Introduction: Photodynamic diagnosis (PDD) is a method of improving cystoscopic detection of bladder lesions. Whilst there is good evidence to support improved diagnosis over white light (WL), this has not clearly translated into a reduction in recurrence rates when PDD is used at transurethral resection of the tumour (TURBT). To date there has been mixed evidence with a recent Cochrane review concluding that there may be benefit to PDD TURBT, though there was a low certainty of evidence. The PHOTO trial looked to study the efficacy of PDD by means of a large pragmatic randomised trial. However whilst recurrence rates were reduced in the PDD cohort initially, over a longer duration of follow up there was no benefit of PDD seen. The objective of this further analysis is to explore the possible causes for the pattern observed, looking at whether the learning curve associated with PDD may have led to this observation and the implications this may have on clinical practice. Methods: The PHOTO trial was conducted across 22 hospitals in the United Kingdom. It enrolled patients with new diagnoses of intermediate/high risk bladder cancer who were randomised to have their initial resection performed using WL or PDD. Further follow up and adjuvant treatment was as per established guidelines. Results: 418 patients were included within the intention to treat analysis in the PHOTO trial. Recurrence rates at 3 years showed no significant difference between the PDD and WL Cohort, there was however an initial reduction in recurrence rates seen in the PDD cohort prior to 20 months. Further analyses showed that surgeon experience of PDD was significant. Where resections were undertaken by surgeons who were experienced in PDD (previously performed more than 40 PDD procedures) there was a lower risk of recurrence than those performed by surgeons who had undertaken less than 10 cases using PDD; HR 0.60 (95% CI: 0.40 – 0.92); p=0.019. This was irrespective of whether WL or PDD was used during the resection. Furthermore recurrence rates were unaffected by grade of operating surgeon when consultant was compared to registrar/non consultant career grade: HR 0.94 (95% CI: 0.67-1.33); p=0.736). Conclusions: Data from the PHOTO trial has shown that surgeons with more experience of PDD have better outcomes in both their PDD and WL resections. Our hypothesis is that experience of PDD improves resection technique and as such should be considered as a training tool for all urologists undertaking TURBT regularly. SOURCE OF Funding: The PHOTO trial was funded by the National Institute for Health Research (NIHR)
