(18) F-FDG PET/CT for initial staging in breast cancer patients - Is there a relevant impact on treatment planning compared to conventional staging modalities?

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.

Role of [18F]FDG PET/CT in patients with invasive breast carcinoma of no special type: Literature review and comparison between guidelines

PURPOSE

The recently released EANM/SNMMI guideline, endorsed by several important clinical and imaging societies in the field of breast cancer (BC) care (ACR, ESSO, ESTRO, EUSOBI/ESR, EUSOMA), emphasized the role of [18F]FDG PET/CT in management of patients with no special type (NST) BC. This review identifies and summarizes similarities, discrepancies and novelties of the EANM/SNMMI guideline compared to NCCN, ESMO and ABC recommendations.

METHODS

The EANM/SNMMI guideline was based on a systematic literature search and the AGREE tool. The level of evidence was determined according to NICE criteria, and 85 % agreement or higher was reached regarding each statement. Comparisons with NCCN, ESMO and ABC guidelines were examined for specific clinical scenarios in patients with early stage through advanced and metastatic BC.

RESULTS

Regarding initial staging of patients with NST BC, [18F]FDG PET/CT is the preferred modality in the EANM-SNMMI guideline, showing superiority as a single modality to a combination of contrast-enhanced CT of thorax-abdomen-pelvis plus bone scan in head-to-head comparisons and a randomized study. Its use is recommended in patients with clinical stage IIB or higher and may be useful in certain stage IIA cases of NST BC. In NCCN, ESMO, and ABC guidelines, [18F]FDG PET/CT is instead recommended as complementary to conventional imaging to solve inconclusive findings, although ESMO and ABC also suggest [18F]FDG PET/CT can replace conventional imaging for staging patients with high-risk and metastatic NST BC. During follow up, NCCN and ESMO only recommend diagnostic imaging if there is suspicion of recurrence. Similarly, EANM-SNMMI states that [18F]FDG PET/CT is useful to detect the site and extent of recurrence only when there is clinical or laboratory suspicion of recurrence, or when conventional imaging methods are equivocal. The EANM-SNMMI guideline is the first to emphasize a role of [18F]FDG PET/CT for assessing early metabolic response to primary systemic therapy, particularly for HER2+ BC and TNBC. In the metastatic setting, EANM-SNMMI state that [18F]FDG PET/CT may help evaluate bone metastases and determine early response to treatment, in agreement with guidelines from ESMO.

CONCLUSIONS

The recently released EANM/SNMMI guideline reinforces the role of [18F]FDG PET/CT in the management of patients with NST BC supported by extensive evidence of its utility in several clinical scenarios.

Clinical implications of non-breast cancer related findings on FDG-PET/CT scan prior to neoadjuvant chemotherapy in patients with breast cancer

PURPOSE

Breast cancer (BC) patients undergoing FDG-PET/CT scans for neoadjuvant chemotherapy (NAC) may have additional non-BC related findings. The aim of this study is to describe the clinical implications of these findings.

METHODS

We included BC patients who underwent an FDG-PET/CT scan in our institute between 2011-2020 prior to NAC. We focused on patients with an additional non-BC related finding (i.e. BC metastases were excluded) for which diagnostic work-up was performed. Information about the diagnostic work-up and the clinical consequences was retrospectively gathered. A revision of all FDG-PET/CT scans was conducted by an independent physician to assess the suspicion level of the additional findings.

RESULTS

Of the 1337 patients who underwent FDG-PET/CT, 202 patients (15%) had an non-BC related additional finding for which diagnostic work-up was conducted, resulting in 318 examinations during the first year. The non-BC related findings were mostly detected in the endocrine region (26%), gastro-intestinal region (16%), or the lungs (15%). Seventeen patients (17/202: 8%, 17/1337: 1.3%) had a second primary malignancy. Only 8 patients (8/202: 4%, 8/1337: 0.6%) had a finding that was considered more prognosis-determining than their BC disease. When revising all FDG-PET/CT scans, 57 (202/57: 28%) of the patients had an additional finding categorized as low suspicious, suggesting no indication for diagnostic work-up.

CONCLUSION

FDG-PET/CT scans used for dissemination imaging in BC patients detect a high number of non-BC related additional findings, often clinically irrelevant and causing a large amount of unnecessary work-up. However, in 8% of the patients undergoing diagnostic work-up for an additional finding, a second primary malignancy was detected, warranting diagnostic attention in selected patients.

PET Molecular Imaging in Breast Cancer: Current Applications and Future Perspectives

Positron emission tomography (PET) plays a crucial role in breast cancer management. This review addresses the role of PET imaging in breast cancer care. We focus primarily on the utility of 18F-fluorodeoxyglucose (FDG) PET in staging, recurrence detection, and treatment response evaluation. Furthermore, we delve into the growing interest in precision therapy and the development of novel radiopharmaceuticals targeting tumor biology. This includes discussing the potential of PET/MRI and artificial intelligence in breast cancer imaging, offering insights into improved diagnostic accuracy and personalized treatment approaches.

Therapeutic impact of 18F-FDG PET/CT for initial staging in patients with clinical stage I and IIA, HER2-positive, or triple-negative breast cancer

PURPOSE

While 18F-FDG PET/CT (FDG-PET/CT) is consensual for clinical stage ≥ IIB breast cancers (BC), its benefit for stage I or IIA HER2+ or triple-negative breast cancer (TNBC) patients lacks sufficient evidence. We reported a single-institution, retrospective study evaluating FDG-PET/CT impact on patient management and staging for stage I or IIA HER2+ or Triple-Negative BC.

METHODS

Patients who underwent FDG-PET/CT staging before any treatment between January 2015 and December 2020 at Oscar Lambret Center were included.

EXCLUSIONS

patients with symptoms or conventional imaging suggestive of metastatic dissemination, or with prior malignancies. Initial stage was determined from mammography, breast ultrasound, breast MRI, and clinical examination. Staging and therapeutic impact based on FDG-PET/CT findings collected, including intra- (modification of dose/site/strategy in a type of management previously indicated) and inter-modality (modification of planned treatment strategy) changes.

RESULTS

The cohort included 287 female patients with clinical stage I or IIA, HER2+ , or TNBC. Therapeutic impact observed for 18% of patients (n = 52), with 2% (n = 7) undergoing inter-modality change with omission of planned surgery. The impact on patient management was higher for stage IIA patients (20%, 47/237) than for stage I patients (10%, 5/50). Among stage IIA disease, changes in management were more important for T2N0 patients (22%, 44/205) than for T1N1 patients (9%, 3/32). While not statistically significant, trends suggest usefulness of FDG-PET/CT for T2N0 patients.

CONCLUSION

Considering substantial therapeutic implications, our study suggests the usefulness of FDG-PET/CT for patients with stage IIA, HER2-positive, or Triple-Negative BC with tumor size > 2 cm (T2N0).

Time trends in real-world treatment patterns and survival in patients diagnosed with de novo HER2+ metastatic breast cancer: an analysis of the SONABRE registry

PURPOSE

The aim was to determine whether the real-world first-line progression-free survival (PFS) of patients diagnosed with de novo human epidermal growth factor receptor 2 positive (HER2+) advanced breast cancer (ABC) has improved since the introduction of pertuzumab in 2013. In addition to PFS, we aimed to determine differences in overall survival (OS) and the use of systemic and locoregional therapies.

METHODS

Included were patients systemically treated for de novo HER2+ ABC in ten hospitals in 2008-2017 from the SONABRE Registry (NCT-03577197). First-line PFS and OS in 2013-2017 versus 2008-2012 was determined using Kaplan-Meier analyses and multivariable Cox proportional hazards modelling. First-given systemic therapy and the use of locoregional therapy within the first year following diagnosis were determined per period of diagnosis.

RESULTS

Median and five-year PFS were 26.6 months and 24% in 2013-2017 (n = 85) versus 14.5 months and 10% in 2008-2012 (n = 81) (adjusted HR = 0.65, 95%CI:0.45-0.94). Median and five-year OS were 61.2 months and 51% in 2013-2017 versus 26.1 months and 28% in 2008-2012 (adjusted HR = 0.55, 95%CI:0.37-0.81). Of patients diagnosed in 2013-2017 versus 2008-2012, 84% versus 60% received HER2-targeted therapy and 59% versus 0% pertuzumab-based therapy as first-given therapy. Respectively, 27% and 23% of patients underwent locoregional breast surgery, and 6% and 7% surgery of a metastatic site during the first year following diagnosis.

CONCLUSION

The prognosis of patients with de novo HER2 + ABC has improved considerably. Since 2013 one in four patients were alive and free from progression on first-given therapy for at least five years.

Treatment and survival of patients diagnosed with high-risk HR+/HER2- breast cancer in the Netherlands: a population-based retrospective cohort study

BACKGROUND

Several factors may increase the risk of recurrence of patients diagnosed with hormone receptor-positive human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer (BC). We aim to determine the proportion of patients with high-risk HR+/HER2- BC within the total HR+/HER2- BC cohort and compare their systemic treatments and survival rates with those of patients with low- and intermediate-risk HR+/HER2- BC and triple-negative (TN) BC.

PATIENTS AND METHODS

Women diagnosed with nonmetastatic invasive HR+/HER2- BC and TNBC in the Netherlands between 2011 and 2019 were identified from the Netherlands Cancer Registry. Patients with HR+/HER2- BC were categorised according to risk profile, defined by nodal status, tumour size, and histological grade. High-risk HR+/HER2- BC was defined by either four or more positive lymph nodes or one to three positive lymph nodes with a tumour size of ≥5 cm or a histological grade 3 tumour. Overall survival (OS) and relative survival (RS) were calculated using the Kaplan-Meier and Pohar-Perme method.

RESULTS

In this study of 87 455 patients with HR+/HER2- BC, 44 078 (50%) patients were diagnosed with low risk, 28 452 (33%) with intermediate risk, and 11 285 (13%) with high-risk HR+/HER2- BC. In 3640 (4%) patients, the risk profile could not be defined. Endocrine therapy and chemotherapy were used in 38% and 7% of low-risk, 90% and 47% of intermediate-risk, and 94% and 73% of high-risk patients, respectively. The 10-year OS and RS rates were 84.1% [95% confidence interval (95% CI) 83.5% to 84.7%] and 98.7% (95% CI 97.3% to 99.4%) in low-risk, 75.1% (95% CI 74.2% to 76.0%) and 91.7% (95% CI 89.7% to 93.3%) in intermediate-risk, and 63.4% (95% CI 62.0% to 64.7%) and 72.3% (70.1% to 74.3%) in high-risk patients. The 10-year OS and RS rates of 12 689 patients with TNBC were 69.7% (95% CI 68.6% to 70.8%) and 79.1% (95% CI 77.0% to 80.9%), respectively.

CONCLUSION

The poor prognosis of patients with high-risk HR+/HER2- BC highlights the need for a better acknowledgement of this subgroup and supports ongoing clinical trials aimed at optimising systemic therapy.

Intra and peritumoral PET radiomics analysis to predict the pathological response in breast cancer patients receiving neoadjuvant chemotherapy

OBJECTIVE

The aim of our study was to evaluate the contribution of 18Fluorine-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) radiomic data obtained from both the tumoral and peritumoral area in predicting pathological complete response (pCR) in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy (NAC).

METHODS

Female patients with a diagnosis of invasive ductal carcinoma who received NAC were evaluated retrospectively. The volume of interest (VOI) of the primary tumor (VOI-T) was manually segmented, then a voxel-thick VOI was added around VOI-T to define the peritumoral area (VOI-PT). Morphological, intensity-based, histogram and texture parameters were obtained from VOIs. The patients were divided into two groups as pCR and non-complete pathological response (npCR). A "radiomic model" was created with only radiomic features, and a "patho-radiomic model" was created using radiomic features and immunohistochemical data.

RESULTS

Of the 66 patients included in the study, 21 were in the pCR group. The only statistically significant feature from the primary tumor among patients with pCR and npCR was Morphological_Compacity-T (AUC: 0.666). Between response groups, a significant difference was detected in 2 morphological, 1 intensity, 4 texture features from VOI-PT; no correlation was found between Morphological_Compacity-PT and NGTDM_contrast-PT. The obtained radiomic model's sensitivity and accuracy values were calculated as 61.9% and 75.8%, respectively (AUC: 0.786). When HER2 status was added, sensitivity and accuracy values of the patho-radiomic model increased to 85.7% and 81.8%, respectively (AUC: 0.903).

CONCLUSIONS

Evaluation of PET peritumoral radiomic features together with the primary tumor, rather than just the primary tumor, provides a better prediction of the pCR to NAC in patients with breast cancer.

The Current and Future Roles of Precision Oncology in Advanced Breast Cancer

Breast cancer is a common but heterogeneous disease characterized by several biologic features, including tumor grade, hormone receptor status, human epidermal growth factor receptor 2 status, and gene expression assays. These biologic and genomic features drive treatment decisions. In the advanced disease setting, inter- and intrapatient tumor heterogeneity is increasingly recognized as a challenge for optimizing treatment. Recent evidence and the recent approval of novel radiopharmaceuticals have increased recognition and acceptance of the potential of molecular imaging as a biomarker to impact and guide management decisions for advanced breast cancer.

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.

Breast Cancer Systemic Staging (Comparison of Computed Tomography, Bone Scan, and 18F-Fluorodeoxyglucose PET/Computed Tomography)

After an overview of the principles of bone scintigraphy, contrast-enhanced computed tomography (CE-CT) and 18F-fluorodeoxyglucose (FDG)-PET/CT, the advantages and limits of these modalities in the staging of breast cancer are discussed in this paper. CT and PET/CT are not optimal for delineating primary tumor volume, and PET is less efficient than the sentinel node biopsy to depict small axillary lymph node metastases. In large breast cancer tumor, FDG PET/CT is useful to show extra-axillary lymph nodes. FDG PET/CT is superior to bone scan and CE-CT in detecting distant metastases, and it results in a change of treatment plan in nearly 15% of patients.

The current role of nuclear medicine in breast cancer

Breast cancer is the most common cancer in females worldwide. Nuclear medicine plays an important role in patient management, not only in initial staging, but also during follow-up. Radiopharmaceuticals to study breast cancer have been used for over 50 years, and several of these are still used in clinical practice, according to the most recent guideline recommendations.In this critical review, an overview of nuclear medicine procedures used during the last decades is presented. Current clinical indications of each of the conventional nuclear medicine and PET/CT examinations are the focus of this review, and are objectively provided. Radionuclide therapies are also referred, mainly summarising the methods to palliate metastatic bone pain. Finally, recent developments and future perspectives in the field of nuclear medicine are discussed. In this context, the promising potential of new radiopharmaceuticals not only for diagnosis, but also for therapy, and the use of quantitative imaging features as potential biomarkers, are addressed.Despite the long way nuclear medicine has gone through, it looks like it will continue to benefit clinical practice, paving the way to improve healthcare provided to patients with breast cancer.

Added value of repeat sentinel lymph node biopsy in FDG-PET/CT node-negative patients with ipsilateral breast cancer recurrence

PURPOSE

Repeat sentinel lymph node biopsy (rSLNB) has been suggested for axillary staging in clinically node-negative (cN0) patients with ipsilateral breast tumor recurrence (IBTR). Although rSLNB is technically feasible in this group of patients, the clinical value has not been established. We aimed to assess the added value of rSLNB in cN0 patients with IBTR who underwent optimal clinical staging with FDG-PET/CT.

METHODS

This retrospective single-center cohort study included 119 patients with IBTR-staged cT1-4N0M0 with FDG-PET/CT who underwent rSLNB between 2006 and 2020. Overall recurrence-free survival (RFS) and overall survival (OS) were calculated for subgroups with tumor-positive, tumor negative, and unsuccessful rSLNB.

RESULTS

rSLNB was successful in 79 (66%) of the 119 included patients, of whom 70 (59%) had a tumor negative and 9 (8%) a tumor-positive rSLNB; rSLNB was unsuccessful in the remaining 40 (34%) patients. Patients with a tumor-positive rSLNB had poorer overall 5-year RFS compared to patients with a tumor negative or unsuccessful rSLNB (44% vs. 86% vs. 90%, p = 0.004). Although patients with a tumor-positive rSLNB had worse RFS, the 10-year OS was comparable to a tumor negative or unsuccessful rSLNB (89% vs. 89% vs. 95%, p = 0.701).

CONCLUSION

The incidence of a tumor-positive rSLNB in patients with a negative FDG-PET/CT is low and does not change survival. Therefore, in cN0 patients with IBTR who underwent optimal clinical staging with FDG-PET/CT, we support a patient- and tumor-tailored treatment strategy in which rSLNB may be omitted.

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.

FDG-PET/CT for Primary Staging and Detection of Recurrence of Breast Cancer

Breast cancer is the most frequent cancer diagnosed in women worldwide. Accurate baseline staging is necessary to plan optimal breast cancer management. Early detection and staging of recurrence are also essential for optimal therapeutic management. Hybrid FDG-PET/CT imaging offers high sensitivity in detecting extra axillary lymph nodes and distant metastases. Although FDG-PET/CT has some limitations for low proliferative tumors, low-grade tumors and for well-differentiated luminal breast cancer, PET/CT is useful for the initial staging of breast cancer, regardless of tumor phenotype (luminal, triple negative, or HER2+) and of tumor grade. Although FDG-PET/CT performs better for invasive ductal carcinoma (invasive carcinoma of no specific subtype), it is also helpful for staging invasive lobular carcinomas. At initial staging, FDG-PET/CT becomes very useful for staging from clinical stage IIB (T2N1 or T3N0). FDG-PET/CT could be useful in patients with clinical stage IIA (T1N1 or T2N0), but there is not enough strong evidence to recommend routine use in this subgroup. For clinical stage I (T1N0) patients, FDG-PET/CT offers no added value. In patients with recurrent breast cancer, FDG-PET/CT is more effective than conventional imaging in detecting locoregional or distant recurrence, whether suspected by clinical examination, conventional imaging, or elevation of a tumor marker (CA 15.3 or CEA). PET/CT is effective even in the presence of normal tumor markers. PET/CT is also a powerful imaging modality for performing a whole-body workup of a known recurrence and for determining whether or not the recurrence is isolated.

St Gallen 2019 guidelines understage the axilla in lobular breast cancer: a population-based study

BACKGROUND

The St Gallen 2019 guidelines for primary therapy of early breast cancer recommend omission of completion axillary lymph node dissection (cALND), regardless of histological type, in patients with one or two sentinel lymph node (SLN) metastases. Concurrently, adjuvant chemotherapy is endorsed for luminal A-like disease with four or more axillary lymph node (ALN) metastases. The aim of this study was to estimate the proportion of patients with invasive lobular cancer (ILC) versus invasive ductal cancer of no special type (NST) with one or two SLN metastases for whom cALND would have led to a recommendation for adjuvant chemotherapy.

METHODS

Patients with ILC and NST who had surgery between 2014 and 2017 were identified in the National Breast Cancer Register of Sweden. After exclusion of patients with incongruent or missing data, those who fulfilled the St Gallen 2019 criteria for cALND omission were included in the population-based study cohort.

RESULTS

Some 1886 patients in total were included in the study, 329 with ILC and 1507 with NST. Patients with ILC had a higher metastatic nodal burden and were more likely to have a luminal A-like subtype than those with NST. The prevalence of at least four ALN metastases was higher in ILC (31.0 per cent) than NST (14.9 per cent), corresponding to an adjusted odds ratio of 2.26 (95 per cent c.i. 1.59 to 3.21). Luminal A-like breast cancers with four or more ALN metastases were over-represented in ILC compared with NST, 52 of 281 (18.5 per cent) versus 43 of 1299 (3.3 per cent) (P < 0.001).

CONCLUSION

Patients with ILC more often have luminal A-like breast cancer with at least four nodal metastases. Omission of cALND in patients with luminal A-like invasive lobular cancer and one or two SLN metastases warrants future attention as there is a risk of nodal understaging and undertreatment in one-fifth of patients.

Breast cancer: initial workup and staging with FDG PET/CT

Purpose

Precise staging is needed to plan optimal management in breast cancer. 18F-fluorodeoxyglucose positron emission tomography coupled with computed tomography (FDG-PET/CT) offers high sensitivity in detecting extra axillary lymph nodes and distant metastases. This review aims to clarify in which groups of patients staging with FDG-PET/CT would be beneficial and should be offered. We also discuss how tumor biology and breast cancer subtypes should be taken into account when interpreting FDG-PET/CT scans.

Methods

We performed a comprehensive literature review and rigorous appraisal of research studies assessing indications for FDG-PET/CT in breast cancer. This assessment regarding breast cancer served as a basis for the recommendations set by a working group of the French Society of Nuclear Medicine, in collaboration with oncological societies, for developing good clinical practice recommendations on the use of FDG-PET/CT in oncology.

Results

FDG-PET/CT is useful for initial staging of breast cancer, independently of tumor phenotype (triple negative, luminal or HER2 +) and regardless of tumor grade. Considering histological subtype, FDG-PET/CT performs better for staging invasive ductal carcinoma, although it is also helpful for staging invasive lobular carcinomas. Based on the available data, FDG-PET/CT becomes useful for staging starting from clinical stage IIB. FDG-PET/CT is possibly useful in patients with clinical stage IIA (T1N1 or T2N0), but there is not enough strong data to recommend routine use in this subgroup. For clinical stage I (T1N0) patients, staging with FDG-PET/CT offers no added value.

Conclusion

FDG-PET/CT is useful for staging patients with breast cancer, starting from clinical stage IIB.

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.

Baseline staging imaging for distant metastasis in women with stages I, II, and III breast cancer

Background

In Ontario, there is no clearly defined standard of care for staging for distant metastasis in women with newly diagnosed and biopsy-confirmed breast cancer whose clinical presentation is suggestive of early-stage disease. This guideline addresses baseline imaging investigations for women with newly diagnosed primary breast cancer who are otherwise asymptomatic for distant metastasis.

Methods

The medline and embase databases were systematically searched for evidence from January 2000 to April 2019, and the best available evidence was used to draft recommendations relevant to the use of baseline imaging investigation in women with newly diagnosed primary breast cancer who are otherwise asymptomatic. Final approval of this practice guideline was obtained from both the Staging in Early Stage Breast Cancer Advisory Committee and the Report Approval Panel of the Program in Evidence-Based Care.

Recommendations

These recommendations apply to all women with newly diagnosed primary breast cancer (originating in the breast) who have no symptoms of distant metastasis Staging tests using conventional anatomic imaging [chest radiography, liver ultrasonography, chest-abdomen-pelvis computed tomography (ct)] or metabolic imaging modalities [integrated positron-emission tomography (pet)/ct, integrated pet/magnetic resonance imaging (mri), bone scintigraphy] should not be routinely ordered for women newly diagnosed with clinical stage i or stage ii breast cancer who have no symptoms of distant metastasis, regardless of biomarker status. In women newly diagnosed with stage iii breast cancer, baseline staging tests using either anatomic imaging (chest radiography, liver ultrasonography, chest-abdomen-pelvis ct) or metabolic imaging modalities (pet/ct, pet/mri, bone scintigraphy) should be considered regardless of whether the patient is symptomatic for distant metastasis and regardless of biomarker profile.

18F-fluorodeoxyglucose PET/computed tomography in locoregional staging and assessment of biological and clinical aggressiveness of breast cancer subtypes

OBJECTIVE

We aimed to evaluate the availability of fluorine-18-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in initial axillary lymph node (ALN) staging in breast cancer. The secondary objective is to evaluate the role of FDG PET/CT as a pretest in sentinel lymph node biopsy vs. axillary lymph node dissection when predicting disease aggressiveness.

METHODS

The study evaluated retrospectively 194 breast cancer patients who underwent preoperative 18F-FDG. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FDG PET/CT for ALN metastases were confirmed with histopathology as the gold standard.

RESULTS

The value of the area under curve (AUC), sensitivity and specificity for ALN metastases were determined as 0.847, 78.8% and 92.6%, respectively. The cut-off value of the maximum standardized uptake value (SUVmax) for metastatic ALN detection was calculated as 1.79. PPV, NPV and the accuracy of 18F-FDG PET/CT were 0.933 (93.3%), 0.75 (75%) and 0.837 (83.7%), respectively. The SUVmax value of the primary lesion was significantly correlated with grade, estrogen receptor (ER) status, progesterone receptor (PR) status, SUVmax value of metastatic ALN, Her-2 status and Ki-67 level. Molecular subtypes revealed no statistically significant difference in terms of mean SUVmax value.

CONCLUSION

High values of AUC, sensitivity, specificity, NPV and PPV encourage utilization of PET/CT for locoregional staging of nonmetastatic breast carcinoma. The significant correlation between the primary tumor SUVmax value and grade, ER status, PR status and Ki-67 level increases the prognostic predictive value of the preoperative PET/CT.

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

AIM

Our aim of this study was to evaluate the diagnostic accuracy of staging positron emission tomography/computed tomography (PET/CT) in early breast cancers (EBCs) and to assess its impact on disease management.

PATIENTS AND METHODS

We retrospectively reviewed preoperative PET/CT scans of patients from January 2015 to December 2018 with Stage I/II, clinically T1-T2 N0-N1 breast cancers. The diagnostic performance of PET/CT for nodal (N) and distant metastases (M), its correlation with patient/tumor-specific factors, and its impact on disease management were analyzed using histopathology/clinical follow-up as standards of reference.

RESULTS

Of 158 patients evaluated, 14% of patients were Stage I (T1N0), 60% were Stage IIA (T1N1, T2N0), and 26% were Stage IIB (T2N1). Sensitivity, specificity, and the diagnostic accuracy of PET/CT for axillary staging were 76%, 97%, and 84% and for distant metastasis evaluation were 100%, 98%, and 99%, respectively. The diagnostic accuracy of PET/CT for axillary staging was lower for low-grade, T1 tumors, postmenopausal group, and luminal A pathological subtype (77%, 84%, 81%, and 73%, respectively) compared to high-grade, T2 tumors, premenopausal group, and nonluminal A subtype (88%, 88%, 94%, and 87%, respectively). Distant metastases were detected on PET/CT in overall 16% (n = 25) of the patients (9% in Stage IIA and 27% in Stage IIB). PET/CT also incidentally identified clinically occult internal mammary nodes in 5% (n = 8) and organ-confined synchronous second malignancies in 5% (n = 8) of the patients.

CONCLUSION

Preoperative PET/CT should be considered in all EBCs> 2 cm as it upstages the disease and alters management in about 24% of these patients. Given its high specificity for axillary staging PET/CT, patients with PET-positive axilla can be subjected to axillary dissection and those with PET-negative axilla to sentinel lymph node biopsy. The yield and diagnostic accuracy of PET/CT is less for low-grade tumors <2 cm and with luminal A subtype.

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.

Fully automated analysis for bone scintigraphy with artificial neural network: usefulness of bone scan index (BSI) in breast cancer

OBJECTIVE

Artificial neural network (ANN) technology has been developed for clinical use to analyze bone scintigraphy with metastatic bone tumors. It has been reported to improve diagnostic accuracy and reproducibility especially in cases of prostate cancer. The aim of this study was to evaluate the diagnostic usefulness of quantitative bone scintigraphy with ANN in patients having breast cancer.

PATIENTS AND METHODS

We retrospectively evaluated 88 patients having breast cancer who underwent both bone scintigraphy and ¹⁸F-fluorodeoxyglucose (FDG) positron-emission computed tomography/X-ray computed tomography (PET/CT) within an interval of 8 weeks between both examinations for comparison. The whole-body bone images were analyzed with fully automated software that was customized according to a Japanese multicenter database. The region of interest for FDG-PET was set to bone lesions in patients with bone metastasis, while the bone marrow of the ilium and the vertebra was used in patients without bone metastasis.

RESULTS

Thirty of 88 patients had bone metastasis. Extent of disease, bone scan index (BSI) which indicate severity of bone metastasis, the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and serum tumor markers in patients with bone metastasis were significantly higher than those in patients without metastasis. The Kaplan-Meier survival curve showed that the overall survival of the lower BSI group was longer than that with the higher BSI group in patients with visceral metastasis. In the multivariate Cox proportional hazard model, BSI (hazard ratio (HR): 19.15, p = 0.0077) and SUVmax (HR: 10.12, p = 0.0068) were prognostic factors in patients without visceral metastasis, while the BSI was only a prognostic factor in patients with visceral metastasis (HR: 7.88, p = 0.0084), when dividing the sample into two groups with each mean value in patients with bone metastasis.

CONCLUSION

BSI, an easily and automatically calculated parameter, was a well prognostic factor in patients with visceral metastasis as well as without visceral metastasis from breast cancer.

Screening for distant metastases in patients with ipsilateral breast tumor recurrence: the impact of different imaging modalities on distant recurrence-free interval

Purpose

In patients with ipsilateral breast tumor recurrence (IBTR), the detection of distant disease determines whether the intention of the treatment is curative or palliative. Therefore, adequate preoperative staging is imperative for optimal treatment planning. The aim of this study is to evaluate the impact of conventional imaging techniques, including chest X-ray and/or CT thorax-(abdomen), liver ultrasonography(US), and skeletal scintigraphy, on the distant recurrence-free interval (DRFI) in patients with IBTR, and to compare conventional imaging with ¹⁸F-FDG PET-CT or no imaging at all.

Methods

This study was exclusively based on the information available at time of diagnoses of IBTR. To adjust for differences in baseline characteristics between the three imaging groups, a propensity score (PS) weighted method was used.

Results

Of the 495 patients included in the study, 229 (46.3%) were staged with conventional imaging, 89 patients (19.8%) were staged with ¹⁸F-FDG PET-CT, and in 168 of the patients (33.9%) no imaging was used (N = 168). After a follow-up of approximately 5 years, 14.5% of all patients developed a distant recurrence as first event after IBTR. After adjusting for the PS weights, the Cox regression analyses showed that the different staging methods had no significant impact on the DRFI.

Conclusions

This study showed a wide variation in the use of imaging modalities for staging IBTR patients in the Netherlands. After using PS weighting, no statistically significant impact of the different imaging modalities on DRFI was shown. Based on these results, it is not possible to recommend staging for distant metastases using ¹⁸F-FDG PET-CT over conventional imaging techniques.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05205-z) contains supplementary material, which is available to authorized users.

18F-FDG PET/CT in breast cancer: Evidence-based recommendations in initial staging

Current guidelines do not systematically recommend 18F-FDG PET/CT for breast cancer staging; and the recommendations and level of evidence supporting its use in different groups of patients vary among guidelines. This review summarizes the evidence about the role of 18F-FDG PET/CT in breast cancer staging and the therapeutic and prognostic impact accumulated in the last decade. Other related aspects, such as the association of metabolic information with biology and prognosis are considered and evidence-based recommendations for the use of 18F-FDG PET/CT in breast cancer staging are offered. We systematically searched MEDLINE for articles reporting studies with at least 30 patients related to clinical questions following the Problem/Population, Intervention, Comparison, and Outcome framework. We critically reviewed the selected articles and elaborated evidence tables structuring the summarized information into methodology, results, and limitations. The level of evidence and the grades of recommendation for the use of 18F-FDG PET/CT in different contexts are summarized. Level III evidence supports the use of 18F-FDG PET/CT for initial staging in patients with recently diagnosed breast cancer; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a weak recommendation in this population. In patients with locally advanced breast cancer, level II evidence supports the use of 18F-FDG PET/CT for initial staging; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a strong recommendation in this population. In patients with recently diagnosed breast cancer, the metabolic information from baseline 18F-FDG PET/CT is associated with tumor biology and has prognostic implications, supported by level II evidence. In conclusion, 18F-FDG PET/CT is not recommended for staging all patients with early breast cancer, although evidence of improved regional and systemic staging supports its use in locally advanced breast cancer. Baseline tumor glycolytic activity is associated with tumor biology and prognosis.

Preoperative [18]fluorodeoxyglucose-positron emission tomography/computed tomography in early stage breast cancer: Rates of distant metastases

AIM

To investigate rates of distant metastases (DM) detected with [18]fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT) in early stage invasive breast cancer.

METHODS

We searched the English language literature databases of PubMed, EMBASE, ISI Web of Knowledge, Web of Science and Google Scholar, for publications on DM detected in patients who had 18FDG-PET/CT scans as part of the staging for early stages of breast cancer (stage I and II), prior to or immediately following surgery. Reports published between 2011 and 2017 were considered. The systematic review was conducted according to the PRISMA guidelines.

RESULTS

Among the 18 total studies included in the analysis, the risk of DM ranged from 0% to 8.3% and 0% to 12.9% for stage I and II invasive breast cancer, respectively. Among the patients with clinical stage II, the rate of occult metastases diagnosed by 18FDG-PET/CT was 7.2% (range, 0%-19.6%) for stage IIA and 15.8% (range, 0%-40.8%) for stage IIB. In young patients (< 40-year-old), 18FDG-PET/CT demonstrated a higher prevalence of DM at the time of diagnosis for those with aggressive histology (i.e., triple-negative receptors and poorly differentiated grade).

CONCLUSION

Young patients with poorly differentiated tumors and stage IIB triple-negative breast cancer may benefit from 18FDG-PET/CT at initial staging to detect occult DM prior to surgery.

Rate of Distant Metastases on 18F-FDG PET/CT at Initial Staging of Breast Cancer: Comparison of Women Younger and Older Than 40 Years

Women who have breast cancer and are younger than 40 y have a poorer outcome than older women. A higher rate of undetected metastases at the time of diagnosis in younger women has been proposed to account for this difference. Our main objective was to test this hypothesis by comparing the distant metastasis rate (DMR) on initial ¹⁸F-FDG PET/CT in a group of breast cancer patients younger than 40 y (<40 y group) with that in a group of breast cancer patients older than 40 y (≥40 y group). An assessment of associations between distant metastases and tumor characteristics was a second objective of the present study.

METHODS

A retrospective single-institution study was performed on women who had breast cancer and no prior malignancy, who were asymptomatic for metastatic lesions on initial clinical examination, and who had initial ¹⁸F-FDG PET/CT within 3 mo after pathologic breast cancer diagnosis and before initial treatment. On the basis of these criteria, data for 2 groups of women differing only in age (<40 y and ≥40 y) were extracted from the hospital information system of Curie Institute-Paris. ¹⁸F-FDG PET/CT examinations were reviewed, and the DMR was recorded for each clinical stage subgroup (stages I-III).

RESULTS

For each group (<40 y and ≥40 y), 107 patients were included, with the same number of patients in each clinical stage subgroup (12 stage I patients, 32 stage IIA patients, 30 stage IIB patients, and 33 stage III patients). The ages of the patients (mean ± SD) were 34.5 ± 4.0 y (<40 y group) and 56.0 ± 10.7 y (≥40 y group). No significant difference in DMRs was observed between the <40 y group and the ≥40 y group (DMRs, 21% and 22%, respectively; P = 1). The DMRs in patients not selected for age were 8% for stage I, 11% for stage IIA, 15% for stage IIB, and 44% for stage III.

CONCLUSION

The DMR was not significantly higher in younger breast cancer patients (<40 y) than in older breast cancer patients (≥40 y), ruling out the assumption that undetected metastases at diagnosis explain the poorer outcome of younger women. However, our results highlight the high yield of ¹⁸F-FDG PET/CT for initial breast cancer staging, even in stage II patients, whatever their age.

¹⁸F-FDG PET/CT for Staging and Restaging of Breast Cancer

Many studies have pointed out the role of (18)F-FDG PET/CT (or (18)F-FDG PET) in patients with clinical stage III or II breast cancer. (18)F-FDG PET/CT might advantageously replace other staging procedures, such as bone scanning and possibly contrast-enhanced CT of the thorax or abdomen-pelvis. We discuss the findings, locoregional or distant, that can be expected in different categories of breast cancer and their impact on prognosis and management. We also discuss the role of (18)F-FDG PET/CT in restaging and how (18)F-FDG PET/CT compares with conventional techniques in restaging for patients with suspected disease recurrence. We conclude with some recommendations for clinical practice and future research.

The diagnostic performance of sentinel lymph node biopsy in pathologically confirmed node positive breast cancer patients after neoadjuvant systemic therapy: A systematic review and meta-analysis

PURPOSE

To provide a systematic review and meta-analysis of studies investigating sentinel lymph node biopsy after neoadjuvant systemic therapy in pathologically confirmed node positive breast cancer patients.

METHODS

Pubmed and Embase databases were searched until June 19th, 2015. All abstracts were read and data extraction was performed by two independent readers. A random-effects model was used to pool the proportion for identification rate, false-negative rate (FNR) and axillary pCR with 95% confidence intervals. Subgroup analyses affirmed potential confounders for identification rate and FNR.

RESULTS

A total of 997 abstracts were identified and eventually eight studies were included. Pooled estimates were 92.3% (90.8-93.7%) for identification rate, 15.1% (12.7-17.6%) for FNR and 36.8% (34.2-39.5%) for axillary pCR. After subgroup analysis, FNR is significantly worse if one sentinel node was removed compared to two or more sentinel nodes (23.9% versus 10.4%, p = 0.026) and if studies contained clinically nodal stage 1-3, compared to studies with clinically nodal stage 1-2 patients (21.4 versus 13.1%, p = 0.049). Other factors, including single tracer mapping and the definition of axillary pCR, were not significantly different.

CONCLUSION

Based on current evidence it seems not justified to omit further axillary treatment in every clinically node positive breast cancer patients with a negative sentinel lymph node biopsy after neoadjuvant systemic therapy.

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.