Treatment and Dosimetric Advantages Between VMAT, IMRT, and Helical TomoTherapy in Prostate Cancer

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Medical Dosimetry

DOI:https://doi.org/10.1016/j.meddos.2010.05.001· OSTI ID:21590490

Tsai, Chiao-Ling; Wu, Jian-Kuen; Chao, Hsiao-Ling; Tsai, Yi-Chun ^[1]

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1. Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China)

We investigated the possible treatment and dosimetric advantage of volumetric modulated arc therapy (VMAT) over step-and-shoot intensity-modulated radiation therapy (step-and-hhoot IMRT) and helical tomotherapy (HT). Twelve prostate cancer patients undergoing VMAT to the prostate were included. Three treatment plans (VMAT, step-and-shoot IMRT, HT) were generated for each patient. The doses to clinical target volume and 95% of planning target volume were both {>=}78 Gy. Target coverage, conformity index, dose to rectum/bladder, monitor units (MU), treatment time, equivalent uniform dose (EUD), normal tissue complication probability (NTCP) of targets, and rectum/bladder were compared between techniques. HT provided superior conformity and significantly less rectal volume exposed to 65 Gy and 40 Gy, as well as EUD/NTCP of rectum than step-and-shoot IMRT, whereas VMAT had a slight dosimetric advantage over step-and-shoot IMRT. Notably, significantly lower MUs were needed for VMAT (309.7 {+-} 35.4) and step-and-shoot IMRT (336.1 {+-} 16.8) than for HT (3368 {+-} 638.7) (p < 0.001). The treatment time (minutes) was significantly shorter for VMAT (2.6 {+-} 0.5) than step-and-shoot IMRT (3.8 {+-} 0.3) and HT (3.8 {+-} 0.6) (p < 0.001). Dose verification of VMAT using point dose and film dosimetry met the accepted criteria. VMAT and step-and-shoot IMRT have comparable dosimetry, but treatment efficiency is significantly higher for VMAT than for step-and-shoot IMRT and HT.

• OSTI ID: 21590490
• Journal Information: Medical Dosimetry, Journal Name: Medical Dosimetry Journal Issue: 3 Vol. 36; ISSN 0958-3947
• Country of Publication: United States
• Language: English

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