The Prognostic Value of (18)F-FDG PET/CT for Early Recurrence in Operable Breast Cancer: Comparison with TNM Stage

18F-FDG PET/CT-based deep learning radiomics predicts 5-years disease-free survival after failure to achieve pathologic complete response to neoadjuvant chemotherapy in breast cancer

BACKGROUND

This study aimed to assess whether a combined model incorporating radiomic and depth features extracted from PET/CT can predict disease-free survival (DFS) in patients who failed to achieve pathologic complete response (pCR) after neoadjuvant chemotherapy.

RESULTS

This study retrospectively included one hundred and five non-pCR patients. After a median follow-up of 71 months, 15 and 7 patients experienced recurrence and death, respectively. The primary tumor volume underwent feature extraction, yielding a total of 3644 radiomic features and 4096 depth features. The modeling procedure employed Cox regression for feature selection and utilized Cox proportional-hazards models to make predictions on DFS. Time-dependent receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were utilized to evaluate and compare the predictive performance of different models. 2 clinical features (RCB, cT), 4 radiomic features, and 7 depth features were significant predictors of DFS and were included to develop models. The integrated model incorporating RCB, cT, and radiomic and depth features extracted from PET/CT images exhibited the highest accuracy for predicting 5-year DFS in the training (AUC 0.943) and the validation cohort (AUC 0.938).

CONCLUSION

The integrated model combining radiomic and depth features extracted from PET/CT images can accurately predict 5-year DFS in non-pCR patients. It can help identify patients with a high risk of recurrence and strengthen adjuvant therapy to improve survival.

Advancements in dendritic cell vaccination: enhancing efficacy and optimizing combinatorial strategies for the treatment of glioblastoma

Glioblastomas (GBM) are highly invasive, malignant primary brain tumors. The overall prognosis is poor, and management of GBMs remains a formidable challenge, necessitating novel therapeutic strategies such as dendritic cell vaccinations (DCVs). While many early clinical trials demonstrate an induction of an antitumoral immune response, outcomes are mixed and dependent on numerous factors that vary between trials. Optimization of DCVs is essential; the selection of GBM-specific antigens and the utilization of 18F-fludeoxyglucose Positron Emission Tomography (FDG-PET) may add significant value and ultimately improve outcomes for patients undergoing treatment for glioblastoma. This review provides an overview of the mechanism of DCV, assesses previous clinical trials, and discusses future strategies for the integration of DCV into glioblastoma treatment protocols. To conclude, the review discusses challenges associated with the use of DCVs and highlights the potential of integrating DCV with standard therapies.

Metabolic Parameters as Biomarkers of Response to Immunotherapy and Prognosis in Non-Small Cell Lung Cancer (NSCLC): A Real World Experience

Immune-checkpoint inhibitors (ICIs) have been proven to have great efficacy in non-small cell lung cancer (NSCLC) as single agents or in combination therapy, being capable to induce deep and durable remission. However, severe adverse events may occur and about 40% of patients do not benefit from the treatment. Predictive factors of response to ICIs are needed in order to customize treatment. The aim of this study is to evaluate the correlation between quantitative positron emission tomography (PET) parameters defined before starting ICI therapy and responses to treatment and patient outcome. We retrospectively analyzed 92 NSCLC patients treated with nivolumab, pembrolizumab or atezolizumab. Basal PET/computed tomography (CT) scan parameters (whole-body metabolic tumor volume-wMTV, total lesion glycolysis-wTLG, higher standardized uptake volume maximum and mean-SUVmax and SUVmean) were calculated for each patient and correlated with outcomes. Patients who achieved disease control (complete response + partial response + stable disease) had significantly lower MTV median values than patients who had not (progressive disease) (77 vs. 160.2, p = 0.039). Furthermore, patients with MTV and TLG values lower than the median values had improved OS compared to patients with higher MTV and TLG (p = 0.03 and 0.05, respectively). No relation was found between the other parameters and outcome. In conclusion, baseline metabolic tumor burden, measured with MTV, might be an independent predictor of treatment response to ICI and a prognostic biomarker in NSCLC patients.

Non-invasive Early Response Monitoring of Nanoparticle-assisted Photothermal Cancer Therapy Using 18F-FDG, 18F-FLT, and 18F-FET PET/CT Imaging

Rationale: Since its first implementation nanoparticle-assisted photothermal cancer therapy has been studied extensively, although mainly with focus on optimal nanoparticle design. However, development of efficient treatment protocols, as well as reliable and early evaluation tools in vivo, are needed to push the therapy towards clinical translation. Positron emission tomography (PET) is a non-invasive imaging technique that is currently finding extensive use for early evaluation of cancer therapies; an approach that has become of increasing interest due to its great potential for personalized medicine.

Methods: In this study, we performed PET imaging to evaluate the treatment response two days after nanoparticle-assisted photothermal cancer therapy in tumor-bearing mice. We used three different tracers; 2′-deoxy-2′-¹⁸F-fluoro-D-glucose (¹⁸F-FDG), 3′-deoxy-3′-¹⁸F-fluorothymidine (¹⁸F-FLT), and O-(2'-¹⁸F-fluoroethyl)-L-tyrosine (¹⁸F-FET) to image and measure treatment induced changes in glucose uptake, cell proliferation, and amino acid transport, respectively. After therapy, tumor growth was monitored longitudinally until endpoint was reached.

Results: We found that nanoparticle-assisted photothermal therapy overall inhibited tumor growth and prolonged survival. All three PET tracers had a significant decrease in tumor uptake two days after therapy and these changes correlated with future tumor growth, with ¹⁸F-FDG having the most predictive value in this tumor model.

Conclusion: This study shows that ¹⁸F-FDG, ¹⁸F-FLT, and ¹⁸F-FET are all robust markers for the treatment response of photothermal therapy, and demonstrate that PET imaging can be used for stratification and optimization of the therapy. Furthermore, having a selection of PET tracers that can reliably measure treatment response is highly valuable as the individual tracer might be excluded in certain applications where physiological processes limit their contrast to background.

A hierarchical prognostic model for risk stratification in patients with early breast cancer according to 18 F-fludeoxyglucose uptake and clinicopathological parameters

This study was to investigate a hierarchical prognostic model using clinicopathological factors and 18 F-fludeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) for recurrence-free survival (RFS) in patients with early breast cancer who underwent surgery without neoadjuvant chemotherapy. A total of 524 patients with early breast cancer were included. The Cox proportional hazards model was used with clinicopathological variables and maximum standardized uptake value (SUVmax) on PET/CT. After classification and regression tree (CART) modeling, RFS curves were estimated using the Kaplan-Meier method and differences in each risk layer were assessed using the log-rank test. During a median follow-up of 46.2 months, 31 (5.9%) patients experienced recurrence. The CART model identified four risk layers: group 1 (SUVmax ≤6.75 and tumor size ≤2.0 cm); group 2 (SUVmax ≤6.75 and Luminal A [LumA] or TN tumor >2.0 cm); group 3 (SUVmax ≤6.75 and Luminal B [LumB] or human epidermal growth factor receptor 2 [HER2]-enriched] tumor >2.0 cm); group 4 (SUVmax >6.75). Five-year RFS was as follows: 95.9% (group 1), 98% (group 2), 82.8% (group 3), and 85.4% (group 4). Group 3 or group 4 showed worse prognosis than group 1 or group 2 (group 1 vs. group 3: P = 0.040; group 1 vs. group 4: P < 0.001; group 2 vs. group 3: P = 0.016; group 2 vs. group 4: P < 0.001). High SUVmax (>6.75) in primary breast cancer was an independent factor for poor RFS. In patients with low SUVmax, LumB or HER2-enriched tumor >2 cm was also prognostic for poor RFS, similar to high SUVmax.

Prognostic Value of Metabolic and Volumetric Parameters of FDG PET in Pediatric Osteosarcoma: A Hypothesis-generating Study

Purpose To preliminarily assess the potential prognostic value of various fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) parameters before, during, and after neoadjuvant chemotherapy (NCT). Materials and Methods Thirty-four patients with osteosarcoma were enrolled prospectively from 2008 to 2012 and underwent FDG PET/computed tomography (CT) imaging before (baseline scan), during (interim scan) and after NCT (posttherapy scan). The study was approved by the institutional review board and informed consent was received from patients. Maximum and peak standardized uptake value (SUV_max and SUV_peak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured. Predictive value of FDG PET parameters for event-free survival (EFS) and overall survival (OS) were evaluated. Multivariable Cox regression analysis for EFS and OS was performed by using histologic response and initial presence of metastasis as covariates. Results At baseline scan, SUV_peak, MTV, and TLG were predictive of EFS (P = .006-.03) and OS (P = .001-.03) but not associated with histologic response. At interim and posttherapy scan, SUV_max, SUV_peak, MTV, and TLG were associated with histologic response (P = .0002-.04) and predictive of EFS (P = .004-.02) and OS (P = .001-.03). Multivariable Cox regression analysis revealed that the FDG PET parameters either at baseline, interim, or posttherapy were independently predictive of EFS and OS. In particular, baseline MTV was an independent predictor of EFS (hazard ratio, 5.0 [95% confidence interval {CI}: 1.5, 16.8]) and OS (hazard ratio, 29.4 [95% CI: 2.2, 392.2]). Conclusion SUV_peak, MTV, and TLG either at baseline, interim, or posttherapy were predictive of EFS and OS and may be useful prognostic biomarkers for osteosarcoma. ^© RSNA, 2018 Online supplemental material is available for this article.

Predictive and prognostic potential of volume-based metabolic variables obtained by a baseline 18F-FDG PET/CT in breast cancer with neoadjuvant chemotherapy indication

AIM

To investigate the usefulness of metabolic variables using ¹⁸F-FDG PET/CT in the prediction of neoadjuvant chemotherapy (NC) response and the prognosis in locally advanced breast cancer (LABC).

MATERIAL AND METHODS

Prospective study including 67 patients with LABC, NC indication and a baseline ¹⁸F-FDG PET/CT. After breast tumor segmentation, SUV variables (SUVmax, SUVmean and SUVpeak) and volume-based variables, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were obtained. Tumors were grouped into molecular phenotypes, and classified as responders or non-responders after completion of NC. Disease-free status (DFs), disease-free survival (DFS), and overall survival (OS) were assessed. A univariate and multivariate analysis was performed to study the potential of all variables to predict DFs, DFS, and OS.

RESULTS

Fourteen patients were classified as responders. Median±SD of DFS and OS was 43±15 and 46±13 months, respectively. SUV and TLG showed a significant correlation (p<0.005) with the histological response, with higher values in responders compared to non-responders. MTV and TLG showed a significant association with DFs (p=0.015 and p=0.038 respectively). Median, mean and SD of MTV and TLG for patients with DFs were: 8.90, 13.73, 15.10 and 33.78, and 90.54 and 144.64, respectively. Median, mean and SD of MTV and TLG for patients with non-DFs were: 16.72, 29.70 and 31.09 and 90.89, 210.98 and 382.80, respectively. No significant relationships were observed with SUV variables and DFs. Volume-based variables were significantly associated with OS and DFS, although in multivariate analysis only MTV was related to OS. No SUV variables showed an association with the prognosis.

CONCLUSION

Volume-based metabolic variables obtained with ¹⁸F-FDG PET/CT, unlike SUV based variables, were good predictors of both neoadjuvant chemotherapy response and prognosis.

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.

Current Methods to Define Metabolic Tumor Volume in Positron Emission Tomography: Which One is Better?

Numerous methods to segment tumors using ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET) have been introduced. Metabolic tumor volume (MTV) refers to the metabolically active volume of the tumor segmented using FDG PET, and has been shown to be useful in predicting patient outcome and in assessing treatment response. Also, tumor segmentation using FDG PET has useful applications in radiotherapy treatment planning. Despite extensive research on MTV showing promising results, MTV is not used in standard clinical practice yet, mainly because there is no consensus on the optimal method to segment tumors in FDG PET images. In this review, we discuss currently available methods to measure MTV using FDG PET, and assess the advantages and disadvantages of the methods.

Stathmin and phospho-stathmin protein signature is associated with survival outcomes of breast cancer patients

Currently, Stathmin1 (STMN1) and phospho-STMN1 levels in breast cancers and their clinical implications are unknown. We examined the expression of STMN1 and its serine phospho-site (Ser16, Ser25, Ser38, and Ser63) status by immunohistochemistry. Using Cox regression analysis, a STMN1 expression signature and phosphorylation profile plus clinicopathological characteristics (STMN1-E/P/C) was developed in the training set (n = 204) and applied to the validation set (n = 106). This tool enabled us to separate breast cancer patients into high- and low-risk groups with significantly different disease-free survival (DFS) rates (P < 0.001). Importantly, this STMN1-E/P/C model had a greater prognostic value than the traditional TNM classifier, especially in luminal subtype breast cancer (P = 0.002). Further analysis showed that patients in the low-risk group would benefit more from adjuvant paclitaxel-based chemotherapy (P = 0.002). In conclusion, the STMN1-E/P/C signature is a reliable prognostic indicator for luminal subtype breast cancer and may predict the therapeutic response to paclitaxel-based treatments, potentially facilitating individualized management.

Unusual Horner's Syndrome in Recurrent Breast Cancer: Evaluation Using 18F-FDG PET/CT

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner's syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner's syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner's syndrome using FDG PET/CT.

Prognostic Value of Metabolic and Volumetric Parameters of Preoperative FDG-PET/CT in Patients With Resectable Pancreatic Cancer

In this study, we aimed to evaluate prognostic value of metabolic and volumetric parameters measured from F fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with resectable pancreatic cancer.Fifty-one patients with resectable pancreatic cancer who underwent FDG-PET/CT and curative operation were retrospectively enrolled. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured from FDG-PET/CT. Association between FDG-PET/CT and clinicopathologic parameters was evaluated. The prognostic values of the FDG-PET/CT and clinicopathologic parameters for recurrence-free survival (RFS) and overall survival (OS) were assessed by univariate and multivariate analyses.The 51 enrolled patients were followed up for a median of 21 months (mean ± SD: 23 ± 16 months, range: 1-78 months) with 33 (65%) recurrences and 30 (59%) deaths during the period. SUVmax, MTV, and TLG were associated with Tumor node metastasis (TNM) stage and presence of lymph node metastasis. MTV and TLG were associated with presence of lymphovascular invasion, whereas SUVmax was not. On the univariate analysis, SUVmax, MTV, and TLG were associated with RFS and OS. Also, lymph node metastasis and TNM stage were associated with OS on the univariate analysis. On multivariate analysis, MTV and TLG were independent prognostic factors for RFS and OS. SUVmax was an independent prognostic factor for OS, but not for RFS.Metabolic tumor volume and TLG were independently predictive of RFS and OS in resectable pancreatic cancer. SUVmax was an independent factor for OS, but not for RFS.

Association Between Histone Methyltransferase hSETD1A and Prognosis in Patients With Triple-Negative Breast Cancer After Surgery: A Retrospective Study in the Chinese Female Population

Breast cancer, the most common cancer in women, is a serious public health issue. Triple-negative breast cancer (TNBC), which lacks expression of the estrogen receptor (ER), progesterone receptor, and human epidermal growth factor receptor 2, accounts for ∼15% of breast cancer cases. Treatment of TNBC patients has proven difficult because of the lack of expression of hormone receptors. We conducted a retrospective study to investigate the prognostic impact of histone methyltransferase, hSETD1A, on overall survival in TNBC cases after surgery. In total, 159 TNBC cases were enrolled and clinicopathological characteristics were obtained from medical records. hSETD1A status of each subject was determined using immunohistochemistry. The chi-squared test was used to compare 5-year overall survival rates of all subjects according to clinical characteristics, and both univariate and multivariate analyses were conducted to calculate the hazard ratios and 95% confidence intervals. Advanced tumor-node-metastasis stage stage, larger tumor size, vascular invasion, metastasis in the initial diagnosis, and hSETD1A expression were correlated with worse outcome. Among all factors identified, metastasis in the initial diagnosis had the greatest impact on survival. The results indicated that hSETD1A positivity was correlated with shorter survival among TNBC cases, suggesting it may serve as a prognostic biomarker for patients with TNBC.

The phosphorylation-specific association of STMN1 with GRP78 promotes breast cancer metastasis

Metastasis is a major cause of death in patients with breast cancer. Stathmin1 (STMN1) is a phosphoprotein associated with cancer metastasis. It exhibits a complicated phosphorylation pattern in response to various extracellular signals, but its signaling mechanism is poorly understood. In this study, we report that phosphorylation of STMN1 at Ser25 and Ser38 is necessary to maintain cell migration capabilities and is associated with shorter disease-free survival (DFS) in breast cancer. In addition, we report that glucose-regulated protein of molecular mass 78 (GRP78) is a novel phospho-STMN1 binding protein upon STMN1 Ser25/Ser38 phosphorylation. This phosphorylation-dependent interaction is regulated by MEK kinase and is required for STMN1-GRP78 complex stability and STMN1-mediated migration. We also propose a prognostic model based on phospho-STMN1 and GRP78 to assess metastatic risk in breast cancer patients.

PET Imaging of Breast Cancer: Role in Patient Management

Breast cancer is the most common malignancy in females. Imaging plays a critical role in diagnosis, staging and surveillance, and management of disease. Fluorodeoxyglucose (FDG) PET the imaging is indicated in specific clinical setting. Sensitivity of detection depends on tumor histology and size. Whole body FDG PET can change staging and management. In recurrent disease, distant metastasis can be detected. FDG PET imaging has prognostic and predictive value. PET/MR is evolving rapidly and may play a role management, assessment of metastatic lesions, and treatment monitoring. This review discusses current PET modalities, focusing on of FDG PET imaging and novel tracers.

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

AIM

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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