IMRT

Invasive frame-based: immobilization

Radiotherapy and Oncology 95 (2010) 109–115

l Image-guidance g Quantification of intrafraction motion g Frame-based system SBRT set up A clinical comparison of patient setup and intra-fraction motion using frame-based radiosurgery versus a frameless image-guided radiosurgery system for intracranial lesions Naren Ramakrishna * , Florin Rosca, Scott Friesen, Evrim Tezcanli, Piotr Zygmanszki, Fred Hacker Department of Radiation Oncology, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, MA, USA Contents lists available at ScienceDirect Radiotherapy and Oncology journal homepage: www.thegreenjournal.c m

Passive verifica,on of 102 frame-­‐based set-­‐ups

a r t i c l e i n f o

a b s t r a c t

Article history: Received 12 June 2009 Received in revised form 8 December 2009 Accepted 29 December 2009 Available online 28 January 2010

Background and purpose: A comparison of patient positioning and intra-fraction motion using invasive frame-based radiosurgery with a frameless X-ray image-guided system utilizing a thermoplastic mask for immobilization. Materials and methods: Overall system accuracy was determined using 57 hidden-target tests. Positioning agreement between invasive frame-based setup and image-guided (IG) setup, and intra-fraction displace- ment, was evaluated for 102 frame-based SRS treatments. Pre and post-treatment imaging was also acquired for 7 patients (110 treatments) immobilized with an aquaplast mask receiving fractionated IG treatment. Results: The hidden-target tests demonstrated a mean error magnitude of 0.7 mm (SD = 0.3 mm). For SRS treatments, mean deviation between frame-based and image-guided initial positioning was 1.0 mm (SD = 0.5 mm). Fusion failures were observed among 3 patients resulting in aberrant predicted shifts. The image-guidance system detected frame slippage in one case. The mean intra-fraction shift magnitude observed for the BRW frame was 0.4 mm (SD = 0.3 mm) compared to 0.7 mm (SD = 0.5 mm) for the frac- tionated patients with the mask system. Conclusions: The overall system accuracy is similar to that reported for invasive frame-based SRS. The intra-fraction motion was larger with mask-immobilization, but remains within a range appropriate for stereotactic treatment. These results support clinical implementation of frameless radiosurgery using the Novalis Body Exac-Trac system. ! 2010 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 95 (2010) 109–115

Keywords: Frameless

Radiosurgery Image-guided Stereotactic

Radiotherapy and Oncology 2010;95:109–115

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Radiosurgery has an important role in the treatment of primary brain tumors, metastases, and functional disorders. Effective radi-

infection, and requires pre-medication. Furthermore, the care of patients wearing head frames creates a clinical resource burden