Photodynamic Diagnosis and Therapy for Peritoneal Carcinomatosis from Gastrointestinal Cancers: Status, Opportunities, and Challenges

Selective accumulation of a photosensitizer and the subsequent response in only the light-irradiated target are advantages of photodynamic diagnosis and therapy. The limited depth of the therapeutic effect is a positive characteristic when treating surface malignancies, such as peritoneal carcinomatosis. For photodynamic diagnosis (PDD), adjunctive use of aminolevulinic acid- protoporphyrin IX-guided fluorescence imaging detects cancer nodules, which would have been missed during assessment using white light visualization only. Furthermore, since few side effects have been reported, this has the potential to become a vital component of diagnostic laparoscopy. A variety of photosensitizers have been examined for photodynamic therapy (PDT), and treatment protocols are heterogeneous in terms of photosensitizer type and dose, photosensitizer-light time interval, and light source wavelength, dose, and dose rate. Although several studies have suggested that PDT has favorable effects in peritoneal carcinomatosis, clinical trials in more homogenous patient groups are required to identify the true benefits. In addition, major complications, such as bowel perforation and capillary leak syndrome, need to be reduced. In the long term, PDD and PDT are likely to be successful therapeutic options for patients with peritoneal carcinomatosis, with several options to optimize the photosensitizer and light delivery parameters to improve safety and efficacy.

Diagnostic accuracy of photodynamic diagnosis for upper urinary tract urothelial carcinoma: A systematic review and meta-analysis

BACKGROUND

This study aimed to evaluate the effectiveness of photodynamic diagnosis (PDD) for upper urinary tract urothelial carcinoma (UTUC) by performing a meta-analysis.

METHOD

Relevant articles were retrieved from the Cochrane Library, PubMed, and Embase databases. Studies evaluating the accuracy of PDD for the diagnosis of upper UTUC were included. The pooled sensitivity, specificity, and area under the curve (AUC) were calculated by STATA 16.0 at the per-lesion level.

RESULTS

Six studies with 289 lesions were included in this systematic review and meta-analysis. The pooled results showed that PDD can differentiate upper UTUC from benign lesions with a sensitivity of 0.96 (95 % confidence interval: 0.85-0.99) and a specificity of 0.86 (95 % confidence interval: [0.64-0.95]; AUC, 0.97). Compared with white-light ureterorenoscopy, PDD can significantly improve the additional detection rate of UTUC (RR 0.16, 95 % CI 0.07-0.34 P = 0.000).

CONCLUSIONS

PDD is a valid technique that improves the diagnostic accuracy of UTUC compared with standard white-light ureterorenoscopy at the per-lesion level. PDD is a promising endoscopic technique for upper UTUC.

Cancer cell detection device for the diagnosis of bladder cancer from urine

Bladder cancer is common and has one of the highest recurrence rates. Cystoscopy, the current gold standard diagnosis approach, has recently benefited from the introduction of blue light assisted photodynamic diagnostic (PDD). While blue light cystoscopy improves diagnostic sensitivity, it remains a costly and invasive approach. Here, we present a microfluidic-based platform for non-invasive diagnosis which combines the principle of PDD with whole cell immunocapture technology to detect bladder cancer cells shed in patient urine ex vivo. Initially, we demonstrate with model cell lines that our non-invasive approach achieves highly specific capture rates of bladder cancer cells based on their Epithelial Cell Adhesion Molecule expression (>90%) and detection by the intensity levels of Hexaminolevulinic Acid-induced Protoporphyrin IX fluorescence. Then, we show in a pilot study that the biosensor platform successfully discriminates histopathologically diagnosed cancer patients (n = 10) from non-cancer controls (n = 25). Our platform can support the development of a novel non-invasive diagnostic device for post treatment surveillance in patients with bladder cancer and cancer detection in patients with suspected bladder cancer.

Key transporters leading to specific protoporphyrin IX accumulation in cancer cell following administration of aminolevulinic acid in photodynamic therapy/diagnosis

The administration of aminolevulinic acid allow the formation and accumulation of protoporphyrin IX specifically in cancer cells, which then lead to photocytotoxicity following light irradiation. This compound, when accumulated at high levels, could also be used in cancer diagnosis as it would emit red fluorescence when being light irradiated. The concentration of protoporphyrin IX is pivotal in ensuring the effectiveness of the therapy. Studies have been carried out and showed the importance of various transporters in regulating the amount of these substrates by controlling the transport of various related metabolites in and out of the cell. There are many transporters involved and their expression levels are dependent on various factors, such as oxygen availability and iron ions. It is also important to note that these transporters may also have different expression levels depending on their organ. Understanding the mechanisms and the roles of these transporters are essential to ensure maximum accumulation of protoporphyrin IX, leading to higher efficiency in photodynamic therapy/diagnosis. In this review, we would like to discuss the roles of various transporters in protoporphyrin IX accumulation and how their involvement directly affect cancerous microenvironment.

Evolution of photodynamic medicine based on fluorescence image-guided diagnosis using indocyanine green and 5-aminolevulinic acid

New diagnostic techniques based on photodynamic medicine, such as near-infrared fluorescence using indocyanine green (NIR-ICG) and 5-aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD), are aiding navigation tasks across various fields of surgery. Specifically, NIR-ICG is being used for the intraoperative identification of sentinel lymph nodes or blood vessels in organ resection and for blood flow evaluation in surgery. These ICG-fluorescent imaging techniques could provide an additional and potentially valuable way to identify vascular and lymphatic structures in surrounding tissue. 5-Aminolevulinic acid is a precursor of a photosensitizing substance with affinity for tumors; thus, diagnostic laparoscopy using ALA-PDD in combination should improve the accuracy of detecting peritoneal dissemination in patients with advanced gastric cancer. The ability to overlay fluorescent imaging with conventional color images in real time using ALA-PDD and NIR with ICG would be of immense benefit to surgeons, providing good visualization and detection of target lesions not seen with the naked eye. A multi-center clinical study examining the safety and efficacy of ALA-PDD during laparoscopic examination for patients with advanced gastric cancer is currently underway in the form of doctor-initiated trials, and further verification studies will be conducted. Such imaging capability could have broad potential across cancer and vascular surgery.

Hysteroscopic Photodynamic Diagnosis Using 5-Aminolevulinic Acid: A High-Sensitivity Diagnostic Method for Uterine Endometrial Malignant Diseases

STUDY OBJECTIVE

To examine the diagnostic accuracy of hysteroscopic photodynamic diagnosis (PDD) using 5-aminolevulinic acid (5ALA) in patients with endometrial cancer and premalignant atypical endometrial hyperplasia.

DESIGN

A single-center, open-label, exploratory intervention study.

SETTING

University Hospital in Japan.

PATIENTS

Thirty-four patients who underwent hysteroscopic resection in the Department of Obstetrics and Gynecology at Keio University Hospital.

INTERVENTIONS

Patients were given 5ALA orally approximately 3 hours before surgery and underwent observation of the uterine cavity and endometrial biopsy using 5ALA-PDD during hysteroscopic resection. Specimens were diagnosed histopathologically and the diagnostic sensitivity and specificity of hysteroscopic 5ALA-PDD for malignancy in the uterine cavity was determined. Red (R), blue (B), and green (G) intensity values were determined from PDD images, and the relationships of histopathological diagnosis with these values were used to develop a model for objective diagnosis of uterine malignancy.

MEASUREMENTS AND MAIN RESULTS

Three patients were excluded from the study because of failure of the endoscope system. A total of 113 specimens were collected endoscopically. The sensitivity and specificity of 5ALA-PDD for diagnosis of malignancy in the uterine cavity were 93.8% and 51.9%, respectively. The R/B ratio in imaging analysis was highest in malignant lesions, followed by benign lesions and normal uterine tissue, with significant differences among these groups (p <.05). The R/B and G/B ratios were used in a formula for prediction of malignancy based on logistic regression and the area under the receiver operating characteristic curve for this formula was 0.838. At a formula cutoff value of 0.220, the sensitivity and specificity for diagnosis of malignant disease were 90.6% and 65.4%, respectively.

CONCLUSION

To our knowledge, this is the first study of the diagnostic accuracy of 5ALA-PDD for malignancies in the uterine cavity. Hysteroscopic 5ALA-PDD had higher sensitivity and identifiability of lesions. These findings suggest that hysteroscopic 5ALA-PDD may be useful for diagnosis of minute lesions.

Inverted papilloma of the urinary bladder shows fluorescence on photodynamic diagnosis using 5-aminolevulinic acid

Photodynamic diagnosis (PDD) of non-muscle invasive bladder cancer using 5-aminolevulinic acid (5-ALA) has recently attracted attention as a diagnostic method for observing cancer lesions based on fluorescence emission using a fluorescent endoscope. However, there are few reports of false positives associated with benign bladder neoplasms. Here, we provide report of two cases of inverted papillomas of the bladder that were fluorescent on PDD using 5-ALA. In each case, a surface-smooth, pedunculated bladder tumor was observed, which fluoresced red on PDD after oral administration of 5-ALA. Histopathological findings demonstrated inverted papilloma of the bladder. Although inverted papilloma of the bladder is usually regarded as a benign neoplasm, some recent studies have revealed that it could be a risk factor for urothelial carcinoma. Our present report may support the hypothesis that inverted papilloma of the bladder has malignant potential.

Photodynamic diagnosis and therapy for urothelial carcinoma and prostate cancer: new imaging technology and therapy

Photodynamic technology using light-sensitive and fluorescent substances has an important role in an accurate diagnosis for a variety of malignancies, including bladder cancer and prostate cancer. Light-sensitive and fluorescent substances accumulate specifically in tumor cells compared to normal tissue, and by light irradiation and excitation at each specific wavelength, tumor lesion, blood flow, lymph node and so on show fluorescence. 5-Aminolevulinic acid (ALA) is converted to protoporphyrin IX (PpIX) into mitochondria. PpIX is excited by blue light, red fluorescence is emitted in the mitochondria. This phenomenon is the mechanism of ALA-mediated photodynamic diagnosis (ALA-PDD). ALA-PDD has made it possible to visualize smaller lesions and flat lesions that were previously difficult to visualize by endoscope using a white-light source. So accurate diagnosis and complete resection become possible during operation. The accumulation of PpIX in the mitochondria also induces direct mitochondrial damage and subsequent cell death by red and green light. This biological reaction is the ALA-mediate photodynamic therapy (ALA-PDT). ALA-PDT has been developed as a modality for minimum invasive cancer treatment that utilizes low-energy light and photosensitizer. Vascular-activated photosensitizer induces rapid tumor ablation by PDT involving direct tumor cell killing as well as damage to the exposed microvasculature. We summarize the clinical outcomes of PDD and PDT for urothelial carcinoma and prostate cancer.

Two diagnostic criteria of optical spectroscopy for bladder tumor detection: Clinical study using 5-ALA induced fluorescence and mathematical modeling

BACKGROUND

The study proposes to improve bladder cancer diagnosis by photodynamic diagnosis (PDD) using red-light excitation (632.8 nm) of 5-ALA induced-protoporphyrin IX. Employing 9 patients' bladders, two types of signals were used to improve diagnostic accuracy for malignancy and we also present numerical modeling of the scattering coefficient to provide biological explanation of the results obtained.

METHODS

Two modalities of bladder cancer spectral diagnosis are presented: conventional PDD and intensity assessment of the diffusely reflected laser light by fiber-optic spectroscopy. Experiments are done in clinical conditions and as a series of numerical simulations.

RESULTS

High-grade cancerous bladder tissues display twice a higher relative fluorescence intensity (mean value 1, n = 9) than healthy (0.39, n = 9), dysplastic (0.44, n = 5) tissues and CIS (0.39, n = 2). The laser back-scattering signal allows to discriminate most effectively high-grade cancerous and dysplastic tissues from normal. Numerical modeling of diffuse reflectance spectra reveals that spectral behavior of the back-scattered light depends on both, nuclear size and nuclear density of tumoral cells.

CONCLUSIONS

Unlike the fluorescence signal, where its value is higher in the case of pathological tissues, the tendency of the laser signal to, both, decrease or increase in comparison with the signal from normal urothelium, should be perceived as a sign towards neoplasm. Numerical simulation reveals that such a double-analysis at a multiwavelength mode potentially may be used to provide diagnostic accuracy.

Next-generation laser-based photodynamic endoscopic diagnosis using 5-aminolevulinic acid for early gastric adenocarcinoma and gastric adenoma

Background

Photodynamic diagnosis (PDD) is an optical imaging technology based on the fundamental biological features of porphyrin metabolized in cancer cells. We reported the usefulness of laser-based photodynamic endoscopic diagnosis (LPDED) with 5-aminolevulinic acid (5-ALA) for early gastric cancers. However, the first-generation prototype endoscope system had the flaw that the images captured were rather dark. To overcome this, we constructed a next-generation endoscope system for LPDED.

Methods

We evaluated the usefulness of the next-generation prototype endoscope system, called Sie-P2, for brighter LPDED to detect early gastric cancer (EGC) and gastric adenoma. The 14 patients diagnosed with EGC and/or gastric adenoma who underwent endoscopic submucosal dissection (ESD) at our hospital between April 2018 and March 2019 were enrolled consecutively in this study. Patients were administered 5-ALA orally and LPDED was performed 3 h later. The primary endpoint was the presence of fluorescence in tumors when we performed LPDED. The secondary endpoint was to assess the adverse events related to each LPDED procedure.

Results

One patient was excluded because of a contraindication, while the remaining 13 patients (median 72 years, range 56-77; one female) with 16 lesions were assessed. There were 10 elevated lesions and 6 flat/depressed lesions; there were 10 EGCs and 6 adenomas. LPDED-fluorescence was detected in all 16 lesions (sensitivity 100%, 95% confidence interval 79-100%). Two cases showed temporary, though not substantial, elevation in blood liver function tests.

Conclusion

All lesions examined were LPDED-positive, indicating that the Sie-P2 system could be useful.

Evaluation of autofluorescence and photodynamic diagnosis in assessment of bladder lesions

The ability to detect and diagnose bladder cancer early and precisely is crucial for effective treatment. The aim of this study is to assess the utility of optical biopsy performed with autofluorescence cystoscopy (AFC) using the Onco-LIFE system with numerical color values (NCVs) and by ALA/PDD. Histopathological examination of material obtained during TURBT and/or biopsy of the bladder was carried out in 251 patients. In the case of 35 patients, the selection of the specimen collected for histopathological examination was based using ALA/PDD. In the remaining 216 patients, tissue was collected based on the findings of AFC with NCV. Using AFC, the observed NCV ranged from 0 to 3.86; the highest mean NCV was observed in neoplastic muscle invasive lesions and was equal to 3.18. Furthermore, non-muscle invasive tumors were characterized by a mean NCV equal to 1.54. Tissue with inflammation, metaplasia, and healthy tissue demonstrated significantly lower mean NCV values. The presence of a muscle-invasive tumor increased the NCV by approximately 2.86 compared to healthy tissue. The rates of postoperative complications depend on the examining operator and are observed more often, as much as 65.7 % during ALA/PDD. AFC with NCV using the Onco-LIFE system, as well as ALA/PDD are helpful tools for early diagnosis of bladder precancerous and cancer lesions and for performing targeted biopsies. A significant correlation was found between lesion NCV index and the grade of dysplasia or tumor malignancy. Tissue with inflammation, metaplasia, and healthy tissue demonstrated significantly lower mean NCV values. AFE with NCV have a significantly higher sensitivity than specificity. Low rates of postoperative complications are correlated to the experience of the endoscopist and with AFE/NCV in comparison of ALA/PDD.

5-aminolevulinic acid-mediated photodynamic diagnosis using fluorescence ureterorenoscopy for urinary upper tract urothelial carcinoma ∼Preliminary prospective single centre trial∼

OBJECTIVE

To investigate the diagnostic accuracy of 5- aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD) for upper urinary tract tumor (UTUC) including carcinoma in situ (CIS) lesions using flexible fluorescence ureterorenoscopy.

METHODS

A solution of ALA was orally administrated at 20 mg/kg body weight at 3 h prior to surgery. Fluorescence observation was carried out with IMAGE1S OPAL1 PDD system. Positive lesions that were identified as abnormal changes under white light and/or blue light were biopsied, followed by cold-cup biopsy of negative lesions that were normal-looking mucosa under white light and/or blue light. Diagnostic accuracy was analysed by comparing ureterorenoscopic observations under white light or blue light with pathological analysis results.

RESULTS

A total of 31 biopsy specimens were obtained from 10 patients. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PDD to detect UTUC was 100 %, 50 %, 52.4 % and 100 %, respectively. The sensitivity of PDD ureterorenoscopy was significantly higher than that of white light ureterorenoscopy by statistics (p < 0.05). Especially, 5 CIS lesions were detected only by ALA-PDD ureterorenoscopy (p < 0.05). Of 10 patients, one patient (10 %) experienced hypotension during the ALA-PDD.

CONCLUSIONS

ALA-PDD for UTUC is a feasible and safe techniques with acceptable adverse events. Additional advantage of ALA-PDD for UTUC is the high sensitivity to detect CIS lesions with blue light mode.

Preanesthetic severe postural hypotension following 5-aminolevulinic acid pretreatment in patients for photodynamic diagnosis-assisted urological surgery

BACKGROUND

5-Aminolevulinic acid (5-ALA) is utilized for photodynamic diagnosis-assisted (PDD) surgery. However, it has been associated with vasodilation, hence, occasional hypotension.

CASE PRESENTATION

We encountered two patients who had severe postural hypotension following 5-ALA pretreatment prior to an operation. They were scheduled for urological PDD surgery, but upon standing to walk to the operation room, they felt sick because of severe hypotension. One of them underwent the surgery after recovery, but the other surgery was canceled due to a prolonged hypotension that lasted for more than a day.

CONCLUSIONS

Severe postural hypotension may develop as a result of the high concentration of porphyrin precursors, which may affect the nervous system. Severe postural hypotension may be due to 5-ALA-induced autonomic dysfunction as well as vasodilative action of 5-ALA. These observations suggest that in addition to the careful monitoring of patients' vital signs, standing should be avoided following 5-ALA pretreatment.

Significance of in vitro photodynamic cytodiagnosis using 5-aminolevulinic acid in solid pancreatic tumors extracted by endoscopic ultrasound-guided fine-needle aspiration

BACKGROUND

Recently, photodynamic diagnosis using 5-aminolevulinic acid (5-ALA) has gained attention for the diagnosis of neoplastic diseases. In the present study, an in vitro method of photodynamic cytodiagnosis (PDCD) performed using the reagent 5-ALA in the cytodiagnosis of solid pancreatic tumors was developed. Here, we assess the accuracy of PDCD for malignancy.

MATERIALS AND METHODS

EUS-FNA was performed from September 2015 to March 2018 in patients with solid pancreatic tumors at Osaka Rosai Hospital. Samples were diagnosed independently by an expert pathologist and a medical doctor with conventional cytology and PDCD.

RESULTS

A total of 53 patients (35 males, average age: 70.2 years old) were enrolled. The definitive diagnoses were 7 benign lesions and 46 malignant lesions. Using the in vitro PDCD method, the detection of reddish fluorescence in cell samples indicated cancer cells. PDCD had a sensitivity of 91.3% (42/46) and a specificity of 100% (7/7), while conventional cytology had a sensitivity of 93.5% (43/46) and a specificity of 85.7% (6/7). Two patients were successfully diagnosed with malignancy only by the PDCD method.

CONCLUSIONS

In vitro PDCD performed using the 5-ALA method can effectively and safely identify a diagnosis of pancreatic cancer without requiring an expert pathologist. The sensitivity of this technique could be increased in the diagnosis of pancreatic malignancy by combining it with the conventional method.

[Cost-effectiveness analysis of blue light cystoscopy with hexylaminolevulinate in transurethral resection of the bladder]

BACKGROUND

Photodynamic diagnosis using the optical imaging agent hexaminolevulinate (HAL, Hexvix®, Ipsen Pharma GmbH, Ettlingen, Germany) as an adjunct to white light cystoscopy (WLC) during the initial transurethral resection of bladder tumours (TURB) improves the detection rate of bladder cancer and leads to fewer recurrences.

OBJECTIVES

A cost-effectiveness analysis was carried out in order to calculate the consequences for the German healthcare system.

METHODS

We combined a short-term decision tree and a Markov model to evaluate outcomes over a long period of time. The alternatives investigated were HAL-assisted blue light cystoscopy (BLC) as adjunct to WLC (HAL + BLC/WLC) compared with WLC alone in patients undergoing TURB.

RESULTS

HAL + BLC/WLC compared to WLC alone was associated with 0.07 incremental quality-adjusted life years (QALYs) and cost savings of 537 € per patient.

CONCLUSION

HAL + BLC/WLC compared with WLC alone resulted in both cost savings and improved patient outcome rendering it the "dominant" strategy.

Atypical polypoid adenomyoma treated by hysteroscopy with photodynamic diagnosis using 5-aminolevulinic acid: A case report

Surgical resection for atypical polypoid adenomyoma (APA) is an option for fertility preservation. Due to the high recurrence rate of APA, studies have been conducted to improve total resection of tumors. Photodynamic diagnosis (PDD) using 5-aminolevulinic acid (5-ALA) improves tumor resection, but this has not been applied for APA. The patient was 35-year-old. After initial treatment, the APA lesion did not disappear. We performed hysteroscopic tumor resection using 5-ALA-PDD. Only one PDD-positive lesion was found and histopathologically diagnosed as APA. Other areas were PDD-negative and showed no histopathologic APA or malignant findings. This is the first report of hysteroscopic 5-ALA-PDD for APA. This method makes it easy to identify morbid lesions, and may lead to improved total resection and decreased recurrence.

Biosensor device for the photo-specific detection of immuno-captured bladder cancer cells using hexaminolevulinate: An ex-vivo study

Exogenous administration of the photodynamic agent hexaminolevulinate induces Protoporphyrin IX (PpIX) accumulation in malignant tissue. This may enable differentiation from healthy tissues by emission of a distinctive red fluorescence. It provides the photo-specific detection when excited with blue light at 405 nm. This study determines the ex-vivo processing conditions (time, concentration, temperature and addition of a fluorescent dye) required for HAL-induced PpIX fluorescence to successfully discriminate between bladder cancer and benign fibroblast cells shed in urine at the single cell level. HAL-induced fluorescence was 4.5 times brighter in cancer cells than non-cancer cells when incubated in the optimum conditions, and could be used to correctly identified bladder cancer cells captured within a newly developed immunofunctionalized biosensor with 88% efficiency. This biosensor is designed to facilitate the immuno-capture of cancer cells by interaction with carcinoma specific anti Epithelial Cell Adhesion molecule (anti-EpCAM) antibodies. Anti-EpCAM antibodies were immobilized on polyoxazoline (POx) plasma polymers by covalent bonds in microfluidic channels. Combining photodynamic and immunoselective approach therefore constitute a promising approach for the non-invasive diagnosis of bladder cancer with two independent level of confidence.

OBJECTIVE

This study investigate the relationship between different regulatory factors (time, concentration, temperature and addition of a fluorescent dye) and Hexaminolevulinate (HAL)-mediated photodynamic diagnosis of bladder cancer (PDD) in vitro. We examine the natural photosensitizer Protoporphyrin IX (PpIX) fluorescence induced by HAL in several human bladder cancer cell lines and one non-cancer foreskin fibroblast cell line and identify the processing conditions that maximise the difference in fluorescence intensity between malign and benign cell types. The detection of HAL induced fluorescence at a single cell level by a selective cancer cell capture platform is also tested.

MATERIALS AND METHODS

Experiments were performed on cultured monolayer cells and cells in suspension. The cell lines examined included the transitional epithelium carcinoma cell lines HT1197, HT1376, EJ138 and RT4, and the non-cancer foreskin fibroblasts HFF. Cells were incubated with HAL in various doses, time and temperature settings. We also used the nuclear red as a tool to study the PpIX subcellular localization. PpIX fluorescence intensities were measured and analysed using fluorescence microscope software. Finally, we evaluated the possibility of using HAL to discriminate between cancer and non-cancer cells from a mixed cell population using a newly developed immunofunctionalized microfluidic platform.

RESULTS

The accumulation of PpIX in bladder cancer cells was significantly higher than in non-cancer cells, both cultured monolayer cells and cells in suspension. Effectively, the fluorescence intensity was 4.5 times brighter in bladder cancer cells than non-cancer foreskin fibroblast cells when incubated in the optimum condition, in which the nuclear stain adjuvant acted as a fluorescence enhancer. Cancer cells displayed PpIX accumulated mainly in mitochondria but none or very little PpIX was observed in non-cancer cells. HAL-induced fluorescence could be used to correctly identify bladder cancer cells within the EpCAM conjugated POx based microfluidic sensor with an 88% capture selectivity rate.

CONCLUSIONS

These findings prove that the application of HAL-induced PpIX fluorescence can successfully distinguish between cancer and non-cancer cells in vitro. This test can provide advanced second level of confidence on the cancerous nature of cells captured by the immunofunctionalized bladder cancer diagnostic platform.

Fluorescence spectroscopy of Candida albicans biofilms in bone cavities treated with photodynamic therapy using blue LED (450 nm) and curcumin

Fluorescence spectroscopy may assisst in the diagnosis and control of infectious processes associated with bone lesions of the oral cavity. The aim of this study was to analyze, through fluorescence spectroscopy, Candida albicans biofilms formed in artificial bone cavities treated with photodynamic therapy (PDT) mediated with 450-nm blue light-emitting diode (LED) and curcumin. Another aim of this study was to analyze the existence of a correlation between the effectiveness of the photodynamic treatments and the fluorescence spectroscopy images. Artificial bone lesions (n = 40) were made in bovine bones and inoculated with standard suspensions of Candida albicans (ATCC 18804) for biofilm formation (14 days / 36 °C ± 1 °C). The 40 specimens were distributed among four experimental groups (n = 10): L-C- (control), L + C- (LED for 5 min), L-C+ (curcumin for 5 min), and L + C+ (PDT). Aliquots of 100 μL were collected from the bone cavities after treatments and were seeded in duplicate on Sabouraud dextrose agar for 24 h at 36 °C ± 1 °C and the colony-forming units (CFU/ mL) were counted. Before and after each treatment, the specimens were subjected to spectral fluorescence and the images were compared using the Image J program. The log₁₀ CFU/mL were compared with Kruskal-Wallis and Dunn's Multiple Comparison post-test (significance level at 0.05). The fluorescence histogram values before and after treatment were compared using Wilcoxon test (95%).The correlation between Candida albicans log₁₀ CFU/mL and the number of the fluorescence red pixels spectroscopy was verified using Spearman correlation test. The reduction of Candida albicans log₁₀ CFU/mL in the L + C+ (PDT) group was the most relevant and the fluorescence spectroscopy was correlated to the microbiological result. It was concluded that there was a consistency between the number of Candida albicans log₁₀ CFU/mL and the red pixel data of the fluorescence images, demonstrating that the fluorescence diagnostic device reflects the true microbiological condition of Candida albicans biofilms in the bone cavities during the pre-treatment and post-treatment, thus providing the clinician the ability to dynamically, simply, and instantaneously verify the performance of the treatment used.

Atypical endometrial hyperplasia diagnosed by hysteroscopic photodynamic diagnosis using 5-aminolevulinic acid

Endometrial cancer is diagnosed by endometrial biopsy, imaging and hysteroscopy, but it is sometimes difficult to find small lesions. 5-aminolevulinic acid (5ALA) forms protoporphyrin IX, which accumulates in tumors and fluoresces upon light irradiation. 5ALA is used for photodynamic diagnosis (PDD) for detecting malignant diseases. A 60-year-old female was suspected to have endometrial cancer by magnetic resonance imaging. Endometrial biopsy was performed repeatedly, but no malignant lesion was detected. We performed hysteroscopic 5ALA-PDD and could detect a small lesion. The lesion was excised and diagnosed as atypical endometrial hyperplasia histopathologically. This is the first report that showed hysteroscopic 5ALA-PDD can contribute to diagnosis of early-stage neoplastic lesion in the uterine cavity.

Bright spot analysis for photodynamic diagnosis of brain tumors using confocal microscopy

BACKGROUND

In a previous study of photodynamic tumor diagnosis using 5-aminolevulinic acid (5-ALA), the authors proposed using fluorescence intensity and bright spot analyses under confocal microscopy for the precise discrimination of tumorous brain tissue (such as glioblastoma, GBM) from normal tissue. However, it remains unclear if bright spot analysis can discriminate infiltrating tumor in the boundary zone and whether this method is suitable for GBM with no 5-ALA fluorescence or for other tumor types.

METHODS

Brain tumor tissue resected from 5-ALA-treated patients was sectioned to evaluate bright spots under confocal microscopy with a 544.5 - 619.5 nm band-pass filter, which eliminated the fluorescence induced by 5-ALA. Border regions and adjacent normal tissues were observed for differences in bright spot distribution. Histopathology was also conducted by hematoxylin and eosin (H&E) staining of serial slices from the same samples to confirm the locations of tumorous, infiltrating, and normal regions. Bright spot areas were then calculated for the same regions evaluated by histopathology. This method was applied for GBM with and without 5-ALA-induced fluorescence as well as for lower-grade gliomas and other brain tumor types.

RESULTS

The bright spot area was substantially smaller in the GBM body than in normal brain tissues. Bright spot area was also smaller in infiltrating tumors than in normal tissue at the margin. The same bright spot pattern was observed in tumorous tissues with no 5-ALA-induced fluorescence and in non-GBM tumors. The bright spot fluorescence is suggested to arise from lipofuscin based on emission spectra (mainly within 544.5 - 619.5 nm) and optimum excitation wavelength (about 405 nm).

CONCLUSIONS

Bright spot analysis is useful for discriminating infiltrating tumor from bordering normal tissue as an alternative or complement to photodynamic diagnosis with 5-ALA. This method is also potentially useful for tumors with no 5-ALA-derived red fluorescence and other nervous system tumors.

[Usefulness of photodynamic diagnosis in high-grade Bladder Cancer and subsequent BCG failure. Bibliographic review.]

OBJECTIVES

Bladder tumors are thesecond highest incidence urological tumor in the adultpopulation. In recent years, new techniques such as photodynamicdiagnosis have arisen in order to improvethe sensitivity for the detection of non muscle invasivebladder cancer (NMIBC). We intend to update the roleof photodynamic diagnosis in the diagnosis of NMIBC,in cases refractory to BCG and as a treatment in therecurrent bladder cancer.

MATERIAL AND METHOD

We performed a descriptivestudy and bibliographic review on the usefulness of photratatodynamicdiagnosis in NMIBC, early recurrence andrefractoriness to BCG published in the universal medicalliterature.

RESULTS

Photodynamic cystoscopy increases the detectionsensitivity for NMIBC, especially carcinoma in situ(CIS) from 15% to 30% according to the different seriespublished. Regarding high-grade bladder cancer recurrence,photodynamic therapy increases disease-freetime in 20% of patients. In the use of photodynamictechniques for the detection of CIS after BCG, studiesindicate an increase in sensitivity with an increase in therate of false positives.

CONCLUSION

Photodynamic diagnosis could improvesensitivity for the early detection of patients withCIS and/or T1G3. May be, at the same time, an alternativein the recurrence of bladder cancer, especiallyCIS.

Recent advances in optical imaging technologies for the detection of bladder cancer

White-light cystoscopy (WLC) is the diagnostic standard for the detection of bladder cancer (BC). However, the detection of small papillary and subtle flat carcinoma in situ lesions is not always possible with WLC. Several adjunctive optical imaging technologies have been developed to improve BC detection and resection. Photodynamic diagnosis, which requires the administering of a photoactive substance, has a higher detection rate than WLC for the detection of BC. Narrow-band imaging provides better visualization of tumors by contrast enhancement between normal mucosa and well-vascularized lesions. A technology called confocal laser endomicroscopy can be used to obtain detailed images of tissue structure. Optical coherence tomography is a high-resolution imaging process that enables noninvasive, real-time, and high-quality tissue images. Several other optical imaging technologies are also being developed to assist with the detection of BC. In this review, we provide an overview of the strengths and weaknesses of these imaging technologies for the detection of BC.

Topical application of Photofrin® for photodynamic diagnosis of malignant cutaneous neoplasms

OBJECTIVES

The prognosis of patients suffering from malignant cutaneous neoplasms can be improved by early diagnosis. Exact demarcation of tumor margins could contribute to optimum results in surgical excision and reconstruction. The purpose of our study is to evaluate Photofrin^® with a new diagnostic procedure, photodynamic diagnosis (PDD), for the detection of Bowen's disease (squamous cell carcinoma (SCC) in situ), SCC, and basal cell carcinoma (BCC).

MATERIALS AND METHODS

Sixty patients with cutaneous neoplasms received 2.5 mg/mL Photofrin^® solution topically. After a period of 3 hours, the patients underwent fluorescence illumination (λex = 370-450 nm). Guided by their visible fluorescence, lesions were biopsied at four suspicious sites in each patient. All specimens were analyzed and measured by a pathologist. A quantitative analysis of the fluorescence contrast between the neoplasms and healthy tissue was performed using the Red, Blue, and Green (RGB) Mode and Gray Scale (GS). Statistical analysis was performed by the analysis of variance (ANOVA) test for multiple comparisons.

RESULTS

Of the 60 patients (20 Bowen's disease, 20 SCC, and 20 BCC), malignant neoplasms could be clearly distinguished from adjacent healthy tissue under fluorescence illumination (P < 0.0001). The sensitivity of the malignant neoplasms evaluated using the RGB and GS modes combined showed 92.74% in image results. The specificity of the malignant neoplasms evaluated using the RGB and GS modes combined showed 95.77%.

CONCLUSION

Light-induced fluorescence detection using topical Photofrin^® provides a sensitive, noninvasive technique for the early identification of malignant cutaneous neoplasms.

Spectrophotometric photodynamic diagnosis of prostate cancer cells excreted in voided urine using 5-aminolevulinic acid

To evaluate the feasibility of photodynamic diagnosis using 5-aminolevulinic acid (PDD-ALA) for detection of prostate cancer (PCa) cells in urine samples after prostate massage in patients who were suspected to have PCa. One hundred and eighty-nine patients with abnormal digital rectal examination and/or an elevated prostate-specific antigen (PSA) level who underwent initial prostate biopsy were recruited. After prostate massage, the first 60 mL of voided urine was collected. For PDD-ALA, 50 mL was used. The rest of collected urine was used for polymerase chain reaction (PCR) of PSA and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). After incubation for 2 h, the intensity was measured at 635 nm under a 405-nm wavelength excitation. The results of PDD-ALA were compared with those of an initial transrectal ultrasound (TRUS)-guided prostate biopsy. Overall, 126/189 (67%) samples that showed bands of both PSA and GAPDH on PCR in urine samples were analyzed. The area under the curve, sensitivity, and specificity of PDD-ALA were 0.74, 77, and 67%, respectively. The value of PDD-ALA was significantly higher in patients with Gleason scores of 6 (p = 0.03), 7 (p = 0.005), and 8-10 (p = 0.0002) than in those with negative biopsy results. In the multivariate analysis, high PSA density, abnormal findings on TRUS, and a high value of PDD-ALA were significant markers for prediction of positive biopsy results. PDD-ALA was useful to predict positive biopsy results in patients who underwent initial prostate biopsy with suspected PCa. This PCa-detection method has potential for clinical use.

Clinical application of photodynamic medicine technology using light-emitting fluorescence imaging based on a specialized luminous source

The natural amino acid 5-aminolevulinic acid (ALA) is a protoporphyrin IX (PpIX) precursor and a new-generation photosensitive substance that accumulates specifically in cancer cells. When indocyanine green (ICG) is irradiated with near-infrared (NIR) light, it shifts to a higher energy state and emits infrared light with a longer wavelength than the irradiated NIR light. Photodynamic diagnosis (PDD) using ALA and ICG-based NIR fluorescence imaging has emerged as a new diagnostic technique. Specifically, in laparoscopic examinations for serosa-invading advanced gastric cancer, peritoneal metastases could be detected by ALA-PDD, but not by conventional visible-light imaging. The HyperEye Medical System (HEMS) can visualize ICG fluorescence as color images simultaneously projected with visible light in real time. This ICG fluorescence method is widely applicable, including for intraoperative identification of sentinel lymph nodes, visualization of blood vessels in organ resection, and blood flow evaluation during surgery. Fluorescence navigation by ALA-PDD and NIR using ICG imaging provides good visualization and detection of the target lesions that is not possible with the naked eye. We propose that this technique should be used in fundamental research on the relationship among cellular dynamics, metabolic enzymes, and tumor tissues, and to evaluate clinical efficacy and safety in multicenter cooperative clinical trials.