One-time treatment replaces weeks of radiation therapy.
NewYork-Presbyterian/Columbia University Medical Center is finding new ways to use individualized, internal radiation delivered in the operating room immediately after a cancerous tumor is removed. Intraoperative radiotherapy, or IORT, represents an effort to reduce the chance of a cancer recurrence, shorten the duration of conventional postoperative external radiation, and reduce the risk to healthy tissue associated with external radiation.
In 2012, NewYork-Presbyterian Hospital became the first hospital in New York City to offer IORT to women with certain breast cancers. In this therapy, a spherical applicator is used to deliver a single, even dose of radiation to the inside surface of a rounded cavity after a lumpectomy.
Now, physicians at NewYork-Presbyterian/Columbia are expanding these pioneering efforts by offering IORT for other types of cancer in the abdomen and pelvis. Unlike in the breast, the tumor bed in the abdomen and pelvis may not be as clearly defined after surgery, and several sites at risk for recurrence may need to be treated.
Earlier this year, the hospital first used IORT for a woman with recurrent colon cancer in the pelvic cavity. P. Ravi Kiran, MBBS, MS, Msc, FRCS, FACS, Chief and Program Director of the Division of Colorectal Surgery at NewYork-Presbyterian/Columbia, removed the tumor, but could not cut too close to vital blood vessels and other organs. Due to the limitations of surgery, and because the patient had already received a high lifetime cumulative dose of radiation therapy in previous treatments, Dr. Kiran and Clifford Chao, MD, the Chu H. Chang Professor of Radiation Oncology and Chair, Radiation Oncology at NewYork-Presbyterian/Columbia, decided to use IORT to “mop up” any leftover tumor cells. Dr. Chao used a flat radiotherapy applicator to deliver radiation to areas close to blood vessels along the pelvic wall and a spherical applicator to treat a region lower in the pelvic cavity. “We also used a protective wrap, or draping, made of material that shields organs like the bowel or blood vessels from scatter radiation,” Dr. Chao said.
“Because of the way the tumor needs to be removed, or because the spaces between a tumor and large vessels and nerves are too small, microscopic lesions are more likely to be attached to the surface of blood vessels and nerves. IORT allowed us to treat those areas and lower the risk of recurrence,” said Dr. Chao, who is leading the hospital’s IORT efforts.
Other surgeons at the hospital have since used IORT, delivered by tailored applicators, to treat patients with a bile duct tumor and a gynecologic cancer.
In certain breast cancer cases, IORT has eliminated an additional 6–7 weeks of radiation therapy and, according to a 10-year randomized trial published in 2010, yielded the same results as conventional full-breast radiation. Dr. Chao is hopeful that similar benefits will be seen in other types of cancer cases, and he sees this as another step forward for personalized cancer care.
“The possibilities are encouraging,” said Dr. Chao. “We could see patients ahead of time and then work with the surgeon to develop a personalized radiation treatment for the specific tumor.”
“When you open up the abdomen to remove a tumor from the liver, bowel, or pancreas, the terrain of the surgical bed is a more open, uneven surface,” he said. “So we need radiotherapy applicators that suit the specific anatomical terrain. In some areas of the body, the applicator could be a half sphere, an irregular shape for uneven surfaces, or a tiny device that fits into a small space where we have anatomic challenges. We can devise personalized therapy based on a patient’s specific anatomy.”
According to Dr. Kiran, “The availability of IORT offers an opportunity to surgically treat more advanced colorectal cancers. When surgical margins are questionable, local IORT may reduce the chance of cancer recurrence even in advanced cases.”
Dr. Chao is currently working with engineers and physicists from NYP/Columbia and NYP/Weill Cornell Medical Center to design and develop applicators for colorectal, head and neck, lung, and gynecologic cancers.