A decade of intraoperative ultrasound guided breast conservation for margin negative resection - Radioactive, and magnetic, and Infrared Oh My…

Ultrasound-guided breast-conserving surgery compared to conventional breast-conserving surgery

The goal of breast-conserving surgery is to achieve negative tumor margins, since insufficient marginal distance is associated with more local and distant recurrences. This study investigates whether IOUS (intraoperative ultrasound) can reduce the re-resection rate compared to standard breast surgery, regardless of tumor biology and focality.The present study is a monocentric, prospective, randomized, and non-blinded parallel group study conducted between 7/2015 and 2/2018. Patients with sonographically visible breast cancer were randomized into two study arms: 1) breast-conserving surgery with IOUS; 2) conventional arm.364 patients were included in the study and underwent surgery. Tumor biology, size, and focality were equally distributed in both groups (p = 0.497). The study arms did not differ significantly in the proportion of preoperative wire markings (p= 0.084), specimen weight (p = 0.225), surgery duration (p = 0.849), and the proportion of shavings taken intraoperatively (p = 0.903). Positive margins were present in 16.6% of the cases in the IOUS arm and in 20.8% in the conventional arm (p = 0.347). Re-operation was necessary after intraoperative shavings in 14.4% of cases in the US arm and in 21.3% in the conventional arm (p = 0.100).Although the present study showed a clear difference in the rate of positive tumor margins with IOUS compared to conventional breast surgery without IOUS, this was not statistically significant in contrast to the current literature. This could be due to the high expertise of the breast surgeons, the precise wire marking, or the fact that the IOUS technique was not standardized.

Intraoperative Ultrasound-Guided Excision of Non-Palpable and Palpable Breast Cancer: Systematic Review and Meta-Analysis

Wire-guided localization (WGL) is the most frequently used localization technique in non-palpable breast cancer (BC). However, low negative margin rates, patient discomfort, and the possibility of wire dislocation have been discussed as potential disadvantages, and re-operation due to positive margins may increase relapse risk. Intraoperative ultrasound (IOUS)-guided excision allows direct visualization of the lesion and the resection volume and reduces positive margins in palpable and non-palpable tumors. We performed a systematic review on IOUS in breast cancer and 2 meta-analyses of randomized clinical trials (RCTs). In non-palpable BC, 3 RCTs have shown higher negative margin rates in the IOUS arm compared to WGL. Meta-analysis confirmed a significant difference between IOUS and WGL in terms of positive margins favoring IOUS (risk ratio 4.34, p < 0.0001, I2 = 0%). 41 cohort studies including 3291 patients were identified, of which most reported higher negative margin and lower re-operation rates if IOUS was used. In palpable BC, IOUS was compared to palpation-guided excision in 3 RCTs. Meta-analysis showed significantly higher rates of positive margins in the palpation arm (risk ratio 2.84, p = 0.0047, I2 = 0%). In 13 cohort studies including 942 patients with palpable BC, negative margin rates were higher if IOUS was used, and tissue volumes were higher in palpation-guided cohorts in most studies. IOUS is a safe noninvasive technique for the localization of sonographically visible tumors that significantly improves margin rates in palpable and non-palpable BC. Surgeons should be encouraged to acquire ultrasound skills and participate in breast ultrasound training.

Assessment of photoacoustic tomography contrast for breast tissue imaging using 3D correlative virtual histology

Current breast tumor margin detection methods are destructive, time-consuming, and result in significant reoperative rates. Dual-modality photoacoustic tomography (PAT) and ultrasound has the potential to enhance breast margin characterization by providing clinically relevant compositional information with high sensitivity and tissue penetration. However, quantitative methods that rigorously compare volumetric PAT and ultrasound images with gold-standard histology are lacking, thus limiting clinical validation and translation. Here, we present a quantitative multimodality workflow that uses inverted Selective Plane Illumination Microscopy (iSPIM) to facilitate image co-registration between volumetric PAT-ultrasound datasets with histology in human invasive ductal carcinoma breast tissue samples. Our ultrasound-PAT system consisted of a tunable Nd:YAG laser coupled with a 40 MHz central frequency ultrasound transducer. A linear stepper motor was used to acquire volumetric PAT and ultrasound breast biopsy datasets using 1100 nm light to identify hemoglobin-rich regions and 1210 nm light to identify lipid-rich regions. Our iSPIM system used 488 nm and 647 nm laser excitation combined with Eosin and DRAQ5, a cell-permeant nucleic acid binding dye, to produce high-resolution volumetric datasets comparable to histology. Image thresholding was applied to PAT and iSPIM images to extract, quantify, and topologically visualize breast biopsy lipid, stroma, hemoglobin, and nuclei distribution. Our lipid-weighted PAT and iSPIM images suggest that low lipid regions strongly correlate with malignant breast tissue. Hemoglobin-weighted PAT images, however, correlated poorly with cancerous regions determined by histology and interpreted by a board-certified pathologist. Nuclei-weighted iSPIM images revealed similar cellular content in cancerous and non-cancerous tissues, suggesting malignant cell migration from the breast ducts to the surrounding tissues. We demonstrate the utility of our nondestructive, volumetric, region-based quantitative method for comprehensive validation of 3D tomographic imaging methods suitable for bedside tumor margin detection.

Development of intraoperative assessment of margins in breast conserving surgery: a narrative review

OBJECTIVE

We intend to provide an informative and up-to-date summary on the topic of intraoperative assessment of margins in breast conserving surgery (BCS). Conventional methods as well as cutting-edge technologies are analyzed for their advantages and limitations in the hope that clinicians can turn to this for reference. This review can also offer guidance for technicians in the future design of intraoperative margin assessment tools.

BACKGROUND

Achieving negative margins during BCS is one of the vital factors for preventing local recurrence. Conducting intraoperative margin assessment can ensure negative margins to a large extent and possibly relieve patients of the anguish of re-interventions. In recent years, innovative methods for margin assessment during BCS are advancing rapidly. And there is a lack of summary regarding the development of intraoperative margin assessment in BCS.

METHODS

A PubMed search with keywords "intraoperative margin assessment" and "breast conserving surgery" was conducted. Relevant publications were screened manually for its title, abstract and even full text to determine its true relevance. Publications on neo-adjuvant therapy and intraoperative radiotherapy were excluded. References from the searched articles and other supplementary articles were also looked into.

CONCLUSIONS

Conventional methods for margin assessment yields stable outcome but its use is limited because of the demand on pathology staff and the trade-off between time and precision. Conventional imaging techniques pass the workload to radiologists at the cost of a significantly low duration of time. Involving artificial intelligence for image-based assessment is a further improvement. However, conventional imaging is inherently flawed in that occult lesions can't show on the image and the showing ones are ambiguous and open to interpretation. Unconventional techniques which base their judgment on cellular composition are more reassuring. Nonetheless, unconventional techniques should be subjected to clinical trials before putting into practice. And studies regarding comparison between conventional methods and unconventional methods are also needed to evaluate their relative efficacy.

Review of Variables Associated With Positive Surgical Margins Using Scout Reflector Localizations for Breast Conservation Therapy

OBJECTIVE

To evaluate factors contributing to positive surgical margins associated with reflector guidance for patients undergoing breast conserving therapy for malignancy.

MATERIALS AND METHODS

A retrospective IRB-approved review of our institutional database was performed for malignant breast lesions preoperatively localized from January 1, 2018 to December 31, 2020. The following data was recorded using electronic medical records: lesion type and grade, lesion location, reflector and wire placement modality, use of intraoperative ultrasound, margin status, patient age, family history, BMI, and final pathology. Statistical analysis was performed with univariate summary statistics and logistic regression. P < .05 was significant.

RESULTS

A total of 606 image-guided pre-surgical localizations were performed for lumpectomies of breast malignancies. A total of 352 of 606 (58%) wire localizations and 254 of 606 (42%) SCOUT reflector localizations were performed. Sixty out of 352 (17%) of wire-localized patients had positive surgical margins, whereas forty-eight out of 254 (19%) of reflector-localized patients had positive surgical margins. (OR = 1.12, P value: .59). For reflector guided cases, the use of intraoperative ultrasound (IOUS) was associated with decreased positive margin status (OR = 0 .28, 95% CI = [0.14, 0.58]) while in situ disease was associated with increased positive margin status (OR = 1.99, 95% CI = [1.05, 3.75]). No association between modality used for localization (mammography vs. ultrasound) and positive margin status was observed (OR = 0.63, 95% CI = [0.33, 1.19]). No association between positive margins and age, family history, tumor location and BMI was observed.

CONCLUSION

For reflector guided surgeries, the use of IOUS was associated with decreased positive margins, by contrast the presence of ductal carcinoma in situ was associated with increased positive margins. There was no statistically significant difference in surgical outcomes for reflector-guided localization compared to wire localizations of the breast.

Therapeutic applications of radioactive sources: from image-guided brachytherapy to radio-guided surgical resection

It is well known nowadays that radioactivity can destroy the living cells it interacts with. It is therefore unsurprising that radioactive sources, such as iodine-125, were historically developed for treatment purposes within radiation oncology with the goal of damaging malignant cells. However, since then, new techniques have been invented that make creative use of the same radioactivity properties of these sources for medical applications. Here, we review two distinct kinds of therapeutic uses of radioactive sources with applications to prostate, cervical, and breast cancer: brachytherapy and radioactive seed localization. In brachytherapy (BT), the radioactive sources are used for internal radiation treatment. Current approaches make use of real-time image guidance, for instance by means of magnetic resonance imaging, ultrasound, computed tomography, and sometimes positron emission tomography, depending on clinical availability and cancer type. Such image-guided BT for prostate and cervical cancer presents a promising alternative and/or addition to external beam radiation treatments or surgical resections. Radioactive sources can also be used for radio-guided tumor localization during surgery, for which the example of iodine-125 seed use in breast cancer is given. Radioactive seed localization (RSL) is increasingly popular as an alternative tumor localization technique during breast cancer surgery. Advantages of applying RSL include added flexibility in the clinical scheduling logistics, an increase in tumor localization accuracy, and higher patient satisfaction; safety measures do however have to be employed. We exemplify the implementation of RSL in a clinic through experiences at the Netherlands Cancer Institute.