metastases (intact) and post- operative surgical .... J. Galvin: None. W.A. Tome: E. Research Grant; Philips Medical System,.
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International Journal of Radiation Oncology Biology Physics
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Warrenville, IL, 2University of Maryland, Baltimore, MD, 3Radiation Therapy Oncology Group, Philadelphia, PA, 4Bodine Cancer Center, Philadelphia, PA, 5Kimmel Cancer Center, Philadelphia, PA, 6Montefiore Medical Center and Albert Einstein College of Medicine of Yeshiva University, Bronx, NY
Outcomes With Hypofractionated Stereotactic Radiation Therapy (hfSRT) in Patients With Intact Brain Metastases and Postoperative Surgical Cavities L. Khan,1 H. Soliman,1 W. Xu,1 M.E. Ruschin,2 N. Phan,3 F. Lochray,1 J. Spears,1 S. Das,1 T. Mainprize,1 and A. Sahgal4; 1University of Toronto, Toronto, ON, Canada, 2Odette Cancer Centre, Toronto, ON, Canada, 3 University of Toronto, University of Toronto, ON, Canada, 4Sunnybrook Health Sciences Center, Toronto, ON, Canada Purpose/Objective(s): Our aim was to report outcomes with 5 fraction (fx) hfSRT in patients with intact brain metastases (intact) and postoperative surgical cavities (cavities). Materials/Methods: Forty intact metastases in 27 patients, and 59 cavities in 58 patients, were identified from a prospective database and reviewed. All patients were treated frameless using a linear accelerator equipped with a 4 mm multileaf collimator, cone-beam CT and robotic couch top. For intact tumors, a 2 mm planning target volume (PTV) was applied to the gross tumor volume (GTV) and, similarly, beyond the post-operative surgical bed to the clinical target volume (CTV) for cavities. Local control (LC) was determined using the competing risk method and overall survival (OS) using KaplanMeier method. Results: Both cohorts were balanced with respect to the proportion of recursive partitioning analysis (RPA) class 1 vs 2, prior whole brain radiation and treated with salvage intent (w33%), proportion of patients on a targeted biologic agent at the time of hfSRT (w30%), and disease specific graded prognostic index (dsGPA) score. However, the median maximal GTV diameter/volume was 1.7cm (range 0.6-5.1 cm)/4.17cc (range 1-26.7cc,) for intacts, and for cavities the pre-operative CTV diameter/volume was 3.2cm (range 1.2-7.5cm))/11.6cc (range 1.6 -61 cc) and post-operatively 2.9cm (range 1.5-6.2 cm)/11.9 cc (range 0.538cc). 30Gy in 5 fx was most commonly prescribed in both cohorts (range, 25-37.5Gy). The median follow-up interval was 11.8 months (range, 1-32.5 months) and 12.8 months (range 1- 41.5 months) for intacts and cavities, respectively. There were no significant differences (p Z 0.52) in LC rates at 6 months and 1 year for intacts (97% and 80%, respectively) as compared to cavities (95% and 82%, respectively). When comparing LC for only intact lesions 2cm to cavity cases with a pre-operative diameter 2cm, no significant difference in the risk of recurrence at 6 months and 1 year were observed (p Z 0.47). Dose to 90% of the PTV (D90) significantly predicted LC for both intact (p7mm (12 cases) and PTV D90%95% passed pre-enrollment credentialing, pretreatment centralized real-time rapid review disqualified 5.7% of reviewed cases, prevented unacceptable deviations in 24% of reviewed cases, and limited the final unacceptable deviation rate to 5% of analyzable cases. Pre-treatment review ensured high concordance with protocol criteria and is deemed necessary in future hippocampal avoidance trials and potentially useful in other similar radiation therapy technique trials. Acknowledgment: This project was supported by RTOG grant U10 CA21661 and CCOP grant U10 CA37422 from the National Cancer Institute (NCI). Author Disclosure: V. Gondi: None. M.P. Mehta: G. Consultant; Elekta, Phillips. N. Stock Options; Accuray. D. Manfredi: None. Y. Xiao: None. J. Galvin: None. W.A. Tome: E. Research Grant; Philips Medical System, Accuray. K. Advisory Board; View Ray Inc. Q. Patent/License Fee/ Copyright; Wisconsin Alumni Research Foundation. W.A. Tome: E. Research Grant; Philips Medical System, Accuray. K. Advisory Board; View Ray Inc. Q. Patent/License Fee/Copyright; Wisconsin Alumni Research Foundation.
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Real-Time Pretreatment Review Limits Unacceptable Deviations: Quality Assurance (QA) Results of RTOG 0933 V. Gondi,1 M.P. Mehta,2 D. Manfredi,3 Y. Xiao,4 J. Galvin,5 W.A. Tome,6 and W.A. Tome6; 1Cadence Brain Tumor Center and CDH Proton Center,
Outcome of Cerebral Arteriovenous Malformation After Linear Accelerator Radiosurgical Retreatment P.L. Moraes,1,2 R. Ferrigno,3 H.R. Segreto,4 E. Weltman,5 R.S. Dias,4 A.J. Giordani,4 S. Benabou,6 and R.A. Segreto4; 1Sa˜o Joaquim Hospital -
