Intraperitoneal photodynamic therapy in the Fischer 344 rat using 5-aminolevulinic acid and violet laser light: a toxicity study

Intraoperative fluorescent spectroscopy and photodynamic therapy of recurrent pelvis minor tumors with local radiation damage

This work presents the results of performing intraoperative photodynamic therapy (IOPDT) on 22 patients with recurrent pelvic tumors

(cervical cancer – in 18 patients, cancer of the corpus uteri – in 3 patients, cancer of the anal canal – in 1 patient). Prior to the PDT procedure, the patients were injected with photolon photosensitizer (PS) at a dose of 1.0–1.1 mg/kg. After the injection of PS, local fluorescence spectroscopy of tumor lesions was performed to determine the accumulation of drug in various areas of tumors and healthy tissue. Intraoperative laser irradiation was carried out 3–5 hours after the photolon injection with light at 662 nm wavelength using "Latus-2" laser device with a power density of 140 mW/cm2and the density of light energy of 40–60 J/cm2, the number of irradiation fields was 3–5 depending on the anatomical features.

The follow-up period after surgical treatment combined with PDT was from 6 to 24 months. Analyzing the immediate results of the treatment, there were no undesirable events or increase in the number of postoperative complications compared to patients treated without IOPDT. Were registered: transient increase in ALT and AST levels – in 5 patients (13.6%), reduction of oxygenation during anesthesia – in 20 (90.9%), transient fevers in the postoperative period – in 7 (31.8%).

It was noted that IOPDT with photolon drug, while slightly extending the time of the operation, is well tolerated by patients and does not lead to an increase in the number of early postoperative complications or the length of hospitalization.

Treatment of peritoneal carcinomatosis with photodynamic therapy: Systematic review of current evidence

BACKGROUND

Peritoneal carcinomatosis results when tumour cells implant and grow within the peritoneal cavity. Treatment and prognosis vary based on the primary cancer. Although therapy with intention-to-cure is offered to selective patients using cytoreductive surgery with chemotherapy, the prognosis remains poor for most of the patients. Photodynamic therapy (PDT) is a cancer-therapeutic modality where a photosensitiser is administered to patients and exerts a cytotoxic effect on cancer cells when excited by light of a specific wavelength. It has potential application in the treatment of peritoneal carcinomatosis.

METHODS

We systematically reviewed the evidence of using PDT to treat peritoneal carcinomatosis in both animals and humans (Medline/EMBASE searched in June 2017).

RESULTS

Three human and 25 animal studies were included. Phase I and II human trials using first-generation photosensitisers showed that applying PDT after surgical debulking in patients with peritoneal carcinomatosis is feasible with some clinical benefits. The low tumour-selectivity of the photosensitisers led to significant toxicities mainly capillary leak syndrome and bowel perforation. In animal studies, PDT improved survival by 15-300%, compared to control groups. PDT led to higher tumour necrosis values (categorical values 0-4 [4=highest]: PDT 3.4±1.0 vs. control 0.4±0.6, p<0.05) and reduced tumour size (residual tumour size is 10% of untreated controls, p<0.001).

CONCLUSION

PDT has potential in treating peritoneal carcinomatosis, but is limited by its narrow therapeutic window and possible serious side effects. Recent improvement in tumour-selectivity and light delivery systems is promising, but further development is needed before PDT can be routinely applied for peritoneal carcinomatosis.

[Intraperitoneal photodynamic therapy for peritoneal metastasis of epithelial ovarian cancer. Limits and future prospects]

High peritoneal recurrence rate in advanced epithelial ovarian cancer after complete macroscopic cytoreductive surgery and platinum-based chemotherapy, raises the issue of peritoneal microscopic disease management and requires the development of additional locoregional treatment strategies. Photodynamic therapy is an effective treatment already applied in other medical and surgical indications. After administration of a photosensitizer which accumulates in cancer cells, illumination with a light of adequate wavelength may induce photochemical reaction between photosensitizer and tissue oxygen which lead to reactive oxygen species production and cytotoxic phenomenon. Photodynamic therapy's ability to treat superficial lesions disseminated on large area makes it an excellent candidate to insure destruction of microscopic peritoneal metastases in addition to macroscopic cytoreductive surgery in order to decrease peritoneal recurrence rate. Development of intraperitoneal photodynamic therapy has been limited by its poor tolerance related to the lack of specificity of photosensitizers and the location of the metastases in proximity to adjacent intraperitoneal organs. Our aim is to review clinical data concerning intraperitoneal photodynamic therapy and epithelial ovarian cancer to identify the limits of this strategy and to provide solutions which may be applied to solve these barriers and enable safe and effective treatment. Targeted photosensitizers and innovative illumination solutions are mandatory to continue research in this field and to consider the feasibility of clinical trials.

Photodynamic therapy of ovarian cancer peritoneal metastasis with hexaminolevulinate: a toxicity study

CONTEXT

While photodynamic therapy (PDT) is a promising treatment for peritoneal carcinomatosis, its use is often limited because of the toxicity of photosensitizers. In this study, safety of PDT with hexaminoevulinate (HAL), a second generation photosensitizer, is assessed.

METHODS

PDT of the peritoneal cavity was performed in a rat model of peritoneal carcinomatosis. Rats were treated according to different protocols: with full or half HAL dose, after intraperitoneal or oral administration of HAL, 4 or 8h after its injection, using red or green light, after protection of the liver or cooling of the abdominal wall. Toxicity was assessed by blood tests quantifying hematocrit, liver and muscular enzymes and by pathological examination of abdominal and intrathoracic organs after treatment. The results were analyzed in the light of quantification of fluorescence and protoporphyrin IX (PPIX) content of the same organs.

RESULTS

PDT with HAL induced rhabdomyolysis, intestinal necrosis and liver function test anomalies, leading to death in 2 out of 34 rats. The liver and the intestine contained high levels of PPIX (3-5 times more than tumor nodules).

CONCLUSION

HAL PDT lacked specificity. However, the strategy associating diagnosis, treatment and evaluation of the results in one single procedure was effective and should be tested with other photosensitizers.

PDT dose parameters impact tumoricidal durability and cell death pathways in a 3D ovarian cancer model

The successful implementation of photodynamic therapy (PDT)-based regimens depends on an improved understanding of the dosimetric and biological factors that govern therapeutic variability. Here, the kinetics of tumor destruction and regrowth are characterized by systematically varying benzoporphyrin derivative (BPD)-light combinations to achieve fixed PDT doses (M × J cm(-2)). Three endpoints were used to evaluate treatment response: (1) Viability evaluated every 24 h for 5 days post-PDT; (2) Photobleaching assessed immediately post-PDT; and (3) Caspase-3 activation determined 24 h post-PDT. The specific BPD-light parameters used to construct a given PDT dose significantly impact not only acute cytotoxic efficacy, but also treatment durability. For each dose, PDT with 0.25 μM BPD produces the most significant and sustained reduction in normalized viability compared to 1 and 10 μM BPD. Percent photobleaching correlates with normalized viability for a range of PDT doses achieved within BPD concentrations. To produce a cytotoxic response with 10 μM BPD that is comparable to 0.25 and 1 μM BPD a reduction in irradiance from 150 to 0.5 mW cm(-2) is required. Activated caspase-3 does not correlate with normalized viability. The parameter-dependent durability of outcomes within fixed PDT doses provides opportunities for treatment customization and improved therapeutic planning.

Development of a new illumination procedure for photodynamic therapy of the abdominal cavity

A homogeneous illumination of intra-abdominal organs is essential for successful photodynamic therapy of the abdominal cavity. Considering the current lack of outstanding light-delivery systems, a new illumination procedure was assessed. A rat model of peritoneal carcinomatosis was used. Four hours after intraperitoneal injection of hexaminolevulinate, a square illuminating panel connected to a 635-nm laser source was inserted vertically into the abdominal cavity. The abdominal incision was sutured and a pneumoperitoneum created prior to illumination. Light dosimetry was based on the calculation of the peritoneal surface by MRI. The rats were treated with a light dose of 20, 10, 5 or 2.5 J/cm(2) administered continuously with an irradiance of 7 mW/cm(2). The homogeneity of the cavity illumination was assessed by quantification of the photobleaching of the tumor lesions according to their localization and by scoring of that of the liver and of the bowel immediately after treatment. Photobleaching quantification for tumor lesions relied on the calculation of the fluorescence intensity ratio (after/before treatment) after recording of the lesions during blue-light laparoscopy and determination of their fluorescence intensity with Sigmascan Pro software. The procedure led to a homogeneous treatment of the abdominal cavity. No statistical difference was observed for the photobleaching values according to the localization of the lesions on the peritoneum (p=0.59) and photobleaching of the liver and of the intestine was homogeneous. We conclude that this procedure can successfully treat the major sites involved in peritoneal carcinomatosis.

Intraperitoneal photodynamic therapy for an ovarian cancer ascite model in Fischer 344 rat using hematoporphyrin monomethyl ether

With limited treatment options, intraperitoneal spread of ovarian cancer is a common problem leading to high morbidity. Intraperitoneal photodynamic therapy combined with debulking surgery to treat residual disease is an alternative choice for clinicians. Hematoporphyrin monomethyl ether (HMME) is a promising second-generation photosensitizer developed in China. Our study was designed to investigate the phototoxicity of HMME on ovarian cancer. NuTu-19, a cell line derived from adenocarcinoma of Fischer 344 rat, and its allogeneic graft ascites tumor model was used in this study. HMME was confirmed to be localized in cytolysosome, and HMME-based photosensitization induced direct necrosis as well as mitochondria damage. The photocytotoxicity of HMME was both light- and drug dose-dependent and no significant dark cytotoxicity was observed in NuTu-19 cells. With the ascite tumor-bearing Fischer 344 rat model, HMME-based intraperitoneal photodynamic therapy was proved to be useful in improving the prognosis of ovarian cancer. Thus, this study provides evidence that HMME-based photodynamic therapy is an effective adjuvant therapy for ovarian cancer.

Laparoscopic Photodynamic Diagnosis of Ovarian Cancer Peritoneal Micro Metastasis: An Experimental Study

The goal of this study was to assess the interest of photodynamic diagnosis (PDD) for laparoscopic detection of peritoneal micro metastasis in ovarian carcinoma. Using an experimental animal model, intraperitoneal injection of aminolevulinic acid (ALA) and hexylester of aminolevulinic acid (He-ALA) were compared in order to improve laparoscopic detection of ovarian peritoneal carcinomatosis. Twenty-one 344 Fischer female rats received an intra peritoneal injection of 106 NuTu-19 cells. At day 22, carcinomatosis with micro peritoneal metastasis was obtained. Rats were randomized in three groups concerning intra peritoneal injection before laparoscopic staging: 5-ALA hydrochloride, HE-ALA and sterile water. Using D Light system, laparoscopic peritoneal exploration was performed with white light (WL) first and then with blue light (BL). The main objective was to assess feasibility and sensibility of laparoscopic PDD for nonvisible peritoneal micro metastasis of ovarian cancer. The main parameter was the confirmation of neoplasic status of fluorescent foci by histology. Concerning PDD after intraperitoneal injection of 5-ALA, mean values of lesions seen is higher than without fluorescence (32 vs 20.7; P = 0.01). Using He-ALA, mean values of detected lesions is higher than without fluorescence (42.9 vs 33.6; P < 0.001). Neoplasic status of fluorescent foci was confirmed in 92.8% of cases (39/42). Using 5-ALA, fluorescence of cancerous tissue is significantly higher than that of normal tissue in all the rats (ratio 1.17) (P = 0.01). With He-ALA, intensity of fluorescence is significantly higher in cancerous tissue compared to normal tissue, irrespective of the rat studied (ratio 1.22; P < 0.001).

UV Light-Emitting Diode-Induced Fluorescence Detection Combined with Online Sample Concentration Techniques for Capillary Electrophoresis

The application of an ultraviolet (UV) light-emitting diode (LED) to on-line sample concentration/fluorescence detection in capillary electrophoresis (CE) is described. The utility of a UV-LED (peak emission wavelength at 380 nm, approximately 2 mW) for fluorescence detection was demonstrated by examining both a naturally fluorescent (riboflavin) compound and a nonfluorescent compound (tryptophan), respectively. The detection limit for riboflavin was determined to be 0.2 ppm by the normal MEKC mode, which was improved to 3-7 ppb when dynamic pH-junction technique was applied. On the other hand, the detection limit of the tryptophan derivative was determined to be 1.5 ppm using the MEKC mode, which was improved to 3 ppb when the sweeping-MEKC mode was applied. In an analysis of an actual sample, the concentrations of riboflavin in beer, and tryptophan in urine and milk samples were determined, respectively.

Laparoscopic fluorescence detection of ovarian carcinoma metastases using 5-aminolevulinic acid-induced protoporphyrin IX

BACKGROUND

The aim of the current clinical study was to evaluate the in vivo fluorescence detection of ovarian carcinoma metastases in a second-look laparoscopic procedure after intraperitoneally applied 5-aminolevulinic acid (ALA).

METHODS

Five hours before laparoscopic surgery, ALA was applied intraperitoneally via short infusion in a concentration of 30 mg/kg bodyweight in a sterile, 1% solution. Application of ALA resulted in the endogenous production of the fluorescent photosensitizer, protoporphyrin IX (PP IX). The Combilight PDD 5133 system served as a light source, permitting the switch from white light mode to blue light mode to excite the PP IX accumulated in the ovarian tissue specimens. By means of blue light illumination, intraperitoneally located red fluorescent lesions, which were suspected to be metastases, underwent a biopsy. In addition, several biopsy specimens were taken from nonfluorescent areas of the peritoneal cavity.

RESULTS

In 13 of 29 patients, ovarian carcinoma was confirmed histologically or cytologically. In 12 of these patients, metastases were visible by red fluorescence. In total, 123 biopsies were performed. Comparison of histologic assessment of the biopsy specimens with the fluorescence detection showed that strong red fluorescence had a sensitivity of 92% for detecting tumor tissue on specimens. In only 2% of all biopsy specimens was endometriosis observed in benign tissue specimens using fluorescence. In four of 13 patients with ovarian carcinoma, lesions were detected under fluorescence, which were not observed under white light illumination.

CONCLUSIONS

Laparoscopic fluorescence detection of endogenous PP IX after intraperitoneal application of ALA may provide a higher sensitivity of finding peritoneal metastases of epithelian ovarian carcinoma compared with conventional laparoscopy. Direct visualization of in vivo fluorescence after ALA application may improve the early detection of intraperitoneal ovarian carcinoma micrometastases. The high tissue selectivity of PP IX accumulation in tumor tissue specimens also offers the opportunity for therapeutic approaches using photodynamic therapy in the future.

Photodynamic diagnosis of ovarian cancer using hexaminolaevulinate: a preclinical study

The unfailing detection of micrometastases during surgery of patients suffering from ovarian cancer is mandatory for the optimal management of this disease. Thus, the present study aimed at determining the feasibility of detecting micrometastases in an ovarian cancer model using the intraperitoneal administration of the photosensitiser precursor hexaminolaevulinate (HAL). For this purpose, HAL was applied intraperitoneally at different concentrations (4-12 mM) to immunocompetent Fischer 344 rats bearing a syngeneic epithelial ovarian carcinoma. The tumours were visualised laparoscopically using both white and blue light (D-light, Karl Storz, Tuttlingen, Germany), and the number of peritoneal micrometastases detected through HAL-induced photodiagnosis (PD) was compared to standard white light visualisation. Fluorescence spectra were recorded with an optical fibre-based spectrofluorometer and the fluorescence intensities were compared to the protoporphyrin IX (PpIX) fluorescence induced by 5-aminolevulinic acid under similar conditions. The number of metastases detected by the PD blue light mode was higher than when using standard white light abdominal inspection for all applied concentrations. Twice as many cancer lesions were detected by fluorescence than by white light inspection. The hexyl-ester derivative produced higher PpIX fluorescence than its parent substance aminolevulinic acid at the same concentration and application time. Fluorescence contrast between healthy and cancerous tissue was excellent for both compounds. To overcome poor diagnostic efficiency and to detect peritoneal ovarian carcinoma foci in the large surface area of the human peritoneal cavity, HAL fluorescence-based visualisation techniques may acquire importance in future and lead to a more correct staging of early ovarian cancer.