Radiation Therapy in Skin Cancer

Radiation therapy is an effective treatment for most skin cancers and at times an alternative for surgery, according to an expert at the CURE® Educated Patient® Skin Cancer Summit.

Dr. Ryan T. Jones, a radiation oncologist at Tennessee Oncology, spoke about how radiation therapy is used to treat skin cancer, the process a patient will go through with this treatment and potential short- and long-term side effects.

In an interview with CURE®, Jones spoke about the common misconception people tend to have about radiation therapy – that the radiation therapy of today is the same as it was back in the day.

“Patients hear stories from family members or friends who had treatment many years ago and assume their experience will be the same,” Jones said. “To the contrary, our specialty – one of the most technologically driven in all of medicine – has evolved similarly to the degree that cell phones have evolved in the last 20 years.”

Jones explained in his presentation that patients can think of radiation therapy like energy used in various forms to intentionally damage tissue. Researchers have studied how different forms of energy behave in tissue, developing machines to isolate them and use them treat cancers.

“These different kinds you learned about back in grade school science class have their pros and cons on how they behave in tissue, on how precise they allow us to be, on what kinds of damage they do,” Jones added. “And there's just a small number of doctors in the U.S. who are trained in this area to deliver energy to treat cancers. We’re called radiation oncologists, there are about 5,000 of us, we make up less than 1% of physicians in the US.”

Because skin cancer can spread on to nerves towards the base of the skull, machines can be used to spin around and customize the way the energy forms outside of a target and at depth, said Jones.

Radiation therapy can be separated into several different types: definitive, adjuvant, neoadjuvant and palliative. Definitive radiation therapy is when it’s the main treatment and is used instead of surgery. Adjuvant is when the radiation therapy is added on after surgery, for a patient whose cancer has high-risk features and is thus more likely to come back post-surgery. Neoadjuvant radiation therapy is performed before surgery to help make a complete surgical resection, though this is rarely done in cases of skin cancer, Jones said. The last type, palliative radiation therapy, is used in metastatic patients to provide symptom relief in painful or bothersome sites.

Definitive radiation therapy is not the primary treatment for skin cancers – that would be surgery. However, in certain cases, it is a better option for patients, Jones explained.

“Side effects from radiation – you can think of them in the short term, we call those acute, or long term, in say six months and later or years later, we call those late,” said Jones. “And older patients, just from not having say 80 years life expectancy beyond their current age, late side effects at times aren't as heavily weighted.”

Radiation therapy may also become the first option for patients who are medically inoperable and thus cannot undergo surgery or are too ill for surgery. Sometimes, the location of the cancer makes surgery less ideal, added Jones. These types of cases occur if it is a central face tumor, especially on the eyelids, tip of the nose or lips, that is larger than 5 millimeters and/or when a clear surgery are not possible, or if it is a larger tumor of the ear, forehead, upper lip or scalp.

Conversely, definitive surgery is preferred over radiation therapy in cases where the cancer has recurred in an area that previously had radiation, if a patient has genetic conditions (nevoid basal cell carcinoma (Gorlin) syndrome, xeroderma pigmentosum, ataxia telangiectasia, Li-Fraumeni syndrome, and at times, connective tissue diseases like scleroderma), if the cancer is located in an area where surgery is simple (extremities or torso), if the patient is young and if the tumor is large (larger/deeper tumors may have a better cure rate, although at the expense of functional/cosmetic impairment).

“Radiation compares quite well to surgery where our control of the original sites is very high,” said Jones.

He further explained that several machine types are typically used in radiation therapy: linear accelerators that use high-energy photos and electrons, superficial photons that do the same in a slightly weaker form, brachytherapy that uses a radioactive material, electronic brachytherapy, and Harrison Anderson Mick (HAM) applicators that are used to determine the shape of where the radiation is distributed.

“And it's all planned on software ahead of time,” said Jones. “I describe to patients (that) it's like building a website customized for your case.”

A patient’s radiation oncologist will determine what tool is best to use for their cancer type, weighing the pros and cons of each choice. Before they get to that step, however, the patient will first receive a referral after they’ve been diagnosed. They will then have a consultation to discuss their case, what tools are available and what the possible side effects are. This will typically be followed by a simulation phase, which may include a CT scan to define the area and position the body will be treated in. Next, treatment planning will occur, in which the team of doctors will design the software ahead of the treatment. Treatment generally occurs three to eight times for up to seven weeks, Jones said, and will usually be fairly quick 15-minute sessions. Finally, patients will have follow-up post-treatment to receive help with any side effects they’re experiencing and monitor for disease recurrence.

“The side effects are generally like a bad sunburn in the short term can be redness, peeling, itching, some pain, loss of hair, which could be temporary or permanent,” Jones said.

Sometimes, patients may experience long term side effects, such as telangiectasias (wispy confined blood vessels that often show up late in areas that received radiation therapy), hypopigmentation, hair loss, wound-healing issues or injury to bone.

“The first few months can be a little cosmetically unsettling, but we work through you, it generally heals, and there are other tools in our toolbox if it's in a small minority where it's just really struggling to heal and needs some extra help,” Jones added.

Looking toward the future of radiation therapy, Jones expressed that the current understanding of how radiation behaves in the body is outstanding, and the machinery that delivers this energy to tissue is incredibly advanced.

“I personally believe the biggest breakthroughs in cancer care will be the development of drugs that allows us to deliver lower radiation dose for the same effect, called ‘radiosensitizers,’” he said.

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