Evaluation of Diagnostic Accuracy and Impact of Preoperative Positron Emission Tomography/Computed Tomography in the Management of Early Operable Breast Cancers

Comparison of [18F] FDG PET/CT and [18F]FDG PET/MRI in the Detection of Distant Metastases in Breast Cancer: A Meta-Analysis

PURPOSE

This meta-analysis aims to assess and compare the diagnostic effectiveness of [18F] FDG PET/CT and [18F] FDG PET/MRI for distant metastases in breast cancer patients.

METHODS

A comprehensive search of the PubMed and Embase databases was performed to identify relevant articles until September 22, 2023. Studies were eligible to be included if they assessed the diagnostic performance of [18F] FDG PET/CT and/or [18F] FDG PET/MRI in detecting distant metastases of breast cancer patients. The DerSimonian and Laird method was used to assess sensitivity and specificity, and then transformed through the Freeman-Tukey double arcsine transformation.

RESULTS

29 articles consisting of 3779 patients were finally included in this study. The overall sensitivity of [18F] FDG PET/CT in diagnosing distant metastases of breast cancer was 0.96 (95% CI: 0.93-0.98), and the overall specificity was 0.95 (95% CI: 0.92-0.97). The overall sensitivity of [18F] FDG PET/MRI was 1.00 (95% CI: 0.97-1.00), and the specificity was 0.97 (95% CI: 0.94-1.00). The results suggested that [18F] FDG PET/CT and [18F] FDG PET/MRI appears to have similar sensitivity (P = .16) and specificity (P = .30) in diagnosing distant metastases of breast cancer.

CONCLUSIONS

The results of our meta-analysis indicated that [18F] FDG PET/CT and [18F] FDG PET/MRI in diagnosing distant metastases of breast cancer appear to have similar sensitivity and specificity. Patients who have access to only one of these modalities will not have the accuracy of their staging compromised. In clinical practice, both of these imaging techniques have their respective strengths and limitations, and physicians should take these into account when making the most suitable choice for patients.

Correlation between tumor to liver SUV ratio and molecular subtypes of invasive breast carcinoma in PET CT

Background

Breast cancer is known to be one of the most cancer affecting women around the globe and the second most common cancer in general. In third worlds countries, breast cancer is the most cause of cancer death. Early diagnosis and accurate follow-up of these patients affect the management. There are multiple prognostic factors most important one is the immunohistochemical molecular markers in the specimens including human epidermal growth factor, progesterone, and estrogen receptors (HER2, PR, ER). In breast cancer, the HER2 positive molecular subtype is associated with a bad prognosis and aggressive histological features, yet while following neoadjuvant chemotherapy, it achieves an increased pathological complete response rate. 18F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) has proved to be an effective and accurate imaging technique for lymph node and distant metastasis assessment, tumor staging, restaging of recurrence, treatment response, and follow-up. In breast cancer, tumor molecular subtype, tumor size, proliferation index, and histological grade correlated with 18F-fluoro-2-deoxy-d-glucose (FDG) uptake. This study evaluates the possible correlation between tumor to liver and tumor to spleen (standardized uptake value) SUV max ratio and the four different molecular subtypes in patients with pathologically proven primary breast cancer.

Results

Tumor to liver and tumor to spleen SUV max ratio (TLR, TSR) was a significant parameter for HER2 molecular subtype identification (P value = 0.0005 and 0.014 respectively) and luminal A molecular subtype identification (P value = 0.016 and 0.037 respectively). The specificity, sensitivity, and area under the receiver operating-characteristic curve (AUC) of TLR parameters for HER2-positive subtype identification were 89.4%, 83.3%, and 0.89, respectively. The specificity, sensitivity, and AUC of the TSR parameter for HER2-positive subtype identification were 57.9%, 100%, and 0.83, respectively.

Conclusions

TLR and TSR appeared to be valuable for HER2- and luminal A molecular subtype detection. thus, 18F-FDG PET/CT could be a beneficial tool for prediction of tumor biological characteristics that help in management of breast cancer patients.

Prediction of Sentinel Lymph Node Biopsy Status in Breast Cancers with PET/CT Negative Axilla

Background and Aim  Prior knowledge of axillary node status can spare a lot of patients with early breast cancer morbidity due to an unnecessary axillary dissection. Our study compared various metabolic and pathological features that can predict the sentinel lymph node biopsy (SLNB) status in patients with positron emission tomography/computed tomography (PET/CT) negative axilla.

Patients and Methods  All consecutive patients with early breast cancers (< 5 cm) with PET/CT negative axilla who underwent breast surgery and SLNB from November 2016 to February 2020 were included. Various primary tumor (PT) pathological variables and metabolic variables on PET/CT such as maximum standardized uptake value (PT-SUV _max ), metabolic tumor volume (PT-MTV), and total lesion glycolysis (PT-TLG) were compared using univariate and multivariate analyses for prediction of SLNB status.

Results  Overall 70 patients, all female, with mean age 55.6 years (range: 33–77) and mean tumor size 2.2 cm (range: 0.7–4.5), were included. SLNB was positive in 20% of patients ( n  = 14) with nonsentinel nodes positive in 4% ( n  = 3) patients. Comparing SLNB positive and negative groups, univariate analysis showed significant association of SLNB with low tumor grade, positive lymphovascular invasion (LVI), positive estrogen receptor (ER) status with lower mean K _i -67 index (34.41 vs. 52.02%; p  = 0.02), PT-SUV _max (5.40 vs. 8.68; p  = 0.036), PT-MTV (4.71 cc vs. 7.46 cc; p  = 0.05), and PT-TLG (15.12 g/mL.cc vs. 37.10 g/mL.cc; p  = 0.006). On multivariate analysis, only LVI status was a significant independent predictor of SLNB status (odds ratio = 6.23; 95% confidence interval: 1.15–33.6; p  = 0.033).

Conclusion  SLNB is positive in approximately 20% of early breast cancers with PET/CT negative axilla and SLNB status appears to be independent of PT size. SLNB+ PTs were more likely to be LVI+ and ER + ve, with lower grade/K _i -67/metabolic activity (SUV _max /MTV/TLG) compared with SLNB–ve tumors. Logistic regression analysis revealed LVI status as the only significant independent predictor of sentinel lymph node status.

Sensitivity, Specificity and the Diagnostic Accuracy of PET/CT for Axillary Staging in Patients With Stage I-III Cancer: A Systematic Review of The Literature

BACKGROUND/AIM

Axillary lymph node (ALN) status plays a key role in the staging of breast cancer. Positron Emission Tomography/Computed Tomography (PET/CT) using 18-Fluorodeoxyglucose (¹⁸FDG) can visualise ALN metastasis. However, its utility compared to current methods is unclear. We systematically reviewed the role of ¹⁸FDG PET/CT in breast cancer staging.

MATERIALS AND METHODS

PubMed, Ovid and Cochrane were searched systematically up until August 2020. Included papers had true positive (TP), false positive (FP), true negative (TN) and false negative (FN) rates, sensitivity, specificity, accuracy, positive (PPV) and negative predictive value (NPV).

RESULTS

Nine studies (n=1486) were included, showing: i) sensitivity=52.2%, ii) specificity=91.6%, iii) PPV=77.8%, iv) NPV=77.2, and v) accuracy=77.3%.

CONCLUSION

¹⁸FDG-PET/CT has a low sensitivity but high specificity for ALN disease. Therefore, ultrasound-guided biopsy could be considered in a positive CT/PET. Modest accuracy prohibits the use of ¹⁸FDG-PET/CT alone in axillary staging. Prospective research using standardised protocols and quantitative cut-off points is warranted.

Correlation between semiquantitative and volumetric 18F-FDG PET/computed tomography parameters and Ki-67 expression in breast cancer

OBJECTIVES

To evaluate the relationship between semiquantitative and volumetric parameters on 18F-FDG PET/computed tomography (CT), including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), tumor to liver ratio (TLR) and tumor to mediastinum ratio (TMR) with the level of Ki-67 expression in breast cancer.

PATIENT AND METHODS

We retrospectively reviewed 105 female patients with newly diagnosed breast cancer who underwent baseline 18F-FDG PET/CT and had immunohistochemical staining to determine the level of Ki-67 expression. The following PET parameters were measured (SUVmax, SUVmean, MTV, TLG, TLR and TMR) and correlated with level of Ki-67 expression.

RESULTS

Significant moderate positive correlations were found between the PET parameters (primary SUVmax, SUVmean, TLG, TLR and TMR) and level of Ki-67 expression. The primary SUVmax had the highest correlation coefficient (r = 0.461) followed by TMR (r = 0.455) and P value of <0.001 for both. In ROC analysis, primary SUVmax had the largest area under the curve (0.806, P = 0.0001), with sensitivity of 76.5 % and specificity of 75% for prediction of high Ki-67 level. In univariate analysis, all PET parameters, patient age, tumor grade, molecular subtype, estrogen receptor and progesterone receptor status were significantly associated with Ki-67 level. In multivariate regression analysis, only tumor grade [odds ratio (OR) = 20.460, 95% confidence interval (CI): 11.360-29.559, P = <0.0001], molecular subtype (OR = -21.894, 95% CI: -37.921 to -5.866, P = 0.008), SUVmax (OR = 2.299, 95% CI: 0.703-3.895, P = 0.005) and TLR (OR = -4.908, 95% CI: -9.476 to -0.340, P = 0.035) were found to be the strongest independent predictor factors for the level of Ki-67 expression and hence proliferative activity of malignant cells in breast cancer.

CONCLUSION

The semiquantitative parameters and volumetric 18F-FDG PET/CT parameter, that is, TLG correlated well with proliferation marker Ki-67 in breast cancer. 18F-FDG PET/CT imaging can be used as a useful noninvasive diagnostic tool in imaging cellular proliferation and hence may substitute for in vitro testing of molecular markers in the diagnoses and staging of breast cancer.

Impact of 18F-FDG PET, PET/CT, and PET/MRI on Staging and Management as an Initial Staging Modality in Breast Cancer: A Systematic Review and Meta-analysis

OBJECTIVES

We performed a systematic review and meta-analysis to evaluate the impact of 18F-FDG PET, PET/CT, and PET/MRI on staging and management during the initial staging of breast cancer.

METHODS

We searched the PubMed, Embase, Cochrane Library, and KoreaMed databases until March 2020 to identify studies that reported the proportion of breast cancer patients whose clinical stage or management were changed after PET scans. The proportion of changes was pooled using a random-effects model. Subgroup and metaregression analyses were performed to explore heterogeneity.

RESULTS

We included 29 studies (4276 patients). The pooled proportions of changes in stage and management were 25% (95% confidence interval [CI], 21%-30%) and 18% (95% CI, 14%-23%), respectively. When stage changes were stratified according to initial stage, the pooled proportions were 11% (95% CI, 3%-22%) in stage I, 20% (95% CI, 16%-24%) in stage II, and 34% (95% CI, 27%-42%) in stage III. The relative proportions of intermodality and intention-to-treat changes were 74% and 70%, respectively. Using metaregression analyses, the mean age and the proportion of initial stage III to IV and histologic grade II to III were significant factors affecting the heterogeneity in changes in stage or management.

CONCLUSIONS

Currently available literature suggests that the use of 18F-FDG PET, PET/CT, or PET/MRI leads to significant modification of staging and treatment in newly diagnosed breast cancer patients. Therefore, there may be a role for routine clinical use of PET imaging for the initial staging of breast cancer.

Synchronous breast carcinoma and peritoneal mesothelioma

Breast cancer may be associated with other primary cancers via germline mutations; however, sporadic occurrences of other malignancies are rare. With increased use of advanced breast cancer imaging, including MRI and PET/CT, other incidental synchronous cancers are increasingly identified. Such cases can represent unique diagnostic and treatment challenges. Here, we present a case of a young woman diagnosed with primary breast cancer who underwent imaging studies identifying an incidental primary peritoneal mesothelioma.