Radiotherapy for Oropharyngeal Carcinoma With an Uninvolved Contralateral Neck: The Safety of Omission of Contralateral High Level II and Retropharyngeal Lymph Nodes From Elective Target Volumes.

AIMS: To analyse outcomes and patterns of failure in patients with oropharyngeal carcinoma (OPC) treated with definitive volumetric modulated arc therapy with omission of contralateral high level II lymph nodes (HLII) and retropharyngeal lymph nodes (RPLN) in the contralateral uninvolved neck. MATERIALS AND METHODS: Patients with OPC treated between January 2016 and July 2019 were retrospectively identified. In the absence of contralateral neck disease, institutional protocols allowed omission of contralateral HLII and contralateral RPLN in the additional absence of ipsilateral RPLN, soft palate/posterior pharyngeal wall primary. RESULTS: In total, 238 patients with OPC and an uninvolved contralateral neck received definitive (chemo)radiotherapy with bilateral neck treatment. The median follow-up was 30.6 months. Two-year local control, regional control and overall survival were 91.0, 91.6 and 86.5%, respectively. Contralateral HLII were omitted in 159/238 (66.8%) patients; this included 106 patients in whom the primary tumour was at/crossed the midline. The contralateral RPLN region was omitted from elective target volumes for 175/238 (73.5%); this included 114 patients with a primary tumour at/crossed the midline. The mean contralateral parotid dose when contralateral HLII and RPLN were both omitted was 24.4 Gy, compared with 28.3 Gy without HLII/RPLN omission (P < 0.001). Regional progression occurred in 18/238 (7.6%) patients, all involving the ipsilateral neck with one bilateral. There were no recurrences in the contralateral HLII or RPLN regions. CONCLUSION: In patients with OPC and an uninvolved contralateral neck receiving bilateral (chemo)radiotherapy, the omission of contralateral RPLN and HLII from elective target volumes was safe and could lead to reduced contralateral parotid doses.

Evaluation of Locoregional Recurrence Patterns Following Adjuvant (Chemo)Radiotherapy for Oral Cavity Carcinoma.

AIMS: To evaluate patterns of locoregional recurrence following adjuvant (chemo)radiotherapy for oral cavity squamous cell carcinomas. MATERIALS AND METHODS: One hundred and one patients who received adjuvant radiotherapy ± chemotherapy for oral cavity squamous cell carcinoma between 2013 and 2016 were analysed. For documented locoregional recurrence, recurrence imaging was deformably co-registered to the planning computed tomography scan. The volume of recurrence was delineated (Vrec). Vrec coverage by 95% of the corresponding planning target volume prescription dose was determined and the location compared with planning target volumes. Sites of recurrence were classified using a combined volume and centroid-based method: (A) central high dose, (B) peripheral high dose, (C) central low dose, (D) central peripheral dose, (E) extraneous. RESULTS: The median follow-up was 36 months. Forty-three per cent and 53% of patients received radiotherapy to the ipsilateral neck only and bilateral neck, respectively. Three-year overall survival, disease-free survival, local control, regional control and distant metastases-free survival were 63.0, 65.6, 88.0, 85.1 and 85.3%, respectively. Of 10 episodes of primary site recurrences, five were type A, four type B and one was type E. Of 14 episodes of regional recurrence, five were type A, two type C, two type D and five type E. Five of 21 (24%) patients with oral tongue carcinoma with an undissected/unirradiated contralateral neck had a type E contralateral neck recurrence, including 2/11 with pN0, 1/4 with pN1 and 2/6 with pN2 disease. CONCLUSIONS: Marginal and out-of-field recurrences remain a significant pattern of failure. We advocate generous target delineation postoperatively and, for oral tongue carcinomas, a comprehensive approach with bilateral neck irradiation.

Quality Assurance Peer Review of Head and Neck Contours in a Large Cancer Centre via a Weekly Meeting Approach.

AIMS: To assess the impact of weekly scheduled peer review of head and neck contours for definitive and adjuvant radiotherapy cases based on rates of recommended changes. MATERIALS AND METHODS: Retrospective analysis of a prospective database. Recommended changes were prospectively classified as 'major' (change in gross tumour volume and/or high-dose clinical target volume, dose/fractionation) or 'minor' (change in intermediate or elective dose clinical target volumes or organs at risk). Univariate analysis to explore associations between recommended changes and tumour site/stage and radical/adjuvant indication. RESULTS: In total, 307/375 (82%) head and neck cases treated with volumetric-modulated arc therapy were prospectively peer reviewed over a 12-month period; 195 (64%) cases received definitive and 112 (36%) received adjuvant radiotherapy. Overall, 43/307 (14.0%) changes were recommended within the peer review meetings. This comprised 27/307 (8.8%) major changes and 16/307 (5.2%) minor changes; 33/43 (77%) changes were in the clinical target volume. Rates of recommended changes were significantly higher for adjuvant versus definitive radiotherapy (odds ratio 2.26, P = 0.014) and for larynx compared with oropharynx (odds ratio 3.02, P = 0.02). There was no overall correlation between clinician experience and rates of change (P = 0.62). CONCLUSION: Routine weekly meeting contour-based peer review resulted in a number of major and minor changes to treatment. Compliance was high. Peer review was potentially beneficial for all tumour sites/stages/indications and any degree of clinician experience.

Recruitment of patients into head and neck clinical trials: acceptability of studies to patients from perspective of the research team.

We reviewed longitudinal recruitment data to assess recruitment into head and neck cancer trials, and to identify factors that could influence this and affect their acceptability to patients. We retrieved data from the prospective computerised database (2009-2016) to measure acceptability to patients using the recruitment:screening ratio, and compared observational with interventional studies, single specialty (or site) with multispecialty (or site) studies, and "step-up" randomisation with "non-inferiority" randomisation designs. A total of 1283 patients were screened and 583 recruited. The recruitment:screening ratio for all National Institute for Health Research (NIHR) portfolio studies combined was 0.47 (486/1133). Studies that involved treatment by several specialties or at several sites had a significantly adverse impact on acceptability (p=0.01). Recruitment into non-inferiority randomised controlled studies was lower than that into step-up randomised studies (p=0.06). The complexity of a study's design did not compromise recruitment. Treatment across several specialties or several sites and perceived non-inferiority designs, reduced the acceptability of some trials.

Postoperative (Chemo)Radiotherapy for Oral Cavity Squamous Cell Carcinomas: Outcomes and Patterns of Failure.

AIMS: To determine outcomes after adjuvant radiotherapy for squamous cell carcinoma of the oral cavity and to correlate locoregional recurrence patterns with radiotherapy target volumes. MATERIALS AND METHODS: All patients receiving adjuvant radiotherapy±chemotherapy after surgery with curative intent for oral cavity squamous cell carcinoma between 2007 and 2012 were retrospectively analysed. Locoregional recurrences were reconstructed on the planning computed tomography scan by both deformable image co-registration and by visual assessment. Recurrences were categorised as in-field, marginal or out-of-field if >95%, 20-95%, and <20% of the recurrence volume was encompassed by 95% of the prescription isodose, respectively. RESULTS: In total, 106 patients with a median follow-up of 42 months were included. Oral cavity subsites included oral tongue (54%) and floor of mouth (32%). Thirty (28%) patients received concurrent chemotherapy. Fifty-five (52%) patients received bilateral neck radiotherapy. Two year overall, disease-free, local disease-free, regional disease-free and distant metastases-free survival were 72, 83, 92, 89, 94%, respectively. On multivariate analysis, extracapsular nodal spread was the only factor significantly associated with inferior overall survival. Fourteen (13%) patients have experienced locoregional failure. Of the eight local recurrences at the primary tumour site, four, three and one were classified as in-field, marginal and out-of-field, respectively. Of 10 regional recurrences, one, one and eight were in-field, marginal and out-of-field. There were 7/21 (33%) contralateral regional recurrences in patients with pN2a/b disease who did not receive contralateral neck irradiation; there were 0/21 (0%) and 0/9 (0%) contralateral regional recurrences in patients with pN0 or pN1 disease, respectively, who did not receive contralateral neck irradiation. CONCLUSION: Marginal recurrences highlight the need for generous target volume delineation. Based upon rates of contralateral regional recurrences, a comprehensive approach to target volume selection should be advised for tumour subsites with bilateral lymphatic drainage in the presence of pN2a/b disease.