3 Clinical evidence

Summary of clinical evidence

3.1 The main clinical outcomes for the treatment of non-melanoma skin cancer with Ambulight PDT are tumour response rate (including recurrence rates or need for additional treatment), pain during treatment and adverse events. Full details of all clinical outcomes considered by the Committee are available in the assessment report.

3.2 The Committee saw data on a total of 28 patients who were treated with Ambulight PDT.

3.3 Attili et al. (2009) described a pilot study of 12 patients (8 patients with Bowen's disease and 4 patients with basal-cell carcinoma) with a median lesion diameter of 1.1 cm (range 0.6–1.9 cm) treated using a prototype of the Ambulight PDT device with 5-aminolevulinic acid as the photosensitiser. A complete response was reported in 75% (9/12) of patients at 6-month follow-up. At 12 months, 58% (7/12) of patients had complete tumour response (4 patients had peripheral margin failure; 1 had residual nodular component). In all patients for whom treatment was unsuccessful, the lesion size was greater than 1.5 cm in diameter.

3.4 Attili et al. (2009) reported pain immediately after treatment that was recorded using a numerical rating scale (1–10; higher score indicates worse pain). All 12 patients reported a pain score of 2 or less (range 0–2). No patients needed pain relief in the form of local anaesthesia or cool air treatment during therapy. One patient who reported excessive pain during previous PDT commented on the lack of discomfort with Ambulight PDT. These scores were compared retrospectively with those of 50 patients who had received conventional PDT using an inorganic light-emitting diode static lamp source (dose 75 J/cm2). The static lamp cohort had a median numerical rating scale score of 6 (range 1–10). Of the 50 patients, 11 needed local analgesia and all needed cool air treatment.

3.5 The manufacturer's submission presented data on the use of a light-emitting diode light source and methyl aminolevulinate cream (Metvix). These data included five patients with single lesions treated using Ambulight PDT and 11 patients with multiple lesions whose lesions were treated with a range of PDT treatments (at least one lesion site was treated with Ambulight PDT; other sites were treated using conventional PDT or different light-emitting diode sources). Pain immediately after treatment was recorded on a visual analogue scale (1–10; higher score indicates worse pain). For single lesions treated using Ambulight PDT the pain score ranged from 1.5 to 7. For patients with multiple lesions treated using Ambulight PDT the pain scores ranged from 0 to 8. For multiple lesions treated with other PDT, pain scores ranged from 1.5 to 10. Insufficient data were available for analysing summary statistics (mean or median) for Ambulight PDT compared with conventional PDT.

3.6 No adverse events have been reported with Ambulight PDT.

Committee considerations

3.7 The Committee considered that there was some evidence for efficacy of Ambulight PDT but that the quantity of evidence on its use was very limited. The Committee considered that more clinical evidence is needed.

3.8 The Committee noted that the manufacturer of this technology claims that it is equivalent to, but not more effective than, conventional PDT. The Committee also noted that one of the claimed advantages over conventional PDT is that it can be used in ambulatory settings, including patients' homes in selected cases. The Committee considered that the ambulatory nature of the device offers the potential to increase convenience of treatment for patients with impaired mobility. It also noted that patients could be treated with Ambulight PDT who might otherwise have difficulty accessing PDT.

3.9 The manufacturer's submission described various techniques that have been developed to reduce pain during PDT and presented studies demonstrating that reduced irradiance is associated with reduced pain. The Committee considered that there was evidence to suggest that treatment with Ambulight PDT may cause less pain than conventional PDT in some patients.

3.10 The Committee recognised that patient preference plays a significant part in the decision to treat low-risk non-melanoma skin cancer.

3.11 Small non-melanoma skin cancers are common and most have a low risk of progression, but because of incomplete coverage of case reporting, the true incidence is unknown. The Committee was advised that practice varies substantially when deciding on treatment for these lesions and that local service configuration influences the range of treatments that can be offered. Some patients are offered one of a range of treatments including topical chemotherapy, surgical excision, radiotherapy or standard hospital-based PDT, whereas others are not offered treatment. There are no good studies comparing the range of possible treatments.

3.12 The Committee debated the usefulness of a device that treats only single lesions when many patients have multiple lesions needing treatment, and the fact that Ambulight PDT is suitable only for treating lesions of a small size. It also noted the differing views of Expert Advisers about the significance of pain as an issue with conventional PDT.

3.13 The Committee recognised that Ambulight PDT is a new device at a relatively early stage of development with a consequently small evidence base but that the manufacturer is collecting more data. The Committee considered the available clinical evidence and judged that it was insufficient to support the case for routinely adopting Ambulight PDT for treating non-melanoma skin cancers in the NHS in place of current management.

3.14 The Committee recognised that Ambulight PDT is a current treatment option for carefully selected patients.

  • National Institute for Health and Care Excellence (NICE)