title: Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA.
abstract: It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently, the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy.
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR. Electronic address: eyhan@uams.edu.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Han
authors.affiliation: Department of Radiation Oncology, Kyung Hee University Hospital, Seoul, South Korea.
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR.
authors.forename: Jose
authors.initials: J
authors.lastname: Penagaricano
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hardee
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR.
authors.forename: Steve
authors.initials: S
authors.lastname: Morrill
authors.affiliation: Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR.
authors.forename: Vaneerat
authors.initials: V
authors.lastname: Ratanatharathorn
mesh_terms: D002648:Child; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000532:radiotherapy*; D059351:Organ Sparing Treatments / Q000295:instrumentation*; D058958:Organs at Risk / Q000528:radiation effects*; D011835:Radiation Protection / Q000295:instrumentation; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
keywords: Dosimetric comparison; Dynamic jaw; Pediatric cancer; TomoHDA