Improved robotic stereotactic body radiation therapy plan quality and planning efficacy for organ-confined prostate cancer utilizing overlap-volume histogram-driven planning methodology.

Autor: Wu B; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA. Electronic address: binbin.wu@gunet.georgetown.edu., Pang D; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA., Lei S; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA., Gatti J; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA., Tong M; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA., McNutt T; Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, USA., Kole T; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA., Dritschilo A; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA., Collins S; Department of Radiation Medicine, Georgetown University Hospital, Washington, USA.
Jazyk: angličtina
Zdroj: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2014 Aug; Vol. 112 (2), pp. 221-6. Date of Electronic Publication: 2014 Aug 06.
DOI: 10.1016/j.radonc.2014.07.009
Abstrakt: Background and Purpose: This study is to determine if the overlap-volume histogram (OVH)-driven planning methodology can be adapted to robotic SBRT (CyberKnife Robotic Radiosurgery System) to further minimize the bladder and rectal doses achieved in plans manually-created by clinical planners.
Methods and Materials: A database containing clinically-delivered, robotic SBRT plans (7.25 Gy/fraction in 36.25 Gy) of 425 patients with localized prostate cancer was used as a cohort to establish an organ's distance-to-dose model. The OVH-driven planning methodology was refined by adding the PTV volume factor to counter the target's dose fall-off effect and incorporated into Multiplan to automate SBRT planning. For validation, automated plans (APs) for 12 new patients were generated, and their achieved dose/volume values were compared to the corresponding manually-created, clinically-delivered plans (CPs). A two-sided, Wilcoxon rank-sum test was used for statistical comparison with a significance level of p<0.05.
Results: PTV's V(36.25 Gy) was comparable: 95.6% in CPs comparing to 95.1% in APs (p=0.2). On average, the refined approach lowered V(18.12 Gy) to the bladder and rectum by 8.2% (p<0.05) and 6.4% (p=0.14). A physician confirmed APs were clinically acceptable.
Conclusions: The improvements in APs could further reduce toxicities observed in SBRT for organ-confined prostate cancer.
(Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)
Databáze: MEDLINE
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