Phase II Study of Daily Adaptive Radiotherapy for Submandibular Gland-sparing in Head and Neck Cancer

Phase II Randomized Trial of RT-Led Daily Adaptive Radiotherapy for Submandibular Gland-Sparing in Head and Neck Cancer (RTL-DART)

This is a randomized, single centre, single blinded prospective study comparing the standard of care imaging guided radiation therapy and daily adaptive radiotherapy (ART) for submandibular gland-sparing in head and neck cancer

This study will recruit up to 50 patients planned to receive curative (chemo) radiotherapy for (head and neck squamous cell carcinoma) HNSCC with at least one level 1b lesion not being treated electively and with no high dose structure <1cm to spared (submandibular gland) SMG. The effect of daily ART with SMG dose sparing will be studied using both doimetric analysis and externally-validated quantitative metrics of unstimulated salivary flow as an object assessment for submandibular gland function. Patient report outcomes will assess the effect of the intervention on self-reported quality of life following treatment.

Patients, at the time of enrollment, will be randomized into one of the two treatment arms. The patients will be blinded to prevent bias in their quality of life assessments.

Patients in both arms will undergo a baseline functional CT scan along with other assessments including oral and dental assessment, PSS-HNC swallow assessment, unstimulated salivary flow rate test, DMFS160 index, and quality of life questionnaire. The radiation treatment will take approximately 7 weeks to complete. The follow up visits will be at 1.5, 6, 12, and 24 months with assessments similar to baseline.

Inclusion Criteria:

• Age ≥ 18 years
• Histologically proven Squamous Cell carcinoma of head and neck
• Bilateral neck being treated
• At least one level 1b not being treated electively and with no target structure, other than elective level II/III, <1cm to spared SMG
• ECOG PS 0-2
• Planned for curative (chemo)radiotherapy
• Able to receive and understand verbal and written information regarding study and able to give written informed consent
• Be able to lie comfortably on back and to wear immobilization for up to 1 hour

Exclusion Criteria:

• As judged by investigator evidence of systemic disease that makes unsuitable for study
• Pregnancy
• Underlying salivary dysfunction prior to treatment judged by investigator to affect likelihood of benefit from ART