Annual Report 2020
Department of Radiation Oncology
Tetsuo Akimoto, Naoki Nakamura, Sadamoto Zenda, Atsushi Motegi, Hidehiro Hojo, Masaki Nakamura, Yasuhiro Hirano, Shun-ichiro Kageyama, Hidenari Hirata, Shun-ichiro Kageyama
Introduction
Radiotherapy (RT) plays an essential role in the management of cancer patients. It is used as (1) a curative treatment for many patients with loco-regional localized malignant disease, (2) integrated therapy combined with chemotherapy and/or surgery, and (3) palliative treatment for patients for whom curative treatment is not an option. In radiotherapeutic approaches, the radiation dose to the loco-regional tumor must be as high as possible, while the dose to the surrounding normal tissues should be kept as low as possible to keep the severity of radiation-related complications within an acceptable level.
The primary aim of the Department of Radiation Oncology is to develop high-precision RT such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT), stereotactic body RT (SBRT), and proton beam therapy (PBT), and to establish the definitive role of RT in cancer treatment. Another important goal is to establish standard treatments for various types of cancer and optimal irradiation techniques including total dose, fractionation, and radiation fields.
Table 1. Number of patients treated with radiation therapy during 2016-2020
The Team and What We Do
At present, the staff of the Department of Radiation Oncology consists of seven consultant physicians (radiation oncologists), 19 radiation technologists, four medical physicists, one nurse, and one clerk. We have more than 1,000 new patients for conventional RT and more than 300 new patients for PBT every year. Quality assurance of conventional RT and PBT is performed by medical physicists and radiation technologists, and a conference to verify the treatment planning is held every morning in addition to a weekly work conference on research activities. RT and PBT are routinely based on three-dimensional radiation therapy planning and PBT using RT-dedicated multidetector-row helical computed tomography (CT) scanning to confirm the precise radiation dose to administer to the targeted tumors. Respiratory gating has been applied especially in radiotherapeutic management for patients with lung, esophagus, and liver cancer.
Selection of treatment approaches is determined through clinical conferences between radiation oncologists, surgical oncologists, and medical oncologists. Many clinical trials involving RT as the sole or combined treatment modality for various cancers are now in progress.
Our department is responsible for conventional (photon-electron) RT that consists of four linear accelerators, a CT simulator, four treatment planning computer workstations, and other important devices. IMRT and IGRT have been routinely applied for head and neck cancer and prostate cancer. In 2020, IMRT combined with concurrent chemotherapy for locally advanced lung cancer and esophageal cancer and stereotactic irradiation for brain metastases have started. Our department is also responsible for PBT, which is composed of seven operating staff members and one technician for fabricating the compensator and aperture. The staff was sent from manufacturing companies and work in collaboration with other staff members of our department. PBT consists of two treatment rooms, both of which are routinely used for rotational gantry treatment. In one room, for example, line scanning and intensity modulated proton therapy (IMPT) can be used for prostate cancer and head and neck cancer. Our department provides quality assurance and regular maintenance of the PBT machines for precise dose delivery and safe treatment. In 2021, we will start high-dose and low-dose brachytherapy for uterine cervical cancer and prostate cancer.
Research activities
In the Department of Radiation Oncology, the following research activities are in progress.
1) Establishment of optimal combined approaches including RT and chemotherapy for locally advanced head and neck cancer, non-small cell lung cancer and esophageal cancer, etc.
2) Establishment of the clinical usefulness of IMRT for head and neck cancer, localized prostate cancer, and cervical esophageal cancer
3) Hypofractionated IMRT for localized prostate cancer
4) Hypofractionated PBT for localized prostate cancer
5) Evaluation of the feasibility of PBT combined with chemotherapy for inoperable locally advanced non-small cell lung cancer and locally advanced esophageal cancer
6) Evaluation of long-term complications after PBT for pediatric malignancies
7) The role of gene polymorphisms in the development of acute and late radiation-related complications
8) Exploration of biomarkers for head and neck cancer
9) Radiobiological investigation of cellular response to radiation and proton beams
10) Efficacy of liquid biopsy in patients with oligometastases
Clinical trials
The following in-house and multi-institutional clinical trials are in progress
1. Phase II trial of concurrent chemoradiotherapy with 5-FU plus cisplatin for resectable squamous cell carcinoma of the cervical esophagus
2. The Japanese Radiation Oncology Study Group (JROSG) phase II trial of IMRT with concurrent chemoradiotherapy for resectable squamous cell carcinoma of the cervical esophagus
3. JCOG1208: A non-randomized confirmatory study of intensity modulated radiation therapy (IMRT) for T1-2N0-1M0 oropharyngeal cancer
4. JCOG1008: Phase II/III trial of postoperative chemoradiotherapy comparing 3-weekly cisplatin with weekly cisplatin in high-risk patients with squamous cell carcinoma of head and neck
5. Dose escalation study of PBT combined with concurrent chemotherapy for locally advanced esophageal cancer
6. JCOG1408: Phase III study of SBRT for stage I non-small cell lung cancer
7. JCOG1315C: Non-randomized prospective comparative study between surgical resection and proton beam therapy for resectable hepatocellular carcinoma
8. JCOG1801: A phase III randomized controlled trial comparing surgery plus adjuvant chemotherapy with preoperative chemoradiotherapy followed by surgery plus adjuvant chemotherapy for locally recurrent rectal cancer
9. JCOG1806: Avoid MAstectomy using Trastuzumab, pertuzumab and RAdiation Study for Breast Cancer (AMATERAS-BC)
Education
We established an education and training system for residents and junior radiation oncologists through clinical conferences and lectures on radiation oncology, physics, and radiation biology. In addition, a training course on quality assurance in radiation therapy has been regularly held for medical physicists and radiological technologists.
Future Prospects
We are now aiming to establish a system that can provide high-quality and safe high-precision radiation therapy, such as IMRT and SBRT. We would also like to promote the research and development of innovative technologies regarding RT, radiation biology, and medical physics.
List of papers published in 2020
Journal
1. Okumura M, Motegi A, Zenda S, Nakamura N, Hojo H, Nakamura M, Hirano Y, Kageyama SI, Arahira S, Parshuram RV, Kuno H, Hayashi R, Tahara M, Itoh Y, Naganawa S, Akimoto T. Efficacy and safety of accelerated fractionated radiotherapy without elective nodal irradiation for T3N0 glottic cancer without vocal cord fixation. Head Neck.;42(8):1775-1782, 2020.
2. Raturi VP, Hojo H, Hotta K, Baba H, Takahashi R, Rachi T, Nakamura N, Zenda S, Motegi A, Tachibana H, Ariji T, Motegi K, Nakamura M, Okumura M, Hirano Y, Akimoto T. Radiobiological model-based approach to determine the potential of dose-escalated robust intensity-modulated proton radiotherapy in reducing gastrointestinal toxicity in the treatment of locally advanced unresectable pancreatic cancer of the head. Radiat Oncol. 22;15(1):157, 2020.
3. Nishimura Y, Ishikura S, Shibata T, Kodaira T, Ito Y, Tsuchiya K, Murakami Y, Saitoh JI, Akimoto T, Nakata K, Yoshimura M, Teshima T, Toshiyasu T, Ota Y, Ishikawa K, Shimizu H, Minemura T, Nakamura K, Hiraoka M. A phase II study of adaptive two-step intensity-modulated radiation therapy (IMRT) with chemotherapy for loco-regionally advanced nasopharyngeal cancer (JCOG1015). Int J Clin Oncol. 25(7):1250-1259, 2020.
4. Tachibana H, Watanabe Y, Mizukami S, Maeyama T, Terazaki T, Uehara R, Akimoto T. End-to-end delivery quality assurance of computed tomography-based high-dose-rate brachytherapy using a gel dosimeter. Brachytherapy. 19(3):362-371, 2020.
5. Hojo H, Parshuram RV, Nakamura N, Arahira S, Akita T, Mitsunaga S, Nakamura M, Motegi A, Kageyama SI, Zenda S, Okumura M, Ikeda M, Akimoto T. Impact of Proton Beam Irradiation of an Anatomical Subsegment of the Liver for Hepatocellular Carcinoma. Pract Radiat Oncol. 10(4): e264-e271, 2020.