Radioactive seed implants are a specialized form of internal radiation therapy, known as brachytherapy, used in breast cancer treatment. This method involves placing a precisely targeted radiation source directly within the breast. The purpose of these implants is to deliver focused radiation to the area where cancer was located, aiming to reduce the chance of cancer returning. This technique delivers radiation internally, directly to the affected region, differing from external radiation treatments that project beams from outside the body.
What Are Radioactive Seed Implants
Radioactive seed implants are small, often compared to the size of a grain of rice or a sesame seed. These tiny sources consist of radioactive material like Iodine-125 (I-125) or Palladium-103 (Pd-103), sealed within a pellet or capsule. Once placed, these implants deliver a continuous, localized dose of radiation to the specific breast tissue where the tumor was removed or is being targeted.
The internal delivery system allows for a higher concentration of radiation directly to cancer cells, reducing exposure to surrounding healthy tissues. The emitted radiation works by damaging the DNA of cancer cells, hindering their ability to grow and divide, eventually leading to their death. The radioactivity of these seeds naturally decreases over time. Palladium-103 is sometimes preferred over Iodine-125 due to potentially lower radiation exposure to those in close contact with the patient.
How the Procedure Works
Receiving radioactive seed implants involves careful pre-procedure planning. Medical imaging, such as mammography, ultrasound, or MRI, pinpoints the tumor site or the cavity left after tumor removal. This detailed imaging helps the medical team determine the optimal placement for the radioactive seed or seeds.
The implantation procedure is performed in an outpatient setting. A radiologist administers a local anesthetic to numb the breast area, which might cause a brief stinging sensation. A thin, hollow needle containing the radioactive seed is then gently inserted into the breast tissue. Imaging guidance ensures precise needle positioning throughout the insertion. After placement, the needle is withdrawn, leaving the seed embedded in the tissue.
This minimally invasive procedure typically takes 30 to 60 minutes. After implantation, additional images confirm the seed’s exact location, providing a precise map for the surgeon during subsequent tumor removal. A small bandage is then applied to the insertion site. The seed can be implanted several days before the main surgical procedure, which can streamline the patient’s experience on the day of surgery.
Patient Suitability
Radioactive seed implants are primarily for individuals with early-stage breast cancer. Suitability depends on factors like tumor size and stage. This technique proves particularly beneficial for lesions that are non-palpable, meaning they are too small to be detected by touch alone.
The treatment targets the area within the breast where cancer was removed, often following a lumpectomy. It is a form of partial breast radiation, focusing on a localized region of the breast rather than exposing the entire breast. This focused approach helps reduce the likelihood of cancer recurring in the treated area.
This option may be chosen over conventional external beam radiation therapy, which typically requires daily sessions over several weeks, to help shorten the overall treatment duration. It also has the potential to decrease the amount of radiation exposure to healthy breast tissue, which can lead to fewer side effects. However, individuals who are pregnant or breastfeeding are not suitable candidates for this procedure.
After the Procedure
After radioactive seed implantation, patients typically return home the same day. It is common to experience minor discomfort, soreness, or mild pain at the insertion site, along with slight bruising or swelling. This discomfort can often be managed with over-the-counter pain medication.
Patients are advised to keep the insertion site dry for 24 to 48 hours. While showering is permitted the day after, activities like soaking in a tub or swimming are discouraged for a couple of days. Wearing a supportive bra, such as a sports bra, can help minimize breast movement and enhance comfort during recovery. Light daily activities can usually be resumed the day after the procedure, though strenuous arm movements or lifting objects heavier than 10 pounds should be avoided for at least 24 hours.
Follow-up care includes the scheduled surgical removal of both the tumor and the implanted radioactive seed, which commonly occurs within a few days to a week after placement. The removed tissue is then sent for pathological examination to confirm that the cancer and the seed have been successfully excised.
Safety and Precautions
The radiation emitted by radioactive seeds is specifically contained within the breast tissue and is of very low energy. The amount of radiation exposure to other people in close proximity is minimal and is generally not considered to pose a risk. The seeds are securely sealed, which prevents direct contact with the radioactive material itself.
Despite the minimal risk, certain precautions are suggested. Individuals with an implanted seed are advised to limit prolonged close physical contact, such as holding on the lap, with very young children or pregnant individuals for a short duration, typically around 30 minutes per day. Personal items touched by the patient, including clothing, do not become radioactive. Once the radioactive seed is surgically removed, all radioactivity is eliminated from the body.