Pilotstudie zur photodynamischen Diagnostik der Endometriose mittels 5-Aminolävulinsäure

Targeted Imaging of Endometriosis and Image-Guided Resection of Lesions Using Gonadotropin-Releasing Hormone Analogue-Modified Indocyanine Green

Objective

In this study, we utilized gonadotropin-releasing hormone analogue-modified indocyanine green (GnRHa-ICG) to improve the accuracy of intraoperative recognition and resection of endometriotic lesions.

Methods

Gonadotropin-releasing hormone receptor (GnRHR) expression was detected in endometriosis tissues and cell lines via immunohistochemistry and western blotting. The in vitro binding capacities of GnRHa, GnRHa-ICG, and ICG were determined using fluorescence microscopy and flow cytometry. In vivo imaging was performed in mouse models of endometriosis using a near-infrared fluorescence (NIRF) imaging system and fluorescence navigation system. The ex vivo binding capacity was determined using confocal fluorescence microscopy.

Results

GnRHa-ICG exhibited a significantly stronger binding capacity to endometriotic cells and tissues than ICG. In mice with endometriosis, GnRHa-ICG specifically imaged endometriotic tissues (EMTs) after intraperitoneal administration, whereas ICG exhibited signals in the intestine. GnRHa-ICG showed the highest fluorescence signals in the EMTs at 2 h and a good signal-to-noise ratio at 48 h postadministration. Compared with traditional surgery under white light, targeted NIRF imaging-guided surgery completely resected endometriotic lesions with a sensitivity of 97.3% and specificity of 77.8%. No obvious toxicity was observed in routine blood tests, serum biochemicals, or histopathology in mice.

Conclusions

GnRHa-ICG specifically recognized and localized endometriotic lesions and guided complete resection of lesions with high accuracy.

Intraoperative enhanced imaging for detection of endometriosis: A systematic review of the literature

The diagnosis of peritoneal endometriosis during laparoscopy may be difficult due to the polymorphic aspects of the lesions. Enhanced imaging using contrast agents has potential to provide a better identification of peritoneal endometriosis. The aim of this systematic review is to provide an overview of the literature on what is known about the intraoperative laparoscopic visual enhancement of peritoneal endometriosis using contrast agents. A systematic review was done of studies about enhanced imaging during laparoscopy for endometriosis using contrast agents. Clinical studies which contained a description of imaging with a contrast agent and also reported visual findings of endometriosis during laparoscopy, were included. Nine suitable studies were identified. Intraoperative visualization of endometriosis was analyzed with or without histologic confirmation. Four studies evaluated 5-aminolevulinic acid-induced fluorescence (5-ALA), 1 study evaluated indigo carmine, 2 studies evaluated methylene blue (MB), 1 study evaluated indocyanine green (ICG) and 1 study evaluated so-called bloody peritoneal fluid painting. All studies, with a combined total of 171 included patients, showed potential of enhanced visibility of endometriosis using contrast agents. A combined total of 7 complications, all related to the use of 5-ALA, were reported. We conclude that the use of contrast-based enhanced imaging during laparoscopy is promising and that it can provide a better visualization of peritoneal endometriosis. However, based on the limited data no technique of preference can yet be identified.

Laparoscopic Imaging Techniques in Endometriosis Therapy: A Systematic Review

Endometriosis is a common disease associated with pelvic pain and subfertility. Laparoscopic surgical treatment has proven effective in endometriosis, but is hampered by a high rate of recurrence. The aim of this systematic review was to evaluate the intraoperative identification of endometriosis by enhanced laparoscopic imaging techniques, focusing on sensitivity and specificity. A systematic review was conducted according to PRISMA guidelines in PubMed, Embase, Cochrane Library, and Web of Science. Published prospective studies reporting on enhanced laparoscopic imaging techniques during endometriosis surgery were included. General study characteristics and reported outcomes, including sensitivity and specificity, were extracted. Nine studies were eligible for inclusion. Three techniques were described: 5-ALA fluorescence (5-ALA), autofluorescence (AFI), and narrow-band imaging (NBI). The reported sensitivity of 5-ALA and AFI for identifying endometriosis ranged from 91% to 100%, compared with 48% to 69% for conventional white light laparoscopy (WL). A randomized controlled trial comparing NBI + WL with WL alone reported better sensitivity of NBI (100% vs 79%; p < .001). All 9 studies reported an enhanced detection rate of endometriotic lesions with enhanced imaging techniques. Enhanced imaging techniques are a promising additive for laparoscopic detection and treatment of endometriosis. The 5-ALA, AFI, and NBI intraoperative imaging techniques had a better detection rate for peritoneal endometriosis compared with conventional WL laparoscopy. None of the studies reported clinical data regarding outcomes. Future studies should address long-term results, such as quality of life, recurrence, and need for reoperation.

On the Role of Iron and one of its Chelating Agents in the Production of Protoporphyrin IX Generated by 5-Aminolevulinic Acid and its Hexyl Ester Derivative Tested on an Epidermal Equivalent of Human Skin

Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) or its derivatives as precursors of protoporphyrin IX (PPIX) is routinely used in dermatology for the treatment of various pathologies. However, this methodology suffers to some extent from a limited efficacy. Therefore, the main goal of this study was to investigate the modulation and pharmacokinetics of PPIX buildup after a 5 h incubation with ALA (1.5 mM) and one of its derivatives, the hexyl ester of ALA (h-ALA) (1.5 mM), on the human epidermal equivalent Epidex. PPIX production was modulated with (L+) ascorbic acid iron (II) salt (LAI) or the iron (II)-specific chelating agent deferoxamine (DFO). PPIX fluorescence from the Epidex layers was measured up to 150 h after the precursor administration using a microspectrofluorometer (lambda(ex): 400 +/- 20 nm; lambda(det): 635 nm). The maximum PPIX fluorescence intensity induced by h-ALA was about 1.7 x larger than that induced by ALA. The addition of DFO resulted in a more than 50% increase in PPIX fluorescence for both precursors. The decay half life measured for PPIX fluorescence is 30 and 42.5 h, respectively, for ALA and h-ALA. These half lives are doubled when the samples contain DFO. In the samples with the highest fluorescence intensity, a modified fluorescence spectrum was observed after 10 h, with the emergence of a peak at 590 nm, which is attributed to zinc protoporphyrin IX (Zn PPIX).

Fluorescence diagnosis of endometriosis on the chorioallantoic membrane using 5-aminolaevulinic acid

The chorioallantoic membrane (CAM) is a useful model for the fluorescence diagnosis of experimentally induced endometriosis. In our experimental setup 75.7% of the histologically examined tissue preparations were viable and only 24.3% showed signs of necrosis on the CAM after various periods of incubation. Best results were obtained when grafting to the CAM was performed between days 7 and 9 and when implants were left on the CAM for 3-5 days (P < 0.05). We were able to demonstrate that 5-aminolaevulinic acid (ALA) is stored selectively in ectopic endometrium. The subsequent fluorescence of the endometrium shows a rapid increase that reaches a peak after 10-14 h which can be clearly differentiated from the weaker fluorescence of grafted normal peritoneum and fimbriae (P < 0.01).