Application of optical imaging in measuring breast cancer tumor response to neoadjuvant chemotherapy

Abstract

Abstract Background: Breast cancer is the second cause of death and the most prevalent cancer among women. common imaging methods used to diagnose breast cancer are mammography, MRI and ultrasound. main part of breast cancer treatment is the surgical removal of the cancerous tissue. treatment of large tumors usually starts with neoadjuvant chemotherapy (NAC) to shrink the size of the tumor before surgery and also to control distance metastases. Neoadjuvant chemotherapy (NAC) has been established as the standard-of-care treatment for locally advanced inoperable breast cancer. Early knowledge of response to NAC is necessary for providing the optimal treatment strategy. optical imaging has received new interest as a technique to assess tumor response to NAC. Diffuse optical spectroscopy (DOS) uses near-infrared light to provide quantitative spectral information about tissue absorption and scattering properties. We aim to have a review of optical imaging in assessing of breast cancer tumor response to neadjuvant chemotherapy in order to have better understanding of it and it’s application. Methods: Literature search was conducted in PUBMED, SCOPOUS and Google Scholar using terms “breast cancer”, “optical imaging”, “spectroscopy” and “neoadjuvant chemotherapy”. Half of the articles reviewed were identified appropriate considering the title of this article. Result: in one of studies, Diffuse optical spectroscopy (DOS) scans were acquired after the first, third, and last cycle of chemotherapy. As early as after the first chemotherapy cycle, a significant difference between responders and nonresponders was found using DOS, the differences continued during treatment. Using dynamic contrast enhanced MRI (DCE-MRI) a difference between responders and nonresponders was found halfway treatment using tumor volume measurement calculations. DOS was equally effective in predicting tumor response halfway treatment compared with DCE-MRI. Conclusion: DOs is a nonionized, noninvasive, cost-effective technique that does not require breast compression or low breast compression. DOS can detect changes in tumor absorption within the first days after the treatment and so could characterize breast tumor response to NAC at an earlier time than other modalities, and is able to differentiate between responders and nonresponders in early stages of therapy and also it could be combine with other imaging modalities to have better and accurate results.