Radiation Oncology

Introduction
Radiation therapy (RT) plays an essential role in the care of patients with cancer. It is used as curative treatment for many patients with malignant disease, as integrated therapy with chemotherapy and surgery, and as palliative treatment for those in whom curative treatment is not an option. The dose of radiation delivered to the tumor must be as high as possible, while being as low as possible to surrounding normal tissues.
The focus of The Radiation Oncology Division is to develop, evaluate and expand the role of RT in cancer treatment. Establishing optimal irradiation technique, including proton treatment, is also an important goal of the division.

Routine Activities 
The Radiation Oncology Division includes five consultant physicians, eight radiation technologists and two medical physicists. Treatment has been mostly based on three-dimensional planning with isodose distributions, performed by RT-dedicated helical scanning CT, to conform the dose to the tumor. Almost 1,000 new patients were treated annually, and more than 20 clinical trials that involve RT as a sole or a combined treatment modality, for various cancers are ongoing.
The conventional (photon-electron) treatment division is equipped with three treatment machines (a Microtron with 2 gantries, a linear accelerator and a high dose rate brachytherapy unit), a CT-simulator, three treatment planning computer workstations, and many other devices. The proton treatment division, the first such hospital-based treatment facility in Japan, is equipped with a cyclotron capable of generating a 235 MeV proton beam. The proton beam is delivered to three treatment rooms (two isocentrically rotational gantries and one fixed horizontal beam line). In this year, two rotational gantry treatment rooms were routinely used.

New Developments in 2002
1. Proton therapy was initiated in Nov. 1998 at our hospital. Proton therapy was approved as a "highly advanced medical technology" from the Japanese Government in July 2001. Until the end of 2002, we have treated 161 patients with the head & neck, lung, liver and prostate cancer.
2. Optimal margin for proton therapy of prostate cancer was defined by analyzing interfraction motion and patient position-related motion.
3. Pencil beam algorithm for calculating the dose distributions of proton beam has been developing.
4. Long-term survival and toxicity after definitive chemoradiotherapy (CRT) for squamous cell carcinoma (SCC) of the thoracic esophagus were analyzed. CRT for SCC of the esophagus achieved favorable 5-year survival (27%). It was also revealed that cardiopulmonary toxicity and metachronous esophageal carcinoma should be carefully checked-up in the longer follow-up.
5. Hypofractionated RT combined with sequential gemcitabine for unresectable locally advanced pancreatic cancer was initiated.
6. Radiotherapy Quality assurance (QA) survey and audit were initiated in both Japan Radiation Oncology Group (JROG) and Japan Clinical Oncology Group (JCOG).

T. OGINO

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