5‐Aminolevulinic Acid–Based Photodynamic Therapy (ALA‐PDT) for Bowen’s Disease in Chinese Patients: A Multicenter Prospective Study

Background In China, the common treatment for Bowen’s disease (BD) is surgical excision. Although 5‐aminolevulinic acid–based photodynamic therapy (ALA‐PDT) has proven effective for BD in Caucasian patients, there is limited research on its effectiveness in Asian patients. This trial aimed to investigate the efficacy and safety of ALA‐PDT in treating BD patients in China, providing data to standardize its application in Chinese BD patients. Methods A multicenter, prospective clinical study was conducted in seven tertiary hospitals in China. Histopathologically confirmed BD patients received standard ALA‐PDT. After pretreatment, a 20% ALA gel or solution was applied to the lesions and incubated for 3‐4 h. The lesions were illuminated with 635‐nm red LED light at a dose level of 80–120 J/cm 2 . Additional treatments were scheduled every 7–14 days based on lesion regression. Results The study included 35 BD patients with 44 lesions. All patients received 3–6 sessions of ALA‐PDT. Three months after the last treatment, the complete response rate was 97.1% (34/35) for patients and 97.7% (43/44) for lesions. Subgroup analysis indicated that sex ( p = 0.3518), age ( p = 0.6906), number of lesions ( p = 0.7155), lesion location ( p = 0.2241), and size ( p = 0.2898) did not significantly affect effectiveness. During the 12‐month follow‐up, the recurrence rate was 3.0% (1/33). Physicians rated 93.1% (27/29) of cosmetic effects as excellent or good. Meanwhile, patient satisfaction reached 92.6% (25/27). The primary adverse event observed was mild to moderate pain. Photodynamic fluorescence diagnosis showed that 100% (35/35) of the BD lesions exhibited brick‐red fluorescence. Conclusions A regimen of 3–6 sessions of topical ALA‐PDT using 20% ALA, 3‐4‐h incubation, and a red light source leads to high complete response rates, excellent cosmetic effects, good patient tolerance, and minimal adverse reactions in Chinese BD patients. Importantly, the efficacy of ALA‐PDT is not affected by lesion size, location, or number. Trial Registration: Chinese Registry of Clinical Trials: ChiCTR1800019213