Photodynamic therapy as salvage therapy for patients with nasopharyngeal carcinoma experiencing local failures following definitive radiotherapy

Background
Treating local failures of nasopharyngeal carcinoma (NPC) is a challenge. This study evaluates photodynamic therapy (PDT) in the treatment of residual and recurrent NPC.

Method
In this phase II study, patients with local recurrent or residual NPC after curative intent (chemo-) radiation could be included. Exclusion criterion was a tumour depth more than 10 mm. Foscan® 0.15 mg/kg was administered intravenously. After 96 h, the illumination was performed under local anaesthesia with a nasopharyngeal light applicator. Tumour response was measured 10 weeks after illumination by endoscopy, biopsy and CT-scan. Kaplan-Meier method was used for survival analysis.

Results
Twenty-one patients were included. Fourteen patients were treated for residual disease (67%), and two for recurrent (10%). For five patients this distinction could not be made, due to uncertainty about complete response after initial treatment. The median follow-up time was 32 months. Twenty patients (95%) had a complete response 10 weeks post-treatment. Two patients had recurrent local disease at 5 and 7 months post-PDT. They received another course of PDT, one with success. The 2-year local control rate was 75%, progression free survival was 49% and overall survival was 65%. Nine patients (43%) had no evidence of disease and were in a good clinical condition (ECOG Performance Scale 0) at the end of the study period. No serious adverse events were observed.

Conclusion
This study showed that PDT is effective in treating local failures of NPC with a depth of less than 10 mm. The treatment was easy to perform under local anaesthesia. Especially in regions were other modalities like radiation and surgery are limited PDT can be a good alternative treatment.