Gynecologic Cancer: Conformal Radiosurgery Offers Hope

Gynecologic cancers were among the first malignancies treated with ionizing radiation more than a century ago. Today, gynecologic oncologists deliver radiation using sophisticated computerized imaging guidance systems and robotics to offer hope to patients with otherwise untreatable cancers. Stereotactic body radiotherapy is one form of radiosurgery that is proving highly effective in treating gynecologic tumors. Studies by gynecologic oncologist Robert DeBernardo, MD, Director of Minimally Invasive Surgery in Cleveland Clinic’s Ob/Gyn & Women’s Health Institute, show that the technology can shrink, halt the growth of, or completely eliminate 96 percent of targeted lesions in advanced and recurrent gynecologic cancers. “Since the radiation is so highly conformal, we eliminate a lot of the toxicity normally associated with it and can increase the dosage — the tumors don’t stand much of a chance,” notes Dr. DeBernardo. He says that stereotactic body radiotherapy is an option for women with:

• Unresectable, locally advanced disease
• Resectable disease for which the risk of surgical morbidity is high
• Medical risk factors that contraindicate primary surgery
• Certain recurrent ovarian, cervical or endometrial cancers that are unresponsive to chemotherapy or have already been irradiated

Besides stereotactic body radiotherapy, Dr. DeBernardo says there are other specialized radiosurgery technologies that can be used for recurrent and hard-to-treat gynecologic cancers. Radiosurgery, or radiation therapy, can be given in one dose or fractionated into multiple doses and then modified by intensity via the following technologies:

• Mobetron intraoperative electron radiotherapy (IOERT), the first mobile, self-shielded electron linear accelerator, offers one of the most effective and efficient means of delivering radiation at the time of surgery. Its small size means the technology can be brought into the OR for quick delivery of radiation, with better outcomes for breast, head and neck, pancreatic and rectal cancers, as well as cervical and other gynecologic tumors.
• Intensity-modulated radiotherapy (IMRT): This technology first changed the face of radiation oncology by improving tumor control and decreasing normal tissue side effects. IMRT is a type of conformal radiation that shapes radiation beams of varying intensities to the shape of a tumor. IMRT is used to treat prostate, head and neck, and central nervous system cancers, as well as breast, thyroid, lung, gastrointestinal and gynecologic malignancies, and certain types of sarcomas.
• Image-guided radiation therapy (IGRT) uses frequent X-ray, ultrasound or optical imaging during treatment to precisely target and deliver radiation therapy for metastases close to critical areas. IGRT ensures precise patient positioning as the highly focused radiation is delivered. It is used to treat tumors of the lungs, liver and prostate, as well as tumors close to critical organs and tissues.

The Novalis TX radiosurgery system, a type of IGRT, shapes radiation with pinpoint accuracy using high-definition collimation to spare surrounding tissues while targeting metastases close to critical areas. This technology delivers ultrafast radiation, allowing for shorter treatment times, fewer visits and decreased side effects in the treatment of brain, spine, liver and lung cancers, as well as hard-to-treat gynecologic tumors.

• Hyperthermia and IMRT: Heating the surface of a tumor noninvasively can increase blood and oxygen flow, and thus responsiveness to IMRT. Cleveland Clinic’s Taussig Cancer Institute is the only cancer program in Ohio offering hyperthermia for selected gynecologic malignancies, as well as chest wall metastases from breast, some head and neck cancers, and sarcomas. Adding hyperthermia to radiation therapy increases tumor control while minimizing damage to healthy tissue.

“Computers, excellent image guidance and robotics give us the ability to offer highly conformal radiation therapy,” says Dr. DeBernardo. “This makes it easier to direct radiation therapy to a very specific target.” As treatment for gynecologic cancers improves, he is seeing more unusual tumor recurrences, such as those next to a kidney, liver or lung. In such cases, says Dr. DeBernardo, radiosurgery allows patients to avoid significant operative morbidity.