Reinhard Dummer, MD
Professor and Vice-Chairman
Department of Dermatology
University Hospital of Zurich
Zurich, Switzerland

Surgery is the standard first-line treatment approach for primary melanoma. Based on the current recommendations for safety margins, surgery can usually be safely performed without creating disfiguring defects. However, in certain situations, especially in critical localizations such as the periorbital region or the nose, surgery can result in substantial morbidity.

Melanomas on the face are most common in patients of advanced age, who present significant actinic damage. This patient population often suffers from additional co-morbidities that increase the risk of complications during extensive surgical procedures. The most common melanoma type in this population is lentigo maligna melanoma (LMM), which often presents as a large hyperpigmented spot, or macule, that is not well circumscribed.

LMM usually grows intraepidermally for a long time without resulting in any relevant invasion into the dermis. However, it often does extend into the deeper epidermis by proliferating along the hair follicle epithelium.

For LMM in patients of advanced age, superficial radiotherapy using Grenz rays (supersoft x-rays) has been used in Europe for decades. This method was developed in radiotherapy centers in the early decades of the past century. Dermatology departments in Hamburg, Munich, Berlin, Vienna and Zurich defined the treatment protocol for LM, and many of the regimens outlined by these early investigations are still valid today.

Retrospective studies in Munich and Zurich have confirmed high rates of lasting complete remissions with cosmetically acceptable outcomes for LMM following radiation.¹ The 5-year relapse-free tumor-specific survival rate is reported to be between 96 and 98 percent in in situ and microinvasive LMM.² This patient population includes patients who were irradiated due to local disease relapses after surgery. Typically the radiation treatment can be performed on an outpatient basis, without affecting the ongoing use of anticoagulants or other medications that the patient may be on for other unrelated medical conditions.

In Zurich, LMM lesions are generally irradiated with a 10–15 mm safety margin of clinically normal-appearing skin. The patients receive a 10-Gy fraction of Grenz radiation twice a week for a total of 10–12 sessions. It is rare for any side effects to occur outside the irradiation field. However, after 5–6 treatments patients typically experience an intense radiodermatitis within the radiated field and on occasion crust formation may occur as well as some bleeding. Most of the radiodermatitis typically dissipates within 4 to 6 weeks following the completion of therapy. The final cosmetic outcome after 1 – 5 years status post-radiation therapy is usually quite good to excellent, especially in central regions of the face. In other regions of the face the appearance of hypopigmentation or mild telangiectasia may occur and persist indefinitely.

Based on many positive experiences over the last 80 years, we consider superficial radiotherapy to be a reasonable alternative to surgery for LMM, especially in patients who are over 60 years of age.

References

1. Farshad A, Burg G, Panizzon R, Dummer R. A retrospective study of 150 patients with lentigo maligna and lentigo maligna melanoma and the efficacy of radiotherapy using Grenz or soft X-rays. Br J Dermatol Jun 2002; 146(6):1042-6.

2. Schmid-Wendtner MH, Brunner B, Konz B, Kaudewitz P, Wendtner CM, Peter RU, et al. Fractionated radiotherapy of lentigo maligna and lentigo maligna melanoma in 64 patients. J Am Acad Dermatol Sep 2000; 43(3):477-82.