Dose impact of rectal gas on prostatic IMRT and VMAT.

PURPOSE - In this study, we compared the dose impact of the heterogeneity caused by rectal gas using two methods of treatment planning for intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT).

MATERIALS AND METHODS - In addition to the structure set used for the standard treatment plan, we created a structure set for evaluation for each patient. These sets were transferred to the same isocenter as the respective treatment plans for IMRT and VMAT that were to become the standard. Values were then recalculated.

RESULTS - During the standard prostatic IMRT and VMAT treatment planning, all study participants met dose restrictions in place at our hospital. Dose restrictions were fulfilled in treatment plans for evaluation, excluding those with a clinical target volume (CTV) of V 100 % and planning target volume (PTV) of D 95 when the rectum was excluded. However, in treatment plans for evaluation, IMRT was shown to have a higher concordance rate with standard treatment plans than VMAT.

CONCLUSIONS - If rectal gas is present during either IMRT or VMAT, a dose decrease will occur in relation to CTV and PTV, suggesting that a plan does not eliminate adverse effects on organs at risk.

Japanese journal of radiology. 2015 Nov 17 [Epub ahead of print]

Motoharu Sasaki, Hitoshi Ikushima, Masahide Tominaga, Takeshi Kamomae, Taro Kishi, Masataka Oita, Masafumi Harada

Department of Radiological Technology, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan. Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan. , Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan. , Department of Therapeutic Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya, Aichi, 466-8550, Japan. , Department of Radiological Technology, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan. , Graduate School of Health Science, University of Okayama, 2-5-1 Shikata-cho, Okayama Kita-ku, Okayama, 700-8558, Japan. , Department of Radiology and Radiation Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan.

PubMed

E-Newsletters

Newsletter subscription

Free Daily and Weekly newsletters offered by content of interest

The fields of GU Oncology and Urology are rapidly advancing. Sign up today for articles, videos, conference highlights and abstracts from peer-review publications by disease and condition delivered to your inbox and read on the go.

Subscribe