Preoperative risk stratification using metabolic parameters of (18)F-FDG PET/CT in patients with endometrial cancer

The Prognostic Value of Maximum Standardized Uptake Value (SUVmax) of 18F-FDG PET/CT for Risk Stratification and Outcome Prediction in Endometrial Cancer: A Retrospective Analysis

Background and objective Endometrial cancer, the most common gynecological malignancy in developed countries, is frequently diagnosed at an early stage due to the symptomatic presentation of irregular bleeding. We aimed to assess the prognostic value of preoperative PET/CT-derived maximum standardized uptake value (SUVmax) in patients with endometrial cancer and investigated its association with established clinical risk factors and survival outcomes. Methods We retrospectively analyzed 162 patients with endometrial cancer who underwent preoperative PET/CT at Kyorin University Hospital from December 2020 to June 2024. We recorded and assessed the SUVmax of primary uterine tumors against clinical histopathological findings, such as myometrial invasion, lymphovascular space invasion (LVSI), cervical stromal invasion, extrauterine lesions, and histological types. Patients were categorized into recurrence risk groups based on the Japan Society of Gynecologic Oncology (JSGO) 2023 guidelines. Statistical evaluations involved the Mann-Whitney U tests for group comparisons and Kaplan-Meier analysis for overall survival (OS) and progression-free survival (PFS). Results The median SUVmax of primary uterine tumors was 26.0. A higher SUVmax was significantly associated with myometrial invasion, LVSI, and larger tumor diameter (p<0.01). Significant differences in the SUVmax were observed among the various postoperative recurrence risk groups, with higher values observed in the intermediate- and high-risk groups (p<0.01). Kaplan-Meier survival analysis revealed that a higher SUVmax was significantly associated with poorer OS. Conclusions SUVmax derived from preoperative PET/CT can significantly predict endometrial cancer prognosis, correlating with clinical risk factors and OS. Hence, integrating SUVmax into preoperative assessments could enhance risk stratification and inform treatment planning. Prospective studies with larger cohorts are needed to validate these findings and establish standardized SUVmax cutoffs for clinical application.

Radioguided surgery with β decay: A feasibility study in cervical cancer

PURPOSE

Radioguided surgery (RGS) is a technique that helps the surgeon to achieve a tumour resection as complete as possible, by means of the intraoperative detection of particles emitted by a radiotracer that bounds to tumoural cells. This study aimed to investigate the applicability of β-RGS for tumour resection and margin assessment in cervical cancer patients preoperatively injected with [18F]FDG, by means of Monte Carlo simulations.

METHODS

Patients were retrospectively included if they had a recurrent or persistent cervical cancer, underwent preoperative PET/CT to exclude distant metastases and received radical surgery. All PET/CT images were analysed extracting tumour SUVmax, background SUVmean and tumour-to-non-tumour ratio. These values were used to obtain the expected count rate in a realistic surgical scenario by means of a Monte Carlo simulation of the β probe, assuming the injection of 2 MBq/kg of [18F]FDG 60 min before surgery.

RESULTS

Thirty-eight patients were included. A measuring time of ∼2-3 s is expected to be sufficient for discriminating the tumour from background in a given lesion, being this the time the probe has to be over the sample in order to be able to discriminate tumour from healthy tissue with a sensitivity of ∼99% and a specificity of at least 95%.

CONCLUSION

This study presents the first step towards a possible application of our β-RGS technique in cervical cancer. Results suggest that this approach to β-RGS could help surgeons distinguish tumour margins from surrounding healthy tissue, even in a setting of high radiotracer background activity.

Predictive value of PET metabolic parameters for occult lymph node metastases in PET/CT defined node-negative patients with advanced epithelial ovarian cancer

Accurate lymph node metastasis (LNM) prediction is crucial for patients with advanced epithelial ovarian cancer (AEOC) since it guides the decisions about lymphadenectomy. Previous studies have shown that occult lymph node metastasis (OLNM) is common in AEOC. The objective of our study is to quantitatively assess the probability of occult lymph node metastasis defined by 18F-Fluorodeoxyglucose PET/CT in AEOC and explore relationship between OLNM and PET metabolic parameters. The patients with pathologically confirmed AEOC who underwent PET/CT for preoperative staging at our institute were reviewed. Univariate and multivariate analysis were performed to evaluate the predictive value of PET/CT-related metabolic parameters for OLNM. The result of our study showed metastatic TLG index had a better diagnostic performance than other PET/CT-related metabolic parameters. Two variables were independently and significantly associated with OLNM in multivariate analysis: metastatic TLG index and primary tumor location. The logistic model combining metastatic TLG index, primary tumor location, and CA125 might be a promising tool to effectively predict the individualized possibility of OLNM for AEOC patients.

A systematic review about the role of preoperative 18F-FDG PET/CT for prognosis and risk stratification in patients with endometrial cancer

OBJECTIVE

To analyse the available literature on the prognostic value of preoperative ¹⁸F-FDG PET/CT metabolic parameters and their usefulness in risk stratification in patients with endometrial cancer (EC).

MATERIAL AND METHODS

Pubmed searches used "(endometr* OR uter*) AND (PET OR FDG)" as keywords from January-2000 to June-2020. References in included articles were checked for possible publications not included in the first search. Studies evaluating the prognostic value of preoperative ¹⁸F-FDG PET/CT and its role for risk stratification in patients with EC were included. Non-original articles (reviews, editorials, letters, legal cases, interviews, case reports, etc.) were not included.

RESULTS

Twenty-six studies (1918 patients) were selected according to the inclusion criteria in this review. Thirteen studies (939 patients) related to the prognostic role of preoperative ¹⁸F-FDG PET/CT and 14 studies (1036 patients) related to its role in risk stratification were included. Parameters such as SUVmax, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumour were analysed.

CONCLUSIONS

Preoperative SUVmax is useful for non-invasive diagnosis and for deciding the appropriate therapeutic strategy, as it could be used as an independent prognostic marker for recurrence and survival in EC. In addition, both preoperative VTM and GTL could be independent prognostic factors for predicting recurrence and survival, but there is still insufficient scientific evidence. The usefulness of SUVmax for risk stratification is limited (there is insufficient literature that ¹⁸F-FDG PET/CT can replace surgical staging), although VTM and GTL are more accurate and have a valuable role in risk stratification of EC. However, larger multicentre studies with adequate follow-up time are needed to confirm these findings.

PET Parameters are Useful in Predicting Endometrial Cancer Risk Classes and Prognosis

AIM

 We investigate the role of preoperative PET parameters to determine risk classes and prognosis of endometrial cancer (EC).

METHODS

 We enrolled 81 patients with EC who underwent preoperative F-18 FDG PET/CT. PET parameters (SUVmax, SUVmean, MTV, TLG), grade, histology and size of the primary tumor, stage of the disease, the degree of myometrial invasion (MI), and the presence of lymphovascular invasion (LVI), cervical invasion (CI), distant metastasis (DM) and lymph node metastasis (LNM) were recorded. The relationship between PET parameters, clinicopathological risk factors and overall survival (OS) was evaluated.

RESULTS

 The present study included 81 patients with EC (mean age 60). Of the total sample, 21 patients were considered low risk (endometrioid histology, stage 1A, grade 1 or 2, tumor diameter < 4 cm, and LVI negative) and 60 were deemed high risk. All of the PET parameters were higher in the presence of a high-risk state, greater tumor size, deep MI, LVI and stage 1B-4B. MTV and TLG values were higher in the patients with non-endometrioid histology, CI, grade 3 and LNM. The optimum cut-off levels for differentiating between the high and low risk patients were: 11.1 for SUVmax (AUC = 0.757), 6 for SUVmean (AUC = 0.750), 6.6 for MTV(AUC = 0.838) and 56.2 for TLG(AUC = 0.835). MTV and TLG values were found as independent prognostic factors for OS, whereas SUVmax and SUVmean values were not predictive.

CONCLUSIONS

 The PET parameters are useful in noninvasively differentiating between risk groups of EC. Furthermore, volumetric PET parameters can be predictive for OS of EC.

Prognostic value of metabolic tumor volume and total lesion glycolysis from ¹⁸F-FDG PET/CT in lymph node metastases and risk stratification of endometrial carcinoma

Objective

To investigate the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG), measured by preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT), in risk stratification of patients with endometrial carcinoma (EC).

Methods

The patients with pathological diagnosis of EC who underwent preoperative ¹⁸F-FDG PET/CT imaging were retrospectively selected for analysis of the prognostic values of PET parameters in risk classification and lymph node metastases (LNMs). Receiver-operating-characteristic analysis was used to analyze the correlation of PET parameters cutoff values with deep myometrial invasion (MI), lymphovascular space involvement and LNM for prognostic values in risk stratification.

Results

The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for detection of LNM are 83.3%, 99.7%, 90.9%, 99.5% and 99.2%, respectively. The MTV and TLG of primary lesion of EC in the patients with LNM are notably higher than those in patients without LNM, p<0.010. The MTV and TLG of the EC primary lesions in high-risk patients are significantly higher than those in low-risk patients (p<0.010), but the maximum standardized uptake value (SUVmax) is not. The MTV and TLG of primary lesions were superior to SUVmax for predicting of deep MI, LNM and high-risk of EC (p<0.005).

Conclusion

MTV and TLG of primary lesions are more valuable in predicting risk stratification of EC patients. Preoperative ¹⁸F-FDG PET/CT imaging is useful in predicting the LNM of EC and may help guide pelvic lymphadenectomy to avoid unnecessary pelvic lymphadenectomy in EC patients with low-risk stratification.

18F-FDG PET/CT Quantitative Parameters and Texture Analysis Effectively Differentiate Endometrial Precancerous Lesion and Early-Stage Carcinoma

Objective:

This study evaluated the metabolic parameters and texture features of fluorodeoxyglucose positron emission tomography–computed tomography (PET/CT) for the diagnosis and differentiation of endometrial atypical hyperplasia (EAH), EAH with field cancerization (FC), and stage 1A endometrial carcinoma (EC 1a).

Materials and Methods:

We retrospectively analyzed the metabolic parameters of PET/CT in 170 patients with diagnoses confirmed by pathology, including 57 cases of EAH (57/170, 33.53%), 45 cases of FC (45/170, 26.47%), and 68 cases of EC 1a (68/170, 40.0%). Then, the texture features of each tumor were extracted and compared with the metabolic parameters and pathological results using nonparametric tests and linear regression analysis. The diagnostic performance was assessed by the area under the curve (AUC) values obtained from receiver operating characteristic analysis.

Results:

There were moderate positive correlations between the PET standardized uptake values (SUVpeak, SUVmax, and SUVmean) and postoperative pathological features with correlation coefficients (r_s) of 0.663, 0.651, and 0.651, respectively (P < .001). Total lesion glycolysis showed relatively low correlation with pathological characteristics (r_s = 0.476), whereas metabolic tumor volume and age showed the weakest correlations (r_s = 0.186 and 0.232, respectively). To differentiate between the diagnosis of EAH and FC, SUVmax displayed the largest AUC of 0.857 (sensitivity, 82.2%; specificity, 84.2%). Five texture features were screened out as Percentile 40, Percentile 45, InverseDifferenceMoment_AllDirection_offset 1, InverseDifferenceMoment_angle 45_offset 4, and ClusterProminence_angle 135_offset 7 (P < .001) by linear model of texture analysis (AUC = 0.851; specificity = 0.692; sensitivity = 0.871). To differentiate between the diagnoses of FC and EC 1a, SUVpeak displayed the largest AUC of 0.715 (sensitivity, 67.6%; specificity, 77.8%), and 2 texture features were identified as Percentile 10 and CP_angle 135_offset 7 (AUC = 0.819; specificity = 0.871; sensitivity = 0.766; P < .001).

Conclusions:

SUVmax and SUVpeak had the highest diagnostic values for EAH, FC, and EC 1a compared with the other tested parameters. SUVmax, Percentile 40, Percentile 45, InverseDifferenceMoment_AllDirection_offset 1, InverseDifferenceMoment_angle 45_offset 4, and ClusterProminence_angle 135_offset 7 distinguished EAH from FC. SUVpeak, Percentile 10, and ClusterProminence_angle 135_offset 7 distinguished FC from EC 1a. This study showed that the addition of texture features provides valuable information for differentiating EAH, FC, and EC 1a diagnoses.

Preoperative evaluation of residual tumor in patients with endometrial carcinoma by using 18F-FDG PET/CT

Purpose: To evaluate the value of ¹⁸F-FDG positron emission tomography (PET)/computed tomography (CT) for determining the presence of residual tumors after curettage in patients with endometrial cancer. Methods: Preoperative ¹⁸F-FDG PET/CT was performed in 90 women with endometrial cancer. PET/CT parameters and clinical characteristics were compared between patients with and without residual tumors. The clinical characteristics of patients with residual tumors that showed low ¹⁸F-FDG uptake were also analyzed. Results: Among the 90 patients, 86 had residual tumors. ROC analysis identified a lesion SUVmax value of 5.0 as the optimal cut-off value for predicting whether or not patients had a residual tumor. With the SUVmax cut-off of 5, the sensitivity, specificity, positive predictive value, and negative predictive values for residual tumor prediction were 87.2%, 100%, 100%, and 26.7%, respectively. Univariate analysis showed significant associations between the high PET group (SUVmax > 5) and low PET group (SUVmax ≤ 5), and histologic type (P = 0.043) and tumor size (P < 0.001) in patients with residual tumors. In patients with low-grade and clear cell carcinomas and a tumor size < 1.35 cm, the probability of being in the low-PET group was 47.6%. In such patients, major parts of the residual tumors showed low ¹⁸F-FDG uptake, similar to that in patients with no residual tumors. Conclusion: SUVmax was the lone predictive value for the presence of residual tumors after curettage in patients with endometrial cancer. Lesion SUVmax greater than 5 suggested a high possibility of residual tumors. In patients with low-grade and clear cell carcinomas with tumor size < 1.35 cm, residual tumors may present low ¹⁸F-FDG uptake, mimicking the metabolic phenotypes of patients without residual tumors.

Prognostic value of metabolic tumor volume and total lesion glycolysis assessed by 18F-FDG PET/CT in endometrial cancer

OBJECTIVE

Surgical staging is the most confidential method for prognosis prediction. However, in which stage the surgery is needed and the treatment management of these patients is controversial. Presentation of new determinant factors with imaging methods for prediction of poor prognosis can provide better disease management. The aim of our study was to demonstrate the ability of metabolic tumor volume and total lesion glycolysis as a prognostic factor to predict the disease-free survival time, necessity of adjuvant radiotherapy-chemotherapy, and the association of these parameters with the clinicopathological features.

METHODS

Forty-four endometrial cancer diagnosed patients whose PET/CT scans were performed for treatment planning were included in our study. Metabolic parameters (SUVmax, metabolic tumor volume, total lesion glycolysis) of the primary tumor were calculated. Abdominal hysterectomy was performed for all patients. Histopathologic findings were noted. Patients were followed for 31.4 ± 14.8 months.

RESULTS

Metabolic tumor volume and total lesion glycolysis were significant prognostic factors for disease-free survival, whereas SUVmax did not effect disease-free survival. According to regression analysis, only metabolic tumor volume was found significant for radiotherapy planning (cutoff metabolic tumor volume; 26.30 ml). There was significant association between metabolic tumor volume, total lesion glycolysis and early-stage, myometrial invasion, and lymph node positivity. We observed only weak association between SUVmax and myometrial invasion. ROC curve calculated metabolic tumor volume and total lesion glycolysis cutoff values as 19.6 ml and 90 g for early-stage, 14.3 ml and 173.4 g for myometrial invasion, and 29.7 ml and 283.1 g for lymph node positivity, respectively.

CONCLUSION

Metabolic tumor volume and total lesion glycolysis may be used as prognostic factors for endometrial cancer. The association between SUVmax and clinical findings, disease-free survival, histopathological features are weak. Further studies are needed for demonstrating the prognostic value of metabolic volumetric parameters.

The maximum standardized uptake value and extent of peritoneal involvement may predict the prognosis of patients with recurrent ovarian cancer after primary treatment: A retrospective clinical study

We investigated the effect of the maximum standardized uptake value (SUVmax) and peritoneal dissemination derived from F-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) imaging on prognosis in patients with recurrent ovarian cancer.We retrospectively analyzed 145 patients with suspected recurrent ovarian cancer who had undergone F-FDG PET/CT scans after cytoreductive surgery and chemotherapy. The degree of peritoneal spread was classified as localized (1-3 FDG foci) or diffuse (>3 FDG foci). Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off values for predicting recurrence.A total of 145 patients were retrospectively reviewed in this study. 29 patients were excluded as their follow-up results were not available. One hundred sixteen patients were included in the final analysis. The median duration of progression-free survival was 14 months. F-FDG PET/CT detected peritoneal carcinomatosis in 82 patients. With a cut-off SUVmax of 2.0 obtained from the ROC curve analysis, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SUVmax of peritoneal carcinomatosis for predicting recurrence were 77.6%, 87.5%, 65.1%, 97.4%, and 38.9%, respectively. The area under the curve was 0.85. In a multivariate analysis, significant independent prognostic variables were SUVmax of peritoneal disease, peritoneal dissemination, and CA125 levels. In patients with peritoneal involvement, the Kaplan-Meier survival curves showed significantly longer PFS in those with localized disease.SUVmax of peritoneal disease is valuable in predicting the recurrence of ovarian cancer. SUVmax of peritoneal disease, peritoneal dissemination and CA125 level could be used as independent prognostic factors for ovarian cancer patients.

Role of Positron Emission Tomography/Computed Tomography in Preoperative Assessment of Carcinoma Endometrium-a Retrospective Analysis

PET/CT has made significant inroads into routine oncological practice in recent times. In our study, we aim to determine its value in preoperative assessment of endometrial carcinoma. A retrospective study between January 2011 and March 2016 was conducted; we included all cases of carcinoma endometrium with a preoperative PET/CT scan. PET/CT images were analyzed and correlated with histological findings after surgical staging. A total of 46 cases were analyzed, mean age was 59.8 years, BMI 30.8 kg/m2, and most common histology endometrioid type (69.5%). We correlated PET/CT findings with histopathology as reference standard. PET/CT had a sensitivity of 40%, moderate specificity (75%) and accuracy (71.7%), good NPV (91.2%), but poor PPV (16.7%) for lymph node involvement. A total of 10 (21.7%) cases were detected to have distant metabolically active lesions on PET/CT, seven out of these were positive for malignancy. And 90% of them were either non-endometrioid type or grade two and higher. We found that SUV of primary tumor was significantly higher in patients with deep myometrial invasion (p = 0.018), and high-risk histological type of tumor (p = 0.022), though not statistically significant when lymph nodal involvement (p = 0.9), cervical involvement (p = 0.56), or histological grade (p = 0.84) were considered. Sensitivity and specificity of PET/CT in staging endometrial cancer is not high enough to reliably tailor lymphadenectomy. Although SUV of the primary tumor was significantly higher in patients with deep myometrial invasion and high-risk histological type, it's usefulness in classifying patients into predefined risk groups seems to be limited. However, it is useful in detecting distant metastasis especially in high-grade and non-endometrioid type of tumors. Thus, implementation of PET/CT as a surrogate for surgical staging of endometrial cancer remains enigmatic and is open to further research.

Prognostic role of FDG PET-derived parameters in preoperative staging of endometrial cancer

PURPOSE

To investigate the preoperative prognostic role of ¹⁸F-FDG PET/CT in patients with endometrial carcinoma (EC).

METHODS

¹⁸F-FDG PET/CT was performed in 57 patients for EC preoperative staging. Maximum and mean standardized uptake values (SUVmax, mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of primary tumors, at different thresholds of 40%, 50%, 60% (40-50-60), were evaluated and compared with anatomopathological features. The diagnostic performance of PET-parameters (categorized by ROC analysis) in discriminating low-intermediate and high-risk disease and the prognostic role on survival (overall survival -OS; disease free survival - DFS) was evaluated.

RESULTS

The categorized TLG40-50-60 were the only parameters related to FIGO stage I versus II-III-IV (p = 0.0035 for all). The cut-off values for risk stratification were 83.69, 61.81 and 41.32, respectively (sensitivity: 60.00%; specificity; 71.43% for all parameters). Pathological stage 1 (pT1) of the primary tumor was predicted by MTV60 and TLG40-50 (p = 0.0328, 0.0240, 0.0147, respectively). The optimal thresholds were 7.795, 99.55 and 77.58, respectively (sensitivity: 38.46%, 53.85% and 53.85%, respectively; specificity: 88.64%, 79.55% and 81.82%, respectively). SUVmax and SUVmean40-50-60 were the only parameters discriminating endometrioid from non-endometrioid subtype. The corresponding sensitivity was 64.86% and 62.16% for SUVmax and SUVmean 50-60 and 62.16% for SUVmean40; specificity was 70.00% for all parameters. The mean (SD) OS was 79.77% (3.34%) and the mean DFS was 77.89% (3.73%). The tumor type was the only variable significantly associated with OS (p = 0.0486). TLG50 > 77.58 cm³ was the only variable associated with a higher risk of relapse (p = 0.0472).

CONCLUSION

TLG40-50-60 and MTV60 of primary EC have prognostic value in discriminating FIGO and pathological staging. These results suggest a possible role of these parameters in predicting EC aggressiveness, thus improving the preoperative characterization of endometrial cancer.

18F-FDG PET/CT can predict chemosensitivity and proliferation of epithelial ovarian cancer via SUVmax value

PURPOSE

This study aimed to explore the clinical and prognostic significance of ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in epithelial ovarian cancer (EOC).

METHODS

We retrospectively investigated 48 EOC patients who underwent preoperative ¹⁸F-FDG PET/CT and primary cytoreductive surgery at our hospital between January 2010 and June 2015. None of these patients received neoadjuvant chemotherapy. PET/CT parameters including the maximum and average standardized uptake value (SUVmax, SUVavg), the metabolic tumor volume (MTV) were measured. Tumor proliferation marker Ki67 was evaluated using immunohistochemistry. The relationships between the PET/CT parameters and chemosensitivity, tumor proliferation, and overall survival (OS) were analyzed, respectively.

RESULTS

The median (range) SUVmax, SUVavg, and MTV values were 11.42 (3.14-20.20), 4.8 (2.55-9.47), and 150.11 (0.19-792.46), respectively. Overall, 93.8% (45/48) of patients had high-grade serous ovarian cancer. The SUVmax value had a positive correlation with the Ki67 index (P = 0.030, r = 0.314), and a higher SUVmax level was associated with chemosensitivity (P = 0.026). However, neither SUVavg nor MTV had associations with the patients' clinicopathological parameters. None of these three PET/CT parameters were found to be potential predictors of OS.

CONCLUSIONS

Preoperative ¹⁸F-FDG PET/CT had a predictive value on chemosensitivity and proliferation after primary debulking surgery in EOC patients noninvasively.

The Complementary Role of Imaging and Tumor Biomarkers in Gynecological Cancers: An Update of the Literature

Gynecological tumors, including endometrial, cervical and ovarian cancer, have increased in incidence over time. The widespread introduction of screening programs and advances in diagnostic imaging methods has lead to a progressive increase in gynecological cancer detection. Accurate diagnosis and proper monitoring of disease remain the primary target for a successful treatment. In the last years, knowledge about cancer biomarkers has considerably increased providing great opportunities for improving cancer detection and treatment. In addition, in the last few years there has been an important development of imaging techniques. Nowadays, a multimodal approach including the evaluation of serum tumor biomarkers combined with imaging techniques, seems to be the best strategy for assessing tumor presence, spread, recurrence, and/or the response to treatment in female cancer patients In this review we provide an overview of the application of biomarkers combined with novel imaging methods and highlight their roles in female cancer diagnosis and follow-up.

Emerging Molecular Imaging Techniques in Gynecologic Oncology

Molecular imaging (mainly PET and MR imaging) has played important roles in gynecologic oncology. Emerging MR-based technologies, including DWI, CEST, DCE-MR imaging, MRS, and DNP, as well as FDG-PET and many novel PET radiotracers, will continuously improve practices. In combination with radiomics analysis, a new era of decision making in personalized medicine and precisely guided radiation treatment planning or real-time surgical interventions is being entered into, which will directly impact on patient survival. Prospective trials with well-defined endpoints are encouraged to evaluate the multiple facets of these emerging imaging tools in the management of gynecologic malignancies.

Prognostic value of metabolic parameters determined by preoperative ¹⁸F-FDG PET/CT in patients with uterine carcinosarcoma

Objective

To evaluate the prognostic value of metabolic parameters measured by preoperative ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) in patients with uterine carcinosarcoma (UCS).

Methods

Data of 55 eligible patients with UCS who underwent preoperative ¹⁸F-FDG PET/CT and surgical staging were analyzed retrospectively. Maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV_2.5), and total lesion glycolysis (TLG_2.5) of the primary tumors were measured using a SUV threshold of 2.5. The optimal cutoff value of each parameter was determined by time-dependent receiver operating characteristic curve, and its impact on progression-free survival and overall survival was evaluated by Cox proportional hazards model.

Results

During a median follow-up period of 29 (range, 1.5–109.4) months, 47.3% (26/55) of the patients experienced disease progression, and the disease-associated mortality rate was 43.6% (24/55). Univariate analysis determined that hazard ratios (HRs) for disease progression for SUV_max (≥8.33), MTV_2.5 (≥63.92 mL), and TLG_2.5 (≥396.16) were 1.930 (95% confidence interval [CI]=0.793–4.701), 3.264 (95% CI=1.466–7.268), and 2.692 (95% CI=1.224–5.924), respectively. And, HRs for death were 1.979 (95% CI=0.774–5.060), 2.764 (95% CI=1.217–6.274), and 2.721 (95% CI=1.198–6.182), respectively. While peritoneal cytology, histology, and tumor diameter were independent prognostic factors in multivariate analysis, MTV and TLG were not.

Conclusion

Though MTV and TLG of primary UCS were not independent predictors compared to surgically obtained data, MTV and TLG of primary UCS may provide useful information on prognosis especially in patients who are not able to undergo surgical staging.

Role of positron emission tomography-computed tomography in endometrial cancer

Objective:

The efficacy of preoperative ¹⁸F-fluoro-D-glucose (¹⁸F-FDG) positron emission tomography-computed tomography (PET-CT) in endometrium cancer is controversial. We examined the efficacy of PET-CT and the association between maximum standardized uptake value (SUVmax) and prognostic factors in endometrial cancer.

Materials and Methods:

Thirty patients with endometrial cancer underwent preoperative ¹⁸F-FDG/PET-CT. The patients were treated with abdominal hysterectomy with bilateral salpingo-oophorectomy, and bilateral systemic pelvic lymphadenectomy was planned for all patients; paraaortic lymphadenectomy was performed in patients with intermediate and high risk. Tumor histology, grade, depth of myometrial invasion, maximum tumor diameter, lymphovascular invasion, nodal status, and ovarian/adnexal metastases were recorded.

Results:

The mean primary tumor diameter was reported smaller in PET-CT and the effect size of PET-CT was -0.60. The kappa value was 0.06 for myometrial invasion. Pelvic lymph node metastasis was reported in 22.2% of patients in PET-CT. However, 3.7% of patients had pelvic lymph node metastasis. The kappa value for pelvic lymph node metastasis was 0.23, and sensitivity, specificity, and positive and negative predictive values were 100%, 80.7%, 16.6%, and 100%, respectively. Paraaortic lymph node metastasis in PET-CT was suspected in 10%. However, paraaortic lymph node metastasis was found in 6.7% in histopathologic analyses. The kappa value was 0.15. The sensitivity, specificity, and positive and negative predictive values of PET-CT for detecting paraaortic lymph node metastases were 100%, 93.7%, 66.6%, and 100%, respectively. Myometrial invasion and tumor diameter were the only important prognostic factors affecting SUV_max.

Conclusion:

According to our results, PET-CT has a limited role and diagnostic efficacy in endometrial cancer. The indications of FDG/PET-CT in endometrium cancer should be studied further and revised.

Verification of the tumor volume delineation method using a fixed threshold of peak standardized uptake value

We aimed to determine the difference in tumor volume associated with the reconstruction model in positron-emission tomography (PET). To reduce the influence of the reconstruction model, we suggested a method to measure the tumor volume using the relative threshold method with a fixed threshold based on peak standardized uptake value (SUV_peak). The efficacy of our method was verified using ¹⁸F-2-fluoro-2-deoxy-D-glucose PET/computed tomography images of 20 patients with lung cancer. The tumor volume was determined using the relative threshold method with a fixed threshold based on the SUV_peak. The PET data were reconstructed using the ordered-subset expectation maximization (OSEM) model, the OSEM + time-of-flight (TOF) model, and the OSEM + TOF + point-spread function (PSF) model. The volume differences associated with the reconstruction algorithm (%VD) were compared. For comparison, the tumor volume was measured using the relative threshold method based on the maximum SUV (SUV_max). For the OSEM and TOF models, the mean %VD values were -0.06 ± 8.07 and -2.04 ± 4.23% for the fixed 40% threshold according to the SUV_max and the SUV_peak, respectively. The effect of our method in this case seemed to be minor. For the OSEM and PSF models, the mean %VD values were -20.41 ± 14.47 and -13.87 ± 6.59% for the fixed 40% threshold according to the SUV_max and SUV_peak, respectively. Our new method enabled the measurement of tumor volume with a fixed threshold and reduced the influence of the changes in tumor volume associated with the reconstruction model.

Prediction of Recurrence by Preoperative Intratumoral FDG Uptake Heterogeneity in Endometrioid Endometrial Cancer

PURPOSE: To investigate the prognostic value of preoperative intratumoral ¹⁸F-FDG uptake heterogeneity (IFH) derived from positron emission tomography (PET)/computed tomography (CT) in patients with endometrioid endometrial cancer. METHODS: We retrospectively evaluated clinicopathological data from patients with pathologically proven endometrioid endometrial cancer who had undergone ¹⁸F-FDG PET/CT scans before surgery. Patients were divided into two groups according to their IFH. The main outcome measure was disease-free survival (DFS). RESULTS: Between January 2010 and January 2015, data from 72 patients were available for analysis. The median duration of DFS was 23 months (range, 6 to 57 months), and 4 (5.6%) patients experienced recurrence. There were significant differences in tumor size, IFH, and DFS between patients with and without recurrence. In regression analysis, high IFH value [P = .007, hazard ratio (HR) 2.545, 95% confidence interval (CI) 1.468-8.674] was the only independent risk factor for recurrence. The Kaplan-Meier survival graphs showed that DFS significantly differed in groups categorized based on IFH (P < .001, log-rank test). CONCLUSIONS: Preoperative IFH measured by ¹⁸F-FDG PET/CT was associated with recurrence of endometrioid endometrial cancer. The finding supports evidence that FDG-based heterogeneity can be a novel and useful predictor of endometrioid endometrial cancer recurrence.

What Is the Best Preoperative Imaging for Endometrial Cancer?

Although endometrial cancer is surgicopathologically staged, preoperative imaging is recommended for diagnostic work-up to tailor surgery and adjuvant treatment. For preoperative staging, imaging by transvaginal ultrasound (TVU) and/or magnetic resonance imaging (MRI) is valuable to assess local tumor extent, and positron emission tomography-CT (PET-CT) and/or computed tomography (CT) to assess lymph node metastases and distant spread. Preoperative imaging may identify deep myometrial invasion, cervical stromal involvement, pelvic and/or paraaortic lymph node metastases, and distant spread, however, with reported limitations in accuracies and reproducibility. Novel structural and functional imaging techniques offer visualization of microstructural and functional tumor characteristics, reportedly linked to clinical phenotype, thus with a potential for improving risk stratification. In this review, we summarize the reported staging performances of conventional and novel preoperative imaging methods and provide an overview of promising novel imaging methods relevant for endometrial cancer care.

18F-fludrodeoxyglucose maximal standardized uptake value and metabolic tumor burden are associated with major chemotherapy-related tumor markers in NSCLC patients

Objective

Metabolic activity and tumor burden are significant for prognosis and metastasis of non-small cell lung cancer (NSCLC), including maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Chemotherapy resistance is a great challenge for treating NSCLC patients and is also closely related with several biomarkers such as epidermal growth factor receptor (EGFR), p53, and excision repair cross-complementing group 1 protein (ERCC1). Our purpose was to determine the correlation between positron emission tomography/computed tomography (PET/CT) parameters and tumor markers-related chemotherapy resistance in NSCLC.

Methods

Forty-six NSCLC chemotherapy-naïve patients were enrolled. The SUV_max, MTV, and TLG were calculated by PET/CT imaging, and expression of EGFR, p53, and ERCC1 were analyzed by immunohistochemistry on tissues. SUV_max, MTV, and TLG compared for their performance in predicting the expression of EGFR, p53, and ERCC1 were illustrated with statistical analysis.

Results

SUV_max was significantly correlated with p53 expression (P=0.001), and MTV and TLG were significantly associated with ERCC1 (P=0.000; P=0.000). Furthermore, multiple stepwise regression analysis revealed that SUV_max was the primary predictor for p53, MTV and TLG was the primary predictor for ERCC1. SUV_max had a sensitivity of 91% and specificity of 50% for the detection of p53 positive. The sensitivities of MTV and TLG were 83% and 80%, and specificities were 69% and 75% for the detection of ERCC1 positive, respectively. When we suggested p53 or ERCC1 positive, the cutoff value of SUV_max, MTV, and TLG were 7.68, 23.62, and 129.65 cm³, respectively.

Conclusion

SUV_max, MTV, and TLG were closely associated with p53 and ERCC1’ expressions. Therefore, ¹⁸F-fludrodeoxyglucose PET/CT could be a new way of predicting p53 or ERCC1-related chemotherapy effect in NSCLC patients with more convenience.

Prognostic impact of primary tumor SUVmax on preoperative 18F-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography in endometrial cancer and uterine carcinosarcoma

The objective of the present study was to investigate the usefulness of the maximum standardized uptake value (SUV_max) of the primary tumor on preoperative ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) as a prognostic indicator in patients with endometrial neoplasms. A total of 75 patients with endometrial cancer or uterine carcinosarcoma who underwent surgical treatment were included in the present study. All patients underwent preoperative PET/CT, and the correlation between the SUV_max of the primary tumor and clinical outcomes was analyzed. The SUV_max was significantly higher in patients with stage II/III disease, a histology of grade 3 endometrioid adenocarcinoma and carcinosarcoma, a positive lymph node (LN) status, positive lymph-vascular space involvement (LVSI), and deep (≥1/2) myometrial invasion. Receiver operating characteristic curve analysis revealed that the optimal cut-off values of SUV_max for predicting a positive LN, LVSI and deep myometrial invasion were 7.49, 6.45 and 6.45, respectively. The overall survival (OS) and progression-free survival (PFS) of patients with a high SUV_max were significantly lower compared with those of patients with a low SUV_max using the cut-off value of 7.30. However, no significant difference was observed in the OS or PFS between the high and low SUV_max groups when analyzed in carcinosarcoma patients alone. Finally, multivariate analyses demonstrated that the SUV_max of the primary tumor was an independent prognostic factor for impaired PFS in 55 endometrioid adenocarcinoma patients; however, not in all patients, including those with carcinosarcoma. The present findings demonstrated that the SUV_max of the primary tumor may be a useful biomarker for predicting clinical outcomes of patients with endometrial cancer, although its prognostic impact appears to be limited in patients with uterine carcinosarcoma.

Primary tumor SUVmax on preoperative FDG-PET/CT is a prognostic indicator in stage IA2-IIB cervical cancer patients treated with radical hysterectomy

The objective of the present study was to investigate the prognostic value of ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) uptake by primary tumors on positron emission tomography/computed tomography (PET/CT) in surgically resectable cervical cancer. A total of 59 patients with stage IA2-IIB cervical cancer who underwent preoperative FDG-PET/CT, followed by radical hysterectomy and lymphadenectomy, were included in the study. The maximum standardized uptake value (SUV_max) of the primary tumor was measured, and the association between the SUV_max and clinicopathological factors or patient outcomes was analyzed. The SUV_max was significantly higher in patients with an advanced stage, lymph node metastasis, lymph-vascular space involvement and large tumors. The overall survival (OS) and progression-free survival (PFS) of patients with a high SUV_max were significantly lower compared with patients with a low SUV_max, using an optimal cut-off value of 7.36 for OS and 5.59 for PFS obtained from receiver operating characteristic curve analysis. Similarly, OS and PFS in patients with a high SUV_max were significantly lower in 39 patients with stage IB using a cut-off value of 7.90 and 6.69 for OS and PFS, respectively. Finally, multivariate analyses showed that the SUV_max of the primary tumor was an independent prognostic factor for impaired PFS in all patients and those with stage IB alone. These findings demonstrated that a high SUV_max on preoperative PET/CT was correlated with unfavorable clinical outcomes in patients receiving radical hysterectomy, suggesting that the SUV_max of the primary tumor may be a prognostic indicator for surgically-treated, early-stage invasive cervical cancer.

Prognostic value of fluorine-18 fludeoxyglucose positron emission tomography parameters differs according to primary tumour location in small-cell lung cancer

OBJECTIVE

To investigate the prognostic value of fluorine-18 fludeoxyglucose (FDG) positron emission tomography (PET) parameters for small-cell lung cancer (SCLC), according to the primary tumour location, adjusted by conventional prognostic factors.

METHODS

From 2008 to 2013, we enrolled consecutive patients with histologically proven SCLC, who had undergone FDG-PET/CT prior to initial therapy. The primary tumour location was categorized into central or peripheral types. PET parameters and clinical variables were evaluated using univariate and multivariate analysis.

RESULTS

A total of 69 patients were enrolled in this study; 28 of these patients were categorized as having the central type and 41 patients as having the peripheral type. In univariate analysis, stage, serum neuron-specific enolase, whole-body metabolic tumour volume (WB-MTV) and whole-body total lesion glycolysis (WB-TLG) were found to be significant in both types of patients. In multivariate analysis, the independent prognostic factor was found to be stage in the central type, but WB-MTV and WB-TLG in the peripheral type. Kaplan-Meier analysis demonstrated that patients with peripheral type with limited disease and low WB-MTV or WB-TLG showed significantly better overall survival than all of the other groups (p < 0.0083).

CONCLUSION

The FDG-PET volumetric parameters were demonstrated to be significant and independent prognostic factors in patients with peripheral type of SCLC, while stage was the only independent prognostic factor in patients with central type of SCLC.

ADVANCES IN KNOWLEDGE

FDG-PET is a non-invasive method that could potentially be used to estimate the prognosis of patients, especially those with peripheral-type SCLC.

Metabolic Tumor Volume on 18F-FDG PET/CT Improves Preoperative Identification of High-Risk Endometrial Carcinoma Patients

Our objective was to prospectively explore the diagnostic value of (18)F-FDG PET/CT for preoperative staging in endometrial carcinomas and to investigate whether (18)F-FDG PET-specific quantitative tumor parameters reflect clinical and histologic characteristics.

METHODS

Preoperative (18)F-FDG PET/CT was prospectively performed on 129 consecutive endometrial carcinoma patients. Two physicians who did not know the clinical findings or staging results independently reviewed the images, assessing primary tumor, cervical stroma involvement and metastatic spread, and determining maximum and mean standardized uptake value (SUVmax and SUVmean, respectively) for tumor, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). All parameters were analyzed in relation to histomorphologic and clinical tumor characteristics. Receiver-operating-characteristic curves for identification of deep myometrial invasion and lymph node metastases were generated, and MTV cutoffs for predicting deep myometrial invasion and lymph node metastases were calculated.

RESULTS

The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT for the detection of lymph node metastases were 77%-85%, 91%-96%, and 89%-93%, respectively. SUVmax, SUVmean, MTV, and TLG were significantly related to deep myometrial invasion, presence of lymph node metastases, and high histologic grade (P < 0.015 for all) and independently predicted deep myometrial invasion (P < 0.015) and lymph node metastases (P < 0.025) after adjustment for preoperative histologic risk (based on subtype and grade) in endometrial biopsies. Optimal cutoffs for MTV in predicting deep myometrial invasion (20 mL) and the presence of lymph node metastases (30 mL) yielded odds ratios of 7.8 (P < 0.001) and 16.5 (P = 0.001), respectively.

CONCLUSION

(18)F-FDG PET/CT represents a clinically valuable tool for preoperatively evaluating the presence of lymph node metastases in endometrial carcinoma patients. Applying MTV cutoffs for the prediction of deep myometrial invasion and lymph node metastases may increase diagnostic accuracy and aid preoperative identification of high-risk patients, enabling restriction of lymphadenectomy for patients with a low risk of aggressive disease.