5 research outputs found
Multispectral imaging for intraoperative tumour detection in breast cancer surgery
No full textOn average 19% of patients undergoing breast conserving surgery (BCS) require re-excision due to positive margins. Augmenting a surgeon’s intraoperative visualization of margin disease could improve precision. Multispectral imaging (MSI) utilizes spectral differences between normal and tumour tissues to characterise pathology in real-time. The diagnostic accuracy of a custom-built MSI camera was assessed.
BCS patients were recruited to a single centre, prospective study (REC= 08/H0719/37). Multispectral images were acquired from each resection surface of freshly excised BCS specimens. Image pre-processing included data normalization and dimensionality reduction. Intraoperative radiography and gold standard histological analysis were used to extract ground truth. Four machine learning classifiers were used for data analysis.
46 patients were recruited. MSI images provide information about tissues up to depths of 3mm, therefore image analysis was conducted on resection surfaces where tumour was noted within this depth. 6 specimens were excluded due to gross contamination with blue dye or poor image quality. Therefore, 38 surface images from 23 specimens were included for final analysis. Logistic regression resulted in an area under the curve of 89% (SD ± 7), sensitivity 86% (SD ± 12), and specificity 80% (SD ± 8).
MSI can distinguish between normal and malignant breast cancer tissues. Unlike existing systems, MSI provides immediate visualisation and evaluates the entire resection surface. Future work will focus on adapting MSI to overcome spectral artifacts and improving image analysis using varying machine learning classifiers, as speed and accuracy will optimize surgical workflow.Open Acces
Pan-deanery assessment of core surgery educational training days – Are we getting the same deal?
No full textA comparison of spectroscopy and imaging techniques utilizing spectrally resolved diffusely reflected light for intraoperative margin assessment in breast-conserving surgery: a systematic review and meta-analysis
No full textUp to 19% of patients require re-excision surgery due to positive margins in breast-conserving surgery (BCS). Intraoperative margin assessment tools (IMAs) that incorporate tissue optical measurements could help reduce re-excision rates. This review focuses on methods that use and assess spectrally resolved diffusely reflected light for breast cancer detection in the intraoperative setting. Following PROSPERO registration (CRD42022356216), an electronic search was performed. The modalities searched for were diffuse reflectance spectroscopy (DRS), multispectral imaging (MSI), hyperspectral imaging (HSI), and spatial frequency domain imaging (SFDI). The inclusion criteria encompassed studies of human in vivo or ex vivo breast tissues, which presented data on accuracy. The exclusion criteria were contrast use, frozen samples, and other imaging adjuncts. 19 studies were selected following PRISMA guidelines. Studies were divided into point-based (spectroscopy) or whole field-of-view (imaging) techniques. A fixed-or random-effects model analysis generated pooled sensitivity/specificity for the different modalities, following heterogeneity calculations using the Q statistic. Overall, imaging-based techniques had better pooled sensitivity/specificity (0.90 (CI 0.76-1.03)/0.92 (CI 0.78-1.06)) compared with probe-based techniques (0.84 (CI 0.78-0.89)/0.85 (CI 0.79-0.91)). The use of spectrally resolved diffusely reflected light is a rapid, non-contact technique that confers accuracy in discriminating between normal and malignant breast tissue, and it constitutes a potential IMA tool
Diffuse reflectance and fluorescence spectroscopy for breast conserving surgery
No full textPurpose
The major challenge in breast conserving surgery is the high rates of re-excision due to positive resection margins. This study evaluates whether a combined diffuse reflectance spectroscopy (DRS) and laser induced intrinsic fluorescence spectroscopy (IFS) technique can differentiate breast tissue sample types, towards the development of an intraoperative margin assessment tool.
Methods
Breast tissue samples were collected from patients undergoing breast cancer surgery. A handheld DRS-IFS probe was used on the frozen thawed ex-vivo breast samples to acquire spectral data. Machine learning classifiers were used to determine sensitivity, specificity, overall diagnostic accuracy, and the area under the curve (AUC) against “gold-standard” histopathology ground truth.
Results
181 breast tissue samples from 138 patients were interrogated using DRS-IFS. All patients were female, with median age (range) of 56.8 (20–94) years The total number of spectra acquired was 18,349. Following five-fold cross validation for normal versus cancer tissue, extreme gradient boost classifier achieved a sensitivity of 84% (SD ± 13), specificity of 61% (SD ± 16), overall diagnostic accuracy of 75% (SD ± 3), and AUC of 84%.
Conclusion
The results suggests that DRS-IFS can distinguish normal breast tissue from breast cancer with high diagnostic accuracy. For DRS-IFS to be translated into the operating theatre to aid a surgeon’s real-time visualisation for oncologic margin control assessment of intraoperative, the in vivo diagnostic accuracy needs to be determined
Impact of resection margin width on local recurrence following breast conserving surgery and whole breast radiotherapy for pure ductal carcinoma in-situ: a systematic review and meta-analysis
No full textObjective The aim of this study was to determine the impact of margin width and boost radiotherapy on the local recurrence risk of pure ductal carcinoma in situ (DCIS).
Methods and analysis This is a prospectively registered systematic review and meta-analysis reporting relative risk (RR), OR and HR margin width outcomes. Eligible studies included prospective and retrospective case series with defining margin widths and 48 months of minimum follow-up. All patients (100%) received adjuvant whole breast radiotherapy (WBRT).
Results A total of 40 265 patients with pure DCIS in 31 studies were included. ORs and RR were calculated from 15 studies in 12 519 patients, and HRs were calculated from 12 studies in 12 946 patients. Local recurrence was significantly greater with narrower ‘close’ margins; 0.1–1 mm versus >1 mm in RR (2.88, 95% CI 1.86 to 3.90; p2 mm, significantly greater local recurrence was observed in margins 0.1–2 mm in RR (1.72, 95% CI 1.09 to 2.35; p1 mm and 0.1–2 mm versus >2 mm, differences in local recurrence were not statistically significant, once adjusted for boost radiotherapy.
Conclusions In pure DCIS with WBRT, the local recurrence risk reduces as margin width increases up to 2 mm. The strength of the recommendation for a minimum clear margin of 2 mm is limited by a lack of data comparing 1.1–2 mm with >2 mm. The association between recurrence and close margins is not significant following boost radiotherapy, suggesting a possible alternative to re-excision in patients with close margins <2 mm.
Systematic review registration CRD42022308524
