Previous studies have demonstrated that PDL can be used to remove lesions on the vocal cords and elsewhere in the throat causing less damage to surface tissues than other commonly used lasers. In our proposed clinical study, we seek to compare treatment efficacy for RRP by combining PDL with DIM, versus PDL-only treatment, in a total of 30 children with laryngeal papilloma. We will determine whether this combined treatment would be effective and safe in preventing or delaying the RRP recurrence while preserving voice quality. 30 children will be divided randomly into two treatment groups, 15 in each. The experimental group will receive one-time PDL treatment, followed by 3-month oral administration of DIM and an additional 12 months with no treatment. The other group will be treated with PDL-only, as a control, and take a placebo pill for 3 months. All of the patients will be followed for a total of 15 months. We will compare lesion recurrence and laboratory tests between the two groups, to determine efficacy and safety of the new treatment. This is the first study to combine new PDL laser technique with DIM, to develop a new, voice-preserving and long-term effective method of managing laryngeal RRP in children.