Minimal acute toxicity from proton beam therapy for major salivary gland cancer

Acta Oncol. 2020 Feb;59(2):196-200. doi: 10.1080/0284186X.2019.1698764. Epub 2019 Dec 5.

Abstract

Introduction: Proton beam therapy (PBT) reduces normal organ dose compared to intensity-modulated radiation therapy (IMRT) for patients with major salivary gland tumors. It is not known whether this dosimetric advantage is clinically meaningful for reducing acute toxicity.Methods: We evaluated treatment parameters and acute toxicity outcomes of patients with major salivary gland cancers enrolled on the Proton Collaborative Group REG001-09 trial (NCT01255748).Results: One-hundred and five patients with a median age of 61 years were included. The majority had parotid (N = 90) versus submandibular gland (N = 15) tumors. The patients were treated across seven institutions in the United States between 2010 and 2017, most commonly in the postoperative setting (70.5%) although a minority were treated definitively (29.5%). Median PBT dose was 66.5 GyE in 33 fractions; only one patient was prescribed less than 50 GyE. Chemotherapy was given concurrently to 20%. Median follow-up was 14.3 months. Acute grade 2 or higher toxicity included nausea (1.5%), dysgeusia (4.8%), xerostomia (7.6%), mucositis (10.5%) and dysphagia (10.5%).Conclusions: PBT should be strongly considered when ipsilateral radiation therapy is indicated for major salivary gland cancer based on a considerably lower incidence of acute grade 2 or higher toxicity in this analysis compared to historical IMRT outcomes.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Dose Fractionation, Radiation
  • Female
  • Humans
  • Male
  • Middle Aged
  • Proton Therapy* / adverse effects
  • Radiation Injuries / epidemiology
  • Radiation Injuries / etiology
  • Radiation Injuries / pathology
  • Radiation Injuries / prevention & control
  • Radiotherapy Dosage
  • Salivary Gland Neoplasms / pathology
  • Salivary Gland Neoplasms / radiotherapy*
  • Treatment Outcome
  • United States / epidemiology
  • Young Adult