Brachytherapy is the term used to describe the delivery of internal radiation therapy as opposed to external beam radiation therapy. Currently at MMC, we use brachytherapy for treatment of gynecologic malignancies and prostate cancer. Radiation dose is delivered by radioactive sources in or near the tumor. Low dose rate (LDR) brachytherapy is from 0.4 - 2 Gray/hour. High dose rate (HDR) brachytherapy is greater than 12 Gray/hour and is usually around 150 Gray/hour. Generally, for a given dose, increasing the dose rate will increase late effects much more than it will increase tumor control. Fractionation of HDR brachytherapy applications is used to achieve acceptable levels of tumor control while not exceeding the normal late-responding tissue tolerance.
The advantages of HDR brachytherapy over LDR brachytherapy are:
Shorter treatment time in an outpatient setting.
Better optimization of dose distribution.
No radiation exposure to medical personnal with remote afterloading devices.
Current uses for HDR brachytherapy include:
Vaginal dome implants for endometrial cancer
Fletcher-Suit implants for cervical cancer
Interstitial perineal implants for prostate cancer
Partial breast implants
Endoluminal implants for cancers of the lung, biliary tree and esophagus
HDR brachytherapy is an exciting new program which we hope to add to our clinical practice at MMC so that we can further enhance patient care. For more questions please call Dr. Rodger Pryzant at (207) 396-7500.