title: Dosimetric difference amongst 3 techniques: TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC).
abstract: To investigate the dosimetric difference amongst TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC). Ten patients with late-stage (Stage III or IV) NPC treated with TomoTherapy or IMRT were selected for the study. Treatment plans with these 3 techniques were devised according to departmental protocol. Dosimetric parameters for organ at risk and treatment targets were compared between TomoTherapy and IMRT, TomoTherapy and RapidArc, and IMRT and RapidArc. Comparison amongst the techniques was done by statistical tests on the dosimetric parameters, total monitor unit (MU), and expected delivery time. All 3 techniques achieved similar target dose coverage. TomoTherapy achieved significantly lower doses in lens and mandible amongst the techniques. It also achieved significantly better dose conformity to the treatment targets. RapidArc achieved significantly lower dose to the eye and normal tissue, lower total MU, and less delivery time. The dosimetric advantages of the 3 techniques were identified in the treatment of late-stage NPC. This may serve as a guideline for selection of the proper technique for different clinical cases.
authors: Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China. Electronic address: leekarhof@hotmail.com.
authors: Francis Kar-ho
authors: FK
authors: Lee
authors: Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China.
authors: Celia Wai-yi
authors: CW
authors: Yip
authors: Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China.
authors: Frankie Chun-hung
authors: FC
authors: Cheung
authors: Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China.
authors: Alex Kwok-cheung
authors: AK
authors: Leung
authors: Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China.
authors: Ricky Ming-chun
authors: RM
authors: Chau
authors: Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China.
authors: Roger Kai-cheong
authors: RK
authors: Ngan
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D058958:Organs at Risk / Q000528:radiation effects*; D011835:Radiation Protection / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
keywords: IMRT; NPC; RapidArc; TomoTherapy