A comparative study of breast surface reconstruction for aesthetic outcome assessment

Breast cancer is the most prevalent cancer type in women, and while its survival rate is generally high the aesthetic outcome is an increasingly important factor when evaluating different treatment alternatives. 3D scanning and reconstruction techniques offer a flexible tool for building detailed and accurate 3D breast models that can be used both pre-operatively for surgical planning and post-operatively for aesthetic evaluation. This paper aims at comparing the accuracy of low-cost 3D scanning technologies with the significantly more expensive state-of-the-art 3D commercial scanners in the context of breast 3D reconstruction. We present results from 28 synthetic and clinical RGBD sequences, including 12 unique patients and an anthropomorphic phantom demonstrating the applicability of low-cost RGBD sensors to real clinical cases. Body deformation and homogeneous skin texture pose challenges to the studied reconstruction systems. Although these should be addressed appropriately if higher model quality is warranted, we observe that low-cost sensors are able to obtain valuable reconstructions comparable to the state-of-the-art within an error margin of 3 mm.Comment: This paper has been accepted to MICCAI201

Intraoperative Radiotherapy in the Treatment of Breast Cancer: A Review of the Evidence

The surgical treatment of early breast cancer has evolved from the removal of the entire breast and surrounding tissues (mastectomy) to the removal of the tumour together with a margin of healthy tissue (lumpectomy). Adjuvant radiotherapy, however, is still mainly given to the whole breast. Furthermore, external beam radiotherapy is often given several months after initial surgery and requires the patient to attend the radiotherapy centre daily for several weeks. A single fraction of radiotherapy given during surgery directly to the tumour bed (intraoperative radiotherapy) avoids these problems. The rationale and level-1 evidence for the safety and efficacy of the technique are reviewed

Added value of blue dye injection in sentinel node biopsy of breast cancer patients: Do all patients need blue dye?

AbstractBackgroundIn the current study, we evaluated the incremental value of blue dye injection in sentinel node mapping of early breast cancer patients. We specially considered the experience of the surgeons and lymphoscintigraphy results in this regard.Methods605 patients with early stage breast cancer were retrospectively evaluated in the study. Patients underwent sentinel node mapping using combined radiotracer and blue dye techniques. Lymphoscintiraphy was also performed for 590 patients. Blue dye, radioisotope, and overall success rates in identifying the sentinel lymph node were evaluated in different patient groups. The benefit of blue dye and radioisotope in identifying the sentinel lymph nodes was also evaluated.ResultsMarginal benefits of both blue dye and isotope for overall sentinel node detection as well as pathologically involved sentinel nodes were statistically higher in inexperienced surgeons and in patients with sentinel node visualization failure. In the patients with sentinel node visualization on lymphoscintigraphy, 6 sentinel nodes were detected by blue dye only. All these six nodes were harvested by inexperienced surgeons. On the other hand 8 sentinel nodes were detected by dye only in the patients with sentinel node non-visualization. All these nodes were harvested by experienced surgeons.ConclusionsThe use of blue dye should be reserved for inexperienced surgeons during their learning phase and for those patients in whom lymphoscintigraphy failed to show any uptake in the axilla

Cosmetic outcome as rated by patients, doctors, nurses and BCCT.core software assessed over 5 years in a subset of patients in the TARGIT-A trial

Background: The purpose of this research was to assess agreement between four rating systems of cosmetic outcome measured in a subset of patients with early breast cancer participating in the randomised TARGIT-A trial. TARGIT-A compared risk-adapted single-dose intra-operative radiotherapy (TARGIT-IORT) to whole breast external beam radiotherapy (EBRT). Methods: Patients, their Radiation Oncologist and Research Nurse completed a subjective cosmetic assessment questionnaire before radiotherapy and annually thereafter for five years. Objective data previously calculated by the validated BCCT.core software which utilizes digital photographs to score symmetry, colour and scar was also used. Agreement was assessed by the Kappa statistic and longitudinal changes were assessed by generalized estimating equations. Results: Overall, an Excellent-Good (EG) cosmetic result was scored more often than a Fair-Poor (FP) result for both treatment groups across all time points, with patients who received TARGIT-IORT scoring EG more often than those who received EBRT however this was statistically significant at Year 5 only. There was modest agreement between the four rating systems with the highest Kappa score being moderate agreement which was between nurse and doctor scores at Year 1 with Kappa = 0.46 (p \u3c 0.001), 95% CI (0.24, 0.68). Conclusion: Despite similar overall findings between treatment groups and rating systems, the inter-rater agreement was only modest. This suggests that the four rating systems utilized may not necessarily be used interchangeably and it is arguable that for an outcome such as cosmetic appearance, the patient’s point of view is the most important. Trial Registration: TARGIT-A ISRCTN34086741, Registered 21 July 2004, retrospectively registered

A Partially Supervised Bayesian Image Classification Model with Applications in Diagnosis of Sentinel Lymph Node Metastases in Breast Cancer

A method has been developed for the analysis of images of sentinel lymph nodes generated by a spectral scanning device. The aim is to classify the nodes, excised during surgery for breast cancer, as normal or metastatic. The data from one node constitute spectra at 86 wavelengths for each pixel of a 20*20 grid. For the analysis, the spectra are reduced to scores on two factors, one derived externally from a linear discriminant analysis using spectra taken manually from known normal and metastatic tissue, and one derived from the node under investigation to capture variability orthogonal to the external factor. Then a three-group mixture model (normal, metastatic, non-nodal background) using multivariate t distributions is fitted to the scores, with external data being used to specify informative prior distributions for the parameters of the three distributions. A Markov random field prior imposes smoothness on the image generated by the model. Finally, the node is classified as metastatic if any one pixel in this smoothed image is classified as metastatic. The model parameters were tuned on a training set of nodes, and then the tuned model was tested on a separate validation set of nodes, achieving satisfactory sensitivity and specificity. The aim in developing the analysis was to allow flexibility in the way each node is modelled whilst still using external information. The Bayesian framework employed is ideal for this.Comment: 31 pages, 7 figure

Biological dosimetry for breast cancer radiotherapy: a comparison of external beam and intraoperative radiotherapy

Purpose: External beam radiotherapy (EBRT) is the gold standard adjuvant treatment after breast conserving surgery although a recent phase 3 trial has shown the non-inferiority of intraoperative radiotherapy (IORT). Radiation exposure of the heart and cardiac vessels causes an increase in morbidity and mortality following EBRT for breast cancer. We have used γ-H2AX foci formation in peripheral blood lymphocytes as a surrogate marker of dose delivered to the heart and great vessels and have assessed the feasibility of using this technique for biological dosimetry. Methods: 34 patients were recruited, having either EBRT or IORT as part of a randomised controlled trial (TARGIT). Blood samples were taken prior to and after first fraction of radiotherapy, and the γ-H2AX biomarker then quantified. Results: Data were available for 31 patients. Following TARGIT-IORT there was an increase of 0.203 foci per cell (range -1.436 to 1.275) compared with 0.935 foci per cell (range -0.679 to 2.216) in the EBRT group; this difference was highly significant (p = 0.009). As TARGIT-IORT treatment is completed with a single fraction, whilst EBRT requires at least 15 fractions, the actual difference is estimated to be many times more. Conclusions: These data show a significantly greater change in γ-H2AX foci number per cell following one fraction of EBRT compared to TARGIT-IORT. This is the first study to demonstrate this effect using a biomarker and demonstrates a proof of concept methodology for similar applications