Table 6. Management of the Base of Tongue. IL: ipsilateral. BL: bilateral. PE: panendoscopy. Ix: Investigation. Ex: examination. BOT: base of tongue, TBM: tongue base mucosectomy, PT: palatine tonsillectomy TOR: transoral Robotic Assisted Surgery. TLM: transoral laser microsurgery, Dx: diagnosis, Tx: treatment
Novel Techniques
Several novel surgical techniques have been reported in the literature to perform TBM. These include TORS, TLM as well as other endoscopic cautery techniques. The majority of studies focus on outcomes following TORS or TLM (table 7 location percentage is percentage of total primaries found).
There were six studies15,37-41 where 331 patients underwent TORS within the diagnostic workup and, 5 studies with 223 patients underwent TLM16,17,42-44, (Graboyes et al used TLM but in two of 65 patients TORS was used for resection after TLM44). The were two meta-analyses: Meccarellio et al45 and Farooq et al46. The primary studies are all retrospective studies with significant heterogeneity. There are no randomised controlled trials.
The meta analysis by Meccariello et al45 looked at the use of TORS in HNSCCUP for 349 patients over 12 studies. They found an overall detection rate of 64% in the base of tongue using a TORS approach.
Farooq et al al46 looked at patients undergoing TBM using either TORS or TLM in 556 patients over 21 studies. The pooled rate of positive TBM was 64% in those that had negative clinical examination and imaging (including PET). The detection rate went up to 78% in those patients who had also undergone an EUA and negative tonsillectomy prior to TBM. They also reported a higher detection rate for TLM (91%) versus TORS (74%) but this was based on very limited evidence in 81 total patients.
The current evidence suggests that TBM should be undertaken in the workup of HNSCCUP to increase the chances of primary site identification. There is no evidence to suggest one technique is superior to another. The detection rate is greater in patients who have already undergone a negative tonsillectomy. This does mean further general anaesthetic for those patients who go on to require TBM, or the potential risk of increased complications (theoretical risk of oropharyngeal stenosis) if the procedures are combined. The studies where they are combined often use frozen sections as a surgical decision node, an option not routinely used in the UK. Therefore, the decision on a staged or a combined procedure would currently be based on surgeon preference and on the individual case (ie suspicious scans, or HPV positivity). Higher quality, prospective studies would be required to look at the potential risks and efficacy in primary pickup of combining these procedures in particular palatine tonsillectomy and TBM.