Preoperative FDG-PET for axillary metastases in patients with breast cancer

Diagnostic Performance of FDG-PET/CT Scan as Compared to US-Guided FNA in Prediction of Axillary Lymph Node Involvement in Breast Cancer Patients

Purpose

The aim of this study was to evaluate the diagnostic ability of 2-deoxy-2-[fluorine-18]fluoro-d-glucose (¹⁸F-FDG) PET/non-contrast CT compared with those of ultrasound (US)-guided fine needle aspiration (FNA) for axillary lymph node (ALN) staging in breast cancer patients.

Patients and Methods

Preoperative ¹⁸F-FDG PET/non-contrast CT was performed in 268 women with breast cancer, as well as ALN dissection or sentinel lymph node (SLN) biopsy. One hundred sixty-four patients underwent US-guided FNA in combination with ¹⁸F-FDG PET/CT. The diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. The receiver operating characteristic (ROC) curves were compared to evaluate the diagnostic ability of several imaging modalities.

Results

Axillary ¹⁸F-FDG uptake was positive in 180 patients, and 125 patients had axillary metastases according to the final pathology obtained by ALN dissection and/or SLN dissection. Of the patients with positive ¹⁸F-FDG uptake in the axilla, 21% had false-positive results, whereas 79% were truly positive. Eighty-eight patients had negative ¹⁸F-FDG uptake in the axilla, among which 25% were false-negative. ¹⁸F-FDG-PET/CT had a sensitivity of 86.59% and a specificity of 63.46% in the assessment of ALN metastasis; on the other hand, US-guided FNA had a sensitivity of 91.67% and a specificity of 87.50%. The mean primary cancer size (p = 0.04) and tumor grade (p = 0.04) in combination were the only factors associated with the accuracy of ¹⁸F-FDG PET/CT for detecting metastatic ALNs.

Conclusion

The diagnostic performance of ¹⁸F-FDG PET/CT for the detection of axillary node metastasis in breast cancer patients was not significantly different from that of US-guided FNA. Combining ¹⁸F-FDG PET/CT with US-guided FNA or SLN biopsy could improve the diagnostic performance compared to ¹⁸F-FDG PET/CT alone.

Convolutional Neural Network of Multiparametric MRI Accurately Detects Axillary Lymph Node Metastasis in Breast Cancer Patients With Pre Neoadjuvant Chemotherapy

BACKGROUND

Accurate assessment of the axillary lymph nodes (aLNs) in breast cancer patients is essential for prognosis and treatment planning. Current radiological staging of nodal metastasis has poor accuracy. This study aimed to investigate the machine learning convolutional neural networks (CNNs) on multiparametric MRI to detect nodal metastasis with 18FDG-PET as ground truths.

MATERIALS AND METHODS

Data were obtained via a retrospective search. Inclusion criteria were patients with bilateral breast MRI and 18FDG-PETand/or CT scans obtained before neoadjuvant chemotherapy. In total, 238 aLNs were obtained from 56 breast cancer patients with 18FDG-PET and/or CT and breast MRI data. Radiologists scored each node based on all MRI as diseased and non-diseased nodes. Five models were built using T1-W MRI, T2-W MRI, DCE MRI, T1-W + T2-W MRI, and DCE + T2-W MRI model. Performance was evaluated using receiver operating curve (ROC) analysis, including area under the curve (AUC).

RESULTS

All CNN models yielded similar performance with an accuracy ranging from 86.08% to 88.50% and AUC ranging from 0.804 to 0.882. The CNN model using T1-W MRI performed better than that using T2-W MRI in detecting nodal metastasis. CNN model using combined T1- and T2-W MRI performed the best compared to all other models (accuracy = 88.50%, AUC = 0.882), but similar in AUC to the DCE + T2-W MRI model (accuracy = 88.02%, AUC = 0.880). All CNN models performed better than radiologists in detecting nodal metastasis (accuracy = 65.8%).

CONCLUSION

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Convolutional Neural Network Detection of Axillary Lymph Node Metastasis Using Standard Clinical Breast MRI

BACKGROUND

Axillary lymph node status is important for breast cancer staging and treatment planning as the majority of breast cancer metastasis spreads through the axillary lymph nodes. There is currently no reliable noninvasive imaging method to detect nodal metastasis associated with breast cancer.

MATERIALS AND METHODS

Magnetic resonance imaging (MRI) data were those from the peak contrast dynamic image from 1.5 Tesla MRI scanners at the pre-neoadjuvant chemotherapy stage. Data consisted of 66 abnormal nodes from 38 patients and 193 normal nodes from 61 patients. Abnormal nodes were those determined by expert radiologist based on ¹⁸Fluorodeoxyglucose positron emission tomography images. Normal nodes were those with negative diagnosis of breast cancer. The convolutional neural network consisted of 5 convolutional layers with filters from 16 to 128. Receiver operating characteristic analysis was performed to evaluate prediction performance. For comparison, an expert radiologist also scored the same nodes as normal or abnormal.

RESULTS

The convolutional neural network model yielded a specificity of 79.3% ± 5.1%, sensitivity of 92.1% ± 2.9%, positive predictive value of 76.9% ± 4.0%, negative predictive value of 93.3% ± 1.9%, accuracy of 84.8% ± 2.4%, and receiver operating characteristic area under the curve of 0.91 ± 0.02 for the validation data set. These results compared favorably with scoring by radiologists (accuracy of 78%).

CONCLUSION

The results are encouraging and suggest that this approach may prove useful for classifying lymph node status on MRI in clinical settings in patients with breast cancer, although additional studies are needed before routine clinical use can be realized. This approach has the potential to ultimately be a noninvasive alternative to lymph node biopsy.

Is sentinel lymph node biopsy a viable alternative to complete axillary dissection following neoadjuvant chemotherapy in women with node-positive breast cancer at diagnosis? An updated meta-analysis involving 3,398 patients

BACKGROUND

The use of sentinel lymph node biopsy (SLNB) following neoadjuvant chemotherapy (NAC) in patients presenting with clinically positive lymph nodes remains controversial.

METHODS

A computer-aided search of the literature regarding SLNB in clinically node-positive breast cancer treated with NAC was carried out to identify the false negative rate (FNR), sentinel lymph node identification rate (IR), and axillary pathological complete response (pCR).

RESULTS

Nineteen articles were used in the analysis yielding 3,398 patients. The pooled estimate of the FNR was 13% and that of the IR was 91%. The adjusted pCR rate was 47%. A trend toward significance was observed with only clinical stage N1 (cN1) disease whereby clinical stage N1 was associated with an increased pCR rate when compared to N2 or N3 disease (P = .06).

CONCLUSIONS

SLNB after NAC in biopsy-proven node-positive patients results in reasonably acceptable FNR and IR, making it a valid alternative management strategy to axillary dissection. More refined patient selection and optimal techniques can improve the FNR and IR in this patient population.

Virtual lymph node analysis to evaluate axillary lymph node coverage provided by tangential breast irradiation

PURPOSE

To investigate the coverage of axillary lymph node with tangential breast irradiation fields by using virtual lymph node (LN) analysis.

MATERIALS AND METHODS

Forty-eight women who were treated with whole breast irradiation after breast-conserving surgery were analyzed. The axillary and breast volumes were delineated according to the Radiation Therapy Oncology Group (RTOG) contouring atlas. To generate virtual LN contours, preoperative fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans with identifiable LN were fused with the CT scans, and the virtual LN contour were delineated on the CT.

RESULTS

The median level I and II axillary volume coverage percentages at the VD95% line were 33.5% (range, 5.3% to 90.4%) and 0.6% (range, 0.0% to 14.6%), respectively. Thirty-one LNs in 18 patients were delineated (26 in level I and 5 in level II). In the level I axilla, 84.6% of virtual LNs were encompassed by the 95% isodose line. In the level II axilla, by contrast, none of the virtual LNs were encompassed by the 95% isodose volumes. There was a substantial discrepancy between the RTOG contouring atlas-based axillary volume analysis and the virtual LN analysis, especially for the level I axillary coverage. The axillary volume coverage was associated with the body mass index (BMI) and breast volume.

CONCLUSION

The tangential breast irradiation did not deliver adequate therapeutic doses to the axillary region, particularly those in the level II axilla. Patients with small breast volumes or lower BMI showed reduced axillary coverage from the tangential breast fields. For axillary LN irradiation, individualized anatomy-based radiation fields for patients would be necessary.

(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?

OBJECTIVE

To evaluate the impact of whole-body (18) F-FDG PET/CT on initial staging of breast cancer in comparison to conventional staging modalities.

METHODS

This study included 102 breast cancer patients, 101 patients were eligible for evaluation. Preoperative whole-body staging with PET/CT was performed in patients with clinical stage ≥ T2 tumours or positive local lymph nodes (n = 91). Postoperative PET/CT was performed in patients without these criteria but positive sentinel lymph node biopsy (n = 10). All patients underwent PET/CT and a conventional staging algorithm, which included bone scan, chest X-ray and abdominal ultrasound. PET/CT findings were compared to conventional staging and the impact on therapeutic management was evaluated.

RESULTS

PET/CT led to an upgrade of the N or M stage in overall 19 patients (19 %) and newly identified manifestation of breast cancer in two patients (2 %). PET/CT findings caused a change in treatment of 11 patients (11 %). This is within the range of recent studies, all applying conventional inclusion criteria based on the initial T and N status.

CONCLUSIONS

PET/CT has a relevant impact on initial staging and treatment of breast cancer when compared to conventional modalities. Further studies should assess inclusion criteria beyond the conventional T and N status, e.g. tumour grading and receptor status.

KEY POINTS

• PET/CT may be relevant in staging breast cancer patients at higher risk for metastases • PET/CT may modify the N and M stage in multiple patients • PET/CT may impact treatment planning in breast cancer patients.

Dual time point 2-deoxy-2-[18F]fluoro-D-glucose PET/CT: nodal staging in locally advanced breast cancer

AIM

To assess dual time point 2-deoxy-2-[(18)F]fluoro-D-glucose (18)(F)FDG PET-CT accuracy in nodal staging and in detection of extra-axillary involvement.

MATERIAL AND METHODS

Dual time point [(18)F] FDG PET/CT scan was performed in 75 patients. Visual and semiquantitative assessment of lymph nodes was performed. Semiquantitative measurement of SUV and ROC-analysis were carried out to calculate SUV(max) cut-off value with the best diagnostic performance. Axillary and extra-axillary lymph node chains were evaluated.

RESULTS

Sensitivity and specificity of visual assessment was 87.3% and 75%, respectively. SUV(max) values with the best sensitivity were 0.90 and 0.95 for early and delayed PET, respectively. SUV(max) values with the best specificity were 1.95 and 2.75, respectively. Extra-axillary lymph node involvement was detected in 26.7%.

CONCLUSION

FDG PET/CT detected extra-axillary lymph node involvement in one-fourth of the patients. Semiquantitative lymph node analysis did not show any advantage over the visual evaluation.

Diagnostic and prognostic application of positron emission tomography in breast imaging: emerging uses and the role of PET in monitoring treatment response

Positron emission tomography (PET) is an imaging modality that using radiotracers, permits real-time dynamic monitoring of biologic processes such as cell metabolic behavior and proliferation, and has proven useful as a research tool for understanding tumor biology. While it does not have a well-defined role in breast cancer for the purposes of screening, diagnosis, or prognosis, emerging PET technologies and uses could expand the applications of PET in breast cancer. Positron emission mammography may provide an alternative adjunct imaging modality for the screening and diagnosis of high-risk patients unable to tolerate MRI. The development of radiotracers with the ability to measure hormonal activity could provide a non-invasive way to assess hormone receptor status and functionality. Finally, the role of PET technologies in monitoring early treatment response may prove particularly useful to research involving new therapeutic interventions.

Prognostic Significance of Metabolic Tumor Volume Measured by (18)F-FDG PET/CT in Operable Primary Breast Cancer

PURPOSE

We investigated whether PET indices measured by (18) F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) can predict prognosis in patients with operable primary breast cancer.

METHODS

We reviewed 53 patients with operable primary breast cancer who underwent pretreatment FDG PET/CT. PET indices, maximum standardized uptake value (SUV) and metabolic tumor volume (MTV), were measured in the primary breast tumor (P), metastatic lymph nodes (N) and total tumor (T). The Cox proportional hazards model was used with age, tumor size, clinical lymph node status, method of surgery, presence or absence of neoadjuvant chemotherapy, histological type, histological grade, hormone receptors and HER2 status to predict disease-free survival (DFS) and overall survival (OS).

RESULTS

Median follow-up period was 50 months (range, 17-73 months), during which 17 patients had recurrent disease and nine of whom died. The univariate analysis showed that high SUV of N (NSUV, P = 0.011), MTV of N (NMTV, P = 0.011) and MTV of T (TMTV, P = 0.045) as well as high histological grade (P = 0.008), negative estrogen (P = 0.045) and negative progesterone (P = 0.029) receptor status were associated with shorter DFS. High NSUV (P = 0.035), NMTV (P = 0.035) and TMTV (P = 0.035) as well as high histological grade (P = 0.012) and negative estrogen receptor status (P = 0.009) were associated with shorter OS. NSUV, NMTV and TMTV were found to be significantly associated with high histological grade (P = 0.005). However, those failed to be statistically significant prognostic factors on multivariate analysis.

CONCLUSIONS

PET indices seem to be useful in the preoperative evaluation of prognosis in patients with operable primary breast cancer. NSUV, NMTV and TMTV might be considerable factors associated with patient outcome in operable breast cancer.

The use of FDG-PET in assessing axillary lymph node status in breast cancer: a systematic review and meta-analysis of the literature

Axillary lymph node status is the most powerful prognostic indicator in patients with breast cancer. FDG-PET has been suggested as a non-invasive method of staging the axilla. The aim of this study was to review and aggregate all studies that measured the performance of FDG-PET in patients with breast cancer, using surgically obtained axillary histology as a reference, in a meta-analysis. A systematic review of the literature was performed and data extracted from all eligible studies. These were then analysed using meta-analysis software and summary receiver operating characteristic (SROC) curves were plotted for the aggregate data. The data was then tested to determine which parameters impacted on the sensitivity and specificity of the studies. Sensitivities ranging from 20 to 100% and specificities ranging from 65 to 100% have been reported. An aggregated ROC analysis found an area under the curve of 0.95 (95% CI 0.91-0.97) and a Q* value of 0.89 (95% CI 0.85-0.92) in a total of 25 studies involving 2,460 patients. The AUC and Q* values indicated little difference between the compared study characteristics. The performance of the technique currently remains below, which is required to replace assessment of axillary node status by surgical biopsy and histological assessment. However, sensitivity and specificity are high and FDG-PET may have a role to play under particular circumstances. Moreover, the additional benefit of an assessment of distal metastatic spread provided by FDG-PET requires further investigation.

The Role of Lymphatic Mapping and Sentinel Lymph Node Biopsy in the Staging of Breast Cancer

The widespread application of sentinel lymph node biopsy in the evaluation of patients with breast cancer has allowed for the more limited, selective treatment of regional lymph nodes and decreased the number of complete regional dissections performed in patients without nodal metastases. Surgical excision and pathologic evaluation of nodes for metastases allow for reliable staging and prediction of additional lymph node metastases. Sentinel lymph node biopsy also enables a meticulous histologic evaluation of multiple sections augmented by immunohistochemical staining. The current role of sentinel lymph node biopsy in the staging of breast cancer and ongoing controversies relating to the procedure are discussed.

[The role of preoperative investigation with 18-FDG-PET/CT in primary operable breast cancer]

INTRODUCTION

The widespread use of PET/CT has a potential to change oncological diagnosis fundamentally. In our study we intended to clarify if preoperative PET/CT was able to assess axillary lymph node status, and the potential of these to modify preliminary treatment plans based on conventional diagnostic methods.

PATIENTS AND METHODS

We carried out 18-FDG PET/CT before elective surgery in 52 primary operable breast cancer patients between February 2008 and February 2009 at the DEOEC Clinical Department of Surgery. Total body imaging was performed in all cases; scans were evaluated by two specialists first visually, then semi-quantitatively based on body mass-corrected lesion suvmax values. The assessments were compared with axillary ultrasound and final histological diagnosis.

RESULTS

Two patients were excluded from the study due to failure to report for further treatment. Based on the results obtained from the remaining 50 patients, PET/CT showed a sensitivity of 80%, a specificity of 100%, positive and negative predictive values of 100% and 84.6% respectively for detecting axillary lymph node metastases. The same figures for axillary ultrasound, in respective order, were 30%, 81.8%, 60% and 56.2%. Prompted by the PET/CT results, we modified 9 patients' (18%) preliminary, conventional diagnosis-based treatment schemes.

CONCLUSIONS

In case of a positive axillary PET/CT, it is unnecessary to perform SNB--axillary block dissection is called for with no further deliberation. Preoperative PET/CT can facilitate patient selection as regards possible benefit from neoadjuvant therapy. Preoperative PET/CT has a potential to modify the original management plan in about 15 to 20%. In case of a negative PET/CT scan, further studies are necessary to be able to spare the axilla from surgical intervention with confidence.

Multidisciplinary care for patients with breast cancer

The care of patients with breast cancer has become increasingly complex with advancements in diagnostic modalities, surgical approaches, and adjuvant treatments. A multidisciplinary approach to breast cancer care is essential to the successful integration of available therapies. This article addresses the key components of multidisciplinary breast cancer care, with a special emphasis on new and emerging approaches over the past 10 years in the fields of diagnostics, surgery, radiation, medical oncology, and plastic surgery.

Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in combination with ultrasonography for axillary staging in primary breast cancer

Background

Accurate evaluation of axillary lymph node (ALN) involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG PET/CT) and axillary ultrasonography (AUS) for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary ¹⁸F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB) and preoperative systemic chemotherapy (PSC).

Methods

One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent ¹⁸F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND). Using ¹⁸F-FDG PET/CT, we studied both a visual assessment of ¹⁸F-FDG uptake and standardized uptake value (SUV) for axillary staging.

Results

In a visual assessment of ¹⁸F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of ¹⁸F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either ¹⁸F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12) in ¹⁸F-FDG PET uptake only, 80% (4 of 5) in AUS positive only, and 100% (28 of 28) in dual positive. By the combination of AUS and ¹⁸F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary ¹⁸F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03).

Conclusion

The diagnostic accuracy of ¹⁸F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their limited sensitivities, the high radiation exposure by ¹⁸F-FDG PET/CT and also costs of the examination, it is likely that AUS will be more cost-effective in detecting massive axillary tumor burden. However, when we cannot judge the axillary staging using AUS alone, metabolic approach of ¹⁸F-FDG PET/CT for axillary staging would enable us a much more confident diagnosis.

Is there a role for positron emission tomography in breast cancer staging?

Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) is a radiotracer imaging method that is used in the care of patients with cancer. We conducted a nonsystematic review of the literature regarding the applicability of this technique in patients with breast cancer, encompassing the impact of FDG-PET on surgical management, including axillary node staging and sentinel lymph node biopsy; the use of FDG-PET in the evaluation of the primary tumor; the role of FDG-PET in the evaluation of distant metastases both at diagnosis and in the investigation of suspected recurrence; and the ability of FDG-PET to predict treatment response. FDG-PET is not sufficiently sensitive to replace histologic surgical staging of the axilla. Although FDG avidity of the primary tumor has been shown to be an unfavorable indicator, there is insufficient information to recommend its routine use for this indication. FDG-PET is more sensitive than conventional imaging in the detection of metastatic or recurrent disease, but the impact of increased sensitivity on patient care and outcome has not been demonstrated. The data regarding prediction of treatment response are insufficient to reach any conclusion. There are a number of prospective, adequately powered clinical trials currently in progress that should provide more definitive answers regarding the role, if any, of this technique in the management of patients with breast cancer.

Combined approach of perioperative 18F-FDG PET/CT imaging and intraoperative 18F-FDG handheld gamma probe detection for tumor localization and verification of complete tumor resection in breast cancer

Background

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has become an established method for detecting hypermetabolic sites of known and occult disease and is widely used in oncology surgical planning. Intraoperatively, it is often difficult to localize tumors and verify complete resection of tumors that have been previously detected on diagnostic PET/CT at the time of the original evaluation of the cancer patient. Therefore, we propose an innovative approach for intraoperative tumor localization and verification of complete tumor resection utilizing ¹⁸F-FDG for perioperative PET/CT imaging and intraoperative gamma probe detection.

Methods

Two breast cancer patients were evaluated. ¹⁸F-FDG was administered and PET/CT was acquired immediately prior to surgery. Intraoperatively, tumors were localized and resected with the assistance of a handheld gamma probe. Resected tumors were scanned with specimen PET/CT prior to pathologic processing. Shortly after the surgical procedure, patients were re-imaged with PET/CT utilizing the same preoperatively administered ¹⁸F-FDG dose.

Results

One patient had primary carcinoma of breast and a metastatic axillary lymph node. The second patient had a solitary metastatic liver lesion. In both cases, preoperative PET/CT verified these findings and demonstrated no additional suspicious hypermetabolic lesions. Furthermore, intraoperative gamma probe detection, specimen PET/CT, and postoperative PET/CT verified complete resection of the hypermetabolic lesions.

Conclusion

Immediate preoperative and postoperative PET/CT imaging, utilizing the same ¹⁸F-FDG injection dose, is feasible and image quality is acceptable. Such perioperative PET/CT imaging, along with intraoperative gamma probe detection and specimen PET/CT, can be used to verify complete tumor resection. This innovative approach demonstrates promise for assisting the oncologic surgeon in localizing and verifying resection of ¹⁸F-FDG positive tumors and may ultimately positively impact upon long-term patient outcomes.