 Welcome to my paper presentation on role of signal enhancement ratio in evaluation of residual disease in breast cancer after breast conserving surgery and neojuven chemotherapy. Myself Dr. Alan Johnson, 30 APG resident in the department of radio diagnosis and imaging aims profile. Following breast conserving surgery and neojuven chemotherapy for breast cancer, several modifications occur in the treated breast which can cause difficulties in image interpretation, especially when a local recurrence is suspected. It becomes challenging to distinguish whether it is a post treatment tissue modification or a tumor occurrence. In detecting residual disease and determining its extent is important for further treatment planning. If there is no residual disease in the breast then further surgery is unnecessary. If there is a small amount of residual disease then patient might benefit from a reaction. If extensive residual disease remains in the breast then mastectomy might be the treatment of choice. MRI is often used in clinical practice being considered more sensitive in discriminating between post treatment tissue modification and tumor occurrence. Several previous studies have reported the role of MRI in evaluating patients who have undergone treatment for breast cancer. However, these studies mainly focused on the morphological analysis of postoperative sites. But only little is known about the utility of kinetic evaluation including the washout kinetics in predicting residual disease in breast cancer. However, qualitative assessment of washout kinetics can prove to be difficult in post treatment breast MRI. Hence, quantitative assessment of washout kinetics may result in higher diagnostic performance in evaluation of residual disease. Signal enhancement ratio or SER is a quantitative imaging metric calculated from dynamic contrast enhanced breast MRI that reflects the rate of contrast washout inhalation. Hence, the purpose of this study was to determine the diagnostic performance of signal enhancement ratio in evaluation of residual disease in breast cancer after breast conserving surgery and neo-ageven chemotherapy. We retrospectively reviewed breast MRI studies of patients who met our inclusion criteria, which were patients who went, who underwent dynamic contrast enhanced breast MRI at our 3D system for assessment of residual disease after breast conserving surgery for neo-ageven chemotherapy. And either had received a follow up pathological proven diagnosis after undergoing reaccession or mastectomy or had lesion stability come from that more than one year of follow up. In DCE MRI images were acquired before contrast and sequentially acquired in five phases after contrast administration with a temporary resolution of 68 seconds. SER is a unitless index that reflects the rate of contrast washout between the early phase and the delayed phase after contrast delivery, which is calculated by the formula shown here. Where S0 is the signal intensity before contrast administration, S1 is the signal intensity at 68 seconds, and S2 is the signal intensity at 340 seconds after contrast delivery. SER was calculated on a voxel by voxel basis with a commercial computer edit detection system, which generated a SER color map, and a small size region of interest was drawn in the SER color map to calculate the absolute SER values. A total of 14 patients met your inclusion criteria out of which 12 had undergone breast conserving surgery and 2 had undergone neo-ageven chemotherapy for breast cancer before undergoing MRI in our institute. On follow up of the patients after MRI, out of the 14 patients, 4 patients were histopathologically proven to have residual breast C and rest of the 10 patients had no residual breast disease, breast CA. It was found that patients with residual breast CA had significantly higher SCR values as compared to patients with no residual breast CA. If we just consider only morphological characteristics like tick or irregular limb enhancement, nodular or non-mass like enhancement around the post-operative sites as positive for residual cancer, it yielded a sensitivity of 100% and the specificity of 50%. However, if we consider SER as a diagnostic criteria with an arbitrary cutoff value of 90, it yielded a similar sensitivity of 100%, but a higher specificity and a higher positive predictive value of 90 and 80 respectively. Illustrating a few example cases. This is a case of a 29 year old female who had undergone six cycles of neo-ageven chemotherapy for infiltrating ductile carcinoma. Subtraction image shows a large heterogeneously enhancing mass lesion with irregular shape and speculated margins. Corresponding SCR map shows areas of high SCR shown by the regions colored in blue. Absolute value was obtained by drawing a small 2D ROI which revealed a high SCR value of 161 and the corresponding kinetic analysis revealed washout kinetics. The patient further went on to undergo modified radical mastectomy and revealed residual invasive memory carcinoma with minimal treatment effect in the breast. This is a 40 year old female who also had undergone six cycles of neo-ageven chemotherapy for infiltrating ductile carcinoma. The subtraction image shows a heterogeneously enhancing mass lesion with irregular shape and speculated margins. The SCR map shows no corresponding areas of increased SCR. That means we cannot see any regions colored in blue corresponding to the enhancing mass lesion. And the absolute value obtained by drawing a 2D region of interest revealed a low SCR value of 21 and the corresponding kinetic analysis revealed persistent enhancement. This patient also further underwent modified radical mastectomy and the histopathology revealed no residual tumor. This is a case of 66 year old female who had underwent wide local excision for infiltrating ductile carcinoma. The subtraction image shows post-operative cavity with irregular, thick rim enhancement. Corresponding SCR map does not show any areas of increased SCR and the absolute value obtained by drawing a 2D ROI on the thick irregular rim enhancement and then cloning it onto the SCR map reveals a low absolute value of 34. The corresponding kinetic analysis revealed persistent enhancement. The patient further underwent re-excision which revealed no residual breast semen. This is a 30 year old female who had underwent wide local excision for infiltrating ductile carcinoma. The subtraction image shows post-operative cavity with irregular, thick rim enhancement. The corresponding SCR map shows areas of increased SCR as shown by the blue region along the anterior rim of the post-operative cavity. Small 2D ROI drawn here reveals a high absolute SCR value of 168 and the corresponding washout kinetic analysis shows washout kinetics. The patient further underwent modified radical mastectomy which revealed foci of residual tumor along the anterior margin of the post-operative cavity. Hence, SCR maps offer an easy method for quantitative assessment of washout kinetics of enhancing areas in post-treatment breast and in detection of residual cancer. Higher specificity offered by SCR in detecting residual cancer can help in reducing the number of unnecessary revision surgeries and mastectomies. However, studies with higher sample size would be required to find out a more accurate cutoff for SCR in identifying residual cancer. These are my references. Thank you for your patient listening. I would like to end by thanking the organizers for providing me this opportunity to present this paper. Thank you.