A New Treatment for Skin Cancer: Skin Surface Brachytherapy
A 62-year-old patient with a 15x20 centimeter area of squamous cell carcinoma on the right side of his scalp and temple—and expanding close to his eye—presented an interesting challenge for the Radiation Oncology Division in the Baystate Regional Cancer Program.
Surgery to remove the irregular-shaped area of cancer was not a good option because it would require a large skin graft and substantial healing time. And low-level electron beam radiation therapy is not as effective on curved surfaces.
But a new procedure that treats basal and squamous cell carcinomas on the surface of the skin, and particularly on non-flat surfaces such as the nose and shin, was the ideal treatment option for this patient, says Brian Acker, MD, chief, Radiation Oncology.
Skin surface brachytherapy is a new tool in the program’s treatment arsenal that can help patients with non-melanoma skin cancers that are located on curved surfaces, he says. The procedure can also benefit elderly patients with poor circulation and ones with other medical complications in which skin cancer excision would not be ideal, he adds.
“Our perspective on skin surface brachytherapy is that it is an excellent alternative modality to treat skin cancer patients in which surgery is not a good solution for the patient for a variety of reasons,” says Dr. Acker.
Fewer Treatments and Side Effects
For many years, Baystate’s radiation oncologists have used electron beam radiation therapy to treat tumors deep within the body. But for patients with a skin surface cancer in which surgery is not an option, they can use a low-level electron beam because it does not penetrate very far into the skin.
However, says Dr. Acker, there are limitations to the electron beam, such as effectively treating curved surfaces. Skin surface brachytherapy is designed to overcome those limitations, he says.
With the electron beam procedure, patients receive treatment daily five days a week for a total of 22 treatments, while skin surface brachytherapy requires just 10 treatments. In addition to the increased convenience this offers, other advantages of the new procedure include greater precision and no side effects other than the usual fatigue and sunburn-like effect on the skin that is typical with any form of radiation therapy, says Dr. Acker.
Increased Incidence of Skin Cancer
Dr. Richard Arenas, who is the chief of Surgical Oncology at Baystate, says there is a likelihood that because the population is getting older Baystate will see more skin cancer patients.
“There is going to be an increasing number of patients who unfortunately have skin cancers that are not going to be ideally treated with surgery or surgery alone. With this technology in our arsenal, we offer a more comprehensive program for treating skin cancer,” says Dr. Arenas.
How It Works
Prior to the procedure, Dr. David Chin, chief of Medical Physics, maps out the size and depth of the lesions, determines the amount of curvature, and uses mathematical planning software to calculate how long the radiation source will stay on one location, typically 8 to 10 seconds. The radiation team marks the affected area of the skin with opaque wires so that it shows up on a CT scan and they can ensure they are treating the correct area.
To perform the skin surface brachytherapy procedure, radiation oncologists use a Freiburg Flap applicator—a flexible silicone beaded rubber mat fitted with catheters—that is placed on top of the affected area. The catheters are attached to a remote after-loading machine that sends the high intensity radiation through the catheters and onto the lesions.
In the case of the 62-year-old man with the large area of squamous cell carcinoma on his scalp, Dr. Chin used a thermoplastic mask, which he molded to the shape of the patient’s head, and mounted the Freiburg applicator on top of it in order to direct the radiation to the exact locations.
“We connect these catheters to the after-loading machine that contains a tiny radiation source about the size of a grain of rice, Iridium 192. It works quickly, which is good so the patient doesn’t have to sit there for long,” says Dr. Acker.
While the preparation for the procedure can be very time consuming and laborious for medical physicist, the end result is a more successful outcome for the patient, says Dr. Acker. “In some ways, this is a simple technique, but in order to perform it safely, you have to be extremely precise. It requires meticulous attention to detail to do it effectively and safely, and we have a well-trained team to do that.”
To learn more or refer a patient, call the Baystate Regional Cancer Program at 413-794-9338.