Influence of neoadjuvant chemotherapy on diffuse reflectance spectra of tissue in breast surgery specimens

Abstract

Diffuse reflectance spectroscopy (DRS) can discriminate different tissue types based on optical characteristics. Since this technology has the ability to detect tumor tissue, several groups have proposed to use DRS for margin assessment during breast-conserving surgery for breast cancer. Nowadays, an increasing number of patients with breast cancer are being treated by neoadjuvant chemotherapy. Limited research has been published on the influence of neoadjuvant chemotherapy on the optical characteristics of the tissue. Hence, it is unclear whether margin assessment based on DRS is feasible in this specific group of patients. We investigate whether there is an effect of neoadjuvant chemotherapy on optical measurements of breast tissue. To this end, DRS measurements were performed on 92 ex-vivo breast specimens from 92 patients, treated with neoadjuvant chemotherapy and without neoadjuvant chemotherapy. Generalized estimating equation (GEE) models were generated, comparing the measurements of patients with and without neoadjuvant chemotherapy in datasets of different tissue types using a significance level of 5%. As input for the GEE models, either the intensity at a specific wavelength or a fit parameter, derived from the spectrum, was used. In the evaluation of the intensity, no influence of neoadjuvant chemotherapy was found, since none of the wavelengths were significantly different between the measurements with and the measurements without neoadjuvant chemotherapy in any of the datasets. These results were confirmed by the analysis of the fit parameters, which showed a significant difference for the amount of collagen in only one dataset. All other fit parameters were not significant for any of the datasets. These findings may indicate that assessment of the resection margin with DRS is also feasible in the growing population of breast cancer patients who receive neoadjuvant chemotherapy. However, it is possible that we did not detect neoadjuvant chemotherapy effect in the some of the datasets due to the small number of measurements in those datasets.

Toward the use of diffuse reflection spectroscopy for intra-operative tissue discrimination during sarcoma surgery

“…For some histological subtypes and locations, classification performance may benefit from an increased number of samples. Furthermore, the developed tumor classification model showed no significant differences in performance between patients who received neoadjuvant therapy and those who did not, confirming previous conclusions in the literature 39 and further emphasizing the robustness of the classification method across different patient groups.…”

Biophotonic technologies for assessment of breast tumor surgical margins—A review

“…The team attributed their findings to the higher reflectance intensity from proteins such as elastin, and desmosine and isodesmosine cross-linkers in microcalcifications. DRS is also demonstrated to be useful in assessing margins of specimens from patients that underwent neoadjuvant chemotherapy suggesting its wide applicability for all specimen types [74]. In fact, Boer et al incorporated optical fibers at the tip of a biopsy needle to perform continuous DRS measurements along an entire needle trajectory during US imaging guided breast biopsy procedures in five patients.…”