PDD-guided tumor excision combined with photodynamic therapy in patients with extramammary Paget's disease

Photodynamic diagnosis (PDD) is a technique that plays a role in visualizing tumor size during the assessment of surgery. Photodynamic therapy (PDT) is a treatment apart from surgery, chemotherapy, radiotherapy, and immunotherapy that is approved for several types of tumors and nonmalignant diseases. The purpose of this study was to illustrate the efficiency and safety of PDD-guided tumor excision combined with ALA-PDT in patients with extramammary Paget's disease (EMPD).In our study, 7 cases of EMPD were treated with PDD-guided tumor excision combined with ALA-PDT. After removal of the tumor detected by PDD, each tumor region was irradiated with 177 J/cm2 using a 635 nm laser for 15 min. Two to four ALA-PDT cycles were applied during and after surgery. EMPD was confirmed by biopsy.PDD may forecast tumor margins in EMPD to guide surgery, and PDT has an inhibitory effect on tumor growth. There was no local recurrence in the follow-up of 2.9 years (range, 0.8-5 years). Only one patient experienced distant recurrence under the armpit. The patients with EMPD were able to complete the treatment protocol, with good results and no significant side effects.The present study demonstrated an effective protocol using PDD for diagnosis and PDT for multiple therapies, showing potential as a clinical treatment for EMPD.