Combination Therapy For Teal
The treatment recommended depends upon which subtype of Intermediate Risk a patient’s cancer falls into. For example, in patients with Favorable Intermediate-Risk prostate cancer, permanent seed implants alone are preferred. On the other hand, the Unfavorable IntermediateRisk subtype tends to behave more like High-Risk. In these men, a combination of seed radiation and intensity modulated radiation therapy (IMRT) is used. There is no evidence that either type of seed implant is superior to the other in terms of cancer cure rates. When combined with seeds, IMRT is usually delivered over an approximately four to five-week period and may commence several weeks prior to or after the seed implant.
When treating with IMRT alone, studies show that adding a short course of hormone therapy improves overall survival. Although there is no data to guide us, with the high radiation doses achieved using combination therapy, the anticancer effects may be sufficient enough so that the added boost from hormone therapy may no longer be necessary. However, because combination radiation therapy does not target prostate cancer that has spread outside the prostate to the pelvic lymph nodes, a certain proportion of patients with Unfavorable Intermediate-Risk prostate cancer—those who may have microscopic and thus undetected prostate cancer cells—may still benefit by receiving a short course of hormone therapy. This is the reason to consider adding four to six months of hormone therapy in Unfavorable Intermediate Risk prostate cancer patients receiving combination radiation therapy. Whether adding IMRT and TIP to a seed implant is still necessary for men whose PSMA Pet scan shows no metastases has not been tested in prospective trials and remains unanswered.
Sean M. McBride, MD, MPH is a board-certified radiation oncologist with an expertise in treating primary genitourinary (prostate, bladder, kidney, and testicular) and head and neck (oral cavity, base of tongue, tonsil, larynx, hypopharynx, sinus, nasopharynx, and thyroid) malignancies. Dr. McBride works with a dedicated team of medical oncologists, surgeons, and medical physicists to help deliver individualized care using sophisticated radiation therapy techniques including image-guided, stereotactic radiosurgery (IGRT), intensity modulated radiation therapy (IMRT), and brachytherapy.
Michael Zelefsky, MD is Chief of Memorial Sloan Kettering’s Brachytherapy Service. In addition, he was instrumental in pioneering the use of IMRT and IGRT for prostate cancer. He is Editor-in-Chief of Brachytherapy, Chairman of the National Patterns of Care Study for Genitourinary Cancers, and past president of the American Brachytherapy Society. He has received several awards including the Boyer Award for Excellence in Clinical research, the Outstanding Teaching Award in the Department of Radiation Oncology at Memorial Sloan Kettering, the 2009 Henschke Medal, and the 2009 Emanuel Van Descheuren Award for Excellence in Translational Research.