Survey of radiation field and dose in human papillomavirus- positive oropharyngeal cancer: is de-escalation actually applied in clinical practice?

Purpose: Studies on de-escalation in radiation therapy (RT) for human papillomavirus-positive (HPV(+)) oropharyngeal cancer (OPC) are currently ongoing. This study investigated the current practice regarding the radiation dose and field in the treatment of HPV(+) OPC. Materials and Methods: The Korean Society for Head and Neck Oncology conducted a questionnaire on the primary treatment policy. Among them, for HPV(+) OPC scenarios, radiation oncologists were questioned regarding the field and dose of RT. Results: Forty-two radiation oncologists responded to the survey. In definitive concurrent chemoradiotherapy (CCRT) treatment for stage T2N1M0 OPC, most respondents prescribed a dose of >60 Gy to the primary tonsil and involved ipsilateral lymph nodes. However, eight of the respondents prescribed a relatively low dose of <= 54 Gy. For stage T2N1M0 OPC, postoperative adjuvant RT was prescribed by eight and nine respondents with a lower dose of <= 50 Gy for the ipsilateral tonsil and involved neck, respectively. In definitive CCRT in complete remission after induction chemotherapy for initial stage T2N3M0 OPC, de-escalation of the tonsil and involved neck were performed by eight and seven respondents, respectively. Regarding whether de-escalation is applied in radiotherapy for HPV(+) OPC, 27 (64.3%) did not do it at present, and 15 (35.7%) were doing or considering it. Conclusion: The field and dose of prescribed treatment varied between institutions in Korea. Among them, dose de-escalation of RT in HPV(+) OPC was observed in approximately 20% of the respondents. Consensus guidelines will be set in the near future after the completion of ongoing prospective trials.