title: Office-based transurethral devascularisation of low grade non-invasive urothelial cancer using diode laser. A feasibility study.
abstract: OBJECTIVE
  Frequent recurrence of non-muscle invasive bladder tumours (NMIBC) requiring transurethral resection of bladder tumour (TUR-BT) and lifelong monitoring makes the lifetime cost per patient the highest of all cancers. A new method is proposed for the removal of low grade NMIBCs in an office-based setting, without the need for sedation and pain control and where the patient can leave immediately after treatment.
  
  
  METHODS
  An in vitro model was developed to examine the dose/response relationship between laser power, treatment time, and distance between laser fibre and target, using a 980 nm diode laser and chicken meat. The relationship between depth and extent of tissue destruction and the laser settings was measured using microscopy and non-parametric statistical analysis. A patient with low grade stage Ta tumour and multiple comorbidity, and therefore not fit for general anaesthesia, had a tumour devascularised using the laser at the tumour base, in the outpatient department. The tumour was left in the bladder.
  
  
  RESULTS
  In the in vitro model, depth of tissue destruction increased with laser illumination up to 30 seconds, where median depth was 4.1 mm. With longer illumination the tissue destruction levelled off. The width of tissue destruction was 2-3 mm independent of laser illumination time. The in vivo laser treatments devascularised the tumour, which was later shed from the mucosa and passed out with the urine in the days following treatment. Pain score was 0 on a visual log scale (0-10). The tumour had completely disappeared two weeks after treatment.
  
  
  CONCLUSIONS
  This diode laser technique may provide almost pain-free office-based treatment of low grade urothelial cancer using flexible cystoscopes in conscious patients. A prospective randomised study will be scheduled to compare the technique with standard TUR-BT in the operating theatre.
authors.affiliation: Department of Urology, Bispebjerg/Frederiksberg Hospital, Copenhagen University, Ndr. Fasan vej 57, DK-2000, Frederiksberg.
authors.forename: Gregers G
authors.initials: GG
authors.lastname: Hermann
authors.affiliation: Department of Urology, Bispebjerg/Frederiksberg Hospital, Copenhagen University, Ndr. Fasan vej 57, DK-2000, Frederiksberg.
authors.forename: Karin
authors.initials: K
authors.lastname: Mogensen
authors.affiliation: Centre for Nuclear Technologies (Nutech), Technical University of Denmark (DTU), DK-4000 Roskilde, Denmark.
authors.forename: Lars R
authors.initials: LR
authors.lastname: Lindvold
authors.affiliation: Department of Dermatology, Bispebjerg Hospital, Copenhagen University, Bispebjerg Bakke 23, DK-2400, Copenhagen, NV, Denmark.
authors.forename: Christina S
authors.initials: CS
authors.lastname: Haak
authors.affiliation: Department of Dermatology, Bispebjerg Hospital, Copenhagen University, Bispebjerg Bakke 23, DK-2400, Copenhagen, NV, Denmark.
authors.forename: Merete
authors.initials: M
authors.lastname: Haedersdal
mesh_terms: D000556:Ambulatory Surgical Procedures / Q000379:methods*; D000818:Animals; D002645:Chickens; D003558:Cystoscopy; D005240:Feasibility Studies; D006801:Humans; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D001749:Urinary Bladder Neoplasms / Q000601:surgery*; D019459:Urothelium / Q000601:surgery*
keywords: TUR-BT; bladder tumour; outpatient; treatment