Cancer systemic therapeutics and radiotherapy are often associated with dermatological toxicities that may reduce patients’ quality of life and impact their course of cancer treatment. These toxicities cover a wide range of conditions that can be complex to manage with increasing severity. This review provides details on twelve common dermatological toxicities encountered during cancer treatment and offers measures for their prevention and management, particularly in the Australian/New Zealand context where skincare requirements may differ to other regions due to higher cumulative sun damage caused by high ambient ultraviolet (UV) light exposure. Given the frequency of these dermatological toxicities, a proactive phase is envisaged where patients can actively try to prevent skin toxicities.

Adjuvant radiation therapy (ART) for macroscopic regional nodal cutaneous melanoma has evolved. A significant step was the discovery of targeted therapies, particularly towards V600E-mutated melanoma, and immunotherapy under its different kinds. Prior to this, the defining trial was the Australia and New Zealand Melanoma Trials Group (ANZMTG) 01.02/Trans-Tasman Radiation Oncology Group (TROG) 02.01 phase III trial that showed that ART using three-dimensional conformal radiotherapy (3DCRT) decreased in-field recurrence by 50% (48 Gray (Gy) in 20 fractions). After the advent of systemic therapies, a trial of the combination targeted therapy of dabrafenib plus trametinib toward BRAF V600-mutant nodal cutaneous melanoma showed that all 35 patients achieved a pathological response. Radiotherapy (RT) was found to be safe to give with concurrent combination therapy. A retrospective immunotherapy study found that in 71 patients that received ART after a first recurrence, further in-field recurrence significantly decreased (p = 0.01). For those tumours that do recur in-field, there are now competing therapies like Talimogene laherparepvec or T-VEC. Generally, ART is now used at the first recurrence. The challenge now is to find which melanomas are truly radiosensitive if ART is to have any future role in this scenario.

Definitive Radiotherapy (RT) brings tissue conservation. Skin cancer RT area delineation can be a challenge especially in basal cell carcinoma (BCC) with morpheaform features. We report our initial experience of 11 consecutive patients imaged with Optical Coherence Tomography (OCT) prior to treatment. The gross tumour volume (GTV) was marked by a radiation oncologist (RO) using a strong light only. OCT was then done by a dermatologist blinded to the RO markings. The difference in areas, if any, were computed and tabulated. Relevant outcomes were recorded. Of the 11 patients there were nine females and two males. Average age was 65 (47-87) years. Patients had initially a total of 13 lesions between them. Of the initial 13 lesions, seven were lesions without previous treatment, five were recurrent post-surgery, one post-cryotherapy. The most common site was the nose (8/13), then lips (2/13). Eyelid, scalp and temple had one each. There were a mix of BCC histologies; infiltrating (4/13), nodular (5/13) morpheaform (3/13) and one was unclassified. The initial RO GTV area on average was 584 (50-2400) mm 2 , the average OCT area was 420 (63-2350) mm 2. OCT decreased the size of the GTV with an average change of 164 (-1650 to + 760) mm 2 , that is, 28%. The assistance of OCT was not limited to morpheaform lesions. OCT also found three more BCCs, and one lesion thought clinically to be BCC was not. OCT avoided a geographic miss. Three (3/11) were treated with other modalities; two with Moh's surgery, one with Rhenium-188. Eight patients with ten lesions were treated with definitive RT. RT was planned using the OCT area as the correct area. All had clinical complete response (CR) at post-RT follow up. In the five patients having OCT following RT, all had a continuing complete response at an average of 6.8 months post-RT.