Radiation Therapy for Skin Cancer
Written by: Dr. Meakin
Radiation therapy can be used as a primary treatment or as an adjunct to surgery with our dermatologic surgical colleagues for the treatment of squamous cell and basal cell skin cancers. Radiation therapy can be delivered with superficial penetrating electron beam or orthovoltage beam which is ideal for treating cancers of the skin. The radiation oncologist works closely with the physicist and treatment planning team to customize the treatment to cover the depth and perimeter of the skin cancer with a border of normal skin to effectively eradicate the cancer while disturbing as little normal tissue as possible.
Many basal cell cancers and squamous cell cancers around the nose, eyes, ears, and lips may be better treated with primary radiation treatment as surgery may lead to less desirable cosmetic results at these delicate sites. Larger tumors that may lead to significant surgical defects may also be best approached with primary radiation. This nonsurgical approach requires short 15 minute daily visits generally for three to five weeks to deliver the treatment. The tumor will slough off during this period along with some adjacent normal skin but generally heal with new skin with a smooth surface in the ensuing 2 to 6 weeks. Although this treatment may take longer, there is no need for anesthesia, cessation of blood thinner use by the patient, and working patients can continue to work without interruption or days off the job. The cure rate with radiation is roughly equivalent to surgical options although there are some sites that are best managed by one modality or another and surgery is preferred in the very young patients.
Radiation may also be used following surgery for high risk squamous cell and basal cell lesionsthat have close positive margins, large-size, nerve invasion, high growth rate, or the possibility of nodal involvement. Radiation used after surgery improves the control rate beyond surgery alone in these high risk scenarios. The timing of the radiation and determination of the treatment site require close coordination with the dermatologic surgeon and radiation oncologist. Anticipated use of radiation may allow the surgeon to forego extensive surgical grafts, flaps or reconstruction if the combined modality approach is known ahead of time. These issues must be addressed up front with the physician “team” approach for the best outcome.
Radiation therapy is also used at times for less common skin cancers such as melanoma, merkel cell, skin lymphomas, and sweat and oil gland origin tumors. Radiation used in these scenarios is commonly given to the primary site and nodal bed in high risk presentations. Radiation is used to prevent local and regional recurrence with these more aggressive cancers and require close coordination with the surgical oncologist. Deeper penetrating radiation beams may be necessary the depending on the site of the body being treated. Treatment courses may still span 2 to 6 weeks with short daily 15 minute visits depending on the cancer type and site being treated.
All the SERO sites are equipped with the most modern treatment machines that can deliver a variable depth of penetration depending on the needs required for the individual skin cancer. Every cancer center has trained physicians and staff to make customize lead blocks, wax molds, and surface dose enhancers to get the best coverage and cosmetic result for the skin cancer site being treated. Generally photos are taken before, during and then after the treatment for documentation and to aid in follow-up. SERO has a long history of treating skin cancers given the high rate of skin cancer in the Carolinas and our greater than 30 year history of serving this region. Challenging and difficult cases are frequently presented in tumor board forums with many cancer specialists present to aid in acquiring the most current information available. Second opinions and multidisciplinary panels are so vitally important yet easy to obtain for all challenging skin cancer cases.