Photodynamic Diagnosis Research Articles

Triply pH-activatable porphyrin as a candidate photosensitizer for near-infrared photodynamic therapy and diagnosis

To achieve highly selective tumor therapy and diagnosis, we have developed a novel low-pH-activatable photosensitizer, AI4P, which is a porphyrin derivative possessing four 5-diethylaminoindole units. These 5-diethylaminoindole units enhance internal conversion from the first excited singlet state to suppress fluorescence and photosensitization of singlet oxygen. Upon decreasing pH, AI4P becomes protonated form. This protonated form exhibited strong absorption at 740 nm, which is the optimal wavelength for light penetration through living tissues. In addition, the protonated form exhibited efficient fluorescence and photosensitization. Therefore, AI4P is proposed as a triply activatable near-infrared photosensitizer that can activate near-infrared absorption, fluorescence, and photosensitization simultaneously. The activation ratio was over 200, which represents almost complete activation.

Abstract 4595: SERGE- the development of an optical sensor for the detection glioblastoma recurrence

Abstract Objective: Total gross resection is the clinical most positive prognostic treatment of brain cancer. Tumor recurrence is a frequent event in patients undergone neurosurgical removal of the primary cancer. Current surveillance of the disease requires cost-intensive and infrastructural sophisticated means and is applied in an infrequent manner. Better tools to monitor the therapy success in order to increase the chances of total gross resection of the recurrent lesion are of high clinical need. Concept and Results: Photodynamic diagnosis (PDD) is a clinical applied procedure that exploits metabolic alterations in brain tumor cells to discriminate of cancerous tissue from healthy brain parenchyma. This project aims to develop an implant-prototype that enables the surveillance of any tumor recurrence at the primary tumor resection cavity by applying the principles of PDD. We present initial electro-engineering details and the study design to probe its functionality in vitro and in vivo. Supported by the Volkswagen Foundation the project aims to create evidences for the technological feasibility and therapeutic benefit of SERGE as a future class III medical device. Citation Format: Igor Fischer, Daniel Hänggi, Ulf Dietrich Kahlert. SERGE- the development of an optical sensor for the detection glioblastoma recurrence [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4595.

Future strategies to enhance kidney preservation in upper urinary tract urothelial carcinoma.

Though radical nephroureterectomy remains the gold standard treatment for high grade or invasive disease in upper tract urothelial cancer (UTUC), kidney-sparing surgery has become preferred for low risk disease, in order to minimize morbidity and preserve renal function. Many methods exist for endoscopic management, whether via an antegrade percutaneous or retrograde ureteroscopic approach, including electroresection, laser ablation, and fulguration. There has been an increase in use of adjuvant intracavitary therapy, predominantly using mitomycin and bacillus Calmette-Guerin (BCG), to reduce recurrence after primary endoscopic management for noninvasive tumors, although efficacy remains questionable. Intraluminal BCG has additionally been used for primary treatment of CIS in the upper tract, with around 50% success. Newer investigations include use of narrow band imaging or photodynamic diagnosis with ureteroscopy to improve visualization during diagnosis and treatment. Genomic characterization may improve selection for kidney-sparing surgery as well as identify actionable mutations for systemic therapy. The evolution in adjuvant management has seen strategies to increase the dwell time and the urothelial contact of intraluminal agents. Lastly, chemoablation using a hydrogel for sustained effect of mitomycin is under investigation with promising early results. Continued expansion of the armamentarium available and better identification and characterization of tumors ideal for organ-sparing treatment will further improve kidney preservation in UTUC.

899 - Dynamic contrast-enhanced magnetic resonance imaging can improve diagnostic accuracy of detecting bladder carcinoma in situ in combination with photodynamic diagnosis?

899 - Dynamic contrast-enhanced magnetic resonance imaging can improve diagnostic accuracy of detecting bladder carcinoma in situ in combination with photodynamic diagnosis?

PT348 - A prospective clinical trial of photodynamic diagnosis with oral 5-aminolevulinic acid for upper urinary tract carcinoma

PT348 - A prospective clinical trial of photodynamic diagnosis with oral 5-aminolevulinic acid for upper urinary tract carcinoma

Mitomycin C-induced cell cycle arrest enhances 5-aminolevulinic acid-based photodynamic therapy for bladder cancer

Photodynamic therapy (PDT) and diagnosis (PDD) using 5-aminolevulinic acid (ALA) to control the production of the intracellular photosensitizer protoporphyrin IX (PpIX) are commonly used clinically. Previously, we demonstrated that dormant and drug-induced dormancy-like cancer cells accumulated high PpIX levels, making them sensitive to ALA-PDT. Because EAU Guidelines awarded a level of evidence of 1a to mitomycin C, the drug is widely used to treat bladder cancer. In this study, we investigated that the effect of mitomycin C-induced cell cycle arrest on porphyrin metabolism, including that induced by ALA-PDT. T24 human urinary bladder carcinoma cells were selected for this research. T24 cells were irradiated using a light-emitting diode emitting red light for the ALA-PDT assay. Cell cycle analysis was conducted by flow cytometry using bromodeoxyuridine. Cell viability was confirmed using the MTT or colony formation assay. Furthermore, mRNA gene expression analysis was performed using our previously reported methods. The cell cycle of T24 cells was arrested at G2/M phase by mitomycin C. PpIX accumulation was dramatically increased by mitomycin C treatment. Cell viability after ALA-PDT was remarkably decreased by mitomycin C pretreatment. The gene expression of porphyrin transporters was consistent with the metabolic and morphological results. Finally, we confirmed that ALA-PDT combined with mitomycin C treatment exerted a long-term inhibitory effect on cell proliferation. This study demonstrated a new approach to enhance the effects of ALA-PDT using drugs that induce a dormancy-like status and upregulate porphyrin metabolism.

Photodynamic diagnosis and photodynamic therapy in basal cell carcinoma using a novel laser light source.

The aim of the present study was evaluating the effects and safety of new laser light source in PDD and PDT of basal cell carcinoma, BCC. The patients presented challenging localizations of the tumor or tumor combined with Gorlin syndrome. The PDD and PDT was performed in 50 patients with 54 histologically confirmed BCCs. The photosensitizer precursor, 5-ALA in cream, was used and the tumors were then illuminated, for PDD at 405 nm, and for PDT at 638 nm by means of newly designed laser. The novel feature of the laser was the combination of violet and red light in a single fiber output which enabled us to perform PDD and PDT alternatingly. The patients received one or more PDT sessions and they were observed during the next 36 months. The complete responses (CR, remissions) of the lesions were considered as no visible tumor after that time period. CR were observed in 87 % of the lesions in the entire group of patients. The results of present study show that the new laser allowing for both PDD and PDT was effective in producing satisfactory responses in the treatment of basal cell carcinoma.

Clinical uses of 5-aminolaevulinic acid in photodynamic treatment and photodetection of cancer: A review.

ALA-mediated Photodynamic Therapy (ALA-PDT) is one of the most promising fields in Photodynamic therapy (PDT) research for cancer treatment. 5-aminolaevulinic acid (ALA) is the prodrug of the photosensitiser Protoporphyrin IX (PpIX). After ALA administration, cells generate PpIX through the haem biosynthetic pathway. Although the exact reasons for ALA/PpIX selectivity are unknown, it is believed that due to the special regulation of haem enzymes, PpIX is accumulated in the tumours. Both ALA and its derivative ALA Methyl ester, are mainly used in dermatology. Besides, ALA-PDT has been employed for palliative and even curative treatment of endoscopically accessible tumours. Lung, oesophagus, gastric and bladder carcinomas, and also oral premalignant lesions, gynaecological intraepithelial neoplasias and Barrett's oesophagus are the conditions mostly treated with ALA-PDT. However, due to the limited penetration of ALA and light, non-dermatologic uses of ALA-PDT have not moved beyond phase I clinical trials. On the other hand, ALA-induced PpIX fluorescence is successfully employed for the Photodynamic Diagnosis (PDD) or assistance in cytoreductive surgery (Fluorescence-guided Resection, FGR). ALA has been approved for the FGR of high-grade gliomas and ALA Hexyl ester, for fluorescence cystoscopy in the diagnosis of bladder cancer. ALA-FGR is currently applied in brain, bladder, lung, colon cancers, etc. and ALA-PDD for oral premalignancies, gynaecological intraepithelial lesions and peritoneal metastases, among others. Besides, PDT can be applied concomitantly in the same diagnostic procedure. This review aimed to analyse the state of the art of clinical uses of ALA in the areas of treatment and detection in the non-dermatologic oncology fields.

Shedding Light on Bladder Cancer Diagnosis in Urine.

Blue light cystoscopy (BLC) is the most recent clinical approach in the detection and diagnosis of bladder cancer, a common type of cancer with a high rate of recurrence. Representing a significant advance over previous approaches, this photodynamic diagnostic technique uses a photosensitiser prodrug as an adjunct to white light cystoscopy to enhance the in vivo detection of malignant tissues in the bladder based on their distinctive fluorescence. Whilst it does improve detection rates, BLC remains an invasive and costly procedure. Meanwhile, a variety of noninvasive urine detection methods and related microdevices have been developed, none of which have yet entered routine clinical use due to unsatisfactory sensitivity. Following a brief description of the current approaches and their limitations, we provide here a systematic review of a newer niche research aiming to develop a noninvasive adaptation of photodynamic diagnosis. The research to date surrounding the ex situ use of photosensitiser prodrugs for urinary diagnosis of bladder cancer is also discussed.

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.

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. 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. 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. 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.

The conjugation of targeted therapy and image-guided phototdynamic therapy of cancer in vitro and in vivo

Integration of multi-functional diagnosis and treatment competencies can improve effect of the drug and its visual distribution to the location of tumor focus site, and play a pivotal role by visualizing the tumor size in the assessment of chemotherapy. With the objective of developing integrated multi-therapeutic and diagnostic agent that could target the kinase receptor with high expression in tumor cells, herein, a biologically releasable drug-drug conjugate compound 9 with dual therapeutic and diagnostic effects was designed, synthesized and evaluated for pharmacodynamics and diagnostic functions in vitro and in vivo. The results of antitumor effects evaluations and compound 9 visual imaging indicated that compound 9 not only improved the anti-proliferative activity of chemotherapy and photodynamic treatment (PDT) in vitro and in vivo compared with those of compound 8 and PpIX but also allowed the photodynamic diagnosis (PDD). The present study verified a facile and effective strategy using a drug-drug conjugate to integrate diagnosis and multi-therapies, showing its potential a candidate clinical drug.

Solubilization of Hexyl Aminolevulinate by Surfactants for Tumor Fluorescence Detection.

Hexyl aminolevulinate (HAL) is a lipophilic derivative of 5-aminolevulinic acid (5-ALA) and can induce more protoporphyrin IX (PpIX) formation and stronger fluorescence intensity (FI) than 5-ALA, which will greatly facilitate photodynamic diagnosis and therapy. The main drawback of HAL is its low solubility in neutral aqueous media. In this study, surfactants were used to increase HAL solubility in the cell culture medium and serum, followed by in vitro fluorescence formation measurement in human pancreatic cancer cells (SW1990) and in vivo fluorescence detection in tumor-bearing mice. The results showed that Tween 80 (TW80) and Kolliphor® HS 15 (HS15) increased the solubility of HAL in the selected media. Although TW80 and HS15 exhibited in vitro cytotoxicity at high concentrations (5mgmL-1 ), they facilitated fluorescent signal formation at the early stage of cell incubation. When surfactants were used, the FI should be determined without the routine washing process because surfactant-containing culture medium caused the loss of synthesized PpIX during the washing process. When HAL dissolved in TW80 solution was injected intraperitoneally into pancreatic cancer-bearing mice at a dose of 50mgkg-1 , the tumors exhibited red fluorescence, which indicated that systemic administration of surfactant-solubilized HAL might be applicable for tumor fluorescence detection in vivo.

Successful preservation of the proximal stomach tube by evaluating blood flow using indocyanine green for gastric tube cancer: a case report

BackgroundThere have been two reports on preserving the proximal gastric tube by using intraoperative indocyanine green (ICG)-based photodynamic detection to evaluate blood flow through the anastomosis for gastric tube cancer after esophagectomy. However, in those cases, the period since the first operation was > 3 years 11 months, and there have been no reports of cases with < 1-year periods after the first operation.Case presentationA 59-year-old man underwent video-assisted thoracic subtotal esophagectomy and gastric tube reconstruction after two courses of preoperative chemotherapy for middle thoracic esophageal cancer. After half a year, follow-up upper gastrointestinal endoscopy showed a submucosal tumor in the posterior wall of the pre-pyloric region. We performed a biopsy, and the results led to a diagnosis of gastric cancer (moderately differentiated adenocarcinoma: tub2). Clinically, the patient was described as having stage IB (cT2N0M0) gastric cancer of the reconstructed gastric tube. To avoid total gastrectomy, we tried to evaluate the blood flow of the proximal part of the gastric tube by intraoperative ICG-based photodynamic detection. Intraoperative findings confirmed neo-vascularization from the remnant cervical esophagus to the upper region of the gastric tube approximately 7 cm through the esophagogastric anastomosis. Therefore, we dissected the distal part of the gastric tube approximately 4 cm from the esophagogastric anastomosis and then performed Roux-en-Y gastro-jejunostomy via the ante-sternum route. The postoperative course was stable, and the patient was discharged on the 14th postoperative day.ConclusionsICG-based photodynamic diagnosis was found to be simple and less invasive. Therefore, even if the postoperative period is short, this method should be considered for evaluation of blood flow prior to performing less invasive surgery.

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.

Hexaminolevulinate blue light cystoscopy (Hal) assisted transurethral resection of the bladder tumour vs white light transurethral resection of the bladder tumour in non-muscle invasive bladder cancer (NMIBC) : a retrospective analysis.

Bladder cancer is the eleventh most commonly diagnosed cancer worldwide. The recurrence rate of this cancer can be very high, up to 45%. Photodynamic diagnosis (PDD) is more sensitive than standard procedures for the detection of malignant tumours. The aim of the study was to evaluate oncological outcomes in white light TURB (WL-TURB) and hexaminolevuninate blue light TURB (Hal-TURB). This was a retrospective longitudinal single-center study. In the period between January 2016 and October 2016 WL-TURB was the only therapeutic option available. From November 2016 until April 2017 all TURBs were fluorescence-guided (Hal-TURB). Kaplan-Meier curves have been used to estimate recurrence free survival rates. One hundred and eleven patients underwent Hal- TURB and 137 underwent WL-TURB. Recurrence rate after 12 months was 19.8% (22 out of 111 patients) and 37.2% (51 out of 137 patients) in HAL-group and WL-group respectively (p < 0.01). The recurrence-free period was longer in HAL-group rather than WL-group (8.9 months vs 7.3 months, p < 0.05). Moreover, the recurrence rate during the first 6 months was 3.7% in patients who underwent HAL-TURB and 16% in those who received WL-TURB (p < 0.01). The results of the study show that recurrence-free survival was longer in patients undergoing HAL-TURB compared to the patients who received standard WL-TURB.

Current Standards in the Endoscopic Management of Bladder Cancer: A Survey Evaluation among Urologists in German-Speaking Countries

Introduction: To assess the current diagnostic, treatment, and documentation strategies for bladder cancer (BC) in German-speaking countries. Materials and Methods: A 14-item web-based survey was distributed among members of the German, Austrian, and Swiss Associations of Urology, addressing physicians who perform cystoscopies and transurethral resection of bladder tumors (TURB). Results: The survey was responded to by 308 of 5,564 urologists with a mean age of 49.5 years (response rate: 5.5%). The majority of participants (57.3%) practice in an outpatient setting. White light cystoscopy only is used by 60.2%, with additional photodynamic diagnosis and narrow band imaging by 36.8 and 12.5%, respectively. Endoscopic findings are documented in written form by 93.5%, followed by image capture (33.7%) and a central data archive (20.8%). Inpatient hospital urologists document cystoscopic findings by freehand drawing (21.4 vs. 11.4%, p = 0.017), and with a fixed bladder scheme (31.3 vs. 7.4%, <0.05) significantly more frequently. Cystoscopic findings are mainly conveyed to other health professionals in written form (77.4%), and significantly more often by inpatient urologists (p < 0.05). Conclusions: Significant differences exist in the approach to documenting and communicating cystoscopic BC findings. Accurate graphic documentation of lesions, visualization of the mucosa’s totality, and meticulous consultation of previous surgical reports require improvements to reduce recurrence and progression rates.

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.

Clinical potential of photodynamic diagnosis and therapy of tracheobronchial malignancies in the visible and infrared spectral ranges

AbstractThis article describes a video endoscopy system intended for fluorescence‐based imaging of the tracheobronchial tree in the visible (VIS) and near‐infrared (NIR) regions of the spectrum. This system helps acquire both fluorescence images (VIS/NIR) and a white‐light image of the same area and has been developed on the basis of a standard bronchofiberscope with several diode lasers used as the light sources to excite Vis and NIR, the white‐light source, and photodynamic irradiation. A multimodal video system forms images and gives the possibility to perform targeted photodynamic therapy and control the dose of light irradiation through assessing the degree of photobleaching.The system capability is illustrated through clinical examples. The paper describes the procedure for photodynamic theranostics with chlorin e6 in patients with central lung cancer. The possibility of additional accurate localization of tumor lesions and their borders with NIR imaging is shown; to acquire a NIR image, a common dose of indocyanine green (ICG) used in angiography was administered to patients during the examination. It is also demonstrated that the same lesions can be identified using a combination of two dyes: chlorin e6 + ICG.

Fluorescence detection of deep intramucosal cancer excited by green light for photodynamic diagnosis using protoporphyrin IX induced by 5-aminolevulinic acid: an ex vivo study.

.Significance: The diagnostic depth of photodynamic diagnosis (PDD) for gastric cancer with protoporphyrin IX (PpIX) is limited, which leads to missing intramucosal cancers in screening and surgery.Aim: The reason is that the excitation light, whose wavelength is determined by the highest absorption peak of PpIX (), is strongly attenuated by mucosal tissues. We investigated an excitation wavelength that can extend the diagnostic depth of PpIX fluorescence at the mucosal subsurface.Approach: By calculating the depth-dependent intensity of the excitation light in porcine gastric mucosa for each wavelength, relationships among the wavelength, fluorophore depth, and fluorescence intensity were assessed and fluorescence images of PpIX pellets located at different fluorophore depths were compared experimentally by changing the excitation wavelength.Results: The numerical calculation showed that a 505-nm excitation light provided the highest fluorescence intensities at a fluorophore depth deeper than 1.1 mm. In the fluorescence observation, the fluorescence intensities at fluorophore depths of 0 and 1.0 mm at 405 nm were and units, whereas those at 505 nm were and units, respectively.Conclusion: The experimental results suggest that the diagnosis depth of PDD with PpIX for intramucosal cancer can be extended by 505-nm excitation light.