Brachytherapy

Brachytherapy is derived from the Greek word “brachy,” which means short or small. Brachytherapy uses small radioactive isotopes or seeds placed close to the tumor.

What is brachytherapy, and how does it work?

Brachytherapy is a treatment option that uses small radioactive seeds to deliver radiation to tumors. It can deliver radiation either deep within the body (for example, to gynecological and prostate cancers) or to a superficial surface such as the skin.

What are some advantages of brachytherapy?

• The treatment is highly localized, so radiation exposure to nearby normal tissues is limited.
• Brachytherapy uses isotopes with different energies that are able to penetrate tissues to varying depths.
• Treatment planning and delivery has become more sophisticated over the past decade with advances in image guidance, surgery, and medicine.

What type of imaging may be used with brachytherapy?

Our gynecologic, prostate cancer and general brachytherapy programs routinely use real-time guidance via one or more of the following imaging methods, in our state-of-the-art suite:

• Ultrasound
• CT scan
• Magnetic Resonance Imaging (MRI)

What does brachytherapy help treat?

• Cancer (such as prostate, gynecologic, and other cancers)
• Noncancerous proliferative diseases (keloids, coronary artery in-stent restenosis, peripheral vascular disease)

What is prostate brachytherapy?

It can be beneficial whether you have early, intermediate or high-risk disease. It can also be beneficial if you have prostate cancer that recurs after radiation therapy. It can be used with or without external beam radiotherapy.

Implants can be permanent or temporary:

• Permanent seed implant: uses a very low dose rate (vLDR) iodine or palladium source. Seeds are implanted under ultrasound guidance. Afterwards, seed placement is confirmed by CT and/or MRI.
• Temporary implant: uses a high dose rate (HDR) technique with an iridium source. The source travels through catheters inserted under ultrasound guidance.

MRI can allow the radiation oncologist to precisely localize tumors within the prostate, so that ablative doses can be given directly to the tumor while sparing surrounding tissues.

What is gynecologic brachytherapy?

• Usually an outpatient procedure
• Commonly used to treat endometrial and cervical cancer
• Uses an iridium seed that travels through an applicator for a treatment time that ranges from 5 to 15 minutes

Is treatment different for gynecologic patients who have been treated with a hysterectomy?

• For patients treated with hysterectomy, vaginal cylinder brachytherapy with or without external beam radiotherapy may be recommended to reduce the risk of recurrence at the vaginal cuff. This outpatient treatment is delivered 2 days per week for a total of 2-6 treatments.
• For patients who have not had a hysterectomy, tandem-based brachytherapy application is performed under general anesthesia. The total number of treatments may vary from 3-5, either as an outpatient (2 days per week), or inpatient (3-4 day hospitalization).
• Select patients with gynecologic cancer may require interstitial brachytherapy, where the radiation oncologist places catheters directly within and surrounding a tumor. Interstitial brachytherapy is performed under image-guidance using a combination of ultrasound, CT and/or MRI. These procedures are performed under anesthesia and require an inpatient hospitalization. At the time of treatment, an iridium source is inserted through each individual catheter to deliver a highly conformal brachytherapy dose. Interstitial brachytherapy is given twice daily for a treatment time of 10-15 minutes.

What is surface applicator brachytherapy?

Surface applicator brachytherapy can be an excellent treatment option for patients with certain cutaneous malignancies or medically refractory benign conditions. This form of treatment involves creating a customized applicator that is specifically designed to maximize dosimetric coverage to potentially geometrically complex lesions. After CT radiation treatment planning, brachytherapy is then administered through the applicator on an outpatient basis.

What are some other brachytherapy treatments?

Other treatments covered on the general brachytherapy service include coronary artery radiation therapy for in-stent restenosis, brachytherapy for peripheral vascular disease, radioembolization for select liver malignancies, esophageal brachytherapy, and endobronchial brachytherapy.

Innovative Applications

What innovative research is happening at Brigham and Women’s Hospital?

Our department is constantly exploring innovative uses of advanced technologies to improve patient outcomes with brachytherapy.

Optimizing Brachytherapy Delivery with MRI-Guidance for Gynecologic Cancer

Lead physicist: Robert Cormack, PhD

Image-guided brachytherapy for gynecologic cancer offers significant potential to improve tumor control and increase cure rates. CT and MR-based brachytherapy planning also reduces the risk of bladder or bowel toxicity. With MRI guidance at the time of the procedure, we are developing novel methods to track catheter placement and positioning for real-time evaluation of the HDR brachytherapy dose. We are also developing novel MRI sequences to identify residual tumor in collaboration with the Surgical Planning Laboratory within the Advanced Multimodality Image Guided Operating (AMIGO) suite.