Pulsed Radiofrequency Ablation for the Treatment of Glossopharyngeal Neuralgia Secondary to Oropharyngeal Carcinoma

Abstract

Background: The management of glossopharyngeal neuralgia due to oropharyngeal carcinoma is particularly difficult because of rich innervations of the area, erosive nature of neoplasm and dynamic pain evoked by the functional movements like swallowing and chewing. Few case reports have shown the efficacy of pulsed radiofrequency (PRF) treatment in primary and secondary glossopharyngeal neuralgia in non-cancer patients. However, the efficacy of PRF ablation of the glossopharyngeal nerve in oral cancer patients is not known. Objectives: This study was conducted to evaluate the efficacy and safety of PRF ablation of the glossopharyngeal nerve for the management of oropharyngeal cancer pain involving the base of the tongue, tonsillar fossa, and oropharynx. Study Design: Prospective interventional clinical trial. Setting: Tertiary care hospital and medical education and research institute. Methods: A total of 25 adult patients suffering from oropharyngeal carcinoma, complaining of severe pain in the area mainly supplied by glossopharyngeal nerve, were included. The patients underwent fluoroscopy-guided PRF ablation of the glossopharyngeal nerve of the affected site 3 times at 42°C temperature for 120 seconds with 22-gauge, 10 cm long, 5 mm active tip radiofrequency needle. They were followed up for one year for pain relief, nausea-vomiting and sleep disturbances. The treatment was considered effective if there was 50% reduction in pain score at 2 weeks. Results: There was significant reduction in the overall pain score including site specific pain, odynophagia and ear pain after radiofrequency ablation (P < 0.0001) in all the patients. This was associated with decreased opioid consumption (P < 0.001), lesser nausea/vomiting, and improved sleep. The treatment was effective in 23 out of 25 patients (92%) for more than 3 months. No major complication was observed in any patient. The average duration of effective pain relief was 5 to 9 months. Limitations: Patients having bilateral glossopharyngeal neuralgia or an advanced stage of oral cancer with large lymph nodes at the angle of mandible were not included. This study was a singlecenter observational clinical trial and further multi-center, randomized, controlled trails are needed to obtain higher level of evidence. Conclusion: Our results showed that PRF ablation can be used effectively and safely for the treatment of glossopharyngeal neuralgia secondary to oropharyngeal carcinoma. Key words: Glossopharyngeal neuralgia, ear pain, odynophagia, oral cancer pain, pulsed radiofrequency ablation, side effects