Non-metastatic cutaneous squamous cell carcinoma treated with photodynamic therapy using intravenous mTHPC

Photodynamic therapy (PDT) is a method of treating various pathologies. In this retrospective study with prospective intent, a total of 22 patients with T1/T2 N0 cutaneous squamous cell carcinoma (SCC) were treated with intravenous mTHPC (meta-tetrahydroxyphenylchlorin) and surface illumination PDT. Comparisons with the clinical features, rate of recurrence and overall outcome were made.

Surface illumination PDT was offered under local anaesthesia. 0.05 mg/kg mTHPC was administered intravenously into the midcubital vein 48 h prior to tissue illumination. A single-channel 652 nm diode laser was used for illumination and light was delivered at 20 J/cm² per site. Lesion response evaluation was carried out according to Response Evaluation Criteria In Solid Tumors (RECIST).

Clinical assessment revealed that 16 patients had lesions of <2 cm in size (T1), while the rest were T2. No nodal involvement was identified in any of the patients. None of the patients had a locally recurrent lesion. During the 3-year follow-up, 20/22 patients had complete response (CR) and this was after one round of treatment. Two patients suffered from recurrent disease within 3 years of the follow-up, and they underwent surgical resection.

PDT achieved high efficacy in the treatment of T1N0 cutaneous squamous cell carcinoma with greatly reduced morbidity and disfigurement. The technique is simple, can commonly be carried out in outpatient clinics, and is highly acceptable to patients.