Photodynamic Diagnosis (PDD) in Flexible Cystoscopy - DaBlaCa-11

Photodynamic diagnostic (PDD) is a technique where a photodynamic drug is installed preoperatively in the bladder. Mucosa cells with a higher metabolism than normal urothelial cells, e.g. cancer cells, absorbs this drug which is utilized during cystoscopy where blue light is absorbed by the drug, making the surgeon able to distinguish tumor cells from normal cells and thus being able to identify flat lesions and small papillomas missed in white light cystoscopy.

The use of PDD at this primary transurethral resection of bladder tumour (TURB) has been shown to be associated with a lower recurrence rate within the first year, probably mostly owing to a higher detection rate of small papillomas and dysplasia that therefore can be relevantly treated at an early stage.

Despite the use of PDD at the primary TURB, a high number of patients experience an early recurrence and patients with carcinoma in situ (CIS) treated with bacillus Calmette-Guerin (BCG) may have recurrence of their CIS or recurrence of papillomas despite the peroperative use of PDD.

Whereas the use of PDD is well established in the TURB setting, the use of PDD in the follow-up setting with flexible cystoscopy in the outpatient clinic is not investigated. Feasibility studies have been successful but the clinical relevance and benefits have not been investigated so far.

Thesis The thesis of the study is that the use of PDD in the outpatient clinic in patients with a high recurrence risk undergoing follow-up flexible cystoscopy will result in diagnosis of papillomas earlier than by the use of conventional flexible cystoscopy in white light. Thus, a higher number of tumours can be treated in the outpatient setting without the need for procedures in general anesthesia. Furthermore, the number of follow-up cystoscopies can be reduced if PDD is used at the first cystoscopy following TURB.

Aims To investigate whether the use of PDD when performing a flexible cystoscopy in the outpatient clinic can reduce the number of recurrences of large size papillomas that cannot be treated by simple fulguration without general anesthesia. Furthermore, to investigate whether the use of PDD in follow-up cystoscopy in patients with earlier complete response to BCG on CIS, can increase the detection rate of CIS recurrences.