Value of fluorodeoxyglucose positron emission tomography in women with breast cancer

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Special Relevance of FDG-PET as an Upfront Diagnostic Modality at Initial Diagnosis and in Suspected Recurrence in Patients of Breast Carcinoma Hailing From Lower Socioeconomic Status Owing to Relative Late Presentation: A Pilot Study in a Medical College Hospital Setting in India

FDG-PET has found relatively limited use in routine management of breast carcinoma due to its limited utility in assessing the primary and axillary lymph node status. The aim of the study was to assess its role in a medical school and municipal hospital setting of Mumbai, where majority belongs to the lower socioeconomic status and presents relatively late and hence whole body FDG-PET could find important place for assessing whole body disease status that would justify being used upfront in this group of patients. Thus, the premise of this study was that FDG-PET will have special relevance in this particular setting for evaluation of patients of breast carcinoma with respect to initial staging, detection of locoregional recurrence and metastasis and assessing response to systemic treatment. A total of 52 patients proven to have breast carcinoma, who had undergone (18)F FDG-PET for disease staging at initial diagnosis and in in recurrent disease staging with a few cases as a baseline study for early treatment monitoring purposes over a study period of 3 years, were included in this analysis. 33.3 % of patients with pretreatment baseline FDG-PET were upstaged with diagnosis of additional lesions in the adrenal gland, liver, internal mammary, cervical lymph nodes and the mediastinum. On a lesion specific analysis, the percentage of increased lesion detection (including both lymph node with distant metastasis) by FDG-PET was 42.7 %. FDG-PET was found to be 100 % sensitive and specific for confirming recurrent breast cancer. Four out of 18 patients on chemotherapy underwent second FDG-PET after first cycle of chemotherapy, showed responsiveness to chemotherapy by decreased maximum standardized uptake value (SUVmax). FDG-PET showed 9 liver lesions in 6 patients, only 3 of them was reported in USG. In one patient USG abdomen was inconclusive between hemangioma and metastasis, FDG-PET ruled out liver metastasis in this patient. In the examined patient population belonging to lower socioeconomic status, where usual presentation is relatively late, upfront whole body survey with FDG-PET or PET/CT is of considerable value in view of higher probability of existence of metastatic disease, thus can be an important one-stop shop tool in assessing whole body disease status in a single examination. It also proved efficacious in diagnosing loco regional and distant recurrence, metabolic characterization of lump and early response to treatment in the examined few cases following one cycle of chemotherapy in locally advanced breast cancer.

Radionuclide methods for breast cancer staging

Staging at initial presentation is one of the important prognostic factors for patients with breast cancer. Depending on the extent of disease spread, staging is divided into locoregional and distant or systemic. Locoregional staging includes axillary and internal mammary lymph node evaluation and distant or systemic staging includes evaluation of sites beyond the lymph node. Fluorodeoxyglucose-positron emission tomography (FDG-PET) is not sensitive to detect small metastasis in axillary lymph node. The current standard of axillary lymph node staging in early-stage breast cancer is therefore sentinel lymph node biopsy. Internal mammary lymph nodes are not commonly included in routine staging. In advanced-stage breast cancer, FDG-PET and PET/computed tomography (CT) are the modalities of choice to evaluate locoregional and distant metastasis. FDG-PET and PET/CT often detect occult metastasis, which is not visible on any other modalities including diagnostic CT scan. Detection of occult metastasis may potentially change in treatment options. This is particularly important in locally advanced breast cancer, which tends to develop early distant metastasis.

Role of FDG-PET/CT in evaluating surgical outcomes of operable breast cancer--usefulness for malignant grade of triple-negative breast cancer

BACKGROUND

The aim of this study was to evaluate the significance of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for speculating the malignant level and prognostic value of operable breast cancers.

METHODS

Of 578 consecutive patients with primary invasive breast cancer who underwent curative surgery between 2005 and 2010, 311 patients (53.8%) who received FDG-PET/CT before initial therapy were examined.

RESULTS

Receiver operating characteristics (ROC) curve analysis showed the cutoff value of the maximum standardized uptake value (SUVmax) to predict cancer recurrence was 3.8 in all patients and 8.6 in patients with the triple-negative subtype, respectively. In all patients, 3-year DFS rates were 98.8% for patients with a tumor of SUVmax ≤ 3.8 and 91.6% for patients with a tumor of SUVmax > 3.8 (p < 0.001). High value of SUVmax was significantly associated with large tumor size (p < 0.001), lymph node metastasis (p = 0.040), high nuclear grade (p < 0.001), lymphovascular invasion (p = 0.032), negative hormone receptor status (p < 0.001), and positive HER2 status (p = 0.014). Based on the results of multivariate Cox analysis in all patients, high SUVmax (p = 0.001) and negative hormone receptor status (p = 0.005) were significantly associated with poor prognosis. In patients with triple-negative subtype, 3-year DFS rates were 90.9% for patients with a tumor of SUVmax ≤ 8.6 and 42.9% for patients with a tumor of SUVmax > 8.6 (p = 0.002), and high SUVmax was the only significant independent prognostic factor (p = 0.047).

CONCLUSION

FDG-PET/CT is useful for predicting malignant behavior and prognosis in patients with operable breast cancer, especially the triple-negative subtype.

Preoperative PET/CT in early-stage breast cancer

BACKGROUND

The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer.

PATIENTS AND METHODS

A total of 103 consecutive patients with newly diagnosed operable breast cancer with tumors ≥2 cm were independently examined preoperatively with conventional assessment (mammography, breast/axillary ultrasound, chest X-ray and blood samples) and PET/CT with no prior knowledge of the other.

RESULTS

PET/CT identified a primary tumor in all but three patients (97%). PET/CT solely detected distant metastases (ovary, bones and lung) in 6 patients and new primary cancers (ovary, lung) in another two patients, as well as 12 cases of extra-axillary lymph node involvement. In 15 patients (15%), extra-axillary malignancy was detected by PET/CT only, leading to an upgrade of initial staging in 14% (14/103) and ultimately a modification of planned treatment in 8% (8/103) of patients.

CONCLUSIONS

PET/CT is a valuable tool to provide information on extra-axillary lymph node involvement, distant metastases and other occult primary cancers. Preoperative (18)F-fluorodeoxyglucose-PET/CT has a substantial impact on initial staging and on clinical management in patients with early-stage breast cancer with tumors ≥2 cm.

FDG-PET/CT compared with conventional imaging in the detection of distant metastases of primary breast cancer

PURPOSE

Evidence from studies with small numbers of patients indicates that (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) accurately detects distant metastases in the staging of primary breast cancer. We compared the sensitivity and specificity of PET/CT and conventional imaging (CT, ultrasonography, radiography, and skeletal scintigraphy) for the detection of distant metastases in patients with primary breast cancer.

PATIENTS AND METHODS

We performed a retrospective review that identified 225 patients with primary breast cancer seen from January 2000 to September 2009 for whom PET/CT data were available for review. Imaging findings were compared with findings on biopsy, subsequent imaging, or clinical follow-up. Sensitivity and specificity in the detection of distant metastases were calculated for PET/CT and conventional imaging. Fisher's exact tests were used to test the differences in sensitivity and specificity between PET/CT and conventional imaging.

RESULTS

The mean patient age at diagnosis was 53.4 years (range, 23-84 years). The sensitivity and specificity in the detection of distant metastases were 97.4% and 91.2%, respectively, for PET/CT and 85.9% and 67.3%, respectively, for conventional imaging. The sensitivity and specificity of PET/CT were significantly higher than those of conventional imaging (p = .009 and p < .001, respectively). Eleven cases of distant metastases detected by PET/CT were clinically occult and not evident on conventional imaging.

CONCLUSION

PET/CT has higher sensitivity and specificity than conventional imaging in the detection of distant metastases of breast cancer. A prospective study is needed to determine whether PET/CT could replace conventional imaging to detect distant metastases in patients with primary breast cancer.

FDG-PET and other imaging modalities for the evaluation of breast cancer recurrence and metastases: a meta-analysis

Background and purpose

Breast carcinoma is the most common cancer in female patients with a propensity for recurrence and metastases. The accuracy of ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), scintimammography (SMM) and positron emission tomography (PET) in diagnosing the recurrent and/or breast cancer has never been systematically assessed, and present systematic review was aimed at this issue.

Methods

MEDLINE and EMBASE were searched for articles dealt with detection of recurrent and/or metastatic breast cancer by US, CT, MRI, SMM or PET whether interpreted with or without the use of CT. Histopathologic analysis and/or close clinical and imaging follow-up for at least 6 months were used as golden reference. We extracted data to calculate sensitivity, specificity, summary receiver operating characteristic curves and area under the curve and to test for heterogeneity.

Result

In 42 included studies, US and MRI had highest pooled specificity (0.962 and 0.929, respectively); MRI and PET had highest pooled sensitivity (0.9500 and 0.9530, respectively). The AUC of US, CT, MRI, SMM and PET was 0.9251, 0.8596, 0.9718, 0.9386 and 0.9604, respectively. Results of pairwise comparison between each modality demonstrated that AUC of MRI and PET was higher than that of US or CT, p < 0.05. No statistical significance was found between MRI and PET. There was heterogeneity among studies and evidence of publication bias.

Conclusion

In conclusion, MRI seemed to be a more useful supplement to current surveillance techniques to assess patients with suspected recurrent and/or metastatic breast cancer. If MRI shows an indeterminate or benign lesion or MRI was not applicable, FDG-PET could be performed in addition.

Preoperative Staging of Large Primary Breast Cancer With [18F]Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Compared With Conventional Imaging Procedures

Purpose

To evaluate the utility of positron emission tomography (PET) and [18F]fluorodeoxyglucose in the initial staging of large primary breast tumors.

Patients and Methods

This prospective study was approved by the ethics committee, and all patients gave their informed consent before enrollment. Sixty consecutive patients with large (> 3 cm) primary breast cancer diagnosed by clinical examination and breast magnetic resonance imaging (MRI) were entered onto the study. The mean age was 57 ± 13 years. Chest computed tomography (CT), liver ultrasonography, bone scan, and PET/CT were performed in all patients. All findings were histologically confirmed, and/or at least 1 year of follow-up was required. Correlation between parameters was calculated using Pearson's correlation coefficient. P < .05 was considered statistically significant.

Results

Primary tumor was identified by both PET/CT and MRI in all patients. Multifocal and/or multicentric tumors were found in 19 patients by MRI. Axillary lymph node metastases were found in 20 of 52 patients. Extra-axillary metastatic lymph nodes were also found in three patients. One patient showed an infiltrated lymph node in the contralateral axilla. The sensitivity and specificity for PET/CT to detect axillary lymph nodes metastases were 70% and 100%, respectively. PET/CT diagnosed all extra-axillary lymph nodes. The overall sensitivity and specificity of PET/CT in detecting distant metastases were 100% and 98%, respectively; whereas the sensitivity and specificity of conventional imaging were 60% and 83%, respectively. PET led to a change in the initial staging in 42% of patients.

Conclusion

PET/CT underestimates locoregional lymph node staging in large primary breast cancer patients. PET/CT is a valuable tool to discard unsuspected extra-axillary lymph nodes and distant metastases.

Prevalence of overt metastases in locally advanced breast cancer

AIMS

Locally advanced breast cancer (LABC) represents a wide spectrum of clinical presentations and poses significant clinical challenges for both patients and their physicians. Before starting neoadjuvant therapy, most patients undergo staging investigations, including a radioisotope bone scan, liver ultrasound and chest X-ray as per our provincial guidelines. The aim of this study was to document the prevalence of metastatic disease using standard baseline radiological staging in patients with LABC.

MATERIALS AND METHODS

A retrospective chart review was carried out for LABC patients at two large Canadian centres between 2003 and 2006. Data on tumour characteristics and baseline staging tests were collected. Information on any confirmatory imaging (bone X-ray, computed tomography, magnetic resonance imaging, positron emission tomography) undertaken due to the presence of suspicious baseline tests or due to worrying symptoms was also obtained. The prevalence of metastatic disease after each baseline imaging technique was analysed, as was the frequency of discordance between baseline staging tests and confirmatory imaging where applicable.

RESULTS

In total, 144 patients with LABC were assessed. After initial staging investigations, 15 patients (10.4%) were diagnosed as having overt metastatic disease. Confirmatory imaging was carried out on 19 patients (13.2%); five (3.5%) for unexplained symptoms and 14 (9.7%) due to equivocal baseline imaging. These additional investigations isolated a further four subjects with metastatic disease, bringing the overall prevalence of overt metastases to 13.2%.

CONCLUSIONS

Given that the rate of systemic relapse in patients with LABC is very high, current baseline staging investigations probably underestimate the true incidence of metastases. This study has shown that further confirmatory imaging can be helpful, especially in symptomatic patients, as it seems that negative baseline tests in these patients can be falsely reassuring. Accurate staging of patients with LABC has many advantages and, therefore, further research is needed to define the role of newer imaging modalities.

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.

Prone mammoPET acquisition improves the ability to fuse MRI and PET breast scans

PURPOSE

This study compared prone acquisition of PET scans with traditional supine acquisition to improve fusion of PET scans with MRI scans and improve evaluation of enhancing breast lesions detected on MRI.

MATERIALS AND METHODS

MRI breast scans are acquired in the prone position using a breast coil to allow the breasts to hang pendant. An apparatus was fabricated to allow prone acquisition of PET scans. Fused scans from 2 patients acquired both prone and supine were contrasted with those from 3 patients acquired supine only. All 5 MRI scans were acquired on standard scanners. The PET scans were acquired with a PET/CT unit using a low-dose CT scan for attenuation correction. The PET and MRI volumes were matched twice (using a semiautomated registration method) by different operators. The additional value of fusion was judged using reports from the original (nonfused) MRI and PET, joint rereading of the volumes side by side, and examination of fused images.

RESULTS

Of 12 enhancing lesions on breast MRI, 7 demonstrated uptake on PET/CT. In the 3 supine-only cases, the fused images were not interpretable because of the marked distortion of the breasts. In the 2 prone cases, the fused images increased our confidence in characterizing a lesion as benign or malignant. Interpretations were confirmed by clinical follow up in 2 or histologic results in 3 patients.

CONCLUSIONS

PET MRI fusion is feasible and may assist in localizing lesions detected on either study. A more extensive study is underway to confirm the value of this fusion technique.

Baseline radiological staging in primary breast cancer: impact of educational interventions on adherence to published guidelines

RATIONALE

The purpose of baseline radiological staging in newly diagnosed breast cancer patients is to rule out overt metastatic disease. We have previously compared the use of radiological staging at our institution with the recommendations of the Cancer Care Ontario Practice Guidelines Initiative (CCOPGI). Our results demonstrated that between January 2000 to December 2002, a high proportion of our cohort (n = 135) of patients underwent unnecessary investigations.

OBJECTIVES

To implement and assess an educational intervention to encourage staging guideline utilization in a cohort of early breast cancer patients.

METHODS

In January 2003, multidisciplinary educational rounds were held, highlighting the CCOPGI guidelines, and reporting results of the audit of staging investigations. The staging guidelines were then included in the Clinical Practice Guidelines of the Breast Disease Site Group, Toronto-Sunnybrook Regional Cancer Centre. A retrospective chart review was completed that assessed staging investigations from a random sample of a similar group of patients (n = 134) from January 2003 to April 2005, to explore the effects of these educational interventions on clinical practice.

RESULTS

For patients with Stage I breast cancer, there was a significant decrease (P < 0.004) in each type of investigation: a twofold decrease in chest X-rays; 2.5-fold decrease bone scans and fourfold decrease in the number of abdominal ultrasounds. For patients in Stage II, there was no significant change in the proportion of patients undergoing radiological investigations. There was a non-significant trend towards appropriately receiving all three investigations for patients with Stage III disease.

CONCLUSIONS

Our results demonstrate that prior to the educational intervention, many patients with early breast cancer were undergoing inappropriate radiological staging. Since 2003 however, for Stage I patients there has been a significant improvement in adherence with the guidelines. We hypothesize that our educational intervention had a positive impact on improving the utilization of baseline radiological staging in patients with primary breast cancer.