One has to do with the speed of an object, the other with variations in light to enhance the appearance of transitional cell cancers (TCC) for laser therapy. Narrow band imaging (NBI) creates two narrow bands of light (415 and 540 nm); these wavelengths are taken up by hemoglobin thereby enhancing the appearance of surface capillaries (appear brown) and submucosal blood vessels (appear blue). This technology has proven its worth in the detection of bladder cancer but as yet has not been widely applied to the detection of upper tract tumors.1 In this study, among 14 patients with a prior history of upper TCC and among 13 patients with a suspicion of upper tract TCC, the use of NBI detected a tumor “missed” by white light in 7% and 15% of patients, respectively. Furthermore, the NBI revealed an additional tumor in 0% and 8%, respectively, while in 11% of tumors detected by white light, the borders of the tumor were noted to be broader with NBI leading to a more extensive ablation.
NBI is simple to use; it requires no use of photodynamic medications, no “special” flexible or rigid ureteroscope, and no additional set up. One merely hits a switch to move the light source from white light to NBI or back again.
Given the nearly 40% recurrence rate within 5 years for upper tract TCC treated endourologically and the well known multiplicity of TCC of the renal pelvis at the time of presentation, the addition of NBI to the urologist’s armamentarium could well herald better initial therapy as well as an increase in the period to tumor recurrence. This is a wonderful example of better science leading to better urology.
References:
- Tatsugami, K., Kuroiwa, T., Kamoto, H., et al.: Evaluation of narrow-band imaging as a complementary method for the detection of bladder cancer. J. Endourol. 24: 1807-1811, 2010.
J Endourol. 2011 Jan;25(1):19-23.
10.1089/end.2009.0593
PubMed Abstract
PMID: 21247287
UroToday.com Renal Cancer Section
