Editorial Comment to A case in which bladder cancer invaded the ureteral orifice and was resected via photodynamic diagnosis‐assisted transurethral resection involving orally administered 5‐aminolevulinic acid

aminolevulinic acid (5-ALA). Photodiagn. Photodyn. Ther. 2016; 13: 91–6. 7 Filbeck T, Roessler W, Knuechel R, Straub M, Kiel HJ, Wieland WF. 5aminolevulinic acid-induced fluorescence endoscopy applied at secondary transurethral resection after conventional resection of primary superficial bladder tumors. Urology 1999; 53: 77–81. 8 Grimbergen MC, van Swol CF, Jonges TG, Boon TA, van Moorselaar RJ. Reduced specificity of 5-ALA induced fluorescence in photodynamic diagnosis of transitional cell carcinoma after previous intravesical therapy. Eur. Urol. 2003; 44: 51–6. 9 Hendricksen K, Moonen PM, der Heijden AG, Witjes JA. False-positive lesions detected by fluorescence cystoscopy: any association with p53 and p16 expression? World J. Urol. 2006; 24: 597–601. 10 Palou J, Salvador J, Millan F, Collado A, Algaba F, Vicente J. Management of superficial transitional cell carcinoma in the intramural ureter: what to do? J. Urol. 2000; 163: 744–7. Supporting information


Editorial Comment
Editorial Comment to A case in which bladder cancer invaded the ureteral orifice and was resected via photodynamic diagnosis-assisted transurethral resection involving orally administered 5-aminolevulinic acid Watanabe et al. 1 reported an interesting case of bladder cancer in the intramural ureter exhibiting red fluorescence with the use of orally administered 5-aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD). The tumor was resected with negative margins, which did not show red fluorescence by ALA-PDD. The present study reports that an exact diagnosis and precise resection of the bladder tumor in the intramural ureter are possible with the use of ALA-PDD. Faba et al. 2 reported a good oncological outcome for conventional transurethral resection of bladder cancer without T1 or carcinoma in situ in the intramural ureter. ALA-PDD can be considered in patients suspicious for bladder cancer in the intramural ureter, though long-term follow-up for local or upper urinary tract recurrence is needed in the present case, and accumulating information on such cases is necessary.
False-positive results should be noted during ALA-PDD for bladder cancer. 3 Oblique illumination and inflammation can lead to false-positive results, which are often observed at the bladder neck, trigone, and around the orifice. 4 Because ureteral stenosis can occur after resection of the orifice (11.6%), 2 unnecessary surgery should be avoided. Draga et al. 5 reported that the learning curve for surgeons performing transurethral resection under PDD was proportional to the decrease in the number of false positives up to 12-18 months after the initial PDD procedure. Thus, some experience with ALA-PDD and careful observation are necessary to perform ALA-PDD for bladder tumors in the intramural ureter.
The present case also reveals the potential of ALA-PDD for diagnosis of upper urinary urothelial carcinoma (UTUC).
Kata et al. 6 reported the potential of ureteroscopy using 5-ALA, and that ALA-PDD for UTUC can identify tiny lesions and carcinoma in situ, which is missed under conventional white light. 5-ALA can be administered using either an oral or transurethral route. On the other hand, hexaminolevulinate, which is used in Europe for PDD of non-muscle-invasive bladder cancer, is administered via intravesical instillation only. Therefore, ALA-PDD is a promising diagnostic tool for various kinds of cancers including UTUC, and trials of ALA-PDD in the treatment of such cancers are being performed.
The use of ALA-PDD for bladder cancer has recently been approved in Japan and performed in various institutions. We should report the effectiveness of ALA-PDD from Japan, and transurethral resection with ALA-PDD should be approved as a treatment for bladder carcinoma outside of Japan as emphasized by Watanabe et al. in their keynote message.