Efficacy of photodynamic therapy as a treatment for Gorlin syndrome-related basal cell carcinomas

The management of the multiple basal cell carcinomas (BCCs) that develop throughout life of patients with Gorlin syndrome can be challenging. Surgical excision can result in significant disfigurement from scarring and tissue defects. Radiotherapy is contraindicated because of enhanced radiation tumourigenesis in these patients. Photodynamic therapy (PDT) is a simple, repeatable out-patient procedure, which is associated with minimal skin deterioration. It is now routinely used to treat superficial sporadic BCCs, using a topically-applied photosensitiser and external light, but its role in the management of Gorlin syndrome-related BCCs has yet to be established. In particular, Gorlin syndrome is often associated thick, nodular lesions which can be resistant to treatment with topical PDT.

We report our outcome data for 33 Gorlin patients (138 lesions) treated with PDT. Lesion thicknesses were assessed using ultrasound, both prior to treatment and during follow-up, to quantify treatment response and to guide the choice of treatment methods. Topical PDT was used to treat superficial lesions (<2 mm thick) and a systemic photosensitiser +/- light delivered by interstitially-placed optical fibres was employed for thicker lesions (>2 mm).

Local control rates of 56.3% at 12 months were achieved overall. The use of a systemic photosensitiser +/- interstitial light delivery extended the remit of PDT, allowing thicker lesions (>2 mm) to be treated, resulting in local control rates of 59.3% in this group. PDT can be considered as a treatment option for patients with multiple BCCs as a result of Gorlin syndrome. The use of ultrasound to accurately assess lesion thickness helps to select the optimum treatment method. Systemic photosensitisers and interstitial optical fibres can be used to treat thicker lesions, offering a treatment option for patients with thick nodular tumours who wish to avoid surgery.