Tumour 18 F-FDG Uptake on preoperative PET/CT may predict axillary lymph node metastasis in ER-positive/HER2-negative and HER2-positive breast cancer subtypes. Eur Radiol. 2015;25:1172-1181. [PMID: 25298170 DOI: 10.1007/s00330-014-3452-y]

Can we skip invasive biopsy of sentinel lymph nodes? A preliminary investigation to predict sentinel lymph node status using PET/CT-based radiomics

BACKGROUND

Sentinel lymph node (SLN) biopsy (SLNB) is considered the gold standard for detecting SLN metastases in patients with invasive ductal breast cancer (IDC). However, SLNB is invasive and associated with several complications. Thus, this study aimed to evaluate the diagnostic performance of a non-invasive radiomics analysis utilizing 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) for assessing SLN metastasis in IDC patients.

METHODS

This retrospective study included 132 patients with biopsy-confirmed IDC, who underwent 18F-FDG PET/CT scans prior to mastectomy or breast-conserving surgery with SLNB. Tumor resection or SLNB was conducted within one-week post-scan. Clinical data and metabolic parameters were analyzed to identify independent SLN metastasis predictors. Radiomic features were extracted from each PET volume of interest (VOI) and CT-VOI. Feature selection involved univariate and multivariate logistic regression analysis, and the least absolute shrinkage and selection operator (LASSO) method. Three models were developed to predict SLN status using the random forest (RF), decision tree (DT), and k-Nearest Neighbors (KNN) classifiers. Model performance was assessed using the area under the receiver operating characteristic curve (AUC).

RESULTS

The study included 91 cases (32 SLN-positive and 59 SLN-negative patients) in the training cohort and 41 cases (29 SLN-positive and 12 SLN-negative patients) in the validation cohort. Multivariate logistic regression analysis identified Ki 67 and TLG as independent predictors of SLN status. Five PET-derived features, three CT-derived features, and two clinical variables were selected for model development. The AUC values of the RF, KNN, and DT models for the training cohort were 0.887, 0.849, and 0.824, respectively, and for the validation cohort were 0.856, 0.830, and 0.819, respectively. The RF model demonstrated the highest accuracy for the preoperative prediction of SLN metastasis in IDC patients.

CONCLUSION

The PET-CT radiomics approach may offer robust and non-invasive predictors for SLN status in IDC patients, potentially aiding in the planning of personalized treatment strategies for IDC patients.

Association Between 18F-FDG PET Activity and HER2 Status in Breast Cancer Brain Metastases

Purpose

The objective of this study was to evaluate whether uptake on 18F-fluorodeoxyglucose (18F-FDG) PET could help differentiate HER2-positive from HER2-negative breast cancer brain metastases.

Methods

In this retrospective, cross-sectional study of a cohort of 14 histologically proven breast cancer brain metastases, we analyzed both preoperative 18F-FDG PET/CT and HER2 status of the resected/biopsied brain specimens. The maximum standardized uptake values (SUVmax) of the lesions were normalized to contralateral normal white matter and compared using Mann-Whitney U tests.

Results

The study cohort was comprised of 12 women with breast cancer with a mean age of 59 years (range: 43-76 years) with a total of 14 distinct brain metastatic lesions. The SUVmax ratio of HER2-positive breast cancer brain metastases was significantly greater than that of HER2-negative lesions (3.98 vs 1.79, U = 38.00, p = 0.008).

Conclusion

The SUVmax ratio may help to identify the HER2 status of breast cancer brain metastases, if validated prospectively.

Impact of Imaging Biomarkers and AI on Breast Cancer Management: A Brief Review

Breast cancer stands out as the most frequently identified malignancy, ranking as the fifth leading cause of global cancer-related deaths. The American College of Radiology (ACR) introduced the Breast Imaging Reporting and Data System (BI-RADS) as a standard terminology facilitating communication between radiologists and clinicians; however, an update is now imperative to encompass the latest imaging modalities developed subsequent to the 5th edition of BI-RADS. Within this review article, we provide a concise history of BI-RADS, delve into advanced mammography techniques, ultrasonography (US), magnetic resonance imaging (MRI), PET/CT images, and microwave breast imaging, and subsequently furnish comprehensive, updated insights into Molecular Breast Imaging (MBI), diagnostic imaging biomarkers, and the assessment of treatment responses. This endeavor aims to enhance radiologists' proficiency in catering to the personalized needs of breast cancer patients. Lastly, we explore the augmented benefits of artificial intelligence (AI), machine learning (ML), and deep learning (DL) applications in segmenting, detecting, and diagnosing breast cancer, as well as the early prediction of the response of tumors to neoadjuvant chemotherapy (NAC). By assimilating state-of-the-art computer algorithms capable of deciphering intricate imaging data and aiding radiologists in rendering precise and effective diagnoses, AI has profoundly revolutionized the landscape of breast cancer radiology. Its vast potential holds the promise of bolstering radiologists' capabilities and ameliorating patient outcomes in the realm of breast cancer management.

The influence of receptor expression and clinical subtypes on baseline [18F]FDG uptake in breast cancer: systematic review and meta-analysis

BACKGROUND

To quantify the relationship between [18F]FDG uptake of the primary tumour measured by PET-imaging with immunohistochemical (IHC) expression of ER, PR, HER2, Ki-67, and clinical subtypes based on these markers in breast cancer patients.

METHODS

PubMed and Embase were searched for studies that compared SUVmax between breast cancer patients negative and positive for IHC expression of ER, PR, HER2, Ki-67, and clinical subtypes based on these markers. Two reviewers independently screened the studies and extracted the data. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were estimated by using DerSimonian-Laird random-effects models. P values less than or equal to 5% indicated statistically significant results.

RESULTS

Fifty studies were included in the final analysis. SUVmax is significantly higher in ER-negative (31 studies, SMD 0.66, 0.56-0.77, P < 0.0001), PR-negative (30 studies, SMD 0.56; 0.40-0.71, P < 0.0001), HER2-positive (32 studies, SMD - 0.29, - 0.49 to - 0.10, P = 0.0043) or Ki-67-positive (19 studies, SMD - 0.77; - 0.93 to - 0.61, P < 0.0001) primary tumours compared to their counterparts. The majority of clinical subtypes were either luminal A (LA), luminal B (LB), HER2-positive or triple negative breast cancer (TNBC). LA is associated with significantly lower SUVmax compared to LB (11 studies, SMD - 0.49, - 0.68 to - 0.31, P = 0.0001), HER2-positive (15 studies, SMD - 0.91, - 1.21 to - 0.61, P < 0.0001) and TNBC (17 studies, SMD - 1.21, - 1.57 to - 0.85, P < 0.0001); and LB showed significantly lower uptake compared to TNBC (10 studies, SMD - 0.77, - 1.05 to - 0.49, P = 0.0002). Differences in SUVmax between LB and HER2-positive (9 studies, SMD - 0.32, - 0.88 to 0.24, P = 0.2244), and HER2-positive and TNBC (17 studies, SMD - 0.29, - 0.61 to 0.02, P = 0.0667) are not significant.

CONCLUSION

Primary tumour SUVmax is significantly higher in ER-negative, PR-negative, HER2-positive and Ki-67-positive breast cancer patients. Luminal tumours have the lowest and TNBC tumours the highest SUVmax. HER2 overexpression has an intermediate effect.

Combined 18F-FDG and 18F-Alfatide II PET May Predict Luminal B (HER2 Negative) Subtype and Nonluminal Subtype of Invasive Breast Cancer

Noninvasive PET molecular imaging using radiopharmaceuticals is important to classify breast cancer in the clinic. The aim of this study was to investigate the combination of ¹⁸F-FDG and ¹⁸F-Alfatide II for predicting molecular subtypes of invasive breast cancer. Forty-four female patients with clinically suspected breast cancer were recruited and underwent ¹⁸F-FDG and ¹⁸F-Alfatide II PET/CT within a week. Tracer uptake in breast lesions was assessed using the maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), and SUV_max ratio of ¹⁸F-FDG to ¹⁸F-Alfatide II (FAR). Invasive breast cancer lesions were further classified as luminal A subtype, luminal B subtype, human epidermal growth factor receptor-2 (HER2) overexpressing subtype, and triple negative subtype according to the expression of the estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67. Among 44 patients, 35 patients were pathologically diagnosed with invasive breast cancer. The SUV_max and SUV_mean of ¹⁸F-FDG were significantly higher in the ER-negative group than those in the ER-positive group, as well as in the PR-negative group than those in the PR-positive group. However, the SUV_max and SUV_mean of ¹⁸F-Alfatide II were higher in the ER-positive group and the PR-positive group. By combining ¹⁸F-FDG and ¹⁸F-Alfatide II, the FAR was lower in the ER-positive group and the PR-positive group. The HER2 overexpressing subtype showed the highest SUV_max and SUV_mean for ¹⁸F-FDG while the luminal B (HER2 negative) subtype revealed the lowest values. The luminal B (HER2 negative) subtype showed the highest ¹⁸F-Alfatide II SUV_max, while the triple negative subtype showed the lowest ¹⁸F-Alfatide II SUV_max. The FAR was the lowest in the luminal B (HER2 negative) subtype and much higher in the HER2 overexpressing and triple negative subtypes. FAR less than 1 predicted the luminal B (HER2 negative) subtype with high specificity (93.1%) and NPV (90%). FAR greater than 3 predicted the HER2 overexpressing subtype and triple negative subtype (namely, the nonluminal subtype) with very high specificity (100%) and PPV (100%). In summary, FAR, the combined PET parameter of ¹⁸F-FDG and ¹⁸F-Alfatide II, can be used to predict molecular subtypes of invasive breast cancer, especially for the luminal B (HER2 negative) subtype and the nonluminal subtype.

The Relationship between Pathological Features and 18F-FDG PET/CT that Changed the Surgeon's Decision as Neoadjuvant Therapy in Breast Cancer

Objective  Patients diagnosed with breast cancer and decided to undergo surgical treatment can undergo neoadjuvant therapy following their 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography/computed tomography ( ¹⁸ F-FDG PET/CT) findings. The present study aims to determine the statistical significance of these patients whose treatment plan was changed and the reasons for the change in the plan.

Materials and Methods  The demographic features and treatment plans of 151 cases who were diagnosed with any stage of breast cancer were evaluated. These patients consist of those who admitted to Mersin University Hospital Breast Outpatient Clinic between January 2016 and December 2019. All of these patients aged between 41 and 85 years were examined with ¹⁸ F-FDG PET/CT after the decision for surgical treatment is made. The analysis included tumor pathology, side, type, subtype, size, and centricity in this study.

Results  About 18.5% ( n  = 28) of patients' treatment plan was changed after ¹⁸ F-FDG PET/CT. They received neoadjuvant therapy. About 81.5% ( n  = 123) of patients did not receive neoadjuvant therapy. Significant differences were observed between patients changed treatment plan and not changed concerning age, lymph node involvement, tumor size, centricity, and subtypes parameters.

Conclusion  Conventional imaging examinations are used in patients with breast cancer. These examinations may not be sufficient to determine advanced disease requiring neoadjuvant treatment. With ¹⁸ F-FDG PET/CT examination, these advanced stage patients are not overlooked. In our study, approximately one in five patients, treatment plan changed after ¹⁸ F-FDG PET/CT examination.

ACR Appropriateness Criteria® Imaging of the Axilla

This publication reviews the current evidence supporting the imaging approach of the axilla in various scenarios with broad differential diagnosis ranging from inflammatory to malignant etiologies. Controversies on the management of axillary adenopathy results in disagreement on the appropriate axillary imaging tests. Ultrasound is often the appropriate initial imaging test in several clinical scenarios. Clinical information (such as age, physical examinations, risk factors) and concurrent complete breast evaluation with mammogram, tomosynthesis, or MRI impact the type of initial imaging test for the axilla. Several impactful clinical trials demonstrated that selected patient's population can received sentinel lymph node biopsy instead of axillary lymph node dissection with similar overall survival, and axillary lymph node dissection is a safe alternative as the nodal staging procedure for clinically node negative patients or even for some node positive patients with limited nodal tumor burden. This approach is not universally accepted, which adversely affect the type of imaging tests considered appropriate for axilla. This document is focused on the initial imaging of the axilla in various scenarios, with the understanding that concurrent or subsequent additional tests may also be performed for the breast. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

18F-Alfatide II for the evaluation of axillary lymph nodes in breast cancer patients: comparison with 18F-FDG

PURPOSE

¹⁸F-Alfatide II has been translated into clinical use and been proven to have good performance in identifying breast cancer. In this study, we investigated ¹⁸F-Alfatide II for evaluation of axillary lymph nodes (ALN) in breast cancer patients and compared the performance with ¹⁸F-FDG.

METHODS

A total of 44 female patients with clinically suspected breast cancer were enrolled and underwent ¹⁸F-Alfatide II and ¹⁸F-FDG PET/CT within a week. Tracer uptakes in ALN were evaluated by visual analysis, semi-quantitative analysis with maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), and SUV_max ratio of target/non-target (T/NT).

RESULTS

Among 44 patients, 37 patients were pathologically diagnosed with breast cancer with metastatic (17 cases) or non-metastatic (20 cases) ALN. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of visual analysis were 70.6%, 90%, 81.1%, 85.7%, and 78.3% for ¹⁸F-Alfatide II, 64.7%, 90%, 78.4%, 84.6%, and 75% for ¹⁸F-FDG, respectively. By combining ¹⁸F-Alfatide II and ¹⁸F-FDG, the sensitivity significantly increased to 82.4%, the specificity was 85%, the accuracy increased to 83.8%, the PPV was 82.4%, and the NPV significantly increased to 85.0%. Three cases of luminal B subtype were false negative for both ¹⁸F-Alfatide II and ¹⁸F-FDG. The other 2 false negative cases of ¹⁸F-Alfatide II were triple-negative subtype and 3 false negative cases of ¹⁸F-FDG were luminal B subtype too. The AUCs of three semi-quantitative parameters (SUV_max, SUV_mean, T/NT) for ¹⁸F-Alfatide II were between 0.8 and 0.9, whereas those for ¹⁸F-FDG were more than 0.9. ¹⁸F-Alfatide II T/NT had the highest Youden index (76.5%), specificity (100%), accuracy (89.2%), and PPV (100%) among these semi-quantitative parameters. ¹⁸F-Alfatide II uptake as well as ¹⁸F-FDG uptake in metastatic axillary lymph nodes (MALN) was significantly higher than that in benign axillary lymph nodes (BALN). Both ¹⁸F-Alfatide II and ¹⁸F-FDG did not show difference in primary tumor uptake irrespective of ALN status.

CONCLUSION

¹⁸F-Alfatide II can be used in breast cancer patients to detect metastatic ALN, however, like ¹⁸F-FDG, with high specificity but relatively low sensitivity. The combination of ¹⁸F-Alfatide II and ¹⁸F-FDG can significantly improve sensitivity and NPV. ¹⁸F-Alfatide II T/NT may serve as the most important semi-quantitative parameter to evaluate ALN.

The role of fluorodeoxyglucose-PET/computed tomography as a predictor of breast cancer characteristics and prognosis

PURPOSE

Fluorodeoxyglucose-PET/computed tomography (FDG-PET/CT) affects the management of patients with breast cancer. Our study aimed to determine the predictive ability of characteristics such as lymph node involvement or subtype and the prognostic value of pretreatment FDG-PET/CT in breast cancer.

METHOD

A total of 270 patients who were confirmed with breast cancer histopathologically and underwent pretreatment FDG-PET/CT were enrolled in the study. Nuclear medicine specialists obtained the readings and measured the maximum standardized uptake value (SUVmax) of the images. Tumor and lymph node SUVmax were evaluated according to lymph node metastasis and subtype status. Survival outcomes were analyzed by the Kaplan-Meier method.

RESULTS

The lymph node SUVmax and the lymph node/tumor SUVmax ratio were significantly higher in the subgroup of patients with lymph node metastasis than in those without lymph node metastasis. High cutoff lymph node SUVmax value and lymph node/tumor SUVmax ratio were confirmed as significant predictive factors in multivariate analysis. In a comparison of the tumor SUVmax values, the more biological aggressive subtype showed higher tumor SUVmax values. In survival analysis, tumor SUVmax and lymph node SUVmax were significant predisposing factors for disease-free survival in breast cancer. In subgroup analysis, tumor SUVmax was a more significant prognostic factor in patients who had breast cancer with tumor sizes of ≤2 cm. The lymph node SUVmax was more a significant prognostic factor in patients who had breast cancer with lymph node metastasis.

CONCLUSION

In this study, we showed that the SUVmax of FDG-PET/CT was a useful predictor of lymph node metastasis and breast cancer prognosis.

Discordant results in 18F-FDG PET/CT and ultrasound-based assessment for axillary lymph node metastasis detection: A large retrospective analysis in 560 patients with breast cancer

PURPOSE

Ultrasound is the recommended modality to assess axillary lymph node involvement in breast cancer; nevertheless, ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) integrated positron emission tomography/computed tomography (PET/CT) diagnostic efficiency, to identify suspicious lesions, is also considered. We aim to report discrepancies in ultrasound and ¹⁸F-FDG PET/CT results.

METHODS

This single-centered retrospective analysis selected consecutive patients with invasive ductal biopsy-proven breast cancer, for whom divergent ¹⁸F-FDG PET/CT and axillary ultrasound imaging (and/or core needle biopsy if available) had been performed, and described clinical, histological, imaging, and surgery data.

RESULTS

This retrospective study included 560 patients and identified discordant results between ¹⁸F-FDG PET/CT and ultrasound (suspicious ¹⁸F-FDG PET/CT and normal ultrasound imaging and/or core needle biopsy) in 20 (4%) patients. Axillary lymph node involvement was confirmed in 17 (85%) out of these 20 patients. Further, the lymph nodes were smaller than one centimeter in 12 (60%) patients, macrometastasic involvement (involvement >2 mm) was detected in 13 (65%) patients, and more than 3 macrometastases were detected in 6 (30%) patients. All patients had an aggressive breast cancer. The sentinel node biopsy performed in 9 (45%) patients allowed to reveal lymph node involvement, even in cases of macrometastatic involvement.

CONCLUSION

Discordant results were issued from normal ultrasound imaging and/or core needle biopsy, and suspicious ¹⁸F-FDG PET/CT revealed that ¹⁸F-FDG PET/CT may overcome axillary ultrasound limits in the specific case of aggressive breast cancers, especially for axillary lymph nodes smaller than 1 centimeter. Sentinel node biopsy remains a valuable aid, even in patients with macrometastatic involvement.

Harmonized pretreatment quantitative volume-based FDG-PET/CT parameters for prognosis of stage I-III breast cancer: Multicenter study

OBJECTIVES

This study investigated harmonized pretreatment volume-based quantitative FDG-PET/CT parameters in breast cancer patients for prognostic value.

RESULTS

During a median overall follow-up period of 5.3 years, 91 patients had recurrence and 40 died. Multivariate analysis of ER-positive/HER2-negative patients showed high maximum standardized uptake value (SUVmax) (p = 0.018), high total lesion glycolysis (TLG) (p = 0.010), and clinical N-classification (p = 0.0027) as independent negative predictors of RFS, while high maximum SUVmax (p = 0.037), advanced clinical T-classification (p = 0.030), and advanced TNM stage (p = 0.0067) were independent negative predictors of OS. For recurrence and death in HER2-positive patients, high total TLG (p = 0.037, p = 0.0048, respectively) and advanced TNM stage (p = 0.048, p = 0.046, respectively) were independent prediction factors. In the triple-negative group, independent factors related to recurrence and death were high maximum SUVmax (p = 0.0014, p = 0.0003, respectively) and advanced TNM stage (p < 0.0001, p < 0.0001, respectively).

MATERIALS AND METHODS

Records of 546 stage I-III invasive breast cancer patients, including 344 estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, 110 HER2-positive, and 92 triple-negative cases, treated at four institutions were reviewed retrospectively. Harmonized primary tumor and nodal maximum SUVmax, metabolic tumor volume (MTV), and TLG indicated in pretreatment FDG-PET/CT results were analyzed. Evaluations of relationships of clinicopathological factors, volume-based quantitative parameters, recurrence-free survival (RFS), and overall survival (OS) for each subtype were performed with a Cox proportional hazards model and log-rank test.

CONCLUSIONS

The results indicated that potential surrogate markers for prognosis in patients with the three main subtypes of operable breast cancer include harmonized pretreatment quantitative volume-based FDG-PET/CT parameters, particularly whole-lesion SUVmax and TLG.

Visceral fat metabolic activity evaluated by preoperative 18F-FDG PET/CT significantly affects axillary lymph node metastasis in postmenopausal luminal breast cancer

Obesity is known to increase breast cancer risk and aggressiveness in postmenopausal luminal breast cancer and obesity-driven dysfunctional metabolic activity in visceral adipose tissue (VAT) is considered as one of the principal underlying mechanism. We aimed to investigate the relationship between VAT metabolic activity evaluated by preoperative ¹⁸F-FDG PET/CT and axillary lymph node (ALN) metastasis in postmenopausal luminal breast cancer patients. In total, 173 patients were enrolled in study. They all underwent preoperative ¹⁸F-FDG PET/CT and surgery. VAT metabolic activity was defined as the maximum standardized uptake value (SUVmax) of VAT divided by the SUVmax of subcutaneous adipose tissue (V/S ratio). In luminal breast cancer, the patients with ALN metastasis showed significantly higher V/S ratio than the patients without ALN metastasis. Furthermore, V/S ratio was significantly associated with ALN metastasis in luminal breast cancer patients. Erythrocyte sedimentation rate, which reflect the systemic inflammation, was significantly higher in ALN metastasis group than the negative ALN metastasis group in luminal breast cancer patients and showed significant positive correlation with V/S ratio. V/S ratio significantly affects the ALN metastasis status in postmenopausal luminal breast cancer patients and it may be useful as a potential biomarker of obesity-driven systemic inflammation associated with tumor aggressiveness.

Metabolic and volume-based parameters of (18F)FDG PET/CT for primary mass and axillary lymph node metastasis in patients with invasive ductal carcinoma: a retrospective analysis in relation to molecular subtype, axillary lymph node metastasis and immunohistochemistry and inflammatory markers

OBJECTIVE

To evaluate metabolic and volume-based parameters of 18-Fluorodeoxyglucose positron emission tomography/computed tomography ((F)FDG PET/CT) for primary mass and axillary lymph node (ALN) metastasis in relation to molecular subtype, and immunohistochemistry and inflammatory markers in patients with invasive ductal carcinoma.

METHODS

A total of 129 patients (mean±SD age: 49.2±13.0 years) with invasive ductal breast cancer who had (F)FDG PET/CT imaging prior to chemotherapy or surgery were included in this single-center retrospective study. Data on patient age, molecular subtype, ALN metastasis status, inflammatory markers, immunohistochemistry markers and (F)FDG PET/CT imaging parameters for primary mass and ALN were recorded.

RESULTS

ALN metastasis was evident in 52.7% of patients and associated with significantly higher median diameter (P=0.027), MTV (P<0.001) and TLG (P<0.001). NLR was positively correlated with all primary mass (p ranged from 0.041 to 0.001) and ALN (P ranged from 0.026 to <0.001) PET parameters. PET parameters did not change with respect to molecular subtype or immunohistochemistry markers. Primary mass and ALN metastasis PET parameters showed significant positive correlations for TLG (r=0.274, P=0.001) and SUVmax (r=0.358, P<0.001).

CONCLUSION

In conclusion, our findings in a retrospective cohort of invasive ductal breast cancer patients revealed primary mass PET parameters to significantly differ with respect to ALN metastasis status and NLR levels, but not according to molecular subtype or immunohistochemistry markers. Accordingly, our findings highlight the value of acquisition of preoperative PET/CT imaging and role of both metabolic and volume-based parameters in predicting aggressiveness of the tumor as correlated with presence of ALN metastasis and high NLR.

The Evolving Role of FDG-PET/CT in the Diagnosis, Staging, and Treatment of Breast Cancer

The applications of 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/X-ray computed tomography (PET/CT) in the management of patients with breast cancer have been extensively studied. According to these studies, PET/CT is not routinely performed for the diagnosis of primary breast cancer, although PET/CT in specific subtypes of breast cancer correlates with histopathologic features of the primary tumor. PET/CT can detect metastases to mediastinal, axial, and internal mammary nodes, but it cannot replace the sentinel node biopsy. In detection of distant metastases, this imaging tool may have a better accuracy in detecting lytic bone metastases compared to bone scintigraphy. Thus, PET/CT is recommended when advanced-stage disease is suspected, and conventional modalities are inconclusive. Also, PET/CT has a high sensitivity and specificity to detect loco-regional recurrence and is recommended in asymptomatic patients with rising tumor markers. Numerous studies support the future role of PET/CT in prediction of response to neoadjuvant chemotherapy (NAC). PET/CT has a higher diagnostic value for prognostic risk stratification in comparison with conventional modalities. With the continuing research on the treatment planning and evaluation of patients with breast cancer, the role of PET/CT can be further extended.

Predictive value of primary tumor parameters using 18F-FDG PET/CT for occult lymph node metastasis in breast cancer with clinically negative axillary lymph node

OBJECTIVE

This study aimed to demonstrate the clinical significance of total lesion glycolysis (TLG) of primary breast cancer using ¹⁸F-FDG PET/CT to predict axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC) with a clinically negative axillary lymph node (cN-ALN).

METHODS

135 patients, newly diagnosed with IDC with _CN-ALN between July 2016 and October 2017, were retrospectively enrolled. We estimated primary tumor PET/CT parameters including the maximum standard uptake value (SUV_max), metabolic tumor volume (MTV), and TLG, as well as clinicopathologic findings. All patients received breast surgery followed by pathologic axillary lymph node examination.

RESULTS

Of the 135 patients, 31 (23.0%) were diagnosed with pathologically proven metastatic ALN. In univariate analysis, SUV_max, MTV, and TLG of the primary breast tumor were correlated with metastatic ALN along with tumor size, lymphovascular invasion, CD34, and D2-40. On multivariate analysis, TLG (> 5.74, p = 0.009) had independent significance for predicting ALN metastasis in IDC with cN-ALN.

CONCLUSION

We demonstrated that TLG of primary tumors can be useful in predicting pathologic ALN metastasis in IDC patients with cN-ALN.

Accuracy of a nomogram to predict the survival benefit of surgical axillary staging in T1 breast cancer patients

T1 breast cancer patients have favorable clinical outcomes, so that whether axillary stating (AS) surgery can be omitted in these patients is still unclear. This retrospective cohort study developed a nomogram to predict the cancer-specific survival (CSS) of T1 breast cancer patients with and without AS and estimate the survival benefit of AS in these patients.We used surveillance, epidemiology, and end results (SEER) database to identify 232,195 breast cancer patients with T1 tumors diagnosed between 1990 and 2008. In the training cohort, we used the Kaplan-Meier method and the competing risk analysis, with non-CSS as the competing risk, to screen for prognostic factors for CSS. A nomogram to predict the CSS, with receiving AS or not as one of the predictors, was developed and externally validated, using the C-index and calibration plots. The survival benefit of AS can be estimated by the difference of 2 predicted CSS, when the patient was considered as having and not having AS.With a median follow-up of 109 months, the CSS of the study population were 96.3%, 92.3%, and 88.5% at 5, 10, and 15 years, respectively. Significant predictors for CSS identified in the training cohort were used to develop a nomogram, which was validated internally [C-index = 0.707, 95% confidence interval (95% CI) 0.702-0.712] and externally (C-index = 0.704, 95% CI 0.698-0.710). The nomogram was well calibrated. With this nomogram, AS was predicted to have less than 2% benefit of 5-, 10-, and 15-year CSS in 60.6% (140,599/232,195), 15.5% (36,074/232,195), and 8.6% (20,043/232,195) of the entire study population, respectively.The new nomogram can accurately predict the CSS of T1 breast cancer patients, and also be able to estimate the survival benefit of AS in these patients. Prospective studies are needed to confirm our findings.

Volume-based metabolic parameter of breast cancer on preoperative 18F-FDG PET/CT could predict axillary lymph node metastasis

The purpose of our study was to evaluate the association between metabolic parameters on FDG PET/CT and axillary lymph node metastasis (ALNM) in patients with invasive breast cancer.From January 2012 to December 2012, we analyzed 173 patients with invasive ductal carcinoma (IDC) who underwent both initial breast magnetic resonance imaging (MRI) and F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examinations. All metabolic parameters were measured from the tumor volume segmented by a gradient-based method. Once the primary target lesion was segmented, maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were calculated automatically by the MIMvista software.Mean age of 173 patients was 49 years. Of 173 patients, 45 (26%) showed ALNM. On univariate analysis, larger tumor size (>2.2 cm; P = .002), presence of lymphovascular invasion (P < .001), higher SUVmax (>2.82; P = .038), higher SUVmean (>1.2; P = .027), higher MTV (>2.38; P < .001), and higher TLG (>3.98; P = .007) were associated with a higher probability of ALNM. On multivariate analysis, presence of lymphovascular invasion (adjusted odds ratio [OR], 11.053; 95% CI, 4.403-27.751; P < .001) and higher MTV (>2.38) (adjusted OR, 2.696; 95% CI, 1.079-6.739; P = .034) maintained independent significance in predicting ALNM. In subgroup analysis of T2/T3 breast cancer, lymphovascular invasion (adjusted OR, 20.976; 95% CI, 5.431-81.010; P < .001) and higher MTV (>2.38) (adjusted OR, 4.906; 95% CI, 1.616-14.896; P = .005) were independent predictors of ALNM. However in T1 breast cancer, lymphovascular invasion (adjusted OR, 16.096; 95% CI, 2.517-102.939; P = .003) and larger SUV mean (>1.2) (adjusted OR, 13.275; 95% CI, 1.233-142.908; P = .033) were independent predictors while MTV was not.MTV may be associated with ALNM in patients with invasive breast cancer, particularly T2 and T3 stages. In T1 breast cancer, SUVmean was associated with ALNM.

Biologic Profiles of Invasive Breast Cancers Detected Only With Digital Breast Tomosynthesis

OBJECTIVE

The purpose of this study was to analyze the clinicopathologic and immunohistochemical features of invasive breast cancers detected only with digital breast tomosynthesis (DBT), compared with those of cancers detected with both DBT and full-field digital mammography (FFDM).

MATERIALS AND METHODS

The medical records of 261 women (108 without and 153 with symptoms) with invasive breast cancers who underwent FFDM and DBT between April 2015 and June 2016 were retrospectively reviewed. To assess detectability, all DBT and FFDM images were reviewed independently by three radiologists blinded to clinicopathologic information. The reference standard was established by an unblinded consensus review of all images. Clinicopathologic and immunohistochemical features were analyzed according to the detectability status.

RESULTS

Of the 261 cancers, 223 (85.4%) were detected with both DBT and FFDM (both-detected group). Twenty-four cancers (9.2%) not detected with FFDM (DBT-only group) were classified by DBT as a mass (58.3%), architectural distortion (33.3%), or asymmetry (8.3%). The remaining 14 cancers (5.4%) were not detected with either DBT or FFDM (both-occult group). On multivariate analysis, a dense breast parenchyma (p = 0.007), small tumor size (≤ 2 cm; p = 0.027), and luminal A-like subtype (estrogen receptor positive or progesterone receptor positive or both, human epidermal growth factor receptor 2 negative, and Ki-67 expression < 14%; p = 0.008) were significantly associated with the DBT-only group. For 108 screening-detected cancers, a dense breast parenchyma (p = 0.007) and luminal A-like subtype (p = 0.008) also maintained significance.

CONCLUSION

The addition of DBT to FFDM in screening would aid in the detection of less-aggressive subtypes of invasive breast cancers in women with dense breasts.

Predictive Value of 18F-FDG PET/CT for Axillary Lymph Node Metastasis in Invasive Ductal Breast Cancer

BACKGROUND

This study assessed whether primary tumor maximum standardized uptake value (pSUV_max) measured by ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) could improve the prediction of axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC).

METHODS

In this study, 128 IDC patients who underwent pretreatment ¹⁸F-FDG PET/CT and surgical resection of primary tumor with sentinel lymph node biopsy, ALN dissection, or both were analyzed. All the patients were classified as five molecular subtypes. The optimal cutoff values of pSUVmax for all the patients and each molecular subtype for the prediction of ALN metastasis were determined using receiver operating characteristic (ROC) analysis. Furthermore, the prognostic accuracy of ALN metastasis was assessed using c-statistics.

RESULTS

The findings showed ALN metastasis in 52 patients (40.6%). The ¹⁸F-FDG PET/CT procedure had a sensitivity of 48.1% and a specificity of 94.7% for ALN metastasis. In the ROC analysis of pSUVmax for ALN metastasis, the optimal cutoff value was 3.9 for all the patients, 2.8 for the luminal A subtype, 3.3 for the luminal B (human epidermal growth factor receptor 2 [HER2]-negative) subtype, 5.3 for the luminal B (HER2-positive) subtype, 12.7 for the HER2-positive subtype, and 11.5 for the triple-negative subtype. A predictive ALN metastasis model using nodal ¹⁸F-FDG uptake finding gave a c-statistic of 0.714, and a model combination of nodal ¹⁸F-FDG uptake finding with pSUV_max of all the patients gave a c-statistic of 0.736 (P = 0.3926). However, the combination of nodal the ¹⁸F-FDG uptake finding with the pSUV_max of each molecular subtype gave a c-statistic of 0.791 (P = 0.0047).

CONCLUSIONS

Combining the pSUV_max of each molecular subtype with the nodal ¹⁸F-FDG uptake finding can improve the prediction of ALN metastasis in IDC.

Correlation between PET-CT maximum standardized uptake value and HER2 expression in gastric carcinoma

AIM: To investigate the relationship between the maximum standardized uptake value (SUVmax) and human epidermal growth factor receptor 2 (HER2) expression in gastric carcinoma.

METHODS: Sixty-one patients who underwent PET-CT at our hospital and had pathologically proven gastric adenocarcinoma were included, and SUVmax was measured. HER2 expression was detected by immunohistochemistry. The correlation between SUVmax and HER2 expression was analyzed statistically.

RESULTS: Of all the patients, 28 were positive for HER2, with a positive rate of 49.12%. The SUVmax for the HER2 positive group was 4.6448 ± 3.18597, which was significantly higher than that for the HER2 negative group (P = 0.000). There was a moderate positive correlation between SUVmax and HER2, and the correlation coefficient was 0.581. According to the ROC analysis, the area under the curve of SUVmax was 0.83. Taking 5.800 as the threshold of SUVmax, the corresponding sensitivity and specificity were 82.1% and 79.8%, respectively.

CONCLUSION: There is a moderate correlation between SUVmax and HER2 in gastric adenocarcinoma, and SUVmax can help assess the biological characteristics of gastric cancer.

Association between partial-volume corrected SUVmax and Oncotype DX recurrence score in early-stage, ER-positive/HER2-negative invasive breast cancer

PURPOSE

Oncotype DX, a 21-gene expression assay, provides a recurrence score (RS) which predicts prognosis and the benefit from adjuvant chemotherapy in patients with early-stage, estrogen receptor-positive (ER-positive), and human epidermal growth factor receptor 2-negative (HER2-negative) invasive breast cancer. However, Oncotype DX tests are expensive and not readily available in all institutions. The purpose of this study was to investigate whether metabolic parameters on (18)F-FDG PET/CT are associated with the Oncotype DX RS and whether (18)F-FDG PET/CT can be used to predict the Oncotype DX RS.

METHODS

The study group comprised 38 women with stage I/II, ER-positive/HER2-negative invasive breast cancer who underwent pretreatment (18)F-FDG PET/CT and Oncotype DX testing. On PET/CT, maximum (SUVmax) and average standardized uptake values, metabolic tumor volume, and total lesion glycolysis were measured. Partial volume-corrected SUVmax (PVC-SUVmax) determined using the recovery coefficient method was also evaluated. Oncotype DX RS (0 - 100) was categorized as low (<18), intermediate (18 - 30), or high (≥31). The associations between metabolic parameters and RS were analyzed. Multivariate logistic regression was used to identify significant independent predictors of low versus intermediate-to-high RS.

RESULTS

Of the 38 patients, 22 (58 %) had a low RS, 13 (34 %) had an intermediate RS, and 3 (8 %) had a high RS. In the analysis with 38 index tumors, PVC-SUVmax was higher in tumors in patients with intermediate-to-high RS than in those with low RS (5.68 vs. 4.06; P = 0.067, marginally significant). High PVC-SUVmax (≥4.96) was significantly associated with intermediate-to-high RS (odds ratio, OR, 10.556; P = 0.004) in univariate analysis. In multivariate analysis with clinicopathologic factors, PVC-SUVmax ≥4.96 (OR 8.459; P = 0.013) was a significant independent predictor of intermediate-to-high RS.

CONCLUSIONS

High PVC-SUVmax on (18)F-FDG PET/CT was significantly associated with an intermediate-to-high Oncotype DX RS. PVC metabolic parameters on (18)F-FDG PET/CT can be used to predict the Oncotype DX RS in patients with early-stage, ER-positive/HER2-negative breast cancer.

Glycolytic activity in breast cancer using 18F-FDG PET/CT as prognostic predictor: A molecular phenotype approach

AIM

To explore the relationship between basal (18)F-FDG uptake in breast tumors and survival in patients with breast cancer (BC) using a molecular phenotype approach.

MATERIAL AND METHODS

This prospective and multicentre study included 193 women diagnosed with BC. All patients underwent an (18)F-FDG PET/CT prior to treatment. Maximum standardized uptake value (SUVmax) in tumor (T), lymph nodes (N), and the N/T index was obtained in all the cases. Metabolic stage was established. As regards biological prognostic parameters, tumors were classified into molecular sub-types and risk categories. Overall survival (OS) and disease free survival (DFS) were obtained. An analysis was performed on the relationship between semi-quantitative metabolic parameters with molecular phenotypes and risk categories. The effect of molecular sub-type and risk categories in prognosis was analyzed using Kaplan-Meier and univariate and multivariate tests.

RESULTS

Statistical differences were found in both SUVT and SUVN, according to the molecular sub-types and risk classifications, with higher semi-quantitative values in more biologically aggressive tumors. No statistical differences were observed with respect to the N/T index. Kaplan-Meier analysis revealed that risk categories were significantly related to DFS and OS. In the multivariate analysis, metabolic stage and risk phenotype showed a significant association with DFS.

CONCLUSION

High-risk phenotype category showed a worst prognosis with respect to the other categories with higher SUVmax in primary tumor and lymph nodes.

Evaluation of lymph node status after neoadjuvant chemotherapy in breast cancer patients: comparison of diagnostic performance of ultrasound, MRI and ¹⁸F-FDG PET/CT

Objective:

To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities.

Methods:

From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis.

Results:

After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p < 0.001 and p = 0.009, respectively) and MRI (p = 0.045 and p = 0.036, respectively). The percentage diameter decrease, size of tumour deposit in LN, progesterone receptor, HER2 and histological grade were significantly associated with the diagnostic performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95–57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407–29.737).

Conclusion:

Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with diagnostic performance of ultrasound and PET/CT.

Advances in knowledge:

This study is about the diagnostic performance of ultrasound, MRI, PET/CT and combination of each imaging modality for the evaluation of metastatic ALN after NAC. Of many histopathological factors, only the size of tumour deposit within ALN was an independent factor associated with the diagnostic performance of ultrasound and PET/CT.

Early-stage invasive ductal carcinoma: Association of tumor apparent diffusion coefficient values with axillary lymph node metastasis

PURPOSE

To evaluate any association between tumor apparent diffusion coefficient (ADC) values and axillary lymph node metastasis (ALNM) in early-stage invasive ductal carcinoma.

MATERIALS AND METHODS

Records of 270 invasive ductal carcinoma patients with stages T1 and T2 disease who underwent breast magnetic resonance imaging, including diffusion-weighted imaging with b values of 0 and 1000s/mm(2) were reviewed retrospectively. The tumor ADC values were analyzed for their utility in predicting ALNM using multivariate regression analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

Of the 270 patients, 58 (21.5%) experienced ALNM. The mean tumor ADC values were significantly lower in patients with ALNM than in those without metastasis (0.880 × 10(-3) vs. 0.999 × 10(-3)mm(2)/s, P<0.001). A ROC curve demonstrated a tumor ADC value of 0.991 × 10(-3)mm(2)/s to be the optimal cut-off for predicting ALNM. In a multivariate analysis, lower tumor ADC (≤ 0.991 × 10(-3)mm(2)/s; adjusted odds ratio (OR)=5.861, P<0.001), large tumor size (>2 cm; adjusted OR=3.156, P=0.002) and the presence of lymphovascular invasion (adjusted OR=4.125, P<0.001) were independent variables associated with ALNM. When tumor ADC value was added to known risk factors (i.e., tumor size and lymphovascular invasion), a significant improvement in the accuracy of risk prediction for axillary node metastasis was shown (c-statistic=0.758 vs. 0.816, P=0.026).

CONCLUSION

In early-stage invasive ductal carcinoma, lower tumor ADC values are associated with the presence of ALNM.

Correlation between (18)F-FDG uptake on PET/CT and prognostic factors in triple-negative breast cancer

OBJECTIVES

The purpose of this study was to investigate whether a correlation exists between (18)F-fluorodeoxyglucose (FDG) uptake and prognostic factors in triple-negative breast cancer (TNBC).

METHODS

Between January 2009 and December 2013, 103 patients (mean age, 50.6 years) with primary TNBC (mean, 2.6 cm; range, 1.0-6.5 cm) underwent (18)F-FDG PET/CT for initial staging. Correlations between maximum standardized uptake value (SUVmax) on PET/CT and prognostic factors including tumour size, nodal status, histological grade, Ki-67 proliferation index, tumour suppressor p53, and 'basal-like' markers (epidermal growth factor receptor and CK 5/6) were assessed.

RESULTS

The mean SUVmax of the 103 tumours was 10.94 ± 5.25 (range: 2-32.8). There was a positive correlation between SUVmax and Ki-67 (Spearman's rho = 0.29, P = 0.003) and tumour size (Spearman's rho = 0.27, P = 0.006), whereas this relationship was not observed in the nodal status, histological grade, p53 status and 'basal-like' phenotypes. In a multivariate regression analysis, Ki-67 (P < 0.001) and tumour size (P = 0.009) were significantly associated with SUVmax in TNBCs.

CONCLUSIONS

Increased (18)F-FDG uptake on PET/CT was correlated with a high Ki-67 proliferation index and larger tumour size in TNBC. These results suggest a potential role of (18)F-FDG PET/CT in identifying TNBC with more aggressive behaviour.

KEY POINTS

• A wide range of FDG uptake reflected heterogeneity of cancer metabolism. • FDG uptake was correlated with the Ki-67 proliferation index in TNBC. • FDG uptake was correlated with tumour size in TNBC. • FDG uptake was not correlated with 'basal-like' phenotype.

Positron Emission Tomography in Breast Cancer

Gradually, FDG-PET/CT has been strengthening within the diagnostic algorithms of oncological diseases. In many of these, PET/CT has shown to be useful at different stages of the disease: diagnosis, staging or re-staging, treatment response assessment, and recurrence. Some of the advantages of this imaging modality versus CT, MRI, bone scan, mammography, or ultrasound, are based on its great diagnostic capacity since, according to the radiopharmaceutical used, it reflects metabolic changes that often occur before morphological changes and therefore allows us to stage at diagnosis. Moreover, another advantage of this technique is that it allows us to evaluate the whole body so it can be very useful for the detection of distant disease. With regard to breast cancer, FDG-PET/CT has proven to be important when recurrence is suspected or in the evaluation of treatment response. The technological advancement of PET equipment through the development of new detectors and equipment designed specifically for breast imaging, and the development of more specific radiopharmaceuticals for the study of the different biological processes of breast cancer, will allow progress not only in making the diagnosis of the disease at an early stage but also in enabling personalized therapy for patients with breast cancer.