ESTRO meets Asia 2024 - Abstract Book

S36

Invited Speaker

ESTRO meets Asia 2024

Total Neoadjuvant Treatment (TNT). In addition, we are evolving towards more organ-sparing strategies for low seated tumours.

A tailored treatment approach should be based on a multi-disciplinary tumour board discussion taking into account tumour staging including the pelvic MRI, patient performance status and expectations.

This multidisciplinary approach requires input from the different medical specialties such as digestive oncology, colorectal surgery, radiation oncology, radiology, nuclear medicine and pathology. Allied health professionals, such as a nurse practitioner, should also be part of this multidisciplinary team. They can provide support to the team and patients. In addition, informing the patient as objectively as possible about the proposed treatment options and the possible alternatives is important. Decision aids have been developed for this purpose. Patients with node negative T1 rectal cancer can be managed by a local excision. In patients with early rectal cancer primary surgery is standard of care. In some of these patients an organ sparing approach by long-course chemoradiotherapy can be an alternative. A TNT-approach consisting of a combination of (chemo)radiotherapy and chemotherapy followed by TME is preferred for locally advanced disease.

During the session, we will discuss all these aspects in more detail.

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Proton and carbon therapy: recent technological advances

Hikaru Souda

Graduate School of Medicine, Yamagata University, Yamagata, Japan

Abstract

Particle therapy, proton therapy using Bragg peak and carbon ion therapy with high LET, have their origin in Dr. Wilson's paper in 1946. Bragg peak and small scattering by relatively heavy particles enables superior dose distribution compared with photon therapy. High LET of carbon ion beam gives effective damage to a radioresistant tumor such as sarcoma, adenocarcinoma, etc. Proton therapy and carbon therapy had made progress as a research-level technology because it needs a large accelerator, cyclotron or synchrotron to achieve energies of 100-400 MeV/u for ~30 cm beam range. Initial experience of accelerator, broad-beam irradiation system, RBE system, treatment planning system, were well developed in the national laboratories. Nowadays, commercial-level development made some important advance for particle therapy. Proton therapy developed superconducting synchrocyclotron or AVF cyclotron for extremely compact size accelerator. Carbon ion therapy developed a gantry with superconducting magnets and full-energy scanning irradiation. These advances enabled sophisticated clinical irradiations with less manpower even in a small facility. With these technological advances, the number of treatment facility increased in 2000s and 2010s. It enabled multiple facility clinical trials and to produce high-level clinical evidence. Yamagata University is one of the recent carbon ion treatment facility with a fixed port irradiation room and a rotating gantry irradiation room. The number of yearly treated patient is 662 in its third year. The number of patient was quickly increased because of fast irradiation system and patient positioning system, and expansion of the cancer site covered by national health insurance. The rotating gantry use superconducting magnets, but the quench event which