BATH AND SHOWER EFFECTS IN THE RAT PAROTID GLAND EXPLAIN INCREASED RELATIVE RISK OF PAROTID GLAND DYSFUNCTION AFTER INTENSITY-MODULATED RADIOTHERAPY

Peter van Luijk*, Hette Faber, Jacobus M. Schippers, Sytze Brandenburg, Johannes A. Langendijk, Harm Meertens, Robert P. Coppes

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

39 Citations (Scopus)

Abstract

Purpose: To assess in a rat model whether adding a subtolerance dose in a region adjacent to a high-dose irradiated subvolume of the parotid gland influences its response (bath-and-shower effect).

Methods and Materials: Irradiation of the whole, cranial 50%, and/or the caudal 50% of the parotid glands of Wistar rats was performed using 150-MeV protons. To determine suitable (i.e., subtolerance) dose levels for a bath-dose, both whole parotid glands were irradiated with 5 to 25 Gy. Subsequently groups of Wistar rats received 30 Gy to the caudal 50% (shower) and 0 to 10 Gy to the cranial 50% (bath) of both parotid glands. Stimulated saliva flow rate (function) was measured before and up to 240 days after irradiation.

Results : Irradiation of both glands up to a dose of 10 Gy did not result in late loss of function and is thus regarded subtolerance. Addition of a dose bath of I to 10 Gy to a high-dose in the caudal 50% of the glands resulted in enhanced function loss.

Conclusion: Similar to the spinal cord, the parotid gland demonstrates a bath and shower effect, which may explain the less-than-expected sparing of function after IMRT. (C) 2009 Elsevier Inc.

Original languageEnglish
Pages (from-to)1002-1005
Number of pages4
JournalInternational Journal of Radiation Oncology Biology Physics
Volume74
Issue number4
DOIs
Publication statusPublished - 15-Jul-2009

Keywords

  • Radiotherapy
  • Normal tissue damage
  • Parotid gland
  • Xerostomia
  • Dose-volume effects
  • CERVICAL-SPINAL-CORD
  • SALIVARY-GLANDS
  • PROTON-BEAMS
  • NECK-CANCER
  • VOLUME
  • IRRADIATION
  • RADIOSENSITIVITY
  • TOLERANCE
  • DOSIMETRY
  • HEAD

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