Radiation therapy plays rare but useful role in AK management

Little Rock, Ark. - Despite the number of currently available options for the treatment of actinic keratoses (AKs), dermatologists are still challenged by the occasional patient with widespread lesions refractory to multiple modalities.

READ:  Superficial radiation therapy ripe for resurgence

According to Scott M. Dinehart, M.D., director, Arkansas Skin Cancer Center in Little Rock, Ark., radiation therapy is an overlooked but useful alternative in properly selected individuals, offering an excellent cure rate and other benefits.

Speaking at the Winter Clinical Dermatology Conference earlier this year, Dr. Dinehart reported on his experience using radiation therapy as a last-resort option for treating widespread AKs in patients who had failed other treatments. He notes that although he was accumulating positive experience with this intervention, he was reluctant to mention it to colleagues for fear of criticism.

However, in a recent publication, Dr. Dinehart and colleagues summarized outcomes for a series of 16 patients treated over an eight-year period from 2003 to 2010 (Dinehart SM, Graham M, Maners A. J Clin Aesthet Dermatol. 2011;4(7):47-50). Thirteen (81 percent) of the 16 patients in the series had achieved complete remission when followed two weeks after completing the radiation treatment. The remaining three had a significant reduction in lesion count (50 to 99 percent) and achieved complete clearance with subsequent topical therapy.

READ: 6 important trends in PDT treatment for AK

The treatment field remained clear of AKs in all 16 patients when they were seen at six months after radiation therapy, Dr. Dinehart reports.

NEXT: Follow-up on 2010

Follow-up by phone was attempted in 2010. Three of the 16 patients were deceased and only 10 could be contacted, but nine of those individuals "totally agreed" that the treatment had improved their quality of life, Dr. Dinehart says. They also indicated satisfaction with the cosmetic results and their ability to reduce the need for frequent office visits. The only discordant patient noted he had reappearance of lesions after one year.

READ: More common sense needed in treating AKs

"Radiation therapy is expensive, available only to patients who live near a radiation facility, and involves a large time commitment with visits required five days a week for four to six weeks. However, radiation therapy works when other treatments fail, results in long-term remission with excellent cosmesis, and has many other attributes. The woundcare requirement and side effect profile of radiation therapy are minimal, and it treats large fields of subclinically damaged skin to decrease development of new AKs and squamous cell carcinomas," Dr. Dinehart says.

READ: Eradicating actinic keratosis: Pros and cons

"Importantly, by reducing the need for frequent office visits for management of AKs, radiation therapy for appropriate patients can be a life-changing intervention. Radiation therapy for AKs should be rarely used, but the patients I have treated are among the most grateful in my practice," he adds.

Next: Selecting patients for radiation therapy

Patient details

Dr. Dinehart's series of 16 patients included 14 men and two women ages 70 to 87 years (mean 80). Their health status ranged from good to poor, he says.

READ: Painless PDT: The next stage in the evolution

"Radiation therapy for widespread AKs is offered only to patients who have already failed multiple standard treatments, usually to those who are in fair to poor health so that they are not good surgical candidates, and generally only to those who are older than 70 years of age, taking into account the potential for a radiation-induced secondary malignancy. However, younger patients in poor health may also be considered as appropriate candidates," Dr. Dinehart says.

The radiation therapy was performed with fractionated dosages using a combination of photons and electrons and a cumulative dosage ranging from 40 to 60 Gy. After the initial visit, which included consultation with the radiation oncologist and lasted about an hour, treatment sessions were only about five to 20 minutes in duration.

READ: PDT superior to cryotherapy for clearing actinic keratoses

"Otherwise, these patients were coming into the office for lengthy appointments on a frequent regular basis. The need for these visits poses a real quality of life issue and is associated with significant direct and indirect costs," Dr. Dinehart says.

Next: Tolerability and adverse events

Initial indications

Initially, AK patients selected for radiation therapy also had a noninvasive nonmelanoma skin cancer that was the primary indication for radiation, and the treatment field was expanded to encompass the surrounding area of skin with AKs. However, 12 patients in the series had radiation therapy as primary treatment for resistant AKs. Treatment sites were limited to areas of the face and scalp, Dr. Dinehart explains.

READ: Novel strategies minimize actinic keratoses treatment burdens

"Usually, just a small field is treated, but some patients had radiation therapy for the entire scalp. Other anatomic locations with AKs are generally not treated because compared with the head, they tend to have poorer cosmetic outcomes and greater risk for radiation dermatitis," Dr. Dinehart says.

Radiation treatment was well-tolerated and associated with minimal morbidity, especially compared with the inflammatory reactions occurring with some topical therapies. Side effects included dose-dependent alopecia, erythema, crusting and pigmentary alterations, although one patient developed skin breakdown on the posterior aspect of the scalp that required galeal flap reconstruction, he says.

READ: Photodynamic therapy uses broaden as more data emerges

Disclosures: Dr. Dinehart reports no relevant financial interests.