Comparative Evaluation of the Effect of Topical Photodynamic Therapy Versus Topical Calcipotriol on the Clinical and Molecular Characteristics of Oral Leukoplakia: a Randomized Clinical Trial

(i)Rationale/ gaps in existing knowledge,: Oral cancer, one of the top three common cancers in India is usually preceded by Oral potentially malignant disorders in nearly two thirds of the cases like Oral leukoplakia. OL has a high prevalence and malignant transformation rates(0.13% - 40.8%). There are no universal protocols for management in OL ranging from preventive, conservative, medical and surgical interventions. They all have limitations and high recurrence rates requiring regular follow up.

(ii)Novelty: Removal of pathological lesions are believed to reduce the risk of malignant transformation in OL. Surgical methods are associated with morbidity and high recurrence rates. Non -invasive methods (like Photodynamic therapy) that can remove the abnormal lesions would be preferred as they are cheaper, convenient, safe with less morbidity and better patient acceptability. They also have the advantage of repeatability with minimum morbidity and damage to adjacent normal tissues. Non -invasive medical management involves topical application of retinoids which are associated with systemic toxicity, recurrence and development of resistance.

(iii)Objectives,

Primary objective:

To compare the effect of 2.5% Toluidine blue mediated topical photodynamic therapy and topical calcipotriol (0.005%) on clinical response after completion of treatment at 4 weeks from baseline during management of Oral leukoplakia

Secondary objectives:

To compare the effect of 2.5% Toluidine blue mediated topical photodynamic therapy with topical Calcipotriol (0.005%) on lesion size, lesion roughness/ whiteness, and oral health quality of life after completion of treatment at 4 weeks and 12 weeks from baseline during management of Oral leukoplakia To compare the effect of 2.5% Toluidine blue mediated topical photodynamic therapy with topical Calcipotriol (0.005%) on salivary molecular markers ( IL6, TNF-α, PCNA, Survivin and VEGF) after completion of treatment at 4 weeks from baseline To compare the adverse events, time to complete response and recurrence rates between the two groups

(iv)Methods,: An open label randomized clinical trial where Group A (n=83) will receive 4 sessions of Toludine blue mediated photodynamic therapy (Fluence 15J/cm2); GroupB (n=83) will receive twice daily tropical application of Calcipotriol (0.005%) over a period of 4 weeks. The clinical response, lesion thickness/ whiteness, lesion size /area, OHIP-14 scores, adverse events and recurrence rates will be compared with baseline at 4 weeks and 12 weeks after completion of therapy. Sterile PVA ophthalmic sponges will be used to evaluate molecular markers ( IL6, TNF-α, PCNA, Survivin VEGF) from treatment site of lesion at baseline and 4 weeks after completion of treatment by ELISA. The data will be analyzed statistically using Intention to treat and as per protocol analysis at significance levels of p<0.05.

(v)Expected outcome.: The study will validate and verify the effectiveness of the TB mediated PDT protocol in the management of OL as compared to other non invasive method of topical Calcipotriol in terms of clinical response ( complete/ partial/ none), lesion thickness/ whiteness, lesion size and it's effect on oral health quality of life. Adverse events if any and recurrence rates or malignant transformation rates will also help in assessment of safety of the protocol. The molecular markers will help to monitor and determine prognosis of the lessons following treatment.