Gustatory Function Following Radiotherapy to the Head and Neck

Gustatory Function Following Radiotherapy to the Head and Neck

The aim of this study is to assess the effect of RT or chemo-RT on chemosensory gustatory function in patients with HNC. By using detailed dosimetric data derived from the RT planning system, we will be able to calculate mean radiation doses to important structures including the anterior and posterior tongue, oral cavity, parotid and submandibular salivary glands, and correlate them with both qualitative and quantitative data for dysgeusia.

This study aims to collect data from patients with HNC undergoing RT or chemo-RT to correlate quantitative chemosensory gustatory function with

• Detailed dosimetric data for critical structures relevant to perception of taste
• Fungiform papillae density (FPD)
• Use of concurrent platinum based therapy
• Patient reported taste loss using The Taste and Smell Survey (TSS) [14]
• Patient reported toxicity and overall QOL using University Washington Quality of Life Revised Version 4 (UW-QOL v4) [15].
• Clinician reported acute and late toxicity using NCI Common Terminology Criteria for Adverse Events Version 4.0 (CTCAE v4) [16] and Scale of Subjective Total Taste Acuity (STTA) [17].
• Weight (as a surrogate of nutritional status).

This study hopes to demonstrate a dose dependent relationship for loss of taste and to develop a dose constraint for preservation of taste. In turn this will serve as a platform for further research to optimise the technical delivery of radiation either in the form of optimised IMRT or through the use of intensity modulated proton therapy (IMPT).

Inclusion Criteria:

• Age >/= 18 years
• Undergoing unilateral or bilateral RT or concurrent chemo-RT to the head and neck - region using either a conformal or IMRT planning technique or
• No restrictions on tumour sub-site
• No restriction on tumour histology
• No restrictions on radiotherapy dose and fractionation
• For entry into the cross-sectional cohort; patients 12 months post completion of unilateral or bilateral RT or concurrent chemo-RT to the head and neck region using either a conformal or IMRT planning technique.

Exclusion Criteria:

• Patients with pre-existing olfactory or gustatory disorders either self-reported or through objective taste function testing.

• Patients with radiological or clinical involvement of following nerves

  • facial nerve
  • chorda tympani
  • glossopharyngeal nerve
  • lingual nerve
  • greater petrosal nerve
  • geniculate ganglion

• Patients who have undergone a total or partial glossectomy