Accuracy Of Tumor Size Measurement Research Articles

Abstract P3-04-08: Comparison Of Cone Beam Breast CT And Breast MRI In Preoperative Assessment Of Primary Breast Cancer Tumor Size

Abstract Comparison Of Cone Beam Breast CT And Breast MRI In Preoperative Assessment Of Primary Breast Cancer Tumor Size Yinan Ji＊1, Geyi Liao＊1, Ningbing Luo2, Yi Jiang1, Xiaoming Liao1, Wei Tang1, Huawei Yang 1. 1Department of Breast Surgery, 2Department of Radiology, Guangxi Medical University Tumor Hospital, Nanning, China Correspondence to: Dr. Huawei Yang, Department of Breast Surgery, Guangxi Medical University Cancer Hospital, 71 Hedi Road, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China Email: Lordyhw@163.com ＊Contributed equally Background: Breast cancer is the malignant tumor with the highest incidence among women in China, seriously endangering women’s health. After breast cancer is diagnosed, surgery is one of the primary treatments. Assessing the extent of breast cancer is vitally important to formulate the best surgical option, obtain clear margins while minimizing the volume of removed tissue, and improve the treatment outcome and patient’s quality of life. Currently, breast surgery relies heavily on Breast MRI (bMRI) for preoperative assessment. However, bMRI may overestimate the tumor sizes. bMRI is contraindicated in patients with claustrophobia, metal implants, and allergy to gadolinium contrast medium. In addition, bMRI is generally expensive and time-consuming. Some patients find bMRI less favorable for cost and time concerns. Cone Beam Breast CT (CBBCT) is a new modality using Cone Beam CT technology and iodinated contrast media for true 3D high-resolution imaging of the breast. Our previous studies have proved the feasibility of CBBCT in the preoperative assessment of breast cancer. A large-scale study has been done to further examine the clinical significance of CBBCT in pre-operative assessment compared with bMRI. Methods: 273 female primary breast cancer patients were included in this study. The maximal diameters of the tumors were measured in CBBCT and bMRI images by an experienced radiologist. The differences between the image-measured size and surgical pathology size (gold standard) were calculated as ΔDCT and ΔDMR. ΔD ˃ 5mm was considered an overestimation and ΔD ˂-5mm was considered an underestimation. The absolute values of ΔDCT and ΔDMR were also calculated as ΔDCT_abs and ΔDMR_abs. A Student t-test was used to compare the statistical differences between ΔDCT_abs and ΔDMR_abs. Among ΔDCT_abs and ΔDMR_abs, a 5mm cut-off value was used to determine the concordance between image and pathology. The concordance rates of CBBCT-Pathology and bMRI-Pathology were tested with the χ2 method. Factors that may affect the accuracy of tumor size measurement were analyzed. Results: Overall there were no statistically significant differences between ΔDCT_abs and ΔDMR_abs. (0.58±0.68cm vs. 0.65±0.68cm; t=1.653, P=0.100). Using 5mm as the cut-off value of concordance, there was no significant difference in the CBBCT-Pathology and bMRI-Pathology concordance rates (64.8% vs. 60.1%, χ2 =1.320, P=0.251). The overestimation rate of CBBCT was significantly lower than that of bMRI (11.4% vs. 19.4%, χ2=6.810, P=0.009). But there was no significant difference in the underestimation rates (23.8% vs. 20.5%, χ2=0.860, P=0.354). ΔDCT_abs is significantly smaller than ΔDMR_abs among the invasive ductal carcinoma group (P=0.017), the premenopausal group (P=0.004), and the small tumor size (≤2cm) group (P=0.003). ΔDCT_abs and ΔDMR_abs.have no significant differences among the lymph node metastasis group, multi-lesion group, and enhancement type group (P > 0.05). Conclusions: CBBCT is concordant with surgical pathology in breast tumor size measurement and provides more accurate tumor size estimation compared with bMRI. CBBCT can be used as a valuable modality for pre-operative assessment. Citation Format: YINAN JI, Geyi Liao, Ningbing Luo, Yi Jiang, Xiaoming Liao, Wei Tang, Huawei Yang. Comparison Of Cone Beam Breast CT And Breast MRI In Preoperative Assessment Of Primary Breast Cancer Tumor Size [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-04-08.

Preoperative tumor size measurement in breast cancer patients: which threshold is appropriate on computer-aided detection for breast MRI?

BackgroundComputer-aided detection (CAD) can detect breast lesions by using an enhancement threshold. Threshold means the percentage of increased signal intensity in post-contrast imaging compared to precontrast imaging. If the pixel value of the enhanced tumor increases above the set threshold, CAD provides the size of the tumor, which is calculated differently depending on the set threshold. Therefore, CAD requires the accurate setting of thresholds. We aimed to compare the diagnostic accuracy of tumor size measurement using MRI and CAD with 3 most commonly used thresholds and to identify which threshold is appropriate on CAD in breast cancer patients.MethodsA total of 130 patients with breast cancers (80 invasive cancers and 50 ductal carcinoma in situ [DCIS]) who underwent preoperative MRI with CAD and surgical treatment were included. Tumor size was manually measured on first contrast-enhanced MRI and acquired by CAD using 3 different thresholds (30, 50, and 100%) for each tumor. Tumor size measurements using MRI and CAD were compared with pathological sizes using Spearman correlation analysis. For comparison of size discrepancy between imaging and pathology, concordance was defined as estimation of size by imaging within 5 mm of the pathological size. Concordance rates were compared using Chi-square test.ResultsFor both invasive cancers and DCIS, correlation coefficient rho (r) between tumor size on imaging and pathology was highest at CAD with 30% threshold, followed by MRI, CAD with 50% threshold, and CAD with 100% threshold (all p < 0.05). For invasive cancers, the concordance rate of 72.5% at CAD with 30% threshold showed no difference with that of 62.5% at MRI (p = 0.213). For DCIS, the concordance rate of 30.0% at CAD with 30% threshold showed no difference with that of 36.0% at MRI (p = 0.699). Compared to MRI, higher risk of underestimation was noted when using CAD with 50% or 100% threshold for invasive cancers and when using CAD with 100% threshold for DCIS.ConclusionFor CAD analysis, 30% threshold is the most appropriate threshold whose accuracy is comparable to manual measurement on MRI for tumor size measurement. However, clinicians should be aware of the higher risk of underestimation when using CAD with 50% threshold for tumor staging in invasive cancers.

Accuracy of Ultrasound for Preoperative Assessment of Tumor Size in Patients With Newly Diagnosed Breast Cancer: Is It Affected by the Background Parenchymal Echotexture?

To assess the impact of the background parenchymal echotexture on the accuracy of tumor size estimation using breast ultrasound (US). A total of 140 women with newly diagnosed invasive breast cancer from January 2014 to December 2015 were enrolled in this study. Two radiologists retrospectively reviewed US images in consensus for background parenchymal echotexture interpretation. The maximum tumor diameter from static images was recorded. Tumor size measurements were considered as having agreement with histologic results if they were within ±5 mm compared to the pathologic size. The relationship between the accuracy of tumor size measurement by the background parenchymal echotexture and clinicopathologic characteristics was evaluated. Of these 140 patients, 77 (55.0%) showed a homogeneous background parenchymal echotexture, whereas 63 (45.0%) showed a heterogeneous echotexture. The mean tumor size was 1.9 cm (range, 0.5-4.9 cm). The overall accuracy of tumor size measurement was 76.4% (104 of 140). Tumors of women with a homogeneous background parenchymal echotexture were more accurately measured than those of women with a heterogeneous echotexture (87.0% versus 63.5%; P = .001). Tumors with a small size (<2 cm; P = .018) and ductal carcinoma in situ-negative (P = .031), human epidermal growth factor receptor 2 (HER2)-negative (P = .053), and triple-negative (P = .016) types were also more accurately measured. The independent factors associated with inaccurate tumor size measurement were a heterogeneous background parenchymal echotexture, a large tumor size, and the HER2-enriched type (P < .05). The background parenchymal echotexture affected the accuracy of tumor size estimation using breast US. Invasive breast cancers with large (≥2 cm) tumors and the HER2-enriched type showed significantly lower breast US accuracy compared to others.

Accuracy of tumor size measurement in breast cancer using MRI is influenced by histological regression induced by neoadjuvant chemotherapy

Accuracy of tumor size measurement in breast cancer using MRI is influenced by histological regression induced by neoadjuvant chemotherapy

Accuracy of tumor size measurement in breast cancer using MRI is influenced by histological regression induced by neoadjuvant chemotherapy.

The aim of this study was to evaluate whether regressive changes after neoadjuvant chemotherapy for breast cancer affect the accuracy of preoperative MRI measurements of tumor size. Thirty-one patients with breast cancer underwent MRI before and after neoadjuvant treatment. Besides pre- and post-contrast T1-weighted MRI, dynamic MRI with high temporal resolution (turbo-FLASH) was performed. Contrast enhancement in dynamic MRI was quantified using a pharmacokinetic two-compartment model, where two parameters, amplitude and k(ep), were calculated and color coded on transversal parameter maps. Considering the conventional MR images, tumor diameters were measured on the color maps and compared with histological tumor size. Histological regression was scored on a five-point scale regarding cytopathic effects, reactive changes, and tumor cell reduction. The correlation between tumor sizes measured by MRI and histopathology was 0.83 ( p<0.0007) in 12 tumors without regressive changes (score 0), and 0.48 ( p<0.051) in 17 tumors with regressive changes scored 1 or 2, without any tendency for systematic over- or underestimation. In two cases without residual tumor (score 4), MRI likewise showed no signs of persistent tumor. The decrease of the contrast enhancement parameters was significantly more marked in tumors with signs of histological regression than in those without. Whenever MRI is used to judge the response of breast cancer to chemotherapy, the reader must be aware that therapy-induced changes may cause significant over- or underestimation of tumor size. We saw a high precision only when there was either no response - according to histological criteria - or when the tumor had regressed completely.

How accurate is helical CT volumetric assessment in renal tumors?

The aim of this study was to evaluate the accuracy of tumor size measurement on CT studies of renal tumors. Sixteen patients with tumors of the kidneys were imaged by helical CT prior to surgery. Assessment of tumor volume was made by two radiologists on the CT images with the summation of area method, then compared with the resected specimen water displacement volume. Intra- and interobserver agreement for CT measurements were also assessed. There were substantial differences between the CT volume measurement compared with the tumor post-operative volume (mean of differences 30.05+/-91.6, 95%CI: 31.45-91.55). The inter- and intraobservation agreements for tumor measurement by CT was found to be satisfactory (ANOVA: p < 0.0001; t-test: p < 0.05). The CT volumetric measurement by area summation is a method with good inter- and intraexamination reproducibility but not an accurate technique for tumor volume assessment.