Laparoscopic photodynamic diagnosis of ovarian cancer using 5-aminolevulinic acid in a rat model

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.

Establishment of a guided, in vivo, multi-channel, abdominal, tissue imaging approach

Novel tools in humane animal research should benefit the animal as well as the experimentally obtained data. Imaging technologies have proven to be versatile and also in accordance with the demands of the 3 R principle. However, most imaging technologies are either limited by the target organs, number of repetitive imaging sessions, or the maximal resolution. We present a technique-, which enables multicolor abdominal imaging on a tissue level. It is based on a small imaging fiber endoscope, which is guided by a second commercial endoscope. The imaging fiber endoscope allows the distinction of four different fluorescence channels. It has a size of less than 1 mm and can approximately resolve single cells. The imaging fiber was successfully tested on cells in vitro, excised organ tissue, and in mice in vivo. Combined with neural networks for image restauration, high quality images from various abdominal organs of interest were realized. The second endoscope ensured a precise placement of the imaging fiber in vivo. Our approach of guided tissue imaging in vivo, combined with neuronal networks for image restauration, permits the acquisition of fluorescence-microscope like images with minimal invasive surgery in vivo. Therefore, it is possible to extend our approach to repetitive imaging sessions. The cost below 30 thousand euros allows an establishment of this approach in various scenarios.

[Microscopic peritoneal metastases of epithelial ovarian cancers. Clinical relevance, diagnostic and therapeutic tools]

Understanding the biology and progression mechanisms of peritoneal metastases in ovarian epithelial cancers (EOC) is important because peritoneal carcinomatosis is present or will occur during surveillance of a majority of patients. Despite the clinical remission achieved after complete macroscopic cytoreductive surgery and platinum-based chemotherapy, 60% of patients will develop peritoneal recurrence. This suggests that microscopic lesions, which are not eradicated by surgery may be present and may participate in the mechanisms leading to peritoneal recurrence. This paper discusses current available data on microscopic peritoneal metastases, their diagnosis and their treatment. We reviewed all publications dealing with microscopic peritoneal metastases of EOC between 1980 and 2017. The most recent and most relevant publications dealing with the treatment modalities of these metastases were selected. Peritoneal and epiploic microscopic localizations would occur in 1.2 to 15.1% of cases at early-stage and are not treated during conventional surgery. They could represent a potential therapeutic target. Local treatments (intraperitoneal chemotherapy, photodynamic therapy, fluorescence-guided surgery) seem to be necessary in addition to surgery and chemotherapy and may help reduce the risk of peritoneal recurrence. The place of these treatments in the management of EOC remains to be defined by subsequent researches.

A dual-channel endoscope for quantitative imaging, monitoring, and triggering of doxorubicin release from liposomes in living mice

Doxorubicin (Dox) is approved for use in liposomal form for the treatment of ovarian cancer. We previously developed a long-circulating Dox formulation in liposomes containing small amounts of porphyrin-phospholipid, which enables on-demand drug release with near-infrared irradiation. In this study, we present and evaluate a dual-modal, dual-channel light endoscope that allows quantitative reflectance and fluorescence imaging for monitoring of local Dox concentrations in target areas. The endoscope consists of two flexible imaging fibers; one to transmit diagnostic and therapeutic light to the target, and the other to detect fluorescent and reflected light. Thus, the endoscope serves for imaging, for light delivery to trigger drug release, and for monitoring drug concentration kinetics during drug release. We characterized the performance of this endoscope in tissue phantoms and in an in vivo model of ovarian cancer. This study demonstrates the feasibility of non-invasive, quantitative mapping of Dox distribution in vivo via endoscopic imaging.

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.

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.

Successful in vivo tumor visualization using fluorescence laparoscopy in a mouse model of disseminated alveolar rhabdomyosarcoma

BACKGROUND

Surgery for rhabdomyosarcoma is challenging due to a lack of clear delineation between tumor and surrounding tissue. Mutilating surgery can be necessary in difficult tumor localizations. Therefore, novel diagnostic and therapeutic modalities are required. The aim of this study was to evaluate the in vivo tumor detection of RMS using fluorescence laparoscopy and to analyze the efficacy of hypericin-induced photodynamic therapy in a mouse model.

METHODS

Seventeen NOD/LtSz-scid IL2Rγnull-mice were divided into four groups. In group 1, mCherry-expressing tumor cells and in group 2-4 non-transfected tumor cells were xenotransplanted. Three weeks later, one fluorochrome per group (ICG, ICG-cetuximab, hypericin) was injected. Fluorescence laparoscopy was carried out and tumors were resected using fluorescence guidance. In the hypericin group, photodynamic therapy was performed using blue light and apoptosis was evaluated by TUNEL test.

RESULTS

A clear discrimination between healthy and tumor tissue was feasible by fluorescending properties with mCherry expressing tumor cells and after injection of hypericin. No fluorescence was detected in mice injected with ICG and ICG-labeled cetuximab. Hypericin photodynamic therapy induced apoptosis of tumor cells after exposure to blue light.

CONCLUSIONS

Intraoperative photodynamic diagnosis was feasible using mCherry-transfected tumor cells or hypericin. Additionally, intraoperative photodynamic therapy was possible and effective.

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.

Unique diagnostic and therapeutic roles of porphyrins and phthalocyanines in photodynamic therapy, imaging and theranostics

Porphyrinic molecules have a unique theranostic role in disease therapy; they have been used to image, detect and treat different forms of diseased tissue including age-related macular degeneration and a number of different cancer types. Current focus is on the clinical imaging of tumour tissue; targeted delivery of photosensitisers and the potential of photosensitisers in multimodal biomedical theranostic nanoplatforms. The roles of porphyrinic molecules in imaging and pdt, along with research into improving their selective uptake in diseased tissue and their utility in theranostic applications are highlighted in this Review.

Fluorescence thoracoscopy in the detection of pleural malignancy

OBJECTIVE

Conventional thoracoscopy, routinely performed in patients with pleural diseases, is not always conclusive in staging of pleural spread. Fluorescence diagnosis (FD) with 5-aminolaevulinic acid (5-ALA) has been used in the diagnostic purpose for various malignancies. The impact of fluorescence thoracoscopy on diagnosis and staging of pleural malignancies was examined.

METHODS

A total of 23 patients with non-conclusive pleural effusions were enrolled in the prospective single-institution trial. Eligible patients were administered 25 mg/kg of 5-ALA ('Alasense', Niopik, Russian Federation) per os 3 h before video-assisted thoracoscopy. After conventional inspection with white light, thorough fluorescence investigation of the visceral and parietal pleura was performed (D-LIGHT Auto Fluorescent System, Karl Storz, Germany). Biopsy specimens of both normal and abnormal sites, as determined from white-light and FD inspection, were obtained for histological examination.

RESULTS

There was no morbidity or mortality due to the procedure. A definitive diagnosis was obtained in all cases: malignant mesothelioma in 13 cases, other malignancies (pleural metastases) in 8 cases and non-specific inflammation in 3 patients. A total of 118 biopsy specimens were available for histological examination. In 20 patients, all pleural deposits (n = 60) detected by white-light thoracoscopy had bright red fluorescence during FD and were proved to be malignant. Upstaging occurred in 12 patients (57.2%) (unsuspected 21 tumour deposits) due to FD examination. Micrometastases of macroscopically normal pleura were detected, only by FD, in one patient. Comparing the results of histological examination of specimens detected by conventional thoracoscopy with that by fluorescence thoracoscopy, we obtained 82 true positive, 10 false-negative, 23 true negative, 3 false-positive results with a specificity of 88.4%, sensitivity of 89.1% and diagnostic accuracy of 88.9%.

CONCLUSIONS

FD using 5-ALA in the pleural cavity is a feasible diagnostic tool when used in addition to white-light thoracoscopy. It improves visualization of additional lesions or even micrometastases in patients with pleural malignancy.

Update on pleural diseases--2007

BACKGROUND

New information is available on pleural diseases. The authors selected articles to make recommendations on diagnostic and treatment aspects of pleural diseases.

MATERIALS AND METHODS

Eleven articles published in the English language between 2004 and 2007 were chosen. The basis of selection of the articles was the impact on daily practice, change in prior thinking of a disease process or specific treatment modality, as well as proper design and execution of the study. 5-Amino-laevulinic acid with fluorescent light combined with white light may allow further diagnostic yield in undiagnosed pleural disease. FDG-PET may allow prognostication of patients with pleural tumors. Utilizing ultrasound by trained Emergency Department physicians is a rapid and effective technique to evaluate non-traumatic pleural effusions in symptomatic patients. Serum osteopontin levels may distinguish patients exposed to asbestos with benign disease from those with pleural mesothelioma. Administration of streptokinase in patients with empyema does not need for surgical drainage, length of hospital stay, or mortality as compared to conventional treatment with chest tube drainage and intravenous antibiotics. Silver nitrate may be an alternative agent to talc for producing pleurodesis. Routine use of graded talc (50% particles greater than 25 microns) is recommended to reduce the morbidity associated with talc pleurodesis. Study design does not permit us to conclude that aspiration of spontaneous pneumothorax is as effective as chest tube drainage. Pleural catheter may prove to be an important palliative modality in treating debilitated patients or patients with trapped lung who show symptomatic improvement with drainage; however, at the present time, these catheters cannot be considered a first line treatment option for patients with malignant pleural effusion. One of the studies reviewed showed no significant difference in tract metastasis in patients with malignant mesothelioma undergoing an invasive pleural procedure with or without irradiation to the procedure site. However, the design of the trial does not allow us to make this conclusion at the present time.

In vivo high-resolution fluorescence microendoscopy for ovarian cancer detection and treatment monitoring

Background:

In patients with advanced ovarian cancer (OvCa), microscopic residual tumour nodules that remain after surgical debulking frequently escape detection by current treatment assessment methods and lead to disease recurrence. The aim of this study was to evaluate the use of high-resolution fibre-optic fluorescence imaging of the clinically approved photodynamic therapy (PDT) agent benzoporphyin-derivative monoacid ring A (BPD-MA) for detection of microscopic OvCa and for monitoring treatment response.

Methods:

Our fluorescence microendoscope consists of a flexible imaging fibre coupled to a custom epi-fluorescence system optimised for imaging BPD-MA, which, after a single administration, serves as both an imaging agent and a light-activated therapeutic agent. After characterisation in an in vitro OvCa 3D model, we used the flexible imaging fibre to minimally invasively image the peritoneal cavity of a disseminated OvCa murine model using BPD-MA administered intraperitoneally (i.p.). To evaluate longitudinal changes in response to treatment, we compared sets of images obtained before and after PDT with those from untreated mice imaged at the same time points.

Results:

By comparison with histopathology, we report an 86% sensitivity for tumour detection in vivo using the microendoscope. Using a custom routine to batch process-image data in the monitoring study, treated mice exhibited an average decrease of 58.8% in tumour volumes compared with an increase of 59.3% in untreated controls (P<0.05).

Conclusions:

Our findings indicate the potential of this approach as a reporter of treatment outcome that could aid in the rational design of strategies to mitigate recurrent OvCa.

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.

Hypericin-loaded nanoparticles for the photodynamic treatment of ovarian cancer

A photodynamic approach has been suggested to improve diagnosis and therapy of ovarian cancer. As Hypericin (Hy), a natural photosensitizer (PS) extracted from Hypericum perforatum, has been shown to be efficient in vitro and in vivo for the detection or treatment of other cancers, Hy could also be a potent tool for the treatment and detection of ovarian cancer. Due to its hydrophobicity, systemic administration of Hy is problematic. Thus, polymeric nanoparticles (NPs) of polylactic acid (PLA) or polylactic-co-glycolic acid (PLGA) were used as a drug delivery system. Hy-loaded NPs were produced with the following characteristics: (i) size in the 200-300 nm range, (ii) negative zeta potential, (iii) low residual PVAL and (iv) drug loading from 0.03 to 0.15% (w/w). Their in vitro photoactivity was investigated on the NuTu-19 ovarian cancer cell model derived from Fischer 344 rats and compared to free drug. Hy-loaded PLA NPs exhibited a higher photoactivity than free drug. Increasing light dose or incubation time with cells induced an enhanced activity of Hy-loaded PLA NPs. Increased NP drug loading had a negative effect on their photoactivity on NuTu-19 cells: at the same Hy concentration, the higher was the drug loading, the lower was the phototoxic effect. The influence of NP drug loading on the Hy release from NPs was also investigated.

Fluorescence Detection of Pleural Malignancies Using 5-Aminolaevulinic Acid

STUDY OBJECTIVE

Although the use of video-assisted thoracoscopy has improved the diagnostic accuracy in patients presenting with pleural diseases, not all biopsies performed are conclusive and staging of the disease is not always optimal. Fluorescence diagnosis (FD) with 5-aminolaevulinic acid (5-ALA) has been used in the diagnostic workup for various malignancies. The impact of 5-ALA-mediated FD on diagnosis and staging during video-assisted thoracoscopy was examined.

DESIGN

Prospective, single-center study.

SETTING

National cancer center.

PATIENTS

Twenty-six patients with nonconclusive pleural effusions who were scheduled for video-assisted thoracoscopy.

INTERVENTION

Eligible patients were administered 1,500 to 2,500 mg po of 5-ALA before video-assisted thoracoscopy. After conventional inspection with white light, fluorescence inspection of the pleural cavity was performed (D-LIGHT Auto Fluorescent System; Karl Storz; Tuttlingen, Germany). Biopsy specimens of both normal and abnormal sites, as determined from white light and FD inspection, were obtained for histologic examination.

RESULTS

One patient was ineligible, and two patients were not evaluable because of equipment failure. One postoperative death occurred due to preexisting myocardial disease. In another patient, an empyema developed; in another patient, a postoperative infection of the lung developed. Other toxicities were minimal. A definitive diagnosis was obtained in 24 of 25 cases, with malignant mesothelioma in 15 cases, other malignancies in 5 cases, one infection, and three benign diseases. Upstaging occurred in four patients (unsuspected tumor deposits) due to FD examination. In 23 patients, a total of 111 biopsy specimens could be analyzed. When correct findings of white light and FD were compared, FD had an additional value in 21 of 111 biopsies, compared to white light with 16 of 111 biopsies.

CONCLUSIONS

FD using 5-ALA in the pleural cavity is feasible with limited side effects when used in addition to white light inspection. It improved visualization of abnormal lesions and led to upstaging in 4 of 15 mesothelioma patients.

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.

Laparoscopic surgery for gynaecological oncology

PURPOSE OF REVIEW

The use of laparoscopic staging and/or surgery in the field of gynaecological oncology was pioneered in the early 1990s. The issue has been very controversial from the beginning, with some justification in view of the possible consequences of faulty cancer surgery. After more than 10 years, long-term follow-up and comparative studies, both of which are required in clinical oncological research, are now available.

RECENT FINDINGS

A number of papers have confirmed the absence of significant adverse effects on survival after laparoscopic diagnosis or surgery in gynaecological cancers. New developments cover virtually all the basic techniques in cancer surgery, excluding major exenterative surgery. The use of an extraperitoneal technique for aortic dissections is emerging. New indications, such as radical vaginal trachelectomy, pelvic sentinel node identification, interval debulking surgery of adnexal malignancies, or the liberal use of surgical staging of uterine cancers, have been developed as a direct result of the availability of laparoscopic techniques.

SUMMARY

Continuing worldwide interest clearly demonstrates that laparoscopic techniques are now part of the armamentarium of the gynaecological oncologist. Postoperative morbidity and recurrence risk do not seem to be affected. Cost-efficiency of laparoscopic procedures is based on the reduction of hospital stay. Combined training in gynaecological oncology and in laparoscopic surgery is, more than ever, mandatory as a means of avoiding the risk of inadequate staging or the mismanagement of pelvic malignancies. The diversity of techniques, including laparotomy, laparoscopy, and vaginal surgery, allows the individualization of surgical approaches, whereby tumour size and local or general conditions can be taken into account.