[Treatment side effects and follow-up of malignant melanoma]

Side effects in the therapy of malignant melanoma are primarily of importance for radiologists in advanced tumor stages. The available treatment options and their respective side effect profiles have undergone a profound change in recent years after the introduction of modern oncological therapies (e.g. immunotherapy and targeted therapy) with an increasing focus on individual tumor biology and differ significantly from those of classical chemotherapy. The immunotherapeutic agents, in particular ipilimumab, take on a special position because of their specific immune-mediated mechanisms of action and the associated side effects, so-called immune-related adverse events (irAE). The majority of the treatment effects are manifested on the skin (> 50 %) and are generally not detectable by diagnostic radiology. Only a comparatively small proportion of treatment side effects is detectable with diagnostic imaging (15-20 %) but as in the example of therapy-induced colitis with ipilimumab, may be rapidly fatal. In addition to colitis (10-20 %) further therapy side effects apparent in diagnostic imaging are hypophysitis (1.8-17 %), thyroiditis (0.8 %), myositis (1.7 %), fasciitis and sarcoid-like lymph node alterations (6.8 %). To detect radiologically detectable side effects early on and to delineate them especially from tumor progression and (opportunistic) infections, detailed knowledge of the therapeutic methods for melanoma, the mechanisms of action and in particular the sometimes very specific side effects is imperative for radiologists.