Re-excision due to inability to visualize positive margins following breast-conserving surgery is a significant clinical challenge. 5-aminolevulinic acid (5-ALA), a non-fluorescent prodrug, leads to intracellular accumulation of fluorescent porphyrins in tumor cells. This single-centre Phase II randomized controlled trial evaluated the clinical safety, feasibility and diagnostic performance of a new handheld fluorescence imaging device (PRODIGI) combined with 5-ALA hydrochloride (HCl) for intraoperative visualization of invasive breast carcinomas. Fifty-four patients were enrolled in the study and randomized to receive no 5-ALA HCl or orally administered 5-ALA HCl (15 mg/kg or 30 mg/kg BW). Forty-five patients (n = 15/group) were included in the analysis. Fluorescence imaging of the excised surgical specimen was performed and biopsies were collected from within and outside the clinically-demarcated tumor border for blinded histopathological analysis. In the absence of 5-ALA HCl, tissue autofluorescence imaging lacked tumor-specific fluorescent contrast. Administration of 5-ALA HCl resulted in tumors that fluoresced bright red with improved visualization of tumor contrasted against normal tissue autofluorescence. In the 15 mg/kg 5-ALA dose group the positive predictive value (PPV) for detecting tumor inside and outside the grossly demarcated tumor border was 100.0% and 55.6%, respectively and 100.0% and 50.0% respectively in the 30 mg/kg dose group. No drug or device-related adverse events were observed and technical feasibility and clinical integration of this intraoperative tumor visualization approach were confirmed. This is the first known clinical report of visualization of 5-ALA HCl-induced fluorescence in invasive lobular and ductal breast carcinoma using a real-time handheld intraoperative fluorescence imaging device.
Emilie Chamma, Jimmy Qiu, Liis Lindvere-Teene, Kristina Blackmore, Safa Majeed, Robert Weersink, Colleen Dickie, Anthony Griffin, Jay Wunder, Peter Ferguson, Ralph DaCosta
Standard clinical management of extremity soft tissue sarcomas includes surgery with radiation therapy. Wound complications (WCs) arising from treatment may occur due to bacterial infection and tissue breakdown. The ability to detect changes in these parameters during treatment may lead to earlier interventions that mitigate WCs. We describe the use of a new system composed of an autofluorescence imaging device and an optical three-dimensional tracking system to detect and coregister the presence of bacteria with radiation doses. The imaging device visualized erythema using white light and detected bacterial autofluorescence using 405-nm excitation light. Its position was tracked relative to the patient using IR reflective spheres and registration to the computed tomography coordinates. Image coregistration software was developed to spatially overlay radiation treatment plans and dose distributions on the white light and autofluorescence images of the surgical site. We describe the technology, its use in the operating room, and standard operating procedures, as well as demonstrate technical feasibility and safety intraoperatively. This new clinical tool may help identify patients at greater risk of developing WCs and investigate correlations between radiation dose, skin response, and changes in bacterial load as biomarkers associated with WCs.
Transillumination breast spectroscopy (TiBS) uses nonionizing optical radiation to gain information about breast tissue morphological and structural properties. TiBS spectra are obtained from 232 women and compared to mammographic density (MD) quantified using Cumulus. The ability of TiBS to estimate MD is assessed using partial least-squares (PLS) regression methods, which requires TiBS spectra as input (X) and Cumulus MD as target (Y) data. Multiple PLS models are considered to determine the optimal processing technique(s) for the input (X) and target (Y) data. For each model, the association between TiBS estimated MD () and Cumulus MD (Y) is established using Spearman's rank correlation and linear regression analysis. The model that best estimates MD has the fewest assumptions regarding target (Y) and spectral (X) processing. The Spearman's correlation coefficient between predicted MD and Cumulus MD for this model is 0.88, with a regression slope () of 0.93 (95% CI 0.83–1.02) and an R2 of 0.78. The approximation of individual MD was within 10% of Cumulus MD for the majority of women (80%), without stratification on age, body mass index (BMI), and menopausal status. TiBS provides an alternative to mammography assessed MD enabling frequent and earlier use of MD as a risk marker in preventive oncology.
This study investigates the efficacy of low level laser therapy (LLLT) in modulating inducible nitric oxide synthase (iNOS) expression as molecular marker of the inflammation signaling pathway. LLLT was mediated by different therapeutic wavelengths using transgenic animals with the luciferase gene under control of the iNOS gene expression. Inflammation in 30 transgenic mice (iNOS-luc mice, from FVB strain) was induced by intra-articular injection of Zymosan-A in both knee joints. Four experimental groups were treated with one of four different wavelengths (λ=635, 785, 808 and 905nm) and one not laser-irradiated control group. Laser treatment (25 mW cm-2, 5 J cm-2) was applied to the knees 15 minutes after inflammation induction. Measurements of iNOS expression were performed at multiple times (0, 3, 5, 7, 9 and 24h) post-LLLT by measuring the bioluminescence signal using a highly sensitive charge-coupled device (CCD) camera.
The responsivity of BLI was sufficient to demonstrate a significant increase in bioluminescence signals after laser irradiation of 635nm when compared to non-irradiated animals and the other LLLT treated groups, showing the wavelength-dependence of LLLT on iNOS expression during the acute inflammatory process.
Medical diagnostics and screening are becoming increasingly demanding applications for spectroscopy. Although for many years the demand was satisfied with traditional spectrometers, analysis of complex biological samples has created a need for instruments capable of detecting small differences between samples. One such application is the measurement of absorbance of broad spectrum illumination by breast tissue, in order to quantify the breast tissue density. Studies have shown that breast cancer risk is closely associated with the measurement of radiographic breast density measurement. Using signal attenuation in transillumination spectroscopy in the 550-1100nm spectral range to measure breast density, has the potential to reduce the frequency of ionizing radiation, or making the test accessible to younger women; lower the cost and make the procedure more comfortable for the patient. In order to determine breast density, small spectral variances over a total attenuation of up to 8 OD have to be detected with the spectrophotometer. For this, a high performance system has been developed. The system uses Volume Phase Holographic (VPH) transmission grating, a 2D detector array for simultaneous registration of the whole spectrum with high signal to noise ratio, dedicated optical system specifically optimized for spectroscopic applications and many other improvements. The signal to noise ratio exceeding 50,000 for a single data acquisition eliminates the need for nitrogen cooled detectors and provides sufficient information to predict breast tissue density. Current studies employing transillumination breast spectroscopy (TIBS) relating to breast cancer risk assessment and monitoring are described.
Tissue undergoing transformation into a state that is more favourable for tumor growth may present itself with different tissue optical properties and contain different amounts of the major tissue chromophores. Here, we decomposed transillumination spectra obtain in women from various risk levels of developing breast cancer.
A primary goal of preventive oncology is the identification of women at increased risk for breast cancer who would benefit most from risk reducing interventions. An established physical risk assessment technique is the use of mammography to quantify the dense tissue content of the breast. Women with a majority of the breast occupied by dense tissue are at four to six times greater risk of breast cancer than women with the least density. The main drawback of mammography is that it requires exposure to ionising radiation and there are concerns regarding use in young women. Another potential physical risk assessment is Transillumination Breast Spectroscopy (TIBS). TIBS uses non-ionizing optical radiation to measure bulk tissue properties and thus is applicable to women of any age. This study examines the feasibility of using TIBS in vivo to detect mammographic density as an interim indicator of breast cancer risk. TIBS measurements were completed on 300 women with radiological normal mammograms. White light (625 to 1060 nm) was delivered to the breast tissue and transmitted light was detected on the opposite side of the breast. Principal component analysis was used to reduce the spectral data and generate individual 'risk' scores. Agreement between the obtained 'risk' scores and mammographic density was established using density cluster analysis, the Kappa statistic and logistic regression. The agreement between breast density assessed by mammography and by TIBS was statistically significant for all 'risk' scores. Logistic regression indicated a strong association between the TIBS scores and mammographic density. TIBS provides an alternative to x-ray derived mammographic density as a biomarker of breast density and hence cancer risk.
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