Fluorescence staining of human ovarian cancer tissue following application of 5-aminolevulinic acid: fluorescence microscopy studies.

BACKGROUND AND OBJECTIVES: Application of 5-aminolevulinic acid (ALA) for fluorescence-guided second-look laparoscopy has been shown to be a promising new procedure in the early diagnosis of ovarian carcinoma metastases. However, for assessing the reliability of this method, information on the microscopic distribution of protoporphyrin IX (PP IX) in the tissue is needed. Additionally, the selectivity of PP IX uptake is essential for a potential photodynamic therapy (PDT) of ovarian cancer metastases. STUDY DESIGN/MATERIALS AND METHODS: Thirty-six patients with epithelial ovarian cancer and two patients suffering from fallopian tube carcinoma underwent a laparoscopic second-look procedure 5 hours after the application of ALA. In 17 patients 36 fluorescence-guided biopsies were taken from fluorescing and non-fluorescing tissues for further evaluation. Fluorescence microscopy and digital image processing were utilized to determine the presence of PP IX fluorescence. RESULTS: A specificity of 88% and a sensitivity of 100% with a negative predictive value of 100% and a positive predictive value of 91% were calculated for PP IX fluorescence on a microscopic level as marker for ovarian cancer metastases. CONCLUSIONS: On a microscopic scale, ALA-induced PP IX fluorescence is confined to ovarian cancer tumor tissue sparing stromal tissues.

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.

In-vivo investigations on dye-enhanced photothermal tumor therapy with a naphthalocyanine derivative.

Chromophore-enhanced photothermal therapy involves the application of an exogenous chromophore in combination with irradiation, using an appropriate wavelength, exposure duration and sufficient irradiances. The chromophore palladium(II) octabutoxynaphthalocyanine (PdNc(OBu)8) accumulates at satisfactory concentrations and with good selectivity between both tumor and muscle and tumor and skin in tumor-bearing mice. In an attempt to thermally damage tumor tissue with concurrent sparing of adjacent normal tissue, the potential of PdNc(OBu)8 for photothermal therapy was investigated. Using a Balb/c mouse model with subcutaneously implanted EMT6 adenocarcinoma, 90-100 hours after intraperitoneal application of PdNc(OBu)8, the tumor and surrounding tissue were irradiated with a 826nm continuous-wave diode laser. The thermal effects on tumor and normal tissue were evaluated histologically. Our results indicate that after PdNc(OBu)8 administration and tumor irradiation using 5W/cm-for 100 seconds, pronounced selective heating of the tumor was achieved in mice, while in control animals merely an unspecific and marginal overall increase in temperature over the entire irradiation area was observed. Histological evaluation of treated areas indicated that the PdNc(OBu)8-targeted tumor tissue showed severe thermal damage while peripheral tissue like skin and muscle remained largely unaffected. This study shows the potential of creating localized thermal effects by using PdNc(OBu)8 and continuous-wave light for chromophore-enhanced photothermal therapy.