811 Management of Patients with HPV-associated Oropharyngeal Cancer: A Units' Experience

Abstract

Abstract Aim The low positive predictive value (PPV) of initial post-therapy PET-CT in patients with Human papillomavirus (HPV-) associated oropharyngeal squamous cell carcinoma (OPSCC) presents a challenge for teams managing residual disease after initial treatment. We aimed to investigate current management, post treatment surveillance protocols and outcomes of these patients within our unit. Method A retrospective review was performed of p16 positive OPSCC patients treated in 2018. Their primary treatment modality (radiotherapy (RT) or chemoradiotherapy (CRT), neck dissection), post-therapy PET-CT results, management decisions and final clinical outcomes were recorded. Results 38 patients with p16 positive OPSCC were included in the study. 36 (94.7%) received primary CRT or RT, and 2 (5.3%) had primary neck dissections with adjuvant RT. 21 patients were found to have residual disease on the 3-month post-treatment PET-CT. Of these, 9 underwent further PET-CT surveillance, all showing no residual disease. 8 patients received ultrasound +/- fine needle aspiration, from which 1 showed incurable residual and distant metastasis. 2 underwent clinical surveillance, showing no residual disease. 1 had immediate salvage surgery, with further recurrence. 1 patient with persistent disease and lung metastasis received palliative immunotherapy. Conclusions 31 patients were disease free at the end point of this study. This study explores the need for further investigation into features of residual disease in post treatment PET-CT that would indicate initial treatment failure and possible further early intervention. A surveillance strategy following initial post treatment PET-CT needs to be developed to aid in making this decision as early as possible in the post treatment phase.