[Control of aftereffects due to intraoperative radiotherapy]

In cases of treating a pancreatic cancer, an aneurysm and thrombus of the abdominal aorta, necrosis of the vertebral body, and damage to the peripheral nerves can be caused by intraoperative radiotherapy (IORT). These aftereffects have been observed in tests conducted in experimental animal reported by Colorado State University. Similarly, our clinical experiences have led us to set safety guidelines to prevent damage due to IORT. The safety level of a radiation dose for IORT alone is limited to 30 Gy, and for IORT combined with external beam radiotherapy, from 20 Gy (IORT) plus 50 Gy (EBRT). Using these parameters, among 58 cases of a pancreatic tumor treated by IORT, only one case subsequently developed a pseudoaneurysm at the stump of splenic artery.