Randomized Comparison of Low and Conventional Irradiance PDT for Skin Cancer

A Randomized Assessor-blinded Comparison of Low Irradiance and Conventional Irradiance Photodynamic Therapy (PDT) for Superficial Non-melanoma Skin Cancer

This study aims to examine whether the pain of topical photodynamic therapy (PDT) is significantly different when using low irradiance ambulatory light emitting diode (LED) devices compared with conventional higher irradiance hospital based LED light sources when used for superficial non-melanoma skin cancer. The investigators are also investigating the phototoxicity and efficacy of each regime in this randomized assessor-blinded clinical trial.

A randomized assessor-blinded comparative study of low irradiance ambulatory LED devices with conventional hospital-based LED devices for superficial non-melanoma skin cancer. Preliminary observations suggest that low irradiance LEDs cause less pain but are as effective, so the investigators are examining this in a clinical trial of patients with lesions </= 2cm diameter of non-melanoma skin cancer (Bowen's disease and superficial basal cell carcinoma). Patients with these conditions referred to the PDT clinic will be invited to participate and if they are eligible and consent to treatment then they will be prospectively randomized to either ambulatory PDT or conventional PDT. Pain and phototoxicity scores will be recorded and clinical efficacy will be assessed up to one year after the last treatment. Computer-generated block randomization will be performed and at 90% power to detect as significant at the 5% level a mean difference in pain score of 2 in one group compared with 4 in the other, 36 patients will be needed, and as the participants will often be elderly and frail the investigators will aim for a safety margin of recruiting 50 participants to account for drop-outs. Participants will receive two treatments of either arm at a one week interval and will be assessed clinically at three months and if residual disease remains then the two treatments a week apart are repeated. Pain assessed using a visual analogue scale (VAS) score and phototoxicity on a semi-quantitative scale are recorded at 7 days when the participant returns for their second treatment. Follow up for clinical assessment is at 6 months and one year after treatment. Participants also give their opinion of treatment at one year follow up. Assessors of adverse effects and efficacy will be blinded. Data recording and analysis will be undertaken by the study statistician Dr Robert Dawe and analysis will be on an intention to treat basis using appropriate statistical tests comparing the pre-planned outcome measures, with pain as primary outcome and outcome, efficacy and patient satisfaction as secondary outcomes

assess on visual analogue scale (VAS) score of 0 - 10cm, with 0 representing no pain experienced through to 10 representing the worst pain imaginable. The participant marks across a 0-10cm unmarked line where their level of pain experience is and this is measured eg. 2cm if experiencing mild pain or 8.5cm which would represent severe pain

erythema, oedema, blistering, crusting, ulceration on semi-quantitative scale. Erythema is graded as 0 = absent, 1 = mild, 2 = moderate or 3 = severe erythema as assessed by naked eye examination. Oedema is graded as 0 = absent or 1 = present. Likewise crusting or ulceration are each graded as 0 = absent and 1 = present by naked eye examination. Data will be presented and analysed separately ie. erythema data will be presented and then separately whether oedema, crusting or ulceration are present or absent. ie. reporting may appear as example: erythema score 3 of range of 0-3 options; oedema score 1 (binary option of 0 or 1); crusting score 0 (binary option of 0 or 1); ulceration score 0 (binary option of 0 or 1)

clinical assessment by study dermatologist to determine by inspection and palpation whether the lesion is clear, partially clear or not clear - assessed at 3, 6 and 12 months after treatment, with 12 months as the final study outcome endpoint analysed

brief patient questionnaire to evaluate their opinion of the treatment they received. This is assessed as A.efficacy of treatment - 1 = not effective NR; 2 = partIally effective PR; 3 = completely effective CR; B.Side effects of treatment eg. pain and inflammation - 1 = severe; 2 = moderate; 3 = mild; 4 = none/minimal. C.Practicalities of treatment eg. ease of use, travel, time, inconvenience - 1 = very disruptive and difficult; 2 = moderately disruptive and difficult; 3 = minimally disruptive and difficult. The scores of A, B and C will be added to give an overall score with range of overall minimum score option 3 and maximum 10. Patients will also separately be asked to give overall evaluation on a VAS scale of 0 = treatment very poor and would not have again through to 10 = treatment excellent and I would have again - with a continuous line option from 0 - 10 to mark across, providing a separate score with range options 0 to 10

Inclusion Criteria: Bowen's disease or superficial basal cell carcinoma referred for PDT and lesion not greater than 2.4cm diameter Exclusion Criteria: Unable to give consent, >2cm diameter, lesions on highly curved surfaces where ambulatory device would not adhere

presenting study data at British Association of Dermatologists annual meeting Edinburgh 5.7.18 and abstract will be published in Br J Dermatol and full publication will follow

Attili SK, Lesar A, McNeill A, Camacho-Lopez M, Moseley H, Ibbotson S, Samuel ID, Ferguson J. An open pilot study of ambulatory photodynamic therapy using a wearable low-irradiance organic light-emitting diode light source in the treatment of nonmelanoma skin cancer. Br J Dermatol. 2009 Jul;161(1):170-3. doi: 10.1111/j.1365-2133.2009.09096.x. Epub 2009 Mar 19.

Moseley H, Allen JW, Ibbotson S, Lesar A, McNeill A, Camacho-Lopez MA, Samuel ID, Sibbett W, Ferguson J. Ambulatory photodynamic therapy: a new concept in delivering photodynamic therapy. Br J Dermatol. 2006 Apr;154(4):747-50. doi: 10.1111/j.1365-2133.2006.07145.x.

Ibbotson SH. Irradiance is an important determinant of pain experienced during topical photodynamic therapy. J Am Acad Dermatol. 2011 Jul;65(1):201-2. doi: 10.1016/j.jaad.2010.11.060. No abstract available.

Ibbotson SH, Ferguson J. Ambulatory photodynamic therapy using low irradiance inorganic light-emitting diodes for the treatment of non-melanoma skin cancer: an open study. Photodermatol Photoimmunol Photomed. 2012 Oct;28(5):235-9. doi: 10.1111/j.1600-0781.2012.00681.x.