SHORT COMMUNICATION 649
ActaDV ActaDV
Advances in dermatology and venereology Acta Dermato-Venereologica
Ambulatory Photodynamic Therapy for Superficial Basal Cell Carcinoma: An Effective Light Source?
Janneke P. H. M. KESSELS 1, 2, Nedim DZINO 3, Patty J. NELEMANS 4, Klara MOSTERD 1, 2 and Nicole W. J. KELLENERS-SMEETS 1, 2, 5
1
Department of Dermatology, Maastricht University Medical Centre, P. Debyelaan 25, NL-6229 HX Maastricht, 2 GROW School for Developmental Biology and Oncology, Maastricht University, 3 Department of Ophthalmology, Erasmus Medical Centre, Rotterdam, 4 Department of Epidemiology, Maastricht University Medical Centre, Maastricht, and 5 Department of Dermatology, Catharina Hospital Eindhoven, The Netherlands. E-mail: janneke. kessels @ mumc. nl Accepted Jan 12, 2017; Epub ahead of print Jan 17, 2017
Photodynamic therapy( PDT) is a non-invasive treatment for several( pre) malignant superficial skin cancers, such as superficial basal cell carcinoma( sBCC), Bowen’ s disease( BD) and actinic keratosis( AK)( 1, 2). PDT is traditionally known as an in-clinic treatment that can be time-consuming for both patients and healthcare personnel. Conventional PDT( cPDT) can be painful( 3). In order to optimize comfort during treatment, new photosensitizing agents and light sources have been studied over the past decades.
Moseley et al.( 4) reported on the use of a portable lowirradiance illumination source for sBCC. This ambulatory PDT( aPDT) device delivers a standard light dose at low irradiance( 7 mW / cm 2) over a prolonged period of time, compared with other devices, such as the Aktilite( 80 – 90 mW / cm 2, Galderma SA, Lausanne, Switzerland)( 5). It is considered a patient-friendly, out-of-clinic treatment with lower pain scores compared with regular PDT( 4 – 6).
This aim of this study was to evaluate retrospectively the risk of recurrence in patients treated with aPDT for primary sBCC, and the effect of tumour size on recurrence.
MATERIALS AND METHODS
Medical files of patients treated with aPDT between 1 February 2012 and 31 May 2013 in the Catharina Hospital, the Netherlands, were reviewed retrospectively. Inclusion criteria for this study were: patients with a histologically confirmed primary sBCC with a maximum diameter of 2 cm( due to size limitation of the portable PDT device). Exclusion criteria were: patients with genetic disorders causing skin cancer and those using immunosuppressive medication. The primary outcome measure was 1-year probability of remaining tumour-free. Treatment failure was defined as the presence of residual or recurrent tumour during follow-up visits. Follow-up visits were scheduled according to the local hospital protocol 3 and 12 months post-treatment. Secondary outcome measures were cumulative probability of recurrence-free survival at 6 and 18 months, and incidence of adverse events.
In case of slight hyperkeratosis, lesions were prepared by curettage using a wooden spatula to remove scales and crusts, to increase penetration of the active agent. Consecutively methylaminolaevulinic acid( Metvix 16 %, Galderma SA, Penn Pharmaceutical Services, Gwent, UK) was applied to the tumour itself and a 5-mm margin of surrounding normal tissue. A transparent occlusive bandage( Tegaderm ®, 3M Healthcare, Minnesota, USA), was applied, after which the portable PDT device( Ambulight ®, Ambicare Health, Livingston, Scotland, UK) was attached. The device remained switched off for 3 h. Subsequently, it switched on automatically and remained switched on for another 3 h, thereby delivering a total light dose of 75 J / cm 2, with 7 mW / cm 2 irradiance.
The distribution of baseline characteristics was described by absolute numbers and percentages for categorical variables and mean ± standard deviation for age. Kaplan – Meier survival analyses were used to assess the cumulative probability of recurrence-free survival with 95 % confidence intervals( CI) at 6, 12 and 18 months. Differences in recurrence-free survival between groups were tested for significance using the log-rank test. Follow-up ended at the date of a treatment failure or the date of the last follow-up visit. A 2-sided p-value ≤ 0.05 was considered to indicate statistical significance. Analyses were performed using SPSS version 23.0 and Stata version 14.0.
RESULTS
During the study period 125 patients with 143 sBCC were treated with aPDT. The first diagnosed tumour per patient was included for analysis. In case a patient was treated for 2 or more primary sBCC on the same day, the largest tumour was chosen for analysis. A total of 104 patients had a histologically confirmed primary sBCC. Three patients were lost to follow-up directly post-treatment, because they preferred follow-up elsewhere. Thus, 101 patients remained for analysis. Baseline characteristics are shown in Table SI 1.
Median follow-up time was 13 months( range 2 – 23 months) with 59.4 % of patients having completed a follow-up time of at least 12 months and 27 % more than 18 months. In 11 patients treatment failure was observed based on clinical observation, from which 9 occurred within 12 months. Eight of the clinically suspect recurrences were confirmed by histopathological examination, and 3 tumours were re-treated without histological confirmation. A total of 11 recurrences were included in the analysis.
At 3 months there were no patients with residual tumour. At 6, 12 and 18 months the cumulative probability of recurrence-free survival was 93.6 %( 95 % CI 86.3 – 97.1 %), 89.9 %( 95 % CI 81.5 – 94.7 %) and 87.6 %( 95 % CI 77.4 – 93.3 %). For 74 patients data on tumour size was available. These patients were categorized according to tumour size: ≤5, 6 – 10, and > 10 mm. The 1-year probability of recurrence-free survival was 100 % for the ≤ 5 mm size group and 92 %( 95 % CI 78.5 – 97.6 %) and 72.9 %( 95 % CI 42.6 – 89.0 %) for the 6 – 10 mm and > 10 mm groups, respectively, p = 0.014( Fig. S1 1).
Adverse events were reported in 2 patients: one reported blistering and erosions post-treatment, and the other had a bacterial skin infection, which was treated with topical antibacterial ointment.
1 https:// www. medicaljournals. se / acta / content / abstract / 10.2340 / 00015555-2610
This is an open access article under the CC BY-NC license. www. medicaljournals. se / acta Journal Compilation © 2017 Acta Dermato-Venereologica. doi: 10.2340 / 00015555-2610 Acta Derm Venereol 2017; 97: 649 – 650