BACKGROUND: Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is widely used for treating Bowen's disease (BD), but recurrence and tumour cell persistence after ALA-PDT is sometimes problematic. Radiation therapy (RT) is also effective for BD, but is limited by its side-effects, such as refractory ulcers. OBJECTIVE: The objective of the study was to observe a synergic effect of combination therapy with ALA-PDT and RT for BD cases that did not respond effectively to prior ALA-PDT. METHODS: Subjects were BD patients whose lesion did not show complete remission or showed recurrence after prior ALA-PDT. A total of four cases involving four lesions were studied (three male and one female, mean age 69.5). ALA ointment (20%) was applied to the lesions. After 4 to 6h, subjects received combination therapy consisting of excimer-pumped dye laser radiation at 630nm (50J/cm(2) ) followed by electron-beam radiation (3Gy). The combination therapy was repeated every 2 to 3days for a total of four treatments. The lesions were evaluated clinically or histologically after the final combination therapy session. RESULTS: Following combination therapy, all of the lesions disappeared. Recurrence was not detected during the observations periods, which averaged 14.0months in duration. CONCLUSION: Our results indicate that the cure rate of BD could be improved by combination therapy with ALA-PDT and RT. Compared with conventional RT, the synergetic effect of this therapy might reduce the dose of radiation required, thereby also reducing skin side-effects such as refractory ulcers.
BACKGROUND: Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is widely used for treating Bowen's disease (BD), but recurrence and tumour cell persistence after ALA-PDT is sometimes problematic. Radiation therapy (RT) is also effective for BD, but is limited by its side-effects, such as refractory ulcers. OBJECTIVE: The objective of the study was to observe a synergic effect of combination therapy with ALA-PDT and RT for BD cases that did not respond effectively to prior ALA-PDT. METHODS: Subjects were BD patients whose lesion did not show complete remission or showed recurrence after prior ALA-PDT. A total of four cases involving four lesions were studied (three male and one female, mean age 69.5). ALA ointment (20%) was applied to the lesions. After 4 to 6h, subjects received combination therapy consisting of excimer-pumped dye laser radiation at 630nm (50J/cm(2) ) followed by electron-beam radiation (3Gy). The combination therapy was repeated every 2 to 3days for a total of four treatments. The lesions were evaluated clinically or histologically after the final combination therapy session. RESULTS: Following combination therapy, all of the lesions disappeared. Recurrence was not detected during the observations periods, which averaged 14.0months in duration. CONCLUSION: Our results indicate that the cure rate of BD could be improved by combination therapy with ALA-PDT and RT. Compared with conventional RT, the synergetic effect of this therapy might reduce the dose of radiation required, thereby also reducing skin side-effects such as refractory ulcers.
Authors: Yang Hao; Chih Kit Chung; Zhenfeng Yu; Ruben V Huis In 't Veld; Ferry A Ossendorp; Peter Ten Dijke; Luis J Cruz Journal: Pharmaceutics Date: 2022-01-04 Impact factor: 6.321