29 Skin Cancer

Skin Cancer

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THE GEC ESTROHANDBOOKOF BRACHYTHERAPY | Part II Clinical Practice Version 1 - 30/04/2017

Fig. 31.20: Basal cell carcinoma of the left inner canthus in a 76-year old man with results 3 years after hypodermic needle implant with LDR. The deeply infiltrating tumour has disappeared, leaving a re-epithelized skin depression surrounded by post RT acromia in the irradiated area.

and additional excisions were needed in 42%. These very good results are thus obtained with complex surgical procedures which are in fact not feasible in the majority of typically older patients who present with non-melanoma skin tumours (in this study the patients who were not fit for general anaesthesia were excluded). The cosmetic outcome was good in 87% of surgical treatments versus 69% in the radiotherapy group (5% necrosis). However, the brachytherapy dose was very high (66 - 70 Gy), whichmay explain the worse cosmetic results in the radiotherapy group. 13.2 Adverse side effects after HDR brachytherapy Moulds with different techniques using 3-4 Gy three times a week produced acute G1-2 dermatitis in 78%, solved in a few days with topical treatment, 22% developed severe acute toxicity G4, which was healed in 3 weeks time using local cures on an outpatient basis. No cases of later complications were reported with good or very good late cosmetic results. Moulds treating low doses per fraction, 1.8 Gy five days a week, produced acute G4 complication rate in 10% (ulceration) and late good cosmetic results in 98%. In some cases, a slight hypopigmentation of the skin (G1) or small telangiectasia’s (G2) in the radiated area, mainly in cases of large tumours are described, with patchy pigmentation in a reduced number of cases. Cosmetic results are good or very good in all cases. With Leipzig applicators, no late complications are reported. In one study, grade 1 acute skin toxicity was detected in 168 treated lesions (71%) and grade 2 in 81 (34%), late skin hypopigmentation changes were observed in 13 cases (5.5%) and cosmesis was good or excellent in 208 cases (88%). With Valencia applicators the highest skin toxicity was grade 1 RTOG/EORTC, having resolved with topical treatment at 4 weeks in all but one case which required 2 months and there were no grade 2 or higher late adverse events. Electronic brachytherapy produces similar acute toxicity but long term side effects are not yet available.

6.1 Gy, local control at one year was 95 and 90% respectively [54]. Other tumours can benefit fromHDR brachytherapy, as cutaneous metastasis of Merkel cell carcinoma [55], Kaposi sarcoma lesions [56], or cutaneous T-cell carcinoma (mycosis fungoides) [57].

13. ADVERSE SIDE EFFECTS

13.1 Adverse side effects after LDR brachytherapy In general, an excellent or a good cosmetic result is obtained in 78 to 92%of patients after LDR brachytherapy (Fig. 17). Complication rates range between 0 and 13% and are similar to those of external beams. Complications are dose and dose rate dependent. For small tumours (T1-T2) a dose of 60Gy should therefore be recommended. Higher doses result in only a small increment in local control, but a significant rise in complications. For larger tumours, local control rates remain good, but complication rates are higher (5.5% skin necrosis or healing ulcer for lesions larger than 2 cm) and cosmetic outcome is less favourable, because of skin destroyed by the tumour and retraction of the healing scar which occurs afterwards. The risk of complications is highest for tumours on the pinna (4 - 18.5% persistent ulcers) because of poor blood supply. It has been suggested that for basal or squamous cell carcinomas on the pinna, a dose of 55 Gy may be sufficient, since these tumours show very good local control (100%) after a dose of 60 - 66 Gy but a high risk of complications (permanent ulcers 18.5%) [37]. There is one published randomised study compares surgery with radiotherapy (LDR brachytherapy or external radiotherapy) for basal cell carcinomas of the face [3]. Surgery appeared to be better than radiotherapy, both in terms of local control rate and cosmetic outcome. The 4-year actuarial local control was 99.3% in the surgical group compared to 93.5% in the radiotherapy group. However, in 30% of the surgical cases, general anaesthesia was used in 46%, flap reconstructions were needed. In 91% of the treatments, systematic frozen section examination was performed