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Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Carbon-ion radiotherapy for clear cell odontogenic carcinomas
Hiroaki Ikawa1, Masashi Koto2, Kazunori Fugo2
1QST Hospital, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan. ikawa.hiroaki@qst.go.jp.
Background:
Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic malignant tumor. The standard treatment for CCOC is surgical resection and adjuvant radiotherapy (RT). Radiotherapy is generally considered in inoperable cases. However, there are no reports on definitive RT for CCOC, and the role of RT in patients with inoperable CCOC remains unknown. Therefore, in this report, we present two cases of carbon-ion (C-ion) RT for CCOC.
Case Presentation:
In case 1, a 73-year-old man with mandibular CCOC presented with recurrence in the inferior temporal fossa after two tumor resections. The tumor was considered inoperable, and C-ion RT (57.6 Gy in 16 fractions) was administered. The tumor remained controlled even after 20 months of C-ion RT; however, the patient died of other causes. In case 2, a 34-year-old man with maxillary CCOC presented with recurrence in the left sinonasal region after two tumor resections. The tumor was considered inoperable, and C-ion RT (64 Gy in 16 fractions) was administered. However, recurrence was observed in the irradiated field 19 months after the treatment. Subsequently, C-ion RT (64 Gy in 16 fractions) was repeated for the recurrent tumors. Seven years and 6 months after the initial irradiation, the tumor remains controlled, and the patient is alive without any unexpected serious adverse events.
Conclusion:
C-ion RT may be an effective treatment option for patients with inoperable CCOC.
