Evaluation of a commercial automatic treatment planning system for prostate cancers

Kanabu Nawa; Akihiro Haga; Akihiro Nomoto; Raniel A Sarmiento; Kenshiro Shiraishi; Hideomi Yamashita; Keiichi Nakagawa

doi:10.1016/j.meddos.2017.03.004

Evaluation of a commercial automatic treatment planning system for prostate cancers

Med Dosim. 2017;42(3):203-209. doi: 10.1016/j.meddos.2017.03.004. Epub 2017 May 23.

Authors

Kanabu Nawa¹, Akihiro Haga², Akihiro Nomoto², Raniel A Sarmiento³, Kenshiro Shiraishi⁴, Hideomi Yamashita², Keiichi Nakagawa²

Affiliations

¹ Department of Radiology, University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan. Electronic address: knawa.jp@gmail.com.
² Department of Radiology, University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan.
³ Philips Radiation Oncology Systems, Fitchburg, WI.
⁴ Department of Radiology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan.

PMID: 28549556
DOI: 10.1016/j.meddos.2017.03.004

Abstract

Recent developments in Radiation Oncology treatment planning have led to the development of software packages that facilitate automated intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) planning. Such solutions include site-specific modules, plan library methods, and algorithm-based methods. In this study, the plan quality for prostate cancer generated by the Auto-Planning module of the Pinnacle³ radiation therapy treatment planning system (v9.10, Fitchburg, WI) is retrospectively evaluated. The Auto-Planning module of Pinnacle³ uses a progressive optimization algorithm. Twenty-three prostate cancer cases, which had previously been planned and treated without lymph node irradiation, were replanned using the Auto-Planning module. Dose distributions were statistically compared with those of manual planning by the paired t-test at 5% significance level. Auto-Planning was performed without any manual intervention. Planning target volume (PTV) dose and dose to rectum were comparable between Auto-Planning and manual planning. The former, however, significantly reduced the dose to the bladder and femurs. Regression analysis was performed to examine the correlation between volume overlap between bladder and PTV divided by the total bladder volume and resultant V70. The findings showed that manual planning typically exhibits a logistic way for dose constraint, whereas Auto-Planning shows a more linear tendency. By calculating the Akaike information criterion (AIC) to validate the statistical model, a reduction of interoperator variation in Auto-Planning was shown. We showed that, for prostate cancer, the Auto-Planning module provided plans that are better than or comparable with those of manual planning. By comparing our results with those previously reported for head and neck cancer treatment, we recommend the homogeneous plan quality generated by the Auto-Planning module, which exhibits less dependence on anatomic complexity.

Keywords: Automated planning optimization; Interoperator variation; Plan quality; Prostate cancer.

Publication types

Evaluation Study

MeSH terms

Humans
Male
Prostatic Neoplasms / radiotherapy*
Radiotherapy Planning, Computer-Assisted / methods*
Retrospective Studies