Feasibility of Re-irradiation using carbon ions for recurrent head and neck malignancies after carbon-ion radiotherapy

Abstract

Background and purpose: Locoregional recurrence after carbon-ion radiotherapy (CIRT) for primary head and neck malignancies, such as malignant mucosal melanoma, adenoid cystic carcinoma, and sarcoma, occurs occasionally. However, the treatment options are limited. We report on the toxicity and efficacy of re-irradiation using carbon ions for recurrent head and neck malignancies after CIRT. Materials and methods: Data of 48 patients with recurrent head and neck malignancies treated with reirradiation with CIRT at our institution (2007-2016) were retrospectively analyzed. Twenty-one patients (43.8%) had malignant mucosal melanoma, 17 (35.4%) had adenoid cystic carcinoma, six (12.5%) had bone and soft tissue sarcomas, and four patients (8.3%) had other disease types. Tumor recurrences at reirradiation were located in the paranasal cavity (n = 18, 37.5%), nasal cavity (n = 9, 18.8%), nasopharynx (n = 4, 8.3%), orbit (n = 3, 6.3%), cavernous sinus (n = 3, 6.3%), and at other sites (n = 11, 22.9%). The median dose of initial CIRT and that at re-irradiation were 57.6 Gy and 54.0 Gy (relative biological effectiveness [RBE]), respectively. None of the patients received concurrent chemotherapy. Results: The median follow-up period after re-irradiation was 27.1 months. Five patients (10.4%) developed Grade 3 acute toxicities and 18 (37.5%) developed Grade 3 late toxicities, including Grade 5 central nervous system necrosis in one patient. The 2-year local control, locoregional control, progression-free survival, and overall survival rates were 40.5, 33.5%, 29.4%, and 59.6%, respectively. Conclusion: Re-irradiation using carbon ions may be a reasonable treatment option with tolerable toxicity for patients with recurrent head and neck malignancies after CIRT.

Dose-Limiting Organs at Risk in Carbon Ion Re-Irradiation of Head and Neck Malignancies: An Individual Risk-Benefit Tradeoff

“…In this study, 49 patients (42.6%) presented with tumor infiltration of the orbital cavity, and 94 patients (81.7%) had tumors with infiltration of the base of the skull or the immediate surroundings. Furthermore, compared to prior studies on re-irradiation with heavy ions [21], the median PTV of 128.9 cc in this evaluation was extensive, reaching about 50-100% more. In addition, the tumor locations were possibly more challenging in the current analysis (81.7% of them infiltrated the base of the skull).…”

“…Considering all patients for whom dose constraints were exceeded intentionally (n = 49, 42.6%), the dose prescription at CIR was restrictive in the current analysis. Hayashi et al [21] reported absolute dose constraints at CIR of 30 Gy (RBE) for the brainstem and spinal cord and 40 Gy (RBE) for the optic system. Hu et al [6] assumed a recovery from the previous photon radiotherapy set at 70%, independent of the RT interval.…”

Efficacy and feasibility of re-irradiation using carbon ions for pancreatic cancer that recurs after carbon-ion radiotherapy

“…In contrast, the initial RT in our study was high-LET C-ion RT. Hayashi et al [15] reported that the 2-year LC following re-irradiation with C-ion RT in patients with head and neck malignancies whose tumours recurred after initial C-ion RT was 40.5%. This was inferior to the 2-year LC rates following initial C-ion RT reported by Koto et al [23] (83.9%).…”

“…Hayashi et al [15] evaluated 48 patients with recurrent head and neck malignancies treated with C-ion RT re-irradiation and reported 2-year LC and OS rates of 40.5% and 59.6%, respectively. This provided evidence that re-irradiation using carbon ions is a reasonable treatment with tolerable toxicity for patients with recurrent head and neck malignancies after C-ion RT.…”

Radical external beam re‐irradiation in the treatment of recurrent head and neck cancer: Critical review

“…Dmean to OaR was reduced by 86% using IMPT and by 100% when IMIT was used, with significant dosimetric sparing of the contralateral organs (carotid artery, arytenoid, parotid, and submandibular glands), spinal cord, and brainstem. 84 Particle re-irradiation could facilitate dose escalation in the tumor while sparing OaR, and with the expected reduction in long-term side effects of RT, it could also reduce the likelihood of normal tissue complication probability, 85 but any widespread recommendation on its use in clinical practice is biased by short follow-up [86][87][88][89][90][91][92] (Table 3). Available evidence includes only retrospective phase II studies without control arms and with a limited number of patients.…”