Recurrent Lesion Distribution After Photodynamic Therapy for Recurrent Respiratory Papillomatosis

Recurrent respiratory papillomatosis (RRP) is a benign laryngeal tumor, and traditional surgical resection faces the dilemma between excessive tissue removal and high recurrence rates. Photodynamic therapy (PDT), as a "regional clearance" strategy, offers a novel approach to addressing this challenge. However, the anatomical distribution of recurrent lesions following PDT has not been fully elucidated. To evaluate the distribution characteristics of recurrent lesions in different anatomical regions following PDT for RRP, thereby providing evidence to optimize PDT treatment protocols. A retrospective study analyzed 43 RRP patients who underwent PDT (January 2021-December 2024), with 54 recurrence records examined. Postoperative laryngoscopic examinations were performed monthly to assess recurrence. An 11-region anatomical diagram was used to assess lesion distribution and calculate relative recurrence rates across anterior and posterior regions. In-situ and ectopic recurrences were statistically compared. The study found that the epiglottis exhibited the highest relative recurrence rate (75.00%), indicating it is more prone to recurrence than other regions (χ² = 21.850, P = 0.016). Additionally, the recurrence rate in the posterior regions (63.16%) was higher than that in the anterior regions (50.00%) (χ² = 3.54, P = 0.060). Furthermore, in-situ recurrence significantly outweighed ectopic recurrence (χ² = 111.24, P < 0.001). During PDT for RRP, statistically significant differences in relative recurrence rates were observed across anatomical regions, with in-situ recurrence being the most common pattern.