18F-FDG PET/CT can predict nodal metastases but not recurrence in early stage uterine cervical cancer

Based on 3D-PDU and clinical characteristics nomogram for prediction of lymph node metastasis and lymph-vascular space invasion of early cervical cancer preoperatively

PURPOSE

To develop and validate a nomogram based on 3D-PDU parameters and clinical characteristics to predict LNM and LVSI in early-stage cervical cancer preoperatively.

MATERIALS AND METHODS

A total of first diagnosis 138 patients with cervical cancer who had undergone 3D-PDU examination before radical hysterectomy plus lymph dissection between 2014 and 2019 were enrolled for this study. Multivariate logistic regression analyses were performed to analyze the 3D-PDU parameters and selected clinicopathologic features and develop a nomogram to predict the probability of LNM and LVSI in the early stage. ROC curve was used to evaluate model differentiation, calibration curve and Hosmer-Lemeshow test were used to evaluate calibration, and DCA was used to evaluate clinical practicability.

RESULTS

Menopause status, FIGO stage and VI were independent predictors of LNM. BMI and maximum tumor diameter were independent predictors of LVSI. The predicted AUC of the LNM and LSVI models were 0.845 (95%CI,0.765-0.926) and 0.714 (95%CI,0.615-0.813). Calibration curve and H-L test (LNM groups P = 0.478; LVSI P = 0.783) all showed that the predicted value of the model had a good fit with the actual observed value, and DCA indicated that the model had a good clinical net benefit.

CONCLUSION

The proposed nomogram based on 3D-PDU parameters and clinical characteristics has been proposed to predict LNM and LVSI with high accuracy, demonstrating for the first time the potential of non-invasive prediction. The probability derived from this nomogram may have the potential to provide valuable guidance for physicians to develop clinical individualized treatment plans of FIGO patients with early cervical cancer.

The Utility of 18F-FDG-PET-CT Metabolic Parameters in Evaluating the Primary Tumor Aggressiveness and Lymph Node Metastasis of Nasopharyngeal Carcinoma

Background

Following changes in primary tumor (T) and lymph node (N) staging for nasopharyngeal carcinoma (NPC) in the Eighth Edition AJCC Cancer Staging Manual, simplification of T staging has been proposed. However, a limited range of 2-deoxy-2-[fluorine-18] fluoro-D-glucose positron emission tomography-computed tomography (18F-FDG PET-CT) metabolic parameters has been investigated. Therefore, we aimed to evaluate the primary tumor invasiveness and the lymph node metastasis (LNM) of NPC from a metabolic perspective.

Methods

A total of 435 NPC patients underwent 18F-FDG PET/CT before treatment were retrospectively examined. The primary endpoint was differences in standard uptake value (SUV), lean body mass-normalized SUV (SUL), body surface area-normalized SUV (SUS), glucose-normalized SUV (GN), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and glucose-normalized total lesion glycolysis (GNTLG) of primary tumors and LNM between different T and N stages. The metabolic parameters associated with T and N staging were identified.

Results

There were significant differences between all parameters relative to the primary tumor but no significant differences in any parameter relative to the LNM and T stages. Higher mean values of TGNmax, TGNmean, TSUVpeak, and TSUSmax were associated with advanced T stages. Higher mean values of all the LNM parameters were associated with more advanced N stages. Only primary tumor metabolic tumor volume (TMTV), TSUVpeak, TSULmax, and TSUSmax showed a significant positive association with T staging, while lymph node metabolic tumor volume (LNMTV) and TSUSmax were significantly positive in N staging.

Conclusions

Our findings suggest that metabolic parameters are useful indicators of tumor invasiveness and LNM based on the Eighth Edition manual. Compared with volume-dependent parameters, TGNmax, TGNmean, TSUVpeak, and TSUSmax may be better indicators of local tumor aggressiveness. SUSmax of the primary tumor was associated with LNM. In addition to SUVmax, other metabolic parameters (eg, SULmax, SUSmax, GNmax, and GNmean) could evaluate tumor aggressiveness and LNM better.

Molecular image-guided surgery in gynaecological cancer: where do we stand?

PURPOSE

The aim of this review is to give an overview of the current status of molecular image-guided surgery in gynaecological malignancies, from both clinical and technological points of view.

METHODS

A narrative approach was taken to describe the relevant literature, focusing on clinical applications of molecular image-guided surgery in gynaecology, preoperative imaging as surgical roadmap, and intraoperative devices.

RESULTS

The most common clinical application in gynaecology is sentinel node biopsy (SNB). Other promising approaches are receptor-target modalities and occult lesion localisation. Preoperative SPECT/CT and PET/CT permit a roadmap for adequate surgical planning. Intraoperative detection modalities span from 1D probes to 2D portable cameras and 3D freehand imaging.

CONCLUSION

After successful application of radio-guided SNB and SPECT, innovation is leaning towards hybrid modalities, such as hybrid tracer and fusion of imaging approaches including SPECT/CT and PET/CT. Robotic surgery, as well as augmented reality and virtual reality techniques, is leading to application of these innovative technologies to the clinical setting, guiding surgeons towards a precise, personalised, and minimally invasive approach.

Predictive Role of Preoperative Whole-Body 18F-FDG PET/CT for Risk Stratification of Early-Stage (FIGO I-IIA) Cervical Cancer Patients Treated by Surgery

INTRODUCTION

The aim of the present study was to investigate the predictive value of maximum standardized uptake value (SUVmax) measured on preoperative 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in International Federation of Gynecology and Obstetrics (FIGO 2009) stage I-IIA cervical cancer patients who were treated with radical hysterectomy.

METHODS

A total of 47 patients with FIGO stage I-IIA cervical cancer who were evaluated preoperatively with biopsy and 18F-FDG PET/CT followed by radical hysterectomy were included in the study. Correlation between SUVmax and pathological risk factors or survival was studied.

RESULTS

The mean SUVmax was significantly higher in patients with large tumor size (≥4 cm), advanced stage (IIA>IB>IA) and depth of invasion >50%. No significant difference was noted in SUVmax between patients with and without pelvic lymph node involvement (P=0.639). SUVmax of the primary tumor with and without lymph-vascular invasion were 12.95 and 10.35, respectively (P=0.5). No significant difference was noted between patients with high SUVmax and low SUVmax with regards to overall survival (OS) and disease-free survival (DFS), using an optimal cut-off value of 7.65 for OS and DFS obtained from receiver operating characteristic (ROC) curve analysis. Patient with tumor size >4cm had 5.9 times more probability of mortality compared to tumor size <4cm (P=0.09).

CONCLUSION

The present study observations showed that although SUVmax is associated with pathological variables, it does not independently predict oncological outcomes in FIGO stage IA-IIA cervical cancer patients who were treated with radical hysterectomy. These findings suggest that SUVmax of primary tumor may be used for risk stratification, but not for prognostication in surgically treated early-stage cervical cancer patients. Not using other parameters of 18F-FDG PET/CT like metabolic tumor volume (MTV), tumor lysis glycolysis (TLG), small sample size, variation in calculation of SUVmax, histopathologic heterogeneity, inclusion of stage IA patients in the study were constraints of present study. Further studies with large sample size using multi metabolic parameters of 18F-FDG PET/CT, including the SUVmax,SUVmean,SUVpeak, MTV and TLG are needed.

Predictive value of 18 F-FDG PET/CT and serum tumor markers for tumor mutational burden in patients with non-small cell lung cancer

PURPOSE

To investigate the correlations between metabolic parameters (MPs) of 18 F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT), serum tumor markers (STMs), and tumor mutational burden (TMB) in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

In this retrospective study, we enrolled 129 patients with NSCLC (males, 78; females, 51) who underwent baseline TMB and STM tests and 18 F-FDG PET/CT scans before treatment between March 2018 and September 2022. Patients were categorized into TMB-high (TMB ≥10 mutations/Mb; n = 27 [20.9%]) and non-TMB-high (TMB <10 mutations/Mb; n = 102 [79.1%]) groups. Binary logistic regression analyses were performed to determine independent predictors of TMB-high. Univariate and multivariate linear regression analyses were performed to determine independent predictors of TMB level on a log scale. Subgroup analyses for adenocarcinoma (ADC), ADC with EGFR+, ADC with EGFR-, and squamous cell carcinoma (SCC) were performed.

RESULTS

For ADC, all MPs (SULpeak , SULmax , SULmean , MTV, and TLG) were significantly higher in the TMB-high group than the non-TMB-high group; smoker (odds ratio [OR] = 27.08, p = 0.018), EGFR+ (OR = 0.03, p = 0.033), KRAS+ (OR = 7.98, p = 0.083), high CEA (OR = 33.56, p = 0.029), and high CA125 (OR = 13.68, p = 0.030) were independent predictors of TMB-high; and all MPs showed significant positive linear correlations with TMB on a log scale, with SULpeak as an independent predictor. However, no significant correlation was observed for SCC.

CONCLUSION

MPs and STMs can predict the TMB level for patients with ADC, and may serve as potential substitutes for TMB with increased value and easy implementation in guiding immunotherapy through noninvasive methods.

Volumetric PET parameters are predictive for the prognosis of locally advanced cervical cancer

BACKGROUND

The present study evaluates the relationship between PET/CT findings and survival in patients with locally advanced cervical cancer (LACC) with a squamous cell histology.

METHODS

The study included 70 patients with LACC (FIGO stage IB2-IVA). The relationship between pretreatment PET/CT parameters, age, stage, lymph node metastasis and survival was evaluated using the univariate and multivariate Cox proportional hazards model.

RESULTS

The mean age of the 70 patients was 57.4 years and the mean duration of follow-up was 33.6 months. Disease progression occurred in 36 patients and 32 patients died during the follow-up period. In the univariate analysis, MTV-P and TLG-P were found to be related to progression-free survival (PFS), and stage, MTV-P, TLG-P and SUV<inf>max</inf>-Ps were found to be related to overall survival (OS). However, only MTV-P and TLG-P were found to be independent prognostic factors for both PFS and OS.

CONCLUSIONS

The present findings suggest that volumetric PET parameters (MTV-P, TLG-P) predict the progression and survival of the patients with LACC.

Combination of Deauville score and quantitative positron emission tomography parameters as a predictive tool of anti-CD19 chimeric antigen receptor T-cell efficacy

BACKGROUND

Autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is an effective treatment for approximately 40% of relapsed/refractory large B cell lymphomas (LBCL), and early identification of patients at risk for relapse or progression after CAR T-cell therapy represents a clinical need.

METHODS

The authors conducted a single-center prospective study on 47 relapsed/refractory LBCL receiving CAR T-cell therapy to evaluate the prognostic value of baseline and after infusion ¹⁸ F-fluorodeoxyglucose positron emission tomography (PET)-computed tomography. Qualitative and quantitative metabolic parameters were evaluated before lymphodepletion, at day 30 and 90 post-infusion.

RESULTS

Deep variation of standardized uptake value (SUV)_mean between baseline and day 30 correlated with response at day 90 (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.01-2.2); p = .04) and better progression-free survival (PFS) (HR, 0.63; 95% CI, 0.41-0.97); p = .04). In the overall population, 1-year PFS was 63% for Deauville score (DS)1-3 and 39% for DS4-5 patients, respectively (p = .02), however, the prognostic role of DS was lost when survivals are analyzed by considering 38 patients not progressing at 30 days. In these patients, in partial response or stable disease, the combination of DS and variation of SUV_mean allowed identification of three groups with different prognosis: patients with DS1-3 and those with DS4-5 and decreased SUV_mean had similar 1-year PFS of 62% and 61%, whereas patients with DS4-5 and increased SUV_mean had a poorer 1-year PFS of 33% (p = .04).

CONCLUSIONS

PET parameters and association of DS and variation of SUV_mean at 30 days could help in identify patients at high risk of CAR T-cell failure.

LAY SUMMARY

This is a single-center prospective study on 47 lymphoma patients receiving commercial chimeric antigen receptor T-cell therapy aimed to evaluate the prognostic value of baseline and after infusion ¹⁸ F-fluorodeoxyglucose positron emission tomography. Among patients in partial remission or stable disease at day 30, the authors observed two subgroups with significantly different prognosis; patients with Deauville score (DS)4-5 and a concomitant reduction of standardized uptake value (SUV)_mean had higher probability of long-lasting response than those with DS4-5 and an increase of SUV_mean .

Improved stratification of stage-specific survival for cervical uterine cancer by integrating FDG-PET/CT and MRI for lymph node staging in 2018 FIGO classification

OBJECTIVE

Staging carcinoma of the uterine cervix (CCU) by FIGO-2018 suggests stage migration of FIGO-2009 stage I-III patients with lymph node metastasis into FIGO-2018 stage IIIC. We aimed to investigate the prognostic value of lymph node metastases identified by imaging.

METHODS

We enrolled all patients with biopsy-verified CCU from 2007 to 2016 at Odense University Hospital, Denmark. FDG-PET/CT and MRI were performed before clinical examination in general anesthesia. Disease-specific mortality was compared between women with lymph node-positive and lymph node-negative imaging.

RESULTS

In total, 488 patients underwent clinical staging according to FIGO-2009. Lymph node-positive imaging was identified in 146 (30%) patients: 0/36 (0%) in stage IA, 22/195 (11%) in IBI, 14/30 (47%) in IB2, 70/164 (43%) in II and 40/63 (63%) in III. The 5-year cumulative incidence of death due to CCU lymph node-negative vs. lymph node-positive patients was 0.8% vs. 7.1% (p = 0.034) in stage IBI, 0% vs. 34.5% (p = 0.003) in stage IB2, 15.1% vs. 41.4% (p < 0.0001) in stage II, and 33.3% vs. 46.6% (p = 0.28) in stage III by FIGO-2009.

CONCLUSIONS

One of three women with FIGO-2009 stage I-III CCU had suspected lymph node metastasis on imaging and is upstaged to stage IIIC according to FIGO-2018. The cancer-specific mortality by CCU was significantly lower in the lymph node-negative women stages IBI-II, thus supporting stage migration due to suspected lymph node metastasis. However, the exact prognostic value within stage IIIC is challenged, and future revision of FIGO stages may include new sub-stages.

Radiomics model of 18F-FDG PET/CT imaging for predicting disease-free survival of early-stage uterine cervical squamous cancer

BACKGROUND

To explore an effective predictive model based on PET/CT radiomics for the prognosis of early-stage uterine cervical squamous cancer.

METHODS

Preoperative PET/CT data were collected from 201 uterine cervical squamous cancer patients with stage IB-IIA disease (FIGO 2009) who underwent radical surgery between 2010 and 2015. The tumor regions were manually segmented, and 1318 radiomic features were extracted. First, model-based univariate analysis was performed to exclude features with small correlations. Then, the redundant features were further removed by feature collinearity. Finally, the random survival forest (RSF) was used to assess feature importance for multivariate analysis. The prognostic models were established based on RSF, and their predictive performances were measured by the C-index and the time-dependent cumulative/dynamics AUC (C/D AUC).

RESULTS

In total, 6 radiomic features (5 for CT and 1 for PET) and 6 clinicopathologic features were selected. The radiomic, clinicopathologic and combination prognostic models yielded C-indexes of 0.9338, 0.9019 and 0.9527, and the mean values of the C/D AUC (mC/D AUC) were 0.9146, 0.8645 and 0.9199, respectively.

CONCLUSIONS

PET/CT radiomics could achieve approval power in predicting DFS in early-stage uterine cervical squamous cancer.

Roles of DWI and T2-weighted MRI volumetry in the evaluation of lymph node metastasis and lymphovascular invasion of stage IB-IIA cervical cancer

AIM

To determine whether magnetic resonance imaging volumetry on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) could be used to assess lymph node metastases (LNM) and lymphovascular invasion (LVSI) in resectable cervical cancer.

MATERIAL AND METHODS

Sixty-five consecutive patients with cervical cancer were enrolled retrospectively. Tumour size, including maximum transverse diameter, tumour length, and gross tumour volume (GTV), was evaluated on DWI and T2WI. Apparent diffusion coefficient (ADC) values were measured. Univariate, multivariate, and receiver operating characteristic (ROC) curve analyses were performed to determine whether tumour size and ADC could be used to assess LNM and LVSI.

RESULTS

Tumour length on both T2WI and DWI, and T2WI-based and DWI-based GTVs could be used to assess LNM (p=0.002, 0.004, 0.001, and <0.001, respectively). Tumour length on T2WI, T2WI-based GTV, DWI-based GTV, and ADC value could be used assess LVSI (p=0.039, 0.038, 0.012, 0.039, respectively). Multivariate analyses showed both T2WI-based GTV (odds ratio [OR] = 1.044; p=0.008) and DWI-based GTV (OR=1.941; p=0.019) were independent risk factors for LNM. T2WI-based GTV (OR=1.023, p=0.038) and DWI-based GTV (OR=3.275, p=0.008) were independent risk factors for LVSI. No statistically significant difference was identified between the area under the ROC curve (AUC) of the DWI-based GTV and the T2WI-based GTV (0.790 versus 0.775, p=0.113), or the tumour length on both T2WI (0.790 versus 0.734, p=0.185) and DWI (0.790 versus 0.737, p=0.333) for LNM. For LVSI, the AUC of DWI-based GTV was higher than T2WI-based GTV (0.720 versus 0.682, p=0.006).

CONCLUSION

GTV on both T2WI and DWI could be used assess LNM and LVSI. DWI-based GTV might show the greatest potential for assessing LNM and LVSI in resectable cervical cancer.

Sentinel Lymph Node Staging with Indocyanine Green for Patients with Cervical Cancer: The Safety and Feasibility of Open Approach Using SPY-PHI Technique

Simple Summary

While several studies have been conducted on the safety and efficacy of sentinel lymph node technique during minimally invasive radical hysterectomy and indicated that using indocyanine green alone is a better tracer agent, there is now high unmet medical need and growing demand for more data about sentinel lymph node detection and the most suitable tracer in open surgery for cervical cancer, especially after the publishing of the of Laparoscopic Approach to Cervical Cancer (LACC) Trial data. The aim of this study is to assess the feasibility and safety of sentinel lymph nodes with indocyanine green in cervical cancer patients undergoing radical hysterectomy in open surgery and to compare the detection rates of this tracer in the open versus laparoscopic approaches.

Abstract

(1) Background: Sentinel lymph node staging (SLN) with indocyanine green (ICG) in cervical cancer is the standard of care in most national and international guidelines. However, the vast majority of relevant studies about the safety and feasibility of this method are conducted on minimally invasive surgery; (2) Methods: This study is a retrospective analysis of a retrospective collected database of 76 consecutive patients with cervical cancers, who were operated laparoscopically (50%), or laparotomy (50%). Sentinel nodes were defined as the ICG-positive pelvic nodes in the first and second echelons. False negative cases were defined as positive non-sentinel lymph nodes despite successful sentinel mapping or failed mapping bilaterally by per-patient assessment or unilaterally by pelvic sidewall assessment; (3) Results: Regardless of the approach (open or laparoscopic), the SLN technique achieved a total sensitivity, specificity, and negative predictive value (NPV) of 94.7%, 98.6%, and 94.7%, respectively in the entire sample. The bilateral detection rate was as high as 93.4% with identical results in both approaches. The sensitivity and NPV for SNL in open surgery was found to be similar to minimal access surgery; (4) Conclusions: ICG and SPY-PHI technique is a reliable tool to detect sentinel lymph nodes in cervical cancer during laparotomy.

18F-FDG PET/CT Habitat Radiomics Predicts Outcome of Patients with Cervical Cancer Treated with Chemoradiotherapy

PURPOSE

To determine if quantitative features extracted from pretherapy fluorine 18 fluorodeoxyglucose (18F-FDG) PET/CT estimate prognosis in patients with locally advanced cervical cancer treated with chemoradiotherapy.

MATERIALS AND METHODS

In this retrospective study, PET/CT images and outcomes were curated from 154 patients with locally advanced cervical cancer, who underwent chemoradiotherapy from two institutions between March 2008 and June 2016, separated into independent training (n = 78; mean age, 51 years ± 13 [standard deviation]) and testing (n = 76; mean age, 50 years ± 10) cohorts. Radiomic features were extracted from PET, CT, and habitat (subregions with different metabolic characteristics) images that were derived by fusing PET and CT images. Parsimonious sets of these features were identified by the least absolute shrinkage and selection operator analysis and used to generate predictive radiomics signatures for progression-free survival (PFS) and overall survival (OS) estimation. Prognostic validation of the radiomic signatures as independent prognostic markers was performed using multivariable Cox regression, which was expressed as nomograms, together with other clinical risk factors.

RESULTS

The radiomics nomograms constructed with T stage, lymph node status, and radiomics signatures resulted in significantly better performance for the estimation of PFS (Harrell concordance index [C-index], 0.85 for training and 0.82 for test) and OS (C-index, 0.86 for training and 0.82 for test) compared with International Federation of Gynecology and Obstetrics staging system (C-index for PFS, 0.70 for training [P = .001] and 0.70 for test [P = .002]; C-index for OS, 0.73 for training [P < .001] and 0.70 for test [P < .001]), respectively.

CONCLUSION

Prognostic models were generated and validated from quantitative analysis of 18F-FDG PET/CT habitat images and clinical data, and may have the potential to identify the patients who need more aggressive treatment in clinical practice, pending further validation with larger prospective cohorts.Supplemental material is available for this article.© RSNA, 2020.

Defining Characteristics of Nodal Disease on PET/CT Scans in Patients With HIV-Positive and -Negative Locally Advanced Cervical Cancer in South Africa

Literature reports increased FDG nodal uptake in HIV-positive patients. Our aim is to identify differences in presentation and characteristics of FDG-avid lymph nodes between HIV-positive and HIV-negative locally advanced cervical cancer (LACC) patients in our clinical setting. We evaluated 250 pre-treatment ¹⁸F-FDG PET/CT imaging studies from women screened for a phase III randomised controlled trial investigating modulated electro-hyperthermia as a radiosensitiser (Ethics approval: M120477). The number of nodes; size; maximum standardised uptake value (SUVmax); symmetry; and relationship between nodal size and SUVmax uptake, were assessed by region and by HIV status. In total, 1314 nodes with a SUVmax ≥ 2.5 were visualised. Of 128(51%) HIV-positive participants, 82% were on antiretroviral therapy (ART) and 10 had a CD4 count <200 cells/µL. Overall pattern of presentation and nodal characteristics were similar between HIV-positive and -negative groups and the uniformity in presentation of the nodes draining the cervix strongly suggests these nodes may be attributed to malignancy rather than HIV infection. Novel findings: HIV infection is associated with: >four nodes visualised in the neck, symmetrical inguinal lymph nodes, increased rates of supraclavicular node visualisation; FDG-avid axillary nodes were more common, but not exclusive, in HIV-positive participants. ¹⁸F-FDG PET/CT is a reliable staging method for LACC in HIV-positive patients who are not in acute stages of HIV infection, have a CD4 count >200 cells/µL, and/or are on ART and there is a potential risk of underestimating metastatic spread by attributing increased nodal metabolic activity to HIV infection in these patients.

Multimodality Imaging of Uterine Cervical Malignancies

OBJECTIVE. In this article, we provide an updated review on the role of imaging in initial staging, treatment monitoring, and follow-up of cervical cancer with a focus on the role of MRI and FDG PET/CT. In addition, the 2018 International Federation of Gynecology and Obstetrics staging system and its implication on management of cervical cancer are explored. CONCLUSION. Imaging plays a major role in treatment planning and as a prognostic indicator in patients with cervical cancer. MRI and PET/CT have complementary roles: MRI is essential for the local staging of the primary tumor, and PET/CT is the most useful modality for detecting regional nodal and distant metastases.

Radiomics of 18F-FDG PET/CT images predicts clinical benefit of advanced NSCLC patients to checkpoint blockade immunotherapy

INTRODUCTION

Immunotherapy has improved outcomes for patients with non-small cell lung cancer (NSCLC), yet durable clinical benefit (DCB) is experienced in only a fraction of patients. Here, we test the hypothesis that radiomics features from baseline pretreatment 18F-FDG PET/CT scans can predict clinical outcomes of NSCLC patients treated with checkpoint blockade immunotherapy.

METHODS

This study included 194 patients with histologically confirmed stage IIIB-IV NSCLC with pretreatment PET/CT images. Radiomics features were extracted from PET, CT, and PET+CT fusion images based on minimum Kullback-Leibler divergence (KLD) criteria. The radiomics features from 99 retrospective patients were used to train a multiparametric radiomics signature (mpRS) to predict DCB using an improved least absolute shrinkage and selection operator (LASSO) method, which was subsequently validated in both retrospective (N = 47) and prospective test cohorts (N = 48). Using these cohorts, the mpRS was also used to predict progression-free survival (PFS) and overall survival (OS) by training nomogram models using multivariable Cox regression analyses with additional clinical characteristics incorporated.

RESULTS

The mpRS could predict patients who will receive DCB, with areas under receiver operating characteristic curves (AUCs) of 0.86 (95%CI 0.79-0.94), 0.83 (95%CI 0.71-0.94), and 0.81 (95%CI 0.68-0.92) in the training, retrospective test, and prospective test cohorts, respectively. In the same three cohorts, respectively, nomogram models achieved C-indices of 0.74 (95%CI 0.68-0.80), 0.74 (95%CI 0.66-0.82), and 0.77 (95%CI 0.69-0.84) to predict PFS and C-indices of 0.83 (95%CI 0.77-0.88), 0.83 (95%CI 0.71-0.94), and 0.80 (95%CI 0.69-0.91) to predict OS.

CONCLUSION

PET/CT-based signature can be used prior to initiation of immunotherapy to identify NSCLC patients most likely to benefit from immunotherapy. As such, these data may be leveraged to improve more precise and individualized decision support in the treatment of patients with advanced NSCLC.

Combinative evaluation of primary tumor and lymph nodes to predict pelvic lymphatic metastasis in cervical cancer: an integrated PET-IVIM MRI study

Background

The aim of this study was to evaluate the value of combining pelvic lymph node and tumor characteristics on positron emission tomography-intravoxel incoherent motion magnetic resonance (PET-IVIM MR) imaging for predicting lymph node metastasis in patients with cervical cancer, especially in those with negative lymph nodes on PET.

Methods

The medical records of 95 patients with cervical cancer who underwent surgical resection with pelvic lymph node dissection were evaluated. The patients were divided into negative and positive groups according to postoperative pathologic lymph node diagnosis, and comparisons of the PET and IVIM-derived parameters between the two groups were performed. Univariate and multivariate analyses were performed to construct a predictive model of lymph node metastasis.

Results

For all patients, tumor SUV_max, TLG, D_min, PET and MRI for lymph node diagnosis showed significant differences between patients with and without confirmed lymph node metastasis. Univariate and multivariate logistic analysis showed that the combination of tumor TLG, D_min and PET for lymph node diagnosis had the strongest predictive value (AUC 0.913, p < 0.001). For patients with PET-negative lymph nodes, SUV_max, SUV_mean, MTV, TLG, and D_min showed significant between-group differences, and univariate and multivariate logistic analysis showed that TLG had the strongest predictive value.

Conclusions

The combination of tumorTLG, D_min and PET for lymph node diagnosis is a powerful prognostic factor for all patients. TLG has the best predictive performance in patients with PET negative lymph nodes.

Radiomics of 18F Fluorodeoxyglucose PET/CT Images Predicts Severe Immune-related Adverse Events in Patients with NSCLC

Purpose

To investigate the performance of pretreatment fluorine 18 (¹⁸F) fluorodeoxyglucose PET/CT radiomics in predicting severe immune-related adverse events (irSAEs) among patients with advanced non-small cell lung cancer (NSCLC) treated with immunotherapy, which is important in optimizing treatment plans and alleviating future complications with early interventions.

Materials and Methods

The retrospective arm of this study included 146 patients with histologically confirmed stage IIIB-IV NSCLC who were treated with immune checkpoint blockade between June 2011 and December 2017 and who were split into training (n = 97) and test (n = 49) cohorts. A prospective validation arm enrolled 48 patients before initiation of immunotherapy between January 2018 and June 2019 as an independent test cohort. Radiomics features extracted from baseline (preimmunotherapy treatment) PET, CT, and PET/CT fusion images were used to generate a radiomics score (RS) to quantify patient risk for developing irSAEs by an improved least absolute shrinkage and selection operator method. Weighted multivariable logistic regression analysis was then used to develop a nomogram model to predict irSAEs, which was assessed by its calibration, discrimination, and clinical usefulness.

Results

The radiomics nomogram, incorporating the RS, type of immune checkpoint blockade, and dosing schedule, was able to predict patients with and without irSAEs with area under the receiver operating characteristic curve of 0.92 (95% confidence interval [CI]: 0.86, 0.98), 0.92 (95% CI: 0.86, 0.99), and 0.88 (95% CI: 0.78, 0.97) in the training, test, and prospective validation cohorts, respectively. Decision curve analysis showed that the radiomics nomogram model had the highest overall net benefit.

Conclusion

A high RS is a significant risk factor for development of irSAEs, demonstrating the value of PET/CT images in predicting irSAEs. By the identification, at baseline, of patients with NSCLC most likely to have irSAEs, treatment plans can be optimized before initiation of immunotherapy.Supplemental material is available for this article.© RSNA, 2020See also the commentary by Yousefi.

What Is the Role of Imaging at Primary Diagnostic Work-Up in Uterine Cervical Cancer?

PURPOSE OF REVIEW

For uterine cervical cancer, the recently revised International Federation of Gynecology and Obstetrics (FIGO) staging system (2018) incorporates imaging and pathology assessments in its staging. In this review we summarize the reported staging performances of conventional and novel imaging methods and provide an overview of promising novel imaging methods relevant for cervical cancer patient care.

RECENT FINDINGS

Diagnostic imaging during the primary diagnostic work-up is recommended to better assess tumor extent and metastatic disease and is now reflected in the 2018 FIGO stages 3C1 and 3C2 (positive pelvic and/or paraaortic lymph nodes). For pretreatment local staging, imaging by transvaginal or transrectal ultrasound (TVS, TRS) and/or magnetic resonance imaging (MRI) is instrumental to define pelvic tumor extent, including a more accurate assessment of tumor size, stromal invasion depth, and parametrial invasion. In locally advanced cervical cancer, positron emission tomography-computed tomography (PET-CT) or computed tomography (CT) is recommended, since the identification of metastatic lymph nodes and distant metastases has therapeutic consequences. Furthermore, novel imaging techniques offer visualization of microstructural and functional tumor characteristics, reportedly linked to clinical phenotype, thus with a potential for further improving risk stratification and individualization of treatment. Diagnostic imaging by MRI/TVS/TRS and PET-CT/CT is instrumental for pretreatment staging in uterine cervical cancer and guides optimal treatment strategy. Novel imaging techniques may also provide functional biomarkers with potential relevance for developing more targeted treatment strategies in cervical cancer.

Enhancing prognosis prediction using pre-treatment nodal SUVmax and HPV status in cervical squamous cell carcinoma

BACKGROUND

This study was to evaluate the prognostic value of metabolic parameters on F-18-FDG PET/CT and the status of human papillomavirus (HPV) infection and known prognostic variables for predicting tumor recurrence and investigating a prognostic model in patients with locally advanced cervical cancer treated with concurrent chemoradiotherapy (CCRT).

METHODS

A total of 129 patients with cervical squamous cell carcinoma who underwent initial CCRT were eligible for this study. Univariate and multivariate analyses were performed using traditional prognostic factors, metabolic parameters, and HPV infection. Classification and regression decision tree (CART) was used to establish new classification.

RESULTS

Among 129 patients, 29 patients (22.5%) had recurrence after a median follow-up of 60 months (range, 3-125 months). Tumor size, para-aortic lymph node metastasis, nodal SUVmax, and HPV infection status were identified as independent prognostic factors by multivariate analysis. The CART analysis classified the patients into three groups. The first node was nodal SUVmax, and HPV status was the second node for patients with nodal SUVmax ≤7.49; Group A (nodal SUVmax ≤7.49 and HPV positive, HR 1.0), Group B (nodal SUVmax ≤7.49 and HPV negative, HR 3.56), and Group C (nodal SUVmax > 7.49, HR 10.13). Disease-free survival was significantly different among the three groups (p < 0.001).

CONCLUSION

The nodal SUVmax on F-18 FDG PET/CT and HPV infection status before CCRT are powerful independent prognostic factors for the prediction of disease-free survival in patients with cervical squamous cell carcinoma who underwent initial CCRT. We also suggest a simple prognosis prediction model using pre-treatment FDG PET/CT and HPV genotyping; however, it needs further validation in an independent dataset.

Volumetric assessment of apparent diffusion coefficient predicts outcome following chemoradiation for cervical cancer

OBJECTIVE

To determine the utility of volumetric diffusion weighted imaging (DWI) compared to other clinical factors for predicting recurrence and survival in cervical cancer patients treated with definitive chemoradiation.

METHODS AND MATERIALS

We retrospectively studied cervical cancer patients treated with definitive chemoradiation between 2009-2013 at a single institution with a baseline MRI with DWI and 18F-FDG positron emission tomography/computed tomography (FDG-PET) scan. To identify clinical and imaging metrics correlated with survival and recurrence endpoints, variable importance values were calculated from random forest models. To provide clinically relevant threshold values, recursive partitioning analysis dichotomized patients into potential risk groups based on selected metrics. Cox's proportional hazard models assessed the effect of clinical and imaging factors on survival endpoints.

RESULTS

Ninety-three patients were included in the analysis (median age 50 years). At a median follow-up of 35.6 months, 32 patients (34%) had disease recurrence. In the best multivariate model including clinical and imaging parameters, 90th percentile ADC < 1.917 was the only significantly associated factor with worse progression free survival (PFS). Overall survival, PFS, and distant metastasis free survival (DMFS) were significantly different between patient groups divided on 90th percentile ADC with threshold of 1.917 × 10^-3 mm²/s and MRI volume with threshold of 18.9 cc (P = 0.037, P = 0.0002, P = 0.001). High MRI volume and low ADC were associated with worse clinical outcomes.

CONCLUSIONS

Volumetric 90th percentile ADC value of the primary tumor on pretreatment MRI was a significant predictor of PFS and DMFS in cervical cancer patients, independent of established clinical factors and SUV on FDG-PET.

Automatic PET cervical tumor segmentation by combining deep learning and anatomic prior

Cervical tumor segmentation on 3D ¹⁸FDG PET images is a challenging task because of the proximity between cervix and bladder, both of which can uptake ¹⁸FDG tracers. This problem makes traditional segmentation based on intensity variation methods ineffective and reduces overall accuracy. Based on anatomy knowledge, including 'roundness' of the cervical tumor and relative positioning between the bladder and cervix, we propose a supervised machine learning method that integrates convolutional neural network (CNN) with this prior information to segment cervical tumors. First, we constructed a spatial information embedded CNN model (S-CNN) that maps the PET image to its corresponding label map, in which bladder, other normal tissue, and cervical tumor pixels are labeled as  -1, 0, and 1, respectively. Then, we obtained the final segmentation from the output of the network by a prior information constrained (PIC) thresholding method. We evaluated the performance of the PIC-S-CNN method on PET images from 50 cervical cancer patients. The PIC-S-CNN method achieved a mean Dice similarity coefficient (DSC) of 0.84 while region-growing, Chan-Vese, graph-cut, fully convolutional neural networks (FCN) based FCN-8 stride, and FCN-2 stride, and U-net achieved 0.55, 0.64, 0.67, 0.71, 0.77, and 0.80 mean DSC, respectively. The proposed PIC-S-CNN provides a more accurate way for segmenting cervical tumors on 3D PET images. Our results suggest that combining deep learning and anatomic prior information may improve segmentation accuracy for cervical tumors.

Predictive Value of [18F]FDG PET/CT for Lymph Node Metastasis in Rectal Cancer

[¹⁸F]Fluorodeoxyglucose ([¹⁸F]FDG) Positron emission tomography/computed tomography (PET/CT) is commonly used for rectal cancer staging, but improved diagnostic methods for nodal metastases are needed. We aimed to evaluate whether the combination model of the metabolic tumor volume of primary tumor (T_MTV) and maximum standardized uptake value of lymph node (N_SUVmax) on pretreatment [¹⁸F]FDG PET/CT could improve nodal metastases prediction in rectal cancer. We enrolled a total of 166 rectal cancer patients who underwent pretreatment [¹⁸F]FDG PET/CT and surgical resection without neoadjuvant treatment between January 2009 and August 2016. Visual and semiquantitative PET/CT parameters were obtained. Associations between clinicopathological, PET/CT-derived variables and nodal metastases were evaluated by logistic regression analysis. Nodal metastases were confirmed histologically in 68 of the 166 patients (41%). Uni- and multivariate analyses demonstrated T_MTV and N_SUVmax were independent predictive factors for nodal metastases. The c-statistics of the combination model was 0.806 (Standard Error, 0.034; 95% Confidence Interval, 0.737-0.863), which showed significant improvement compared to T_MTV (0.698, P = 0.0002) or N_SUVmax (0.720, P = 0.0008) alone. T_MTV and N_SUVmax are independently correlated with nodal metastases. Furthermore, the combination model showed improved performance for risk prediction; thus, [¹⁸F]FDG PET/CT might have a role in rectal cancer staging and treatment planning.

Combining tumor size and diffusion-weighted imaging to diagnose normal-sized metastatic pelvic lymph nodes in cervical cancers

BACKGROUND

Detecting normal-sized metastatic pelvic lymph nodes (LNs) in cervical cancers, although difficult, is of vital importance.

PURPOSE

To investigate the value of diffusion-weighted-imaging (DWI), tumor size, and LN shape in predicting metastases in normal-sized pelvic LNs in cervical cancers.

MATERIAL AND METHODS

Pathology confirmed cervical cancer patients with complete magnetic resonance imaging (MRI) were documented from 2011 to 2016. A total of 121 cervical cancer patients showed small pelvic LNs (<5 mm) and 92 showed normal-sized (5-10 mm) pelvic LNs (39 patients with 55 nodes that were histologically metastatic, 53 patients with 71 nodes that were histologically benign). Preoperative clinical and MRI variables were analyzed and compared between the metastatic and benign groups.

RESULTS

LN apparent diffusion coefficient (ADC) values and short-to-long axis ratios were not significantly different between metastatic and benign normal-sized LNs (0.98 ± 0.15 × 10^-3 vs. 1.00 ± 0.18 × 10^-3 mm²/s, P = 0.45; 0.65 ± 0.16 vs. 0.64 ± 0.16, P = 0.60, respectively). Tumor ADC value of the metastatic LNs was significantly lower than the benign LNs (0.98 ± 0.12 × 10^-3 vs. 1.07 ± 0.21 × 10^-3 mm²/s, P = 0.01). Tumor size (height) was significantly higher in the metastatic LN group (27.59 ± 9.18 mm vs. 21.36 ± 10.40 mm, P < 0.00). Spiculated border rate was higher in the metastatic LN group (9 [16.4%] vs. 3 [4.2%], P = 0.03). Tumor (height) combined with tumor ADC value showed the highest area under the curve of 0.702 ( P < 0.00) in detecting metastatic pelvic nodes, with a sensitivity of 59.1% and specificity of 78.8%.

CONCLUSIONS

Tumor DWI combined with tumor height were superior to LN DWI and shape in predicting the metastatic state of normal-sized pelvic LNs in cervical cancer patients.

The efficacy of pretreatment and after treatment 18F-FDG PET/CT metabolic parameters in patients with locally advanced squamous cell cervical cancer

OBJECTIVES

Cervical cancer is one of the main causes of cancer death worldwide. Fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (PET/CT) has been playing an increasingly important role in staging and monitoring treatment response in the disease. In the current study, we investigated metabolic F-FDG PET/CT parameters among patients with locally advanced squamous cell cervical cancer treated with concurrent chemoradiotherapy for predicting disease-free survival (DFS).

PATIENTS AND METHODS

Forty-four patients with biopsy-proven locally advanced squamous cell cervical cancer were included in the study. Pretreatment and after treatment F-FDG PET/CT metabolic parameters [metabolic tumor volume, tumor lesion glycolysis, maximum standard uptake value (SUVmax)] for the primary tumor area and/or pelvic/para-aortic lymph nodes and also accompanying distant metastases were analyzed. Treatment response was divided into four groups according to a post-treatment F-FDG PET/CT scan.

RESULTS

For all patients, the 3-year DFS was 79%. Pretreatment primary tumor SUVmax and tumor lesion glycolysis, pelvic lymph node SUVmax, and pretreatment para-aortic lymph node SUVmax were significant prognostic factors for DFS with different cut-off values. In contrast, for metabolic tumor volume-T1, there was no statistical significance for DFS.

CONCLUSION

F-FDG PET/CT cut-off values may help clinicians with their treatment planning and follow-up in locally advanced squamous cell cervical cancer patients.

Combinative evaluation of primary tumor and lymph nodes in predicting pelvic lymphatic metastasis in early-stage cervical cancer: A multiparametric PET-CT study

PURPOSE

The purpose of this study is to investigate the value of combining tumor and pelvic lymph node (PLN) characteristics on PET-CT in predicting PLN metastasis of patients with early-stage cervical cancer, specifically to further reduce the false-negative cases of diagnosis.

METHODS

The [18F] FDG PET-CT imaging data of 394 patients who were newly diagnosed with cervical cancer (FIGO stage, Ia-IIa) were retrospectively studied. We measured size, total lesion glycolysis (TLG) of tumor, metabolic tumor volume (MTV), maximum and mean standardized uptake value (SUVmax, SUVmean) of tumor and lymph node (LN). Diagnostic efficiency was evaluated using receiver operator characteristic (ROC) curve. We also investigated additional CT diagnosis information in PET-negative cases.

RESULTS

Our results indicated both lymph node and tumor parameters were independent risk factors for lymphatic metastasis in early-stage cervical cancer. The diagnosis based on above meaningful parameters, we name it 'combination diagnosis', offered significantly higher predictive value than that based on SUV measurement alone, which the values of AUC were 0.842 and 0.784 respectively (P < 0.05). In PET-negative cases, we also found that tumor TLG, suspicious LN in lymphatic drainage pathway, long/short axis of LN ≤ 2, heterogeneity of LN significantly associated with PLN metastasis. ROC analysis showed combination diagnosis of all these parameters above produced an AUC value of 0.859 (P < 0.05, 95% CI, 0.811-0.899), which was significantly higher than either using tumor TLG alone (AUC = 0.622, Z = 3.919, P < 0.05) or indices derived from CT alone (AUC = 0.727, 0.668, 0.695. Z = 3.620, 5.356, 3.696, P < 0.05).

CONCLUSIONS

We proposed a combination diagnosis method that can better predict PLN metastasis for patients with early-stage cervical cancer. In PET-negative cases, combination diagnosis of TLG of tumor and CT indicators also produced improved prediction by reducing false-negative cases of diagnosis. This combination diagnosis approach has significant implications in cervical cancer patient management and treatment planning.

Chemoradiotherapy for locally advanced cervix cancer without aortic lymph node involvement: can we consider metabolic parameters of pretherapeutic FDG-PET/CT for treatment tailoring?

PURPOSE

Aim of the study was to assess impact of pretherapeutic FDG-PET/CT metabolic parameters on response to chemoradiotherapy (CRT) and survival in locally advanced cervical cancer (LACC) patients without paraaortic lymph node involvement.

METHODS

LACC patients treated with CRT without macrometastatic involvement after paraaortic surgical staging were included. All patients had received at least 45 Gy radiotherapy and five cycles of platinum-based chemotherapy. High-risk histologies were excluded. Two senior nuclear physician experts in gynaecologic oncology reviewed all PET/CT exams, and extracted tumor SUVmax, MTV, and TLG (standardized uptake value, metabolic tumor volume, and total lesion glycolysis respectively). Response to CRT was assessed with a pelvic MRI done after 45 Gy. Medical charts were reviewed for clinical, pathology, and survival data.

RESULTS

Ninety-three patients were included in the study. The overall survival (OS) rates at 2 and 5 years were 83.0% [95%CI: 72.5-89.8] and 71.2% [57.5-81.2] respectively. The RFS rates at 2 and 5 years were 72.5% [61.5-80.9] and 64.4% [52.3-74.2] respectively. Higher cervical SUVmax and TLG were significantly associated with poor response to CRT. In multivariate analysis, cervical SUVmax was the main predictive factor for OS.

CONCLUSION

Cervical tumor SUVmax was demonstrated to be a non-invasive prognostic biomarker for response to treatment and survival in LACC patients without paraaortic involvement. SUVmax and other PET/CT metabolic parameters require further prospective investigation to help tailoring of local treatment.

18F-FDG PET/CT in locally advanced cervical cancer: A review

Cervical cancer is the second most common gynecological cancer worldwide. In locally advanced cervical cancer, ¹⁸F-FDG PET/CT has become important in the initial staging, particularly in the detection of nodal and distant metastasis, aspects with treatment implications and prognostic value. The aims of this study were to review the role of ¹⁸F-FDG PET/CT in uterine cervical cancer, according to the guidelines of the main scientific institutions (FIGO, NCCN, SEGO, SEOM, ESGO, and ESMO) and its diagnostic accuracy compared to conventional radiological techniques, as well as to review the acquisition protocol and its utility in radiotherapy planning, response assessment and detection of recurrence.

Predictive Value of FDG PET/CT to Detect Lymph Node Metastases in Cervical Cancer

PURPOSE

The aim of this study was to determine the prognostic significance of PET/CT findings in women with cervical cancer and describe the normalization of lymph node SUVmax (nSUVmax).

MATERIALS AND METHODS

A retrospective review was performed of 113 patients with cervical cancer who underwent a PET/CT before receiving definitive therapy. SUVmax measurements were normalized to the SUV of the pelvic blood pool. Patient, tumor, and PET/CT data were correlated to extracervical recurrence-free survival (ecRFS) and lymph node pathology.

RESULTS

Of 113 patients, there were 23 (20%) extracervical recurrences. On univariate analysis, stage, histology, nSUVmax, and radiographic size of the primary tumor, and nSUVmax of the most hypermetabolic lymph node were significantly associated with ecRFS. On multivariable analysis, nSUVmax and radiographic size of the primary tumor remained associated with ecRFS (both P < 0.001). Sixty-six patients underwent pelvic, common iliac, and/or para-aortic nodal sampling. The sensitivity, specificity, false-negative, and false-positive rates of PET/CT for lymph node metastases were 53%, 75%, 6%, and 82%, respectively. On univariate analysis, nSUVmax, and radiographic size of the primary tumor, and nSUVmax of the most hypermetabolic lymph node, and radiographic size of the largest lymph node, were associated with the presence of at least one pathologically positive lymph node. On multivariable analysis, only the radiographic size of the largest lymph node remained significantly associated with lymph node metastases (P < 0.001).

CONCLUSIONS

The size and nSUVmax of the primary tumor were associated with ecRFS. PET/CT has a low false-negative rate but high false-positive rate for lymph node metastases.

Quantitative 18F-FDG PET analysis in survival rate prediction of patients with non-small cell lung cancer

The aim of the present study was to investigate the prognostic value of quantitative [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) parameters for patients with non-small cell lung cancer (NSCLC). The present study conducted a retrospective review of the medical records of 203 patients with NSCLC, of which 193 patients underwent baseline 18F-FDG PET/CT prior to initial therapy. Multivariate analyses using Cox's proportional hazards regression were performed for the assessment of the association between initial PET/CT measurements and overall survival (OS). The multivariate models were adjusted for sex, age, smoking status, disease stage, standardized uptake value (SUV), standardized uptake value corrected for lean body mass (SUL), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and standard deviation of SUV (SD). Kaplan-Meier (K-M) estimator curves were constructed following the formation of three approximately equal-sized groups using tertiles for each PET/CT measurement (n=65, 64 and 64). OS curves were plotted using K-M estimator curves. Results demonstrated significant associations between OS and MTVPET volume computerized assisted reporting (PETVCAR), MTV2.5, MTV25%, MTV42% and TLGPETVCAR; however, no significant associations were identified between OS and MTV50%, MTV75%, TLG2.5, all SUV and SUL. Subgroup analyses according to pathology demonstrated that there were statistically significant associations between OS and stage (P<0.001), MTV50% (P=0.002) and MTV42% (P=0.004) in the adenocarcinoma group, and SULmean (P=0.010), MTV25% (P=0.005) and MTV42% (P=0.001) in the squamous cell carcinoma group; however, no significant differences were identified between any other group. Furthermore, there was a significant association between OS and MTV42% (P=0.02) and MTV50% (P=0.04) in the early-stage group; however, no significant differences were identified in the advanced-stage group. K-M estimator curve analyses demonstrated that the pathology (P=0.01), stage (P<0.001) and all PET metabolic parameters with the exception of SD were significantly associated with OS (P<0.05). No significant associations were demonstrated between SD and OS. In conclusion, 18F-FDG PET/CT MTVPETVCAR, MTV2.5, MTV25%, MTV42% and TLGPETVCAR exhibit prognostic values with regard to OS. Overall, selection of appropriate metabolic parameters may predict NSCLC prognosis.

Meta-analysis of PET/CT Detect Lymph Nodes Metastases of Cervical Cancer

Objective

The aim of this study was to assess the diagnostic value of PET/CT for metastatic lymph nodes in cervical cancer patients.

Methods

Searching in the databases including PubMed, Embase, Web of Science, Cochrane Library and Google Scholar about non-invasive modalities for detecting lymph nodes metastases during 2000~2017. Following further screening, the extracted effective data were calculated by Meta-Disc 1.4 software, such as sensitivity (SEN), specificity (SPE), positive likelihood (LR+), and negative likelihood ratio (LR-).

Results

we obtained 27 articles. The pooled estimates for sensitivity of PET/CT were 0.72 (95% CI, [0.69, 0.75]); for specificity were 0.96 (95% CI, [0.96, 0.97]). Its weighted AUC was 0.93.

Conclusion

PET/CT remains to be an effective method for diagnosis of metastatic lymph nodes from cervical cancer.

Value of [18F]FDG PET radiomic features and VEGF expression in predicting pelvic lymphatic metastasis and their potential relationship in early-stage cervical squamous cell carcinoma

PURPOSE

The purpose of this study was to explore the value of 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography/computed tomography ([18F]FDG PET/CT) radiomic features combined with vascular endothelial growth factor (VEGF) expression in predicting pelvic lymphatic metastasis in patients with early-stage cervical squamous cell carcinoma and the added value of radiomic features in predicting VEGF expression.

MATERIALS AND METHODS

Ninety-four newly diagnosed cervical squamous cell carcinoma patients (training dataset: n = 64, validation cohort: n = 30) in stage Ia to IIa, according to the International Federation of Gynecology and Obstetrics (FIGO) staging system, who underwent [¹⁸F]FDG PET/CT were retrospectively analyzed. Radiomic features of the [¹⁸F]FDG PET scans were extracted, and the value of the lymph node sizes, metabolic parameters (both tumor and lymph nodes), radiomic features and VEGF expression level in predicting lymphatic metastasis were evaluated by receiver operating characteristics curves (ROC) and were compared using DeLong test. Moreover, we studied the associations between the [¹⁸F]FDG PET radiomic features and VEGF expression.

RESULTS

Total lesion glycolysis (TLG) and the expression of VEGF were significantly higher in subjects with lymphatic metastasis than in those without. The homogeneity feature derived from the histogram, the skewness, had a certain value in predicting lymphatic metastasis (AUC = 0.803 in training dataset, P < 0.05, 95% CI 0.684, 0.892; AUC = 0.757 in validation dataset, P < 0.05, 95% CI 0.545, 0.904). Additionally, the combination of this radiomic feature and VEGF expression had a significantly superior predictive value (AUC = 0.878, P < 0.05, 95% CI 0.772- 0.947), compared to that of the conventional parameters. Moreover, 26 radiomic features derived from the histogram and GLCM features correlated with VEGF expression.

CONCLUSIONS

In patients with early-stage cervical squamous cell carcinoma, PLN metastasis can be predicted by TLG and the textural feature of homogeneity. Radiomic features in combination with the VEGF expression level improved the prediction accuracy. In addition, some features derived from the histogram and gray-level co-occurrence matrices (GLCM) may have a certain value in predicting the VEGF expression level.

(18F)-FDG PET/CT parameters to predict survival and recurrence in patients with locally advanced cervical cancer treated with chemoradiotherapy

PURPOSE

To identify predictive (¹⁸F)-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT)-based parameters for locoregional control, disease-free survival and overall survival, by testing different thresholds of metabolic tumor volume and total lesion glycolysis in patients with locally-advanced cervical cancer.

PATIENTS AND METHODS

Thirty-seven patients treated with standard chemoirradiation underwent a pretreatment (¹⁸F)-FDG-PET/CT. Using different thresholds of maximum standardized uptake value, the following PET parameters were computed: maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume and total lesion glycolysis for primary tumor and lymph nodes and a new parameter combining the metabolic tumor volume and the distance between lymph nodes and the primary tumor, namely metabolic node distance. Correlation between PET and clinical parameters with clinical outcome (overall survival, disease-free survival, and locoregional control) was assessed using univariate and multivariate analyses (Cox model).

RESULTS

In univariate analyses, PET/CT parameters associated with overall survival and disease-free survival were: metabolic tumor volume and total lesion glycolysis of the primary tumor, total lesion glycolysis of lymph nodes and metabolic node distance. The most predictive threshold segmentation for metabolic tumor volume and total lesion glycolysis was 48% of maximum standardized uptake value for the primary tumor and 30% for the lymph nodes. In multivariate Cox analysis, the total lesion glycolysis of primary tumor 48% and metabolic node distance were the two independent risk factors for overall survival (P<0.01), disease-free survival (P<0.01) and locoregional control (P=0.046).

CONCLUSION

Total lesion glycolysis of primary tumor and distance between the invaded positive lymph node and the primary tumor seem to have the highest predictive value when compared to classical clinical prognostic parameters and may be useful to identify high risk groups at time of diagnosis and to tailor the therapeutic approach in locally-advanced cervical cancer.

Parameters of simultaneous 18F-FDG-PET/MRI predict tumor stage and several histopathological features in uterine cervical cancer

The purpose of this study was to analyze associations between apparent diffusion coefficient (ADC) and standardized uptake values (SUV) values and different histopathological parameters in uterine cervical cancer. 21 patients with primary uterine cervical cancer were involved into the study. All patients underwent a whole body simultaneous¹⁸F-FDG PET/MRI. Mean and maximum SUV were noted (SUV_mean and SUV_max). In all tumors minimal, mean, and maximal ADC values (ADC_min, ADC_mean, and ADC_max) were estimated. Combined parameters were calculated: SUV_max/SUV_mean, ADC_min/ ADC_mean, SUV_max/ADC_min and SUV_max/ADC_mean. In all cases the diagnosis was confirmed histopathologically by tumor biopsy. Histological slices were stained by hematoxilin and eosin, MIB 1 monoclonal antibody, and p16. All histopathological images were digitalized and analyzed by using a ImageJ software 1.48v. The following parameters were estimated: cell count, proliferation index KI 67, total and average nucleic areas, epithelial and stromal areas. Spearman's correlation coefficient was used to analyze associations between ADC and SUV values and histological parameters. P values ≤ 0.05 were considered as statistically significant. ADC_min and ADC_min/ ADC_mean were statistically significant lower in N positive tumors. KI 67 correlated statistically significant with SUV_max (r = 0.59, p = 0.005), SUV_mean (0.45, p = 0.04), ADC_min (r = −0.48, p = 0.03), SUV_max/ADC_min (r = 0.71, p = 0.001), SUV_max/ADC_mean (0.75, p = 0.001). SUV_max correlated well with epithelial area (r = 0.71, p = 0.001) and stromal areas (r = −0.71, p = 0.001). SUV values, ADC_min, SUV_max/ADC_min and SUV_max/ADC_mean correlated statistically significant with KI 67 and can be used to estimate the proliferation potential of tumors. SUV values correlated strong with epithelial area of tumor reflected metabolic active areas.

Investigating multi-radiomic models for enhancing prediction power of cervical cancer treatment outcomes

Quantitative image features, also known as radiomic features, have shown potential for predicting treatment outcomes in several body sites. We quantitatively analyzed ¹⁸Fluorine-fluorodeoxyglucose (¹⁸F-FDG) Positron Emission Tomography (PET) uptake heterogeneity in the Metabolic Tumor Volume (MTV) of eighty cervical cancer patients to investigate the predictive performance of radiomic features for two treatment outcomes: the development of distant metastases (DM) and loco-regional recurrent disease (LRR). We aimed to fit the highest predictive features in multiple logistic regression models (MLRs). To generate such models, we applied backward feature selection method as part of Leave-One-Out Cross Validation (LOOCV) within a training set consisting of 70% of the original patient cohort. The trained MLRs were tested on an independent set consisted of 30% of the original cohort. We evaluated the performance of the final models using the Area under the Receiver Operator Characteristic Curve (AUC). Accordingly, six models demonstrated superior predictive performance for both outcomes (four for DM and two for LRR) when compared to both univariate-radiomic feature models and Standard Uptake Value (SUV) measurements. This demonstrated approach suggests that the ability of the pre-radiochemotherapy PET radiomics to stratify patient risk for DM and LRR could potentially guide management decisions such as adjuvant systemic therapy or radiation dose escalation.

Pretreatment metabolic tumour volume and total lesion glycolysis are not independent prognosticators for locally advanced cervical cancer patients treated with chemoradiotherapy

OBJECTIVE

To evaluate the prognostic significance of metabolic parameters derived from fludeoxyglucose (FDG) positron emission tomography (PET)/CT, in cervical cancer patients treated with concurrent chemoradiotherapy.

METHODS

We retrospectively reviewed medical records from 129 biopsy-proven non-metastatic cervical cancer patients treated with external radiotherapy and intracavitary brachytherapy at our department. Correlation between metabolic parameters and tumour characteristics was evaluated. Prognostic factors for survival, local control and distant metastasis were analysed.

RESULTS

The median follow up for all patients and surviving patients was 30.0 months (range, 3.7-94.7 months) and 50.5 months (range, 14.5-94.7 months), respectively. The 2- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 68 42, 54 and 38%, respectively. The maximum standardized uptake value (SUV_max), SUV_mean, metabolic tumour volume (MTV) and total lesion glycolysis were significantly higher in patients with larger tumours (>4 cm) and partial regression or progressive disease after definitive treatment compared to patients with smaller tumour (≤4 cm) and post-treatment complete response. On univariate analysis, stage, lymph node metastasis, tumour size >4 cm, SUV_max, MTV, SUV_mean and total lesion glycolysis were prognostic factors for OS and DFS. On multivariate analysis, only larger tumour and presence of lymph node metastasis were significant prognostic factors for both OS and DFS. Additionally, extensive stage was a significant prognosticator for DFS.

CONCLUSION

Although, metabolic parameters derived from FDG-PET/CT had a prognostic significance in univariate analysis, the significance was lost in multivariate analysis where tumour stage, size and lymph node status were the only independent parameters. Advances in knowledge: The clinical benefit of using FDG-PET/CT metabolic parameters to evaluate the high-risk patients among cervical cancer patients and to eventually change patient management still needs further clarification.

Effect of different segmentation algorithms on metabolic tumor volume measured on 18F-FDG PET/CT of cervical primary squamous cell carcinoma

Background and purpose

It is known that fluorine-18 fluorodeoxyglucose PET/computed tomography (CT) segmentation algorithms have an impact on the metabolic tumor volume (MTV). This leads to some uncertainties in PET/CT guidance of tumor radiotherapy. The aim of this study was to investigate the effect of segmentation algorithms on the PET/CT-based MTV and their correlations with the gross tumor volumes (GTVs) of cervical primary squamous cell carcinoma.

Materials and methods

Fifty-five patients with International Federation of Gynecology and Obstetrics stage Ia∼IIb and histologically proven cervical squamous cell carcinoma were enrolled. A fluorine-18 fluorodeoxyglucose PET/CT scan was performed before definitive surgery. GTV was measured on surgical specimens. MTVs were estimated on PET/CT scans using different segmentation algorithms, including a fixed percentage of the maximum standardized uptake value (20∼60% SUV_max) threshold and iterative adaptive algorithm. We divided all patients into four different groups according to the SUV_max within target volume. The comparisons of absolute values and percentage differences between MTVs by segmentation and GTV were performed in different SUV_max subgroups. The optimal threshold percentage was determined from MTV_20%∼MTV_60%, and was correlated with SUV_max. The correlation of MTV_{iterative adaptive} with GTV was also investigated.

Results

MTV_50% and MTV_60% were similar to GTV in the SUV_max up to 5 (P>0.05). MTV_30%∼MTV_60% were similar to GTV (P>0.05) in the 5<SUV_max≤10 group. MTV_20%∼MTV_60% were similar to GTV (P>0.05) in the 10<SUV_max≤15 group. MTV_20% and MTV_30% were similar to GTV (P>0.05) in the SUV_max of at least 15 group. MTV_{iterative adaptive} was similar to GTV in both total and different SUV_max groups (P>0.05). Significant differences were observed among the fixed percentage method and the optimal threshold percentage was inversely correlated with SUV_max. The iterative adaptive segmentation algorithm led to the highest accuracy (6.66±50.83%). A significantly positive correlation was also observed between MTV_{iterative adaptive} and GTV (Pearson’s correlation r=0.87, P<0.0001).

Conclusion

MTV_{iterative adaptive} is independent of SUV_max, more accurate, and correlated with GTV. Iterative adaptive algorithm segmentation may be more suitable than the fixed percentage threshold method to estimate the tumor volume of cervical primary squamous cell carcinoma.

Prognostic value of total lesion glycolysis measured by 18F-FDG PET/CT in patients with locally advanced cervical cancer

AIM

The aim of this study was to determine the most relevant parameters of fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) for predicting recurrence in patients with locally advanced cervical cancer.

MATERIALS AND METHODS

Fifty-six patients diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage IIB to IVA cervical cancer who underwent F-FDG PET/CT before definitive chemoradiotherapy were retrospectively enrolled. Various PET parameters, namely, maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor, were analyzed to evaluate the relationship between these PET parameters and recurrence-free survival (RFS). The cut-off values of PET parameters that showed the best trade-off between sensitivity and specificity for RFS were determined by receiver operating characteristic curve analysis.

RESULTS

The median follow-up was 20 months (range, 6-63 months). Univariate analysis indicated that higher FIGO stage [hazard ratio (HR) 5.606, 95% confidence interval (CI) 1.682-18.68, P=0.005], metabolic tumor volume more than 47.81 cm (HR 6.203, 95% CI 1.351-28.481, P=0.019), and TLG more than 215.02 (HR 11.817, 95% CI 1.518-91.963, P=0.018) were associated with RFS. In multivariate analysis, FIGO stage (HR 4.618, 95% CI 1.295-16.463, P=0.018) and TLG more than 215.02 (HR 10.171, 95% CI 1.246-83.044, P=0.030) were independent predictive factors for RFS. Kaplan-Meier curves for RFS indicated that patients with TLG less than or equal to 215.02 showed better RFS (P=0.003).

CONCLUSION

Pretreatment TLG proved to be an independent prognostic factor for RFS in patients with locally advanced cervical cancer treated by definitive chemoradiotherapy.

Prognostic Significance of the Standardized Uptake Value of Pretherapeutic 18F-Labeled 2-Fluoro-2-Deoxyglucose Positron Emission Tomography/Computed Tomography in Patients With Locally Advanced Cervical Cancer

OBJECTIVES

To determine the prognostic significance of the pretreatment and posttreatment maximum standardized uptake value (SUVmax) of F-labeled 2-fluoro-2-deoxyglucose positron emission tomography (PET)/computed tomography imaging in patients with stage IB2-IVA cervical cancer.

METHODS

This was a retrospective review of cervical cancer patients with International Federation of Gynecology and Obstetrics stages IB2-IVA, from March 2008 to April 2014. All patients had pretreatment and posttreatment PET imaging and received primary whole pelvic radiation therapy with concurrent radiosensitizing chemotherapy, followed by intracavitary brachytherapy. Of the 58 patients who met the inclusion criteria, 31 patients (group A) showed no evidence of disease at last follow-up, and 27 patients (group B) presented with recurrence/persistence of disease.

RESULTS

The mean pretreatment SUVmax in group A was 17.65 ± 7.82 versus 18.8 ± 7.77 in group B (P = 0.577). The mean posttreatment SUVmax between the groups was 0.85 ± 1.83 versus 6.05 ± 3.01 (P < 0.001), respectively. The mean difference between pretreatment and posttreatment SUVmax was 17.73 ± 7.50 in group A versus 13.29 ± 7.15 in group B (P = 0.045). In group A, 80.7% of patients demonstrated no posttreatment hypermetabolic activity on PET imaging versus 11.1% in group B. Of the patients who experienced treatment failure, the site of failure was pelvic in 25.9%, distant in 44.4%, and both pelvic and distant in 29.6%.

CONCLUSIONS

No threshold was identified for the pretreatment SUVmax relative to the risk of recurrence. However, distinct correlations were found between the risk of recurrence, percent reduction in SUVmax, and the observation of residual hypermetabolic activity. This finding may help identify candidates for sequential chemotherapy.

Diffusion-Weighted Magnetic Resonance Imaging as a Predictor of Outcome in Cervical Cancer After Chemoradiation

PURPOSE

To determine whether apparent diffusion coefficient (ADC) value is predictive of survival after definitive chemoradiation for cervical cancer independent of established imaging and clinical prognostic factors.

METHODS AND MATERIALS

Between 2011 and 2013, the pretreatment MRI scans for 69 patients treated with definitive chemoradiation for newly diagnosed cervical cancer were retrieved. Scans were acquired with a 1.5-T magnetic resonance scanner, including diffusion-weighted imaging sequences. Mean ADC value was measured within a region of interest in the primary cervical cancer on the baseline MRI scan. Baseline tumor maximum standardized uptake value on positron emission tomography/computed tomography was determined by the reading radiologist. Treatment included external beam radiation therapy to the pelvis followed by brachytherapy in 97%, and with concurrent weekly cisplatin in 99% of patients. Univariate and multivariate analyses were done to investigate the association of clinical and imaging variables with disease control and survival endpoints using a Cox proportional hazard test.

RESULTS

Median follow-up was 16.7 months (range, 3.1-44.2 months). The 1-year overall survival, locoregional recurrence-free survival, and disease-free survival rates were 91%, 86%, and 74%, respectively. The median ADC value was 0.941 × 10^-3 mm²/s (range, 0.256-1.508 × 10^-3 mm²/s). The median standardized uptake value in the primary tumor was 15 (range, 6.2-43.4). In multivariate analysis, higher ADC value (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.15-0.85, P=.02), higher stage (HR 2.4, 95% CI 1.1-5.5, P=.033), and nonsquamous histology (HR 0.23, 95% CI 0.07-0.82, P=.024) were independent predictors of disease-free survival.

CONCLUSIONS

The mean ADC value of the primary tumor on pretreatment MRI was the only imaging feature that was an independent predictor of disease-free survival in cervical cancer patients treated with chemoradiation. Further validation will be needed to determine whether ADC values may prove useful in identifying cervical patients at high risk of recurrence.

Complementary Prognostic Value of Pelvic Magnetic Resonance Imaging and Whole-Body Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Pretreatment Assessment of Patients With Cervical Cancer

OBJECTIVE

The aim of this study was to evaluate the incremental prognostic value of pelvic magnetic resonance imaging (MRI) and whole-body F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) findings compared with clinical-histopathologic factors in patients with newly diagnosed cervical cancer.

METHODS

The institutional review board approved this retrospective study of 114 patients (median age, 40.6 years) with International Federation of Gynecology and Obstetrics (FIGO) stage I-IVB cervical cancer who underwent pretreatment MRI and PET/CT. All scans were reviewed for locoregional tumor extent, pelvic or/and para-aortic lymphadenopathy, and distant metastases. Univariate Cox proportional hazard regression was performed to evaluate associations between clinical-histopathologic factors, imaging findings, and progression-free survival (PFS). Multivariate models were built using independent predictors for PFS. Harrell C was used to measure concordance (C index).

RESULTS

Forty patients progressed within a median time of 10.4 months (range, 0.4-40.3 months). At univariate analysis, age, FIGO stage, tumor histology, tumor grade, and all MRI and PET/CT features were significantly associated with PFS (P < 0.0001 to P = 0.0474). A multivariate model including clinical and imaging parameters (parametrial invasion on MRI and para-aortic lymphadenopathy/distant metastases on PET/CT) had significantly higher concordance for predicting PFS than a model including clinical parameters only (C index: 0.81 [95% confidence interval, 0.75-0.87] vs 0.68 [95% confidence interval, 0.59-0.78]; P < 0.001). The comparison of C indices for the combined clinical and imaging model approached significance when compared with a FIGO stage model (C index: 0.81 [95% confidence interval, 0.75-0.87] vs 0.75 [95% confidence interval, 0.69-0.82]; P = 0.058).

CONCLUSIONS

In patients with newly diagnosed cervical cancer, a prognostic model including combined MRI and PET/CT findings provides information that complements clinical and histopathologic factors.

Relationship of 18F-FDG PET/CT metabolic, clinical and pathological characteristics of primary squamous cell carcinoma of the cervix

The objectives of this retrospective study were to use preoperative ¹⁸fluoro-d-glucose (¹⁸FDG) PET/CT in patients with primary cervical squamous cell carcinoma to explore the relationship between clinical, pathological and metabolic characteristics. Eighty consecutive patients with squamous cell carcinoma of cervix received ¹⁸FDG PET/CT scan before treatment. Metabolic tumor volume (MTV), total lesion glycolysis (TLG) and the peak standardized uptake value (SUVpeak) of the cervical tumors were calculated by an iterative adaptive algorithm. The association of these metabolic markers with serum squamous cell carcinoma antigen (SCC-ag), International Federation of Gynecology and Obstetrics (FIGO) stage, maximum tumor size and depth of cervical stromal invasion of the tumor was determined by the multivariate analysis. MTV and TLG were significantly higher in subjects with serum SCC-ag levels ≥3.95, with FIGO stage 1b2 and with a maximum tumor size of ≥4 cm (p≤0.009). Higher SUVpeak levels were associated with a maximum tumor size of ≥4 cm and with a cervical stromal invasion depth of ≥1/2 (p≤0.003). Multivariate analysis indicated that MTV was independently associated with FIGO stage Ib2 (p=0.041) and depth of cervical stromal invasion (p=0.020). TLG and SUVpeak were independently associated with maximum tumor size (p≤0.004) and depth of cervical stromal invasion (p≤0.013). Significant linear correlation was found between SUVpeak and tumor size; the Pearson correlation coefficient was 0.34 (p=0.002). Metabolic parameters such as MTV, TLG and SUVpeak are able to predict clinical and pathological status in preoperative cervical cancer.

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.