Radionanotargeting and Precision Radiotherapy Planning in Patients with Breast Cancer

Purpose:Through this work dedicated to the study of molecular imaging capabilities for radiotherapy planning in patients with breast cancer, we would like to acknowledge our gratitude and pay respect to one of the most prominent world-class researchers in nuclear medicine, Kalevi Kairemo. Materials and Methods: In this retrospective study, we present our experience of molecular imaging in more than 1,800 women with breast cancer. Participants underwent Mammoscintigraphy/Breast molecular imaging with 99mTc-MIBI for detection of multicentric (MC) breast cancer and SPECT-CT imaging for the diagnosis of multiple ( gt;2) metastatic axillary lymph nodes involvement. In order to evaluate the variability of SLNs localisation and determine how this data may influence the efficacy of the above-mentioned therapeutic strategy, we retrospectively analysed the results of SPECT-CT examinations with 99mTc labelled nanocolloids. All of these findings were evaluated according to impact for subsequent individual radiotherapy planning. Results: We found out that sensitivity, specificity and accuracy of Scintimammo-graphy/Molecular breast imaging (SMG/MBI) with 99mTc -MIBI in the diagnosis of multicentric breast cancer (MC) was 84.3%, 98% and 96.3%, respectively. More of that, the sensitivity of SMG was significantly superior to ultrasound (52.3%) and mammography (54.0%). This advantage was more evident in women with dense breasts. Nowadays, we routinely use SMG/MBI for selecting the best candidates for conservative surgery and postoperative partial breast irradiation. An accurate diagnosis of metastases in regional lymph nodes (LN) can significantly affect the radiotherapy strategy. The prospective evaluation of SPECT-CT with 99mTc -MIBI in 184 primary patients with early breast cancer indicates high sensitivity (94%-96%) of SPECT-CT in the diagnosis of extensive (more than 2 metastases) axillary LN invasion. In these patients, additional SPECT-CT visualisation of individual lymph flow pattern with 99mTc-nannocolloids can be effectively used for 3D planning of simultaneous whole breast and sentinel lymph nodes irradiation. Conclusion: Our accumulated experience in using SMG/MBI and SPECT-CT imaging with tumor-seeking and nanocolloids radiopharmaceuticals 99mTc labelled provides a high informative value and broad usability perspectives in developing cutting-edge radiotherapeutic methods in patients with early and regional breast cancer.