The role of brachytherapy for margin control in oral tongue squamous cell carcinoma

Abstract

Background The aim of this study is to assess the feasibility and effectiveness of using peri-operative brachytherapy (BRTx) for positive/narrow margins present post primary surgical resection of oral tongue squamous cell carcinoma (OTSCC). Methods Prospective single-centre study of patients with OTSCC (T1–3, N0–3, M0) treated with resection of primary tumour ± regional nodal resection and intra-operative insertion of BRTx catheters. BRTx was administered twice daily at 40.8Gy/12Fr for ‘Positive’ (≤2 mm) margins, at 34Gy/10Fr for ‘Narrow’ (2.1-5 mm) margins, and not given for ‘Clear’ (> 5 mm) margins over the course of 5–6 days, 3–5 days post operatively. Results Out of 55 patients recruited 41 patients (74.6%) were treated with BRTx, as 12 patients had clear margins and 2 patients had unfavourable tumour anatomy for catheter insertion. EBRTx was avoided in 64.3% of patients. Overall Survival (OS) at 3 and 5 years was 75.6 and 59.1% respectively, while Disease Specific Survival (DSS) was 82.3 and 68.6% at 3 and 5 years respectively. Recurrence and survival outcomes were not associated with margin status or the use of or specific dose of BRTx on Cox regression analysis. Acute and late toxicity secondary to BRTx was minimal. Conclusions The use of BRTx after primary OTSCC resection with positive/narrow margins ± EBRTx to the neck ± CTx achieves outcomes comparable to traditional treatment of surgery followed by re-resection or EBRTx ± CTx. Morbidity associated with oral cavity EBRTx or secondary resection and reconstruction is thus avoided. Both acute and late toxicity rates are low and compare favourably with other BRTx OTSCC studies. Trial registration Retrospectively registered. https://www.mcgill.ca/rcr-rcn/files/rcr-rcn/2017.06.05_rcn_hn.pdf. Level of evidence 4 Graphical abstract

Is perioperative brachytherapy effective in carcinoma of the tongue?

“…Cox regression analysis indicated that recurrence and survival outcomes were not associated with margin status or the use of a specific dose of HDR-ISBT. Acute and late toxicity, secondary to HDR-ISBT, was minimal [ 24 ].…”

Is There Still a Place for Brachytherapy in the Modern Treatment of Early-Stage Oral Cancer?

“…In many cases, revision surgery for positive or close margins is often challenging due to reconstruction of the primary tongue defect; in these cases, adjuvant RT is an option. Postoperative radiotherapy should be considered also in cases with lymphovascular and/or perineural invasion [ 30 ]. EBRT is associated with numerous acute and late side effects, including mucositis, dysphagia, xerostomia, and neck and mandibular necrosis.…”

“…Ianovski et al [ 30 ] evaluated postoperative HDR BT in patients with stage T1-3N0-3M0 disease, reporting 3- and 5-year OS rates of 75.6% and 59.1%; the DSS rates were 82.3% and 68.6%, respectively. In a preliminary study carried out by our group, postoperative HDR BT was indicated in the following cases: close or positive margins, presence of lymphovascular space or perineural invasion, poor differentiation, or tumour thickness > 5 mm [ 33 ].…”