[口咽癌] mucosal sparing RT 的臨床應用

在HPV positive oropharyngeal cancer 裡面, de-escalation 一直是近期內臨床上研究的熱點

近期內有一篇prospective study 發表在red journal, 值得一讀

其收案條件如下: p16+, AJCC 7th pathologic T1 or T2, N1 to N3, and M0 oropharyngeal cancers, 接受TORS 手術, 術後margin negative, minimal or negative PNI, minimal or negative LVI, 利用proton therapy 去治療, 如果保險不給付的話, 轉用IMRT

RT範圍只針對neck, high risk: 60Gy/ low risk: 54Gy

結果收案 61 個病人,  median follow-up: 38 months; 44個病人 (72%) 接受質子治療. The 2-year local control, locoregional control, distant metastasis–free survival, and overall survival were 98%, 97%, 98%, and 100%. 6 個 grade ≥3 events related to treatment.

因為即使只照射neck, primary site 也還是會有散射劑量, 這篇研究分析結果為mean D95 to the primary target was 10.7 Gy(Proton therapy 組才有畫primary stie, photon組沒有, 所以這個劑量是proton組的), 其實蠻低的, 所以大概可以推論只照脖子, 在這群利用條件篩選過的病人應該是可行的

臨床情境思考: 如果病人符合上述條件, 接受傳統手術, 是不是可以primary site不要接受照射, 因為傳統手術比TORS開的更大, 感覺這樣的策略更有機會成功!

Reference:

1. Anderson JD, DeWees TA, Ma DJ, et al. A Prospective Study of Mucosal Sparing Radiation Therapy in Resected Oropharyngeal Cancer Patients. Int J Radiat Oncol Biol Phys. 2023;115(1):192-201. doi:10.1016/j.ijrobp.2022.06.057