Use of Lymphatic Mapping to Guide Radiotherapy to the Neck in Oropharyngeal Cancer

Summary

Objectives

PRIMARY OBJECTIVE:
I. To determine if a lymphatic mapping-guided approach (experimental arm) for management of the contralateral neck has a non-inferior disease-free survival (DFS) compared to bilateral neck radiation therapy (RT) (control arm) in patients with lateralized oropharyngeal squamous cell carcinoma (OPC) not involving or crossing the midline and without clinical contralateral nodal disease.

SECONDARY OBJECTIVES:
I. Swallowing-related quality of life (M.D. Anderson Dysphagia Inventory [MDADI]) and Xerostomia-related quality of life (Xerostomia Questionnaire [(XQ]).
II. Isolated contralateral neck failure (iCNF), overall survival (OS), loco-regional failure (LRF), distant metastases (DM).
III. Radiation therapy (RT)-related toxicities.
IV. Patient reported toxicities (Patient Reported Outcomes – Common Terminology Criteria, PRO CTCAE).
V. Gastrostomy tube usage.
VI. To perform economic analyses (Canadian CCTG Sites Only: resource utilization, lost productivity, financial toxicity (Financial Index of Toxicity [FIT]) cost-utility analysis using health utilization costs and health utilities EuroQOL (EQ-5D).

EXPLORATORY OBJECTIVES
I. Swallowing function using videofluoroscopic swallow studies (sub-study).
II. Head and Neck Cancer Specific QOL (University of Washington Quality of Life Questionnaire [UW-QOL]).
III. Patters of lymphatic drainage using lymphatic mapping/single photon emission computed tomography-computed tomography (SPECT-CT) imaging.
IV. Predicting contralateral lymphatic drainage on SPECT-CT with pre-treatment imaging (computed tomography/magnetic resonance imaging [CT/MRI]) radiomic features.
V. To correlate baseline tumor somatic mutations with risk of recurrence after treatment.
VI. To correlate circulating cell free tumor deoxyribonucleic acid (DNA) (cfDNA) levels with clinical recurrence after treatment.

OUTLINE: Participants are randomized to 1 of 2 arms.

ARM A: Patients receive technetium Tc-99m sulfur colloid via injection and then undergo SPECT/CT. Patients may undergo radiotherapy if mapping shows draining to contralateral lymph nodes. Patients may also receive standard of care chemotherapy.

ARM B: Patients receive usual radiotherapy. Patients may receive usual standard of care chemotherapy.

After completion of study treatment, patients are followed up at 1 month after treatment, every 3 months for 2 years, and then every 6 months thereafter.