Clinical trial of photodynamic therapy with meso-tetra (hydroxyphenyl) chlorin for respiratory papillomatosis.
ABSTRACT To determine the efficacy of photodynamic therapy (PDT) with meso-tetra (hydroxyphenyl) chlorin (m-THPC) photosensitizer for recurrent respiratory papillomatosis.
Parallel-arm, randomized trial of patients requiring surgery at least 3 times yearly with single PDT 6 or 18 months after enrollment and 12-month follow-up. Disease extent was scored and papillomas were removed during direct endoscopy every 3 months after enrollment.
Tertiary medical centers.
Of 23 patients aged 4 to 60 years enrolled in the study, 15 patients, plus 2 in the late group without PDT owing to airway risk, completed the study. Six patients withdrew voluntarily after PDT.
Intravenous administration of m-THPC 6 days before direct endoscopic PDT with 80 to 100 J of light for adults and 60 to 80 J for children.
Difference in severity scores between the early and late groups and between pre- and post-PDT scores for all patients. Secondary measures were the associations between baseline characteristics and response and changes in immune response and the prevalence of latent viral DNA.
There were significant differences between groups, with marked improvement in laryngeal disease across time after PDT (P = .006). Five of 15 patients were in remission 12 to 15 months after treatment, but there was recurrence of disease after 3 to 5 years. Tracheal disease was not responsive to PDT. No change occurred in the prevalence of latent human papillomavirus DNA. The immune response to virus improved with clinical response.
Use of m-THPC PDT reduces the severity of laryngeal papillomas, possibly through an improved immune response. Failure to maintain remission with time suggests that this is not an optimal treatment.
- SourceAvailable from: PubMed Central[Show abstract] [Hide abstract]
ABSTRACT: In treating juvenile-onset laryngeal papillomatosis, the most difficult aspect is preventing recurrence. After a single treatment, recurrence can begin after as soon as 20 days and the recurrent rate can be higher than 90%. The causes of recurrence include the presence of mucosal cells infected with papilloma virus, which are undetectable with the naked eyes, and surgery-induced infection. Photodynamic therapy (PDT) could effectively solve this problem. Virus-infected cells have a very high metabolic energy for capturing and internalizing the photosensitizer, which, after light stimulation, subsequently induces active oxygen species inside the nucleus, which kill infected cells. The second generation of photosensitizer agents (PA) are locally applied to avoid the intravenous systemic damage caused by first-generation PAs, and this method is widely used for the treatment of genital warts to very good effect.World Journal of Surgical Oncology 08/2014; 12(1):275. · 1.20 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Photodynamic therapy (PDT) is clinically established modality used for treatment of solid cancers and other conditions, which destroys lesions by localized generation of cytotoxic oxygen species mediated by administered drugs (photosensitizers) that are activated at targeted sites by exposure to light. Since over 20 years ago it has become increasingly clear that important contribution to the antitumor effect of PDT is secured by host reaction induced by this therapy and manifested as inflammatory and immune response. Presented is an overview of advances in the understanding of this host response associated with tumor PDT by tracing its evolution from initial breakthroughs and discoveries in the early 1980s, followed by advances preceding recent developments, and concluding with recently acquired knowledge and directions for clinical exploitation. Tribute is given to researchers making important contributions to this field during the last three decades including Drs. Gianfranco Canti, Julia Levy, and Barbara Henderson.Proceedings of SPIE - The International Society for Optical Engineering 03/2007; · 0.20 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: To demonstrate the role of oral acyclovir in monthly regimes after microdebrider assisted excision in 3 patients with adult recurrent respiratory papillomatosis (ARRP). Three patients with ARRP who presented to a tertiary referral hospital in stridor were initially treated with a tracheostomy in order to secure airway. On further evaluation by videolaryngoscopy extensive bilateral laryngeal papillomatosis was noted with history of similar conditions in the past for which they were repeatedly operated. They were admitted and underwent Microlaryngeal surgery and laryngeal microdebrider assisted surgery under general anesthesia. Post operatively a course of oral acyclovir at 800 mg/5 times/day for 5 days was administered. On repeat assessment with videolaryngoscopy at monthly intervals a complete remission of the disease was noted with no residual disease at the end of 1 year in 2 cases. One case had a recurrence. Renal parameters were monitored periodically. It may be concluded that the action of anti viral drugs at regular intervals in addition to a short course of oral steroids lead to rapid recovery and prevented latent virus activation within the laryngo tracheal system hence maintaining long term improvement. This can avoid multiple laryngeal surgeries, repeated respiratory emergencies and risk for malignant transformation in the future thereby reducing morbidity and effect on quality of life.Indian Journal of Otolaryngology and Head & Neck Surgery 01/2014; · 0.05 Impact Factor