5-aminolevulinic Acid Induced Fluorescence Endoscopy Research Articles

Editorial Comment on: A New Generation of Optical Diagnostics for Bladder Cancer: Technology, Diagnostic Accuracy, and Future Applications

[37] Denzinger S, Burger M, Walter B, et al. Clinically relevant reduction in risk of recurrence of superficial bladder cancer using 5-aminolevulinic acid-induced fluorescence diagnosis: 8-year results of prospective randomized study. Urology 2007;69:675–9. [38] Daniltchenko DI, Riedl CR, Sachs MD, et al. Long-term benefit of 5aminolevulinic acid fluorescence assisted transurethral resection of superficial bladder cancer: 5-year results of a prospective randomized study. J Urol 2005;174:2129–33. [39] KriegmairM, Zaak D, Rothenberger KH, et al. Transurethral resection for bladder cancer using 5-aminolevulinic acid induced fluorescence endoscopy versus white light endoscopy. J Urol 2002;168: 475–8. [40] Burger M, Zaak D, Stief CG, et al. Photodynamic diagnostics and noninvasive bladder cancer: is it cost-effective in long-term application? A Germany-based cost analysis. Eur Urol 2007;52: 142–7. [41] Grimbergen MCM, van Swol CFP, Jonges TGN, Boon TA, van Moorselaar RJA. Reduced specificity of 5-ALA induced fluorescence in photodynamic diagnosis of transitional cell carcinoma after previous intravesical therapy. Eur Urol 2003;44:51–6. [42] Wang ZG, Durand DB, Schoenberg M, Pan YT. Fluorescence guided optical coherence tomography for the diagnosis of early bladder cancer in a rat model. J Urol 2005;174:2376–81.

Fluorescence cytology of the urinary bladder

Objectives To assess, on the basis of the tumor-associated fluorescence characteristics of 5-aminolevulinic acid-induced fluorescence endoscopy, the value of fluorescence microscopy and compare it with standard cytologic techniques. 5-Aminolevulinic acid-induced fluorescence endoscopy has proved to be a valuable detection method with a high sensitivity for the endoscopic diagnosis of bladder cancer. Methods We instilled 1.5 g of 5-aminolevulinic acid, dissolved in 50 mL of 5.7% sodium monohydrogen phosphate, into the urinary bladder of 162 patients with suspected transitional cell carcinoma 2 to 3 hours before endoscopy. A lavage solution was obtained for urinary cytology and for fluorescence cytology. The sediments were evaluated for tumor cells. Results Transitional cells suspicious for tumor demonstrated the red 5-aminolevulinic acid-induced protoporphyrin IX fluorescence under the microscope. Fluorescence cytology identified 50 of 58 histologically confirmed neoplastic lesions (G1, 14 of 17; G2, 12 of 14; G3, 15 of 16; and carcinoma in situ, 9 of 11). With urinary cytology, we identified 46 of 58 histologically confirmed tumor lesions (G1, 9 of 17; G2, 12 of 14; G3, 15 of 16; and carcinoma in situ, 10 of 11). The sensitivity of fluorescence cytology was 86% and that of urinary cytology 79%. The specificity of fluorescence cytology was 75% and that of urinary cytology 88%. Conclusions Fluorescence cytology promises to be an effective procedure for the diagnosis of bladder cancer, especially in highly differentiated and flat premalignant tumor lesions. Automated analysis for an objective and a reproducible result appears possible.

Ultraviolet-excited (308 nm) autofluorescence for bladder cancer detection

Objectives To assess the ability of ultraviolet laser-induced autofluorescence for the diagnosis of transitional cell carcinoma of the bladder. Methods We studied 43 patients undergoing transurethral resection with recurrent transitional cell carcinoma of the bladder. Guided through 5-aminolevulinic acid-induced fluorescence endoscopy, the autofluorescence of the red fluorescing areas and the adjacent tissue and inconspicuous-appearing mucosa were measured spectroscopically. The autofluorescence excitation was carried out with a xenon chloride excimer laser operating at 308 nm (AF308). For the evaluation of the autofluorescence spectra, an intensity ratio (335/430 nm) was calculated and correlated with the histologic results of the biopsies taken. Results We analyzed the AF308 spectra of 114 biopsies (21 malignant, 93 benign). The autofluorescence intensity ratios for the benign lesions were a factor of 2 to 7 higher than carcinoma in situ and neoplastic tissue. Therefore, 20 of 21 neoplastic lesions were detected as true positive by AF308. A sensitivity and specificity for AF308 of 95% and 77%, respectively, could be calculated. The sensitivity and specificity for 5-aminolevulinic acid-induced fluorescence endoscopy was 90% and 61%, respectively. By combining the two methods, we calculated a sensitivity of 90% and a specificity of 84%. Conclusions The combination of a sensitive imaging technique such as 5-aminolevulinic acid-induced fluorescence endoscopy and a more specific spectral fluorescence probe technique with autofluorescence at 308 nm is a very efficient procedure in the detection of transitional cell carcinoma of the bladder.

Transurethral Resection For Bladder Cancer Using 5-Aminolevulinic Acid Induced Fluorescence Endoscopy Versus White Light Endoscopy

Endoscopy done under fluorescence induced by 5-aminolevulinic acid has proved to be a procedure with high sensitivity for detecting transitional cell carcinoma of the bladder. In this multicenter, parallel group, phase III study we compared 5-aminolevulinic acid fluorescence endoscopy guided transurethral bladder resection with transurethral bladder resection done using only white light endoscopy. The proportion of tumor-free resected cases in the 2 groups was evaluated. After patient stratification according to participating centers and European Organization for the Research and Treatment of Cancer risk score 65 and 64 were randomized to the 5-aminolevulinic acid fluorescence and white light endoscopy groups, respectively. Residual tumor was evaluated in the 2 groups by repeat transurethral resection 10 to 14 days later. Analysis was performed according to the intent to treat principle with all patients randomized, followed by per protocol analysis. Intent to treat analysis revealed that in the white light endoscopy group 40.6% of cases were resected tumor-free at primary resection, whereas with 5-aminolevulinic acid fluorescence endoscopy guided transurethral resection 61.5% were resected tumor-free (p <0014). On protocol analysis 46.9% patients in the white light and 67.3% in the 5-aminolevulinic acid fluorescence endoscopy groups were resected tumor-free (p <0.031). No difference was noted in the 2 groups in regard to side effects or laboratory findings. The risk of residual tumor after transurethral resection of transitional cell carcinoma is significantly decreased by 5-aminolevulinic acid fluorescence endoscopy.

5-aminolevulinic acid induced fluorescence endoscopy decreases recurrence rate of superficial bladder carcinoma

5-aminolevulinic acid induced fluorescence endoscopy decreases recurrence rate of superficial bladder carcinoma

QUANTIFICATION OF 5-AMINOLEVULINIC ACID INDUCED FLUORESCENCE IMPROVES THE SPECIFICITY OF BLADDER CANCER DETECTION

5-Aminolevulinic acid induced fluorescence endoscopy has outstanding sensitivity for detecting early stage bladder cancer. Nevertheless, a third of the lesions that show specific fluorescence are histologically benign. We decreased the false-positive rate of 5-aminolevulinic acid induced fluorescence endoscopy by incorporating protoporphyrin IX fluorescence quantification into the standard cystoscopy procedure. In 25 cases (53 biopsies) of a history of or suspicion for bladder cancer 5-aminolevulinic acid induced fluorescence endoscopy and fluorescence image quantification were performed. For fluorescence image quantification images obtained with a target integrating color charge-coupled device camera were digitized and stored in a personal computer. Red-to-blue ratios were calculated from fluorescence positive lesions and results were correlated with hematoxylin and eosin histology. Malignant fluorescence positive lesions showed significantly stronger fluorescence intensity than fluorescing lesions with benign histology. A threshold was established that decreased the false-positive rate by 30% without affecting sensitivity. Fluorescence image quantification is a new endoscopic method for objectively selecting multicolor fluorescence bladder lesion images for biopsy. It has the potential of eliminating human error by different surgeons with variable experience in fluorescence endoscopy.

Autofluorescence imaging to optimize 5-ALA-induced fluorescence endoscopy of bladder carcinoma

Objectives. To design an optical system for detecting autofluorescence (AF) of bladder tumors and to determine the success of reducing the false-positive rate of 5-aminolevulinic acid-induced fluorescence endoscopy (AFE). AFE provides significantly higher sensitivity in detecting and localizing bladder carcinoma compared with white light endoscopy. The specificity of AFE is equivalent to white light endoscopy, mostly because of the false-positive fluorescence of chronic cystitis lesions. Laser-induced spectral autofluorescence detection is also an efficient method in the diagnosis of bladder carcinoma. Methods. Bladder tissue was excited to AF using the D-Light (375 to 440 nm) after regular AFE with detection of fluorescence-positive areas. The optical image was produced using a special RGB camera. Biopsies were taken from AFE-positive areas, the peritumoral edges, and normal bladder mucosa. The AF images of the suspicious areas were compared with the AFE images and the histologic results. Results. A total of 43 biopsies were histologically examined (24 benign and 19 neoplastic). AF imaging showed contrast differences between papillary tumors, flat lesions, and normal mucosa. The combination of AFE with AF raised the specificity of AFE alone from 67% to 88%. Conclusions. AF imaging is possible. The value of the method in reducing the false-positive rate of the highly sensitive AFE needs to be validated with higher numbers. The combination of AF with AFE had a 20% higher specificity than AFE alone in our study.

Diagnosis and Treatment of Nonmetastasized Superficial Bladder Cancer must be Reconsidered

Diagnosis and therapy of superficially growing bladder cancer must be reconsidered. With the introduction of 5-aminolevulinic acid induced fluorescence endoscopy, the superficial lesions such as carcinomata in situ and early stages of tumor (dysplasias) can be completely detected besides the exophytic tumors. This is of particular importance because the fate of the patient essentially depends on precisely these tumor entities. With the current methods of investigation, these kinds of tumors are often not detected. If they are revealed by a positive cytology finding, it is mostly not possible to locate them under white light. Dissemination of tumor cells and destruction of the bladder wall (especially the lamina propria mucosae) should be avoided in treatment. However, this occurs of necessity in TUR. This therapy deficit can be dealt with an absolutely ideal way by a coagulation laser (neodymium-YAG laser, holmium-YAG, diode laser etc.). Photodynamic therapy is recommended before carrying out radical cystectomy in tumors resistant to chemotherapy and BCG or in tumor recurrences. Es gibt gute Gründe, die Diagnostik und Therapie des oberflächlichen Harnblasenkarzinoms neu zu überdenken. Mit der Entwicklung der 5-Aminolävulinsäure induzierten Fluoreszenzen doskopie steht nun ein Verfahren zur Verfügung, das es ermöglicht, neben papillären Tumoren auch flache urotheliale Läsionen, wie Carcinomata in situ und Dysplasien mit hoher Sensitivität zu detektieren. Gerade these Läsionen sind von entscheidender prognostischer Bedeutung, werden jedoch mit der konventionellen Weißlichtendoskopie häufig nicht erkannt. Eine intraoperative Tumorzelldissimination und Verletzung der Blasenwand sollte vermieden werden, ist aber eine notwendige Begleiterscheinung der transurethralen Elektroresektion. Diese therapeutischen Defizite können durch den Einsatz des Lasers (Neodymium-YAG-, Holmium-YAG-, Dioden-Laser etc.) vermieden werden. Bei oberflächlichen, BCG-refraktären high-risk-Tumoren stellt die photodynamische Therapie vor Durchführung der Zystektomie eine vielversprechende ultima ratio dar.

Transurethral resection and surveillance of bladder cancer supported by 5-aminolevulinic acid-induced fluorescence endoscopy

Correspondence to Mr Christopher R. Chapple, Urology Research Department, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK. Tel: +44 114 271 2791; fax: +44 114 279 8318 L'Aquilla University, L'Aquilla, Italy

5-Aminolevulinic Acid-Induced Fluorescence Endoscopy for the Detection of Lower Urinary Tract Tumors

The use of a photodynamic fluorescence marker for diagnosis of tumors is an intriguing concept to improve the thoroughness of surgical tumor resection. Complete surgical resection of multifocal bladder tumors and flat lesions such as carcinoma in situ is known to be difficult, and thus a source of recurrences. We report on the recent experience with the intravesical application of the photosensitizer prodrug 5-aminolevulinic acid (5-ALA), which is a nontoxic physiological heme substrate. Initial results from fluorescence diagnosis using krypton laser light, and recent results with a modified incoherent light source constantly showed a 25% increase in urothelial tumor detection in comparison to white light endoscopy. Due to the high sensitivity, the number of biopsies could be decreased constantly in comparison to routine random biopsies taken under white light endoscopy. The results show about 25–30% of cases with fluorescent lesions which are histologically benign. 5-ALA is a promising tool for the diagnosis of bladder cancer. The outcome of the admission study for 5-ALA in urology in Germany is positive, and is being continued by prospective multicenter clinical studies to prove the hypothesis of reduction of tumor recurrence with this method. 5-ALA-based fluorescence endoscopy is strongly recommended for further clinical testing.

Transurethral Resection and Surveillance of Bladder Cancer Supported by 5-Aminolevulinic Acid-Induced Fluorescence Endoscopy

Purpose: We determined whether neoplastic disease, which was missed under white light can be found during transurethral resection of bladder cancer by 5-aminolevulinic acid-induced porphyrin fluorescence. Materials and Methods: 5-Aminolevulinic acid-induced fluorescence endoscopy was carried out in 328 cases. A 3% 5-aminolevulinic acid solution was instilled intravesically in a mean time of 2.8 h before endoscopy. The fluorescence was excited by a special incoherent light source which provided blue light in addition to white light. Results: In 82 (25%) cases additional neoplastic lesions were found only because of their red porphyrin fluorescence which was induced by 5-aminolevulinic acid. 31% of these neoplastic foci which were found in normal and nonspecific inflamed mucosa had a poorly differentiated histology. Conclusions: 5-Aminolevulinic acid facilitates detection of neoplastic disease during transurethral resection of bladder cancer and increases the accuracy of diagnosis.

IS EVERYTHING ALL RIGHT IF NOTHING SEEMS WRONG? A SIMPLE METHOD OF ASSESSING THE DIAGNOSTIC VALUE OF ENDOSCOPIC PROCEDURES WHEN A GOLD STANDARD IS ABSENT

Purpose We demonstrate a simple yet comprehensive method to evaluate the sensitivity of endoscopic procedures when no gold standard is available. Materials and Methods In 208 consecutive patients with superficial bladder cancer 328 endoscopies were performed to compare the sensitivity of white light and 5-aminolevulinic acid induced fluorescence endoscopy. Both procedures were performed during the same session. Results The maximum interval of observable sensitivity for 5-aminolevulinic acid induced fluorescence endoscopy ranged between 78 and 97.5%, and the best estimate for sensitivity based on realistic assumptions was 93.4% (95% confidence intervals 90 to 97.3). The best sensitivity estimate for white light endoscopy was 46.7% (95% confidence intervals 39.4 to 54.3, maximum range 47.2 to 53%). Conclusions This method to determine the maximum possible range of sensitivity estimates for endoscopic procedures without a gold standard is easily applied. Depending on the assumptions a range of reasonable scenarios can be constructed and the corresponding sensitivities can be reported. This approach gives fast and valid results, and could further indicate the diagnostic superiority of 5-aminolevulinic acid induced fluorescence compared to white light endoscopy.

Frequent Genetic Alterations in Simple Urothelial Hyperplasias of the Bladder in Patients with Papillary Urothelial Carcinoma

In order to understand the origin of bladder cancer, very early urothelial lesions must be investigated in addition to more advanced tumors. Tissue from 31 biopsies of 12 patients with urothelial hyperplasias and simultaneous or consecutive superficial papillary tumors were used to microdissect urothelium from 15- microm sections of biopsies. The biopsies were obtained with the recently developed highly sensitive diagnostic method of 5-aminolevulinic acid-induced fluorescence endoscopy (AFE). Besides flat and papillary urothelial neoplasms, the method of photodynamic diagnostics also detects simple urothelial hyperplasias as fluorescent positive lesions. In addition, 12 fluorescence-positive biopsies showing histologically normal urothelium were investigated. Fluorescence in situ hybridization was done using a dual color staining technique of biotinylated centromeric probes of chromosomes 9 and 17 and digoxigenin-labeled gene-specific P1 probes for chromosomes 9q22 (FACC), 9p21(p16/CDKI2), and 17p13(p53). Ten of 14 hyperplasias (70%) showed deletions of chromosome 9. In 7 out of 8 patients with genetic alterations in the hyperplasias the genetic change was also present in the papillary tumor. Six out of 12 samples of microdissected normal urothelium also showed genetic alterations on chromosome 9. Microdissection of urothelial lesions, obtained during AFE, has led to the first unequivocal documentation of genetic changes in urothelial lesions diagnosed as normal in histopathology. Thus, this technical approach is important to provide insight into the earliest molecular alterations in bladder carcinogenesis.

5-aminolevulinic acid-induced fluorescence endoscopy applied at secondary transurethral resection after conventional resection of primary superficial bladder tumors

Objectives. A prospective investigation was carried out to evaluate the use of 5-aminolevulinic acid (5-ALA)-induced fluorescence diagnosis with secondary transurethral resection (TUR). Methods. Fifty patients underwent secondary TUR of the former resection area 6 weeks after conventional TUR for superficial bladder carcinoma. 5-ALA-induced fluorescence diagnosis was used in addition to standard white light endoscopy. All former resection areas were biopsied regardless of fluorescence findings. In addition, specific red fluorescent areas were resected, as were suspicious areas seen at white light endoscopy. Results. One hundred thirty areas or tumors were resected. The sensitivity of fluorescence cystoscopy was 77.8% (95% confidence interval 52.4% to 93.6%). Residual tumors were found in the area of the former resection in 7 (14%) of 50 patients; 4 of these 7 were fluorescence negative and 3 were fluorescence positive. In an additional 7 patients (14%), exclusively fluorescing tumors not visible under white light could be detected outside the areas of former resection (n = 5, Stage pTaG1/2; n = 1, Stage pT1G1/2; n = 1, carcinoma in situ). Conclusions. Despite high sensitivity, fluorescence diagnosis at this early stage of control does not allow us to evaluate sufficiently the granulation tissue of necrotic areas after TUR without biopsy. The main advantage of the 5-ALA-induced fluorescence endoscopy is in the evaluation of untreated urothelium because of the easier detection of tumors not visible by conventional endoscopy.