Original Article

Rapid palliative radiotherapy: comparing IG-IMRT with more conventional approaches

Rajiv Samant^a1a2 c1, Lee Gerig^a1a3, Lynn Montgomery^a1, Miller MacPherson^a4a5, Greg Fox^a1, Robert MacRae^a1a2, Kathy Carty^a1, Steve Andrusyk^a1, Paul Genest^a1a2 and Balazs Nyiri^a1a3

^a1 Division of Radiation Oncology, Department of Radiology, The Ottawa Hospital Cancer Centre

^a2 Faculty of Medicine, University of Ottawa

^a3 Department of Physics, Carleton University, Ottawa, Ontario, Canada

^a4 Department of Medical Physics, Carlo Fidani Peel Regional Cancer Centre, Mississauga, Ontario, Canada

^a5 Department of Radiation Medicine and Physics, The University of Toronto, Toronto, Ontario, Canada

Abstract

Purpose: To assess the efficiency of an integrated imaging, planning, and treatment delivery system to provide image-guided intensity-modulated radiotherapy (IG-IMRT) for patients requiring palliative radiotherapy (PRT).

Methods: Between December 2006 and May 2008, 28 patients requiring urgent PRT were selected to undergo single-session megavoltage computed tomography (MV-CT) simulation, IMRT treatment planning, position verification and delivery of the first faction of radiotherapy on a helical Tomotherapy^® unit. The time required to complete each step was recorded and compared to our standard approach of using either fluoroscopic or CT-based simulation, simplified treatment planning and delivery on a megavoltage unit.

Results: Twenty-eight patients were treated with our integrated IG-IMRT protocol. The median age was 72 years, with 61% men and 39% women. The indications for PRT were: painful bone and soft tissue metastasis (75%); bleeding lesions (14%); and other reasons (11%). The areas treated included the following: hip and/or pelvis (42%); spine (36%); and other areas (21%). The most commonly used dose prescription was 20 Gy in five fractions. Average times for the integrated IG-IMRT processes were as follows: image acquisition, 15 minutes; target delineation, 16 minutes; IMRT treatment planning, 9 minutes; treatment position verification, 10 minutes; and treatment delivery, 12 minutes. The average total time was 62 minutes compared to 66 minutes and 81 minutes for fluoroscopic and CT-simulation-based approaches, respectively. The IMRT dose distributions were also superior to simpler plans.

Conclusions: PRT with an integrated IG-IMRT approach is efficient and convenient for patients, and has potential for future applications such as single-fraction radiotherapy.

Keywords

• Palliative radiotherapy;
• IG-IMRT;
• integrated imaging–planning–treatment

Correspondence:

^c1 Correspondence to: Rajiv Samant, Radiation Oncologist, Division of Radiation Oncology, The Ottawa Hospital Cancer Centre, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada. Email: rsamant@ottawahospital.on.ca