Swallowing-sparing intensity-modulated radiotherapy for head and neck cancer patients: Treatment planning optimization and clinical introduction

Hans Paul van der Laan*, Agata Gawryszuk, Miranda E M C Christianen, Roel Steenbakkers, Erik W Korevaar, Olga Chouvalova, Kim Wopken, Hendrik P Bijl, Johannes A Langendijk

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

40 Citations (Scopus)

Abstract

PURPOSE: To report on the potential benefits of swallowing-sparing intensity-modulated radiation therapy (SW-IMRT) in the first 100 SW-IMRT treated patients, as well as on the factors that influence the potential benefit of SW-IMRT relative to standard parotid sparing (ST)-IMRT.

MATERIAL AND METHODS: One hundred consecutive head and neck cancer patients, scheduled for primary radiotherapy, were included in this prospective cohort study. For each patient, ST-IMRT and SW-IMRT treatment plans were created. All patients were eventually treated with SW-IMRT. Objectives for SW-IMRT were identical to those with ST-IMRT, with additional objectives to spare the swallowing organs at risk (SWOARs). After 20 patients, interim results were evaluated by a multidisciplinary committee.

RESULTS: The mean gain of SW-IMRT relative to ST-IMRT in the first 20 patients was less than expected based on our previous planning comparative study. A critical review of all plans revealed that the results with SW-IMRT could be improved by: (1) gaining experience and attempting to reduce SWOAR dose as much as possible; (2) accepting a moderate shift of dose to unspecified tissues; (3) maximizing SWOAR sparing while keeping PTV coverage exactly according to protocol. In the additional 80 patients, the mean dose to the various SWOARs was further reduced significantly compared to ST-IMRT. Dose reductions with SW-IMRT were largest for patients who received neck irradiation, had a tumour located in the larynx, oropharynx, nasopharynx or oral cavity, and had <75% overlap between SWOARs and PTVs. The mean absolute reduction in predicted physician-rated RTOG grade 2-4 swallowing dysfunction for patients numbered 21-100 was 6.1%, ranging from 0.0% to 17.2%.

CONCLUSIONS: The benefit of SW-IMRT depends significantly on neck radiotherapy, tumour site and the amount of overlap between SWOARs and PTVs. Optimal clinical introduction requires a detailed evaluation and comparison between the standard (ST-IMRT) and new technique (SW-IMRT) in order to fully exploit the potential benefits.

Original languageEnglish
Pages (from-to)282-287
Number of pages6
JournalRadiotherapy and Oncology
Volume107
Issue number3
DOIs
Publication statusPublished - Jun-2013

Keywords

  • Head and neck cancer
  • IMRT
  • Swallowing dysfunction
  • Normal tissue complication probability
  • Clinical implementation
  • DYSPHAGIA
  • DELINEATION
  • THERAPY

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