Wataru Makino1, Joichi Heianna2, Kazuki Ishikawa2, Takeaki Kusada2, Hitoshi Maemoto2, Takuro Ariga2, Akira Matayoshi3, Toshiyuki Nakasone3, Hitoshi Hirakawa4, Shinya Agena4, Yukashi Yamashita4, Hiroyuki Maeda4, Sadayuki Murayama2. 1. Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan. wataru517@gmail.com. 2. Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan. 3. Department of Oral and Maxillofacial Surgery, University Hospital of the Ryukyus, Nishihara, Okinawa, 903-0215, Japan. 4. Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.
Abstract
BACKGROUND: Postoperative chemoradiotherapy is recommended for patients with head and neck squamous cell carcinoma with positive margins or extracapsular extension at high risk of recurrence. However, high-dose radiotherapy in the head and neck region often causes severe acute and late radiation-related adversities. In our institution, the radiation dose has been relatively lower than that used in Western countries to reduce radiation-related toxicities. Therefore, in this study, we examined the treatment outcomes of low-dose postoperative chemoradiotherapy. METHODS: The outcomes of 90 consecutive head and neck squamous cell carcinoma patients who received postoperative radiotherapy between June 2009 and December 2016 were retrospectively analyzed. All patients received postoperative three-dimensional conformal radiotherapy with or without concurrent systemic chemotherapy. The median patient age was 65 years. Concurrent chemoradiotherapy was administered at a total dose of 50.4 Gy in 28 fractions (daily fraction, 1.8 Gy). High-risk patients received 10.8 Gy of boost irradiation in six fractions. For radiotherapy alone, the irradiation dose was up to 54 Gy in 30 fractions and 64.8 Gy in 36 fractions for high-risk patients to increase the treatment intensity. RESULTS: The median follow-up period was 40.5 months. The 3-year locoregional control and overall survival rates were 67.5% and 82.7%, respectively. A significantly higher proportion of patients with oral cavity carcinoma experienced locoregional failure (p = 0.004). The acute adverse events were mild, and the only late adverse event was grade 3 dysphagia (n = 3). CONCLUSION: This study suggests that de-escalation of the postoperative radiation dose can potentially reduce the severe adverse events of irradiation in patients while ensuring its effectiveness. In patients with oral cavity carcinoma, it might be necessary to increase the radiation dose.
BACKGROUND: Postoperative chemoradiotherapy is recommended for patients with head and neck squamous cell carcinoma with positive margins or extracapsular extension at high risk of recurrence. However, high-dose radiotherapy in the head and neck region often causes severe acute and late radiation-related adversities. In our institution, the radiation dose has been relatively lower than that used in Western countries to reduce radiation-related toxicities. Therefore, in this study, we examined the treatment outcomes of low-dose postoperative chemoradiotherapy. METHODS: The outcomes of 90 consecutive head and neck squamous cell carcinoma patients who received postoperative radiotherapy between June 2009 and December 2016 were retrospectively analyzed. All patients received postoperative three-dimensional conformal radiotherapy with or without concurrent systemic chemotherapy. The median patient age was 65 years. Concurrent chemoradiotherapy was administered at a total dose of 50.4 Gy in 28 fractions (daily fraction, 1.8 Gy). High-risk patients received 10.8 Gy of boost irradiation in six fractions. For radiotherapy alone, the irradiation dose was up to 54 Gy in 30 fractions and 64.8 Gy in 36 fractions for high-risk patients to increase the treatment intensity. RESULTS: The median follow-up period was 40.5 months. The 3-year locoregional control and overall survival rates were 67.5% and 82.7%, respectively. A significantly higher proportion of patients with oral cavity carcinoma experienced locoregional failure (p = 0.004). The acute adverse events were mild, and the only late adverse event was grade 3 dysphagia (n = 3). CONCLUSION: This study suggests that de-escalation of the postoperative radiation dose can potentially reduce the severe adverse events of irradiation in patients while ensuring its effectiveness. In patients with oral cavity carcinoma, it might be necessary to increase the radiation dose.