Brachytherapy, also known as internal radiation, involves placing radioactive material into the body near a tumor or its surrounding tissue. The radioactive source may be in the form of seeds, wires, ribbons, or a small sealed container that is implanted temporarily or permanently within the body. In high-dose rate (HDR) brachytherapy, the radioactive source is placed in the body temporarily and removed after the dose has been delivered.1
Treatment of soft tissue sarcoma generally involves radical surgical excision with or without radiation therapy. When soft tissue sarcoma occurs in an extremity, preoperative external beam radiation therapy (EBRT) is used to reduce tumor burden and optimize surgical intervention without significant loss of function to the limb.2 Close or positive margins are a predictor of local failure and worse outcomes, so postoperative radiation therapy may also be administered. Postoperative EBRT requires waiting weeks for wound healing, which may be suboptimal. In addition, EBRT cannot be administered in a high dose nor can it precisely target surgical areas of concern; therefore, postoperative HDR brachytherapy is used to give an immediate boost without the need to wait.3
The volume of irradiated tissue is smaller with HDR brachytherapy, which contributes to lower rates of chronic tissue complications such as edema, fibrosis, dermatitis, and late pathologic fracture. HDR brachytherapy also offers the ability to deliver a large irradiation dose to the lesion with reduced toxicity of the surrounding healthy tissue. In addition, it is delivered in a shorter overall treatment time.4 The National Comprehensive Cancer Network (NCCN) NCCN Evidence Blocks™ state the standard practice is preoperative radiation and EBRT or brachytherapy boost after surgery.
Building a Brachytherapy Service
The radiation oncology department of a rural hospital in northwestern Montana implemented its first HDR intracavity brachytherapy program for endometrial and cervical cancer in February 2017. Treatments are completed in the outpatient setting using an HDR brachytherapy afterloader equipped with iridium-192. A cylinder is placed in the vagina, and catheters attached to the cylinder carry the radioactive sources from the afterloader to the targeted area. Treatment is delivered daily or every other day for 1 week. After each treatment, the cylinder is removed and sent to sterile processing for routine cleaning before the next use.
By June of the same year, the outpatient brachytherapy program expanded to include accelerated partial breast irradiation (APBI). APBI is delivered via a specialized catheter placed in the lumpectomy bed approximately 1 week after the tumor is removed. For this course of treatment, the catheter stays in place for the duration of radiation treatments, which are generally given twice daily for 1 week. At the end of the treatment course, the catheter is removed and the incision is cleansed and dressed per facility protocol.
Recently, postoperative interstitial brachytherapy for the treatment of soft tissue sarcoma was added to the department’s services. Using the same equipment and functionality as intracavity brachytherapy, interstitial treatment involves placing multiple catheters into the surgical bed approximately 1 cm apart. The catheter entry sites are secured to the skin; the tails at the exit sites are cut to length before treatment is delivered. The surgical incision may be left open with a wound vacuum or surgically closed. Treatments are given twice daily for 2 days. After completing the treatment course, the catheters are removed, and if needed, the incision is surgically closed.
HDR brachytherapy is generally well-tolerated and very effective, improving local control and patient outcomes.3 It can be performed in the outpatient setting, which eliminates overnight hospital stays, and delivers high doses of radiation with a high level of accuracy. HDR brachytherapy minimizes the risks of side effects because radiation is delivered precisely without unnecessary damage to healthy tissue and organs close to the tumor.1
As the program continues to grow and expand its oncology services, patients are able to receive quality care close to home rather than have to travel out of state to a large cancer treatment center, which can be expensive, disruptive, and stressful for patients and their families.