Adaptive radiotherapy for invasive bladder cancer: A feasibility study

Journal Article · Wed Mar 01 04:00:00 EST 2006 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2005.0· OSTI ID:20793357

Pos, Floris J ^[1]; Hulshof, Maarten ^[2]; Lebesque, Joos ^[1]; Lotz, Heidi ^[1]; Tienhoven, Geertjan van ^[2]; Moonen, Luc ^[1]; Remeijer, Peter ^[1]

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1. Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
2. Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)

Purpose: To evaluate the feasibility of adaptive radiotherapy (ART) in combination with a partial bladder irradiation. Methods and Materials: Twenty-one patients with solitary T1-T4 N0M0 bladder cancer were treated to the bladder tumor + 2 cm margin planning target volume (PTV{sub CONV}). During the first treatment week, five daily computed tomography (CT) scans were made immediately before or after treatment. In the second week, a volume was constructed encompassing the gross tumor volumes (GTVs) on the planning scan and the five CT scans (GTV{sub ART}). The GTV{sub ART} was expanded with a 1 cm margin for the construction of a PTV{sub ART}. Starting in the third week, patients were treated to PTV{sub ART}. Repeat CT scans were used to evaluate treatment accuracy. Results: On 5 of 91 repeat CT scans (5%), the GTV was not adequately covered by the PTV{sub ART}. On treatment planning, there was only one scan in which the GTV was not adequately covered by the 95% isodose. On average, the treatment volumes were reduced by 40% when comparing PTV{sub ART} with PTV{sub CONV} (p < 0.0001). Conclusion: The adaptive strategy for bladder cancer is an effective way to deal with treatment errors caused by variations in bladder tumor position and leads to a substantial reduction in treatment volumes.

• OSTI ID: 20793357
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 3 Vol. 64; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ACCURACY
BLADDER
CARCINOMAS
COMPUTERIZED TOMOGRAPHY
ERRORS
FEASIBILITY STUDIES
IRRADIATION
PATIENTS
RADIOTHERAPY