Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
ORIGINAL ARTICLE
Year : 2010  |  Volume : 6  |  Issue : 2  |  Page : 194-198

Helical tomotherapy for head and neck squamous cell carcinoma: Dosimetric comparison with linear accelerator-based step-and-shoot IMRT


Department of Radiation Oncology, Tata Memorial Hospital and Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India

Correspondence Address:
Vedang Murthy
Consultant Radiation Oncologist, Tata Memorial Hospital and Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-1482.65245

Rights and Permissions

Background: Linear Accelerator-based Intensity Modulated Radiation Therapy (IMRT), either as step-and shoot (SS) or in dynamic mode, is now considered routine in the definitive management of head and neck squamous cell carcinoma (HNSCC). Helical TomoTherapy (HT) is a new platform to deliver IMRT. This study aims to compare step-and-shoot Intensity Modulated Radiation Therapy (SS IMRT) with dynamic Helical TomoTherapy (HT) dosimetrically in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods: Twelve patients with HNSCC, previously treated with SS IMRT, were re-planned on HT using the same CT dataset. Plans were compared for target coverage and organs-at-risk (OARs) sparing. Sparing of parotids was assessed after stratifying for side (contralateral vs. ipsilateral) and site of disease (laryngopharynx vs. oropharynx). Normal tissue complication probabilities (NTCP) were also compared for the parotid glands. Results: All HT plans showed improvement in target coverage and homogeneity, and reduction in OAR doses as compared to SS IMRT plans. For PTV 66, the mean V 99 improved by 14.65% ( P = 0.02). Dose Homogeneity (D 10-90 ) was significantly better in the HT plans (mean 2.07Gy as compared to 4.5Gy in the SS IMRT plans, P = 0.02). HT resulted in an average reduction of mean parotid dose of 12.66Gy and 18.28Gy for the contralateral and ipsilateral glands ( P = 0.003) respectively. This translated into a 24.09% and 35.22% reduction in Normal Tissue Complication Probability (NTCP) for the contralateral and ipsilateral parotids respectively ( P < 0.01). Site of disease (laryngopharynx vs. oropharynx) did not have any significant impact on parotid sparing between SS IMRT and HT. The maximum dose to the spinal cord showed a mean reduction of 12.07Gy in HT plans ( P = 0.02). Conclusion: Helical Tomotherapy achieved better target coverage with improved OAR sparing as compared to SS IMRT. The significant reduction in mean parotid doses translated into meaningful reduction in NTCP, with potential clinical implications in terms of reduction in Xerostomia and improved quality of life in patients with HNSCC.


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed5523    
    Printed183    
    Emailed2    
    PDF Downloaded497    
    Comments [Add]    
    Cited by others 19    

Recommend this journal