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

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.

Image-guided surgery in gynecologic oncology

Image-guided surgery is a relevant way to reduce surgical morbidity and maximize cytoreductive surgery approach especially in ovarian cancer. Sentinel lymph node detection is a promising approach to avoid radical lymph node dissection and is slightly becoming standard in daily practice in endometrial and cervical cancer surgery even if it needs to be evaluated more precisely. Regarding carcinomatosis of ovarian origin, detection and treatment of microscopic disease could be appropriate to avoid local recurrences. Photodiagnosis and photodynamic therapy are innovative techniques that allow to precise limits of excision (fluorescence-guided surgery) and to treat microscopic disease. Further developments of those strategies are necessary to become standard diagnosis tools and treatment options.

[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.

Dealing with microscopic peritoneal metastases of epithelial ovarian cancer. A surgical challenge

Understanding biology and progression mechanisms of peritoneal metastases of epithelial ovarian cancer (EOC) is a cornerstone in the knowledge and the comprehensive management of the disease. Despite clinical remission after the association of complete cytoreductive surgery and platinum-based chemotherapy, peritoneal recurrence still occurs in 60% of patients. Eligible studies, published from 1980 to June 2016, were retrieved through ClinicalTrials.gov, MEDLINE, Cochrane databases and bibliography searches. We reviewed all publications that deals with microscopic peritoneal metastases of EOC in French and English. To discuss expected benefits of intraperitoneal (IP) chemotherapy, fluorescence-guided surgery or IP photodynamic therapy, we reviewed most recent and relevant studies. The final reference list was generated on the basis of originality and relevance to the broad scope of this review. Published data concerning early-stage ovarian cancer suggest that occult peritoneal or epiploic metastases are present in 1.2%-15.1% of cases. In the frequent case of advanced-stage disease, residual microscopic lesions are ignored by conventional surgery. We are convinced that microscopic peritoneal metastases are a relevant surgical therapeutic target. This article discusses existing data on microscopic peritoneal metastases, the treatment indications, the diagnostic and therapeutic surgical approaches to be developed and their expected benefits. A local therapeutic strategy to target microscopic lesions is needed in addition to complete macroscopic cytoreductive surgery to decrease the rate of peritoneal recurrence. Intraperitoneal chemotherapy, and targeted photodynamic therapy could play a role in this new paradigm. The roles of these different options must be defined by future researches.

INTRAOPERATIVE FLUORESCENCE DIAGNOSIS OF PERITONEAL DISSEMINATION IN PATIENTS WITH GASTRIC CANCER

The study of diagnostic efficiency of intraoperative fluorescence diagnosis (IOFD) of peritoneal dissemination in patients with gastric cancer comparing with standard laparoscopy was performed in P.A. Hertsen MCRI (the branch of NMRRC). The study included 114 patients with verified diagnosis of gastric cancer stage III–IV. For IOFD the domestic medication alasens (the active agent – 5-aminolevulinic acid) was used orally at dose of 30 mg/kg body weight 3 h prior to the study procedure. As the result of fluorescence diagnosis 10 (6.9%) patients had peritoneal tumor dissemination verified morphologically and undetected by standard laporoscopy. The sensitivity of peritoneal revision for standard laparoscopy in patients with gastric cancer stage III–IV was 60.8%, the specificity – 75.8%, the overall accuracy – 69.1%. The sensitivity for IOFD in patients with gastric cancer stage III–IV was 91.1%, the specificity – 93.9%, the overall accuracy – 92.7%. Thus, fluorescence study allowed improving the specificity, the sensitivity and the overall accuracy of diagnostic test. In the trial IOFD had the maximal diagnostic value in patients with visually undetectable microdissemination in «whight» light and with solitary visible peritoneal foci (the average number of additionally detected metastatic lesions in one patient – 1.22 and 1.4, respectively). Moreover, in the case of fluorescence diagnosis the number of detected microfoci of peritoneal dissemination was showed to increase with enlargement of area of tumor invasion to gastric serosa (at average of 2.29 additionally detected lesions in one patient with serosal invasion more than 2 cm2). The obtained results confirm the perspective of use of fluorescence diagnosis for detection of peritoneal dissemination, determination of true tumor extent, staging of the tumor and also for adjustment of following treatment tactics for this group of patients.

Photodynamic diagnosis with 5-aminolevulinic acid for intraoperative detection of peritoneal metastases of ovarian cancer: A feasibility and dose finding study

OBJECTIVE

With a prospective feasibility study, we aimed to analyse the effect of different time points for application and dosage of preoperative oral 5-aminolevulinic acid administration for photodynamic diagnosis of peritoneal metastases in ovarian cancer patients.

MATERIALS AND METHODS

In this prospective cohort study patients were randomly divided into three different groups. 5-Aminolevulinic acid was orally administered 3-14 hours before surgery using a dosage of 1 mg/kg, 4-9 hours using 10 mg/kg, and 9-16 hours using 10 mg/kg, respectively. Fluorescence was recorded intraoperatively using endoscopic equipment. The number and localization, of fluorescing nodules were documented. To analyze sensitivity and specificity samples from fluorescent and non-fluorescent tissues were evaluated histologically. Plasma protoporphyrin concentrations as well as any adverse events were assessed perioperatively.

RESULTS

In total, 26 patients suspected for ovarian cancer underwent intraoperative photodynamic diagnosis with 5-aminolevulinic acid. Most of them suffered from advanced cancer, 72% from FIGO-Stage IIIc. No severe adverse events were observed. Orally applied 5-aminolevulinic acid with a dosage of 1 mg/kg revealed no detectable fluorescence. However, at a dosage of 10 mg/kg fluorescence of metastatic tissue was significantly stronger than of non-affected tissue. If administered 4-9 hours preoperatively best detection rates for peritoneal metastases were obtained resulting in a sensitivity of 75% and a specificity of 100%.

CONCLUSIONS

Photodynamic diagnosis with 5-aminolevulinic acid leads to safe and specific fluorescence detection of peritoneal metastases. 5-Aminolevulinic acid should be used at a dosage of at least 10 mg/kg 4-9 hours preoperatively. Further phase I-II studies are recommended. Lasers Surg. Med. 49:169-176, 2017. © 2016 Wiley Periodicals, Inc.

Photodynamic diagnosis for detection of peritoneal carcinomatosis

BACKGROUND

Peritoneal carcinomatosis is the dissemination of cancer in the peritoneal cavity secondary to abdominal or extra-abdominal malignancies. Accurate assessment of the disease's burden is a challenge because of the complexity of the peritoneal cavity and the small size of the metastatic nodules. Photodynamic diagnosis (PDD) is an emerging technology in tumor diagnosis. A photosensitizer is administered, which is preferentially taken up by cancer cells. The photosensitizer emits fluorescence when exposed to a light of a specific wavelength. This helps distinguish cancer from normal tissues.

METHODS

We systematically reviewed the evidence for using PDD in detecting peritoneal carcinomatosis in both animal and human literature. Both Medline and EMBASE databases were searched (November 2014). The titles and the abstracts of all retrieved citations were inspected, and the full articles of the relevant articles were obtained.

RESULTS

A total of 12 human and 18 animal studies were included. Clinical studies have shown PDD to be a safe modality with no significant adverse effects. It increases the detection of malignant peritoneal nodules by 21%-34% in comparison with white light alone. The sensitivity and specificity of PDD were reported at 83%-100% and 95%-100%, respectively. These findings were supported by multiple animal studies, which have shown an increase in the sensitivity of tumor detection when using PDD (72%-91%) in comparison with white light alone (39%).

CONCLUSIONS

PDD is a promising modality, which improves the detection of peritoneal carcinomatosis lesions. Further research, however, should investigate the impact of PDD on the patients' therapeutic management and final outcomes.

Is photodynamic diagnosis ready for introduction in urological clinical practice?

The aim of this review is to provide an up-to-date review of the available literature on photodynamic diagnosis (PDD) for nonmuscle-invasive bladder cancer, to present the technique in a comprehensive approach and, finally, to discuss the relevance of PDD in clinical practice in terms of indications, outcomes and its development trend. A literature search was conducted up to July 2012, using MEDLINE and EMBASE via Ovid databases to identify published studies on PDD for nonmuscle-invasive bladder cancer. Only English-language and human-based full manuscripts that reported on case series and studies with >40 participants, concerning clinical evidence of the technique, its efficacy and safety data were included. Evidence showed that PDD significantly improves detection of bladder cancer compared with standard white-light cystoscopy, having proven to be more effective for the diagnosis of carcinoma in situ. This condition seems to facilitate more complete resections, resulting in a lower residual tumor rate, which, in turn consecutively leads to higher recurrence-free survival rates. The literature search demonstrated that for mid- and long-term follow-up, PDD showed acceptable outcomes in terms of tumor detection, as well as lower residual tumor and lower recurrence rates compared with white-light cystoscopy. It has proven to be safe and well tolerated; the major limitations of PDD are its low specificity and elevated costs.

Aminolevulinic acid (ALA): photodynamic detection and potential therapeutic applications

Aminolevulinic acid (ALA) is a heme precursor that may have potential applications for photodynamic detection and photodynamic therapy-based treatment of solid tumors in a variety of malignancies. ALA may have a role in other applications in surgical oncology based on its ability to discriminate neoplastic tissue from adjacent normal tissue. In this review, we provide a comprehensive summary of the published studies of ALA in noncutaneous solid malignancies.

Laparoscopic restaging of borderline ovarian tumours (BLOT): a retrospective study of 142 cases

OBJECTIVES

PRIMARY OBJECTIVE

To analyse the impact of restaging, on recurrences and survival, in BLOT.

SECONDARY OBJECTIVE

To cluster patients who could be exempted from restaging.

STUDY DESIGN

This retrospective study, included patients operated for a BLOT, between January 1990, and December 2007, in gynaecological surgery units of the University Hospital of Clermont-Ferrand. Two groups were evaluated: patients with and without optimal restaging.

RESULTS

One hundred and forty-two patients were included. Optimal initial staging rate was 38.7% (n=55). Among the eighty-seven women not initially staged, two groups were compared: restaged (n=45) and non-restaged patients (n=42). Mean follow-up was 80.5 months. Overall survival was 93.7%. Relapse rate was 7.7% (n=11). Disease free survival (DFS) was 88% after a mean follow-up of 80.5 months. One death was noted. Optimal restaging rate was 31.7% (n=45, 43 by laparoscopy). Mean follow-up was of 87.1 months among restaged patients, 84.5 months among non-restaged patients (p=0.93). Relapse incidence was significantly higher in non restaged, than in restaged patients (p=0.008). DFS was significantly longer among restaged than non-restaged patients, (p=0.072). Younger age (p=0.04), conservative treatment (p<10(-4)) or non-diploidy (p=0.04) increased the incidence of relapse.

CONCLUSIONS

When initial staging is missing, restaging improves the patients outcome in comparison to non-restaged groups. Laparoscopy is a valuable surgical option. This study suggests that a selected group of patients, older than 30 years old, submitted to a radical treatment, presenting a diploid, non micropapillar, mucinous BLOT, without visible implants during careful peritoneal inspection, could be exempted from restaging. They represented 11.6% of our population.

Submillimeter-resolution fluorescence laparoscopy of pancreatic cancer in a carcinomatosis mouse model visualizes metastases not seen with standard laparoscopy

BACKGROUND

Staging laparoscopy can visualize peritoneal and liver metastases in pancreatic cancer otherwise undetectable by preoperative imaging. However, false-negative rates may be as high as 18%-26%. The aim of the present study was to improve detection of metastatic pancreatic cancer with the use of fluorescence laparoscopy (FL) in a nude-mouse model with the tumors expressing green fluorescent protein (GFP).

METHODS

The carcinomatosis mouse model of human pancreatic cancer was established by intraperitoneal injections of green fluorescent protein-expressing MiaPaca-2 human pancreatic cancer cells into 6-week-old female athymic mice. Two weeks later, mice underwent diagnostic laparoscopy. Laparoscopy was performed first under standard brightfield lighting, followed by fluorescent lighting. The number of metastatic foci identified within the four quadrants of the peritoneal cavity was recorded. After laparoscopy, the animals were sacrificed, opened, and imaged with the OV-100 Small Animal Imaging system as a positive control to identify metastasis. Tumors were collected and processed for histologic review.

RESULTS

FL enabled visualization of pancreatic cancer metastatic foci not visualized with standard brightfield laparoscopy (BL). Under FL, in 1 representative mouse, 26 separate micrometastatic lesions were identified. In contrast, only very large tumors were seen using BL. Use of the OV-100 images, as positive controls, confirmed the presence of tumor foci. FL thus allowed identification and exact localization of submillimeter tumor foci. Such small-sized tumor foci were not distinguished from surrounding tissue under BL. All malignant lesions were histologically confirmed.

CONCLUSIONS

The use of FL enables the identification of tumor foci that cannot be seen with standard laparoscopy. The technology described in this report has important potential for the clinical development of FL.

Intraoperative photodynamic evaluation of surgical margins during endoscopic extraperitoneal radical prostatectomy with the use of 5-aminolevulinic acid

PURPOSE

Today there are no established techniques to image positive surgical margins (PSM) intraoperatively in endoscopic extraperitoneal radical prostatectomy (EERPE). The intention of this study was to describe the specific technique of photodynamic diagnosis (PDD) in patients undergoing EERPE and report on the potential to detect PSM under PDD.

MATERIALS AND METHODS

Twenty-four patients with clinically organ-confined prostate cancer received 5-aminolevulinic acid 20 mg/kg body weight orally 3 hours prior to nonnerve-sparing EERPE. An endoscopic PDD system (Karl Storz, Tuttlingen, Germany) including a Tricam PDD 3-chip camera head linked with a straight 10-mm telescope and a D-light C system was used. During EERPE, visualization of the surgical margins was performed by means of both white light and PDD at specific steps during standardized prostatectomy in all patients. Positive PDD areas on the prostate specimen were marked with white ink and consequently processed in pathology.

RESULTS

In white light endoscopy, no suspicion of a PSM was raised. Six out of the eight PSM were detected by PDD. In two cases, areas of positive PDD findings were free of prostate cancer and two PSM were not detected by PDD ( one bladder neck, one lateral). The overall sensitivity and specificity were 75% and 88.2%, respectively.

CONCLUSIONS

Laparoscopy offers an appropriate setting for the use of PDD in prostate cancer to visualize possible PSM. Although imaging of PSM by PDD is promising with the technique being feasible and safe, larger series are needed to prove the reproducibility of our results.

Benefits of nanoencapsulation for the hypercin-mediated photodetection of ovarian micrometastases

The high recurrence and lethality of ovarian cancer at advanced stages is problematic, especially due to the development of numerous micrometastases scattered throughout the abdominal cavity. Fluorescence photodetection (PD) used in combination with surgical resection of malignant tissues has been suggested to improve recovery. Based on promising in vivo results for the detection of bladder cancer, hypericin (Hy), a natural photosensitizer (PS), stands as a good candidate for the photodetection of ovarian cancer. However, due to its hydrophobicity, systemic administration of Hy is problematic. Polymeric nanoparticles (NPs) help to overcome these delivery and stability problems and enable intravenous administration of Hy. In this study, Hy-loaded NPs of polylactic acid were produced with the following properties: (i) mean size of 268 nm, (ii) negative zeta potential, (iii) low residual surfactant and (iv) drug loading of 3.7 % (w/w). The potential of hypericin-loaded nanoparticles for the fluorescence photodetection of ovarian metastases in Fischer 344 rats bearing ovarian tumours was compared to free drug. The selectivity of Hy administered with both formulations was assessed first by fluorescence endoscopy, and then quantified after tissue extraction. The results showed an improved selective accumulation of Hy in ovarian micrometastases when NPs were used.