The role of PET/CT in the management of cervical cancer. AJR Am J Roentgenol. 2013;201:W192-W205. [PMID: 23883234 DOI: 10.2214/ajr.12.9830]

Application of PET/MRI in Gynecologic Malignancies

The diagnosis, treatment, and management of gynecologic malignancies benefit from both positron emission tomography/computed tomography (PET/CT) and MRI. PET/CT provides important information on the local extent of disease as well as diffuse metastatic involvement. MRI offers soft tissue delineation and loco-regional disease involvement. The combination of these two technologies is key in diagnosis, treatment planning, and evaluating treatment response in gynecological malignancies. This review aims to assess the performance of PET/MRI in gynecologic cancer patients and outlines the technical challenges and clinical advantages of PET/MR systems when specifically applied to gynecologic malignancies.

An Update on the Role of MRI in Treatment Stratification of Patients with Cervical Cancer

Cervical cancer is the fourth most common cancer in women worldwide and the most common gynaecological malignancy. The FIGO staging system is the most commonly utilised classification system for cervical cancer worldwide. Prior to the most recent update in the FIGO staging in 2018, the staging was dependent upon clinical assessment alone. Concordance between the surgical and clinical FIGO staging decreases rapidly as the tumour becomes more advanced. MRI now plays a central role in patients diagnosed with cervical cancer and enables accurate staging, which is essential to determining the most appropriate treatment. MRI is the best imaging option for the assessment of tumour size, location, and parametrial and sidewall invasion. Notably, the presence of parametrial invasion precludes surgical options, and the patient will be triaged to chemoradiotherapy. As imaging is intrinsic to the new 2018 FIGO staging system, nodal metastases have been included within the classification as stage IIIC disease. The presence of lymph node metastases within the pelvis or abdomen is associated with a poorer prognosis, which previously could not be included in the staging classification as these could not be reliably detected on clinical examination. MRI findings corresponding to the 2018 revised FIGO staging of cervical cancers and their impact on treatment selection will be described.

18F-FDG PET/MRI and 18F-FDG PET/CT for the Management of Gynecological Malignancies: A Comprehensive Review of the Literature

OBJECTIVE

Positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro- D-glucose integrated with computed tomography (18F-FDG PET/CT) or magnetic resonance imaging (18F-FDG PET/MRI) has emerged as a promising tool for managing various types of cancer. This review study was conducted to investigate the role of 18F- FDG PET/CT and FDG PET/MRI in the management of gynecological malignancies.

SEARCH STRATEGY

We searched for relevant articles in the three databases PubMed/MEDLINE, Scopus, and Web of Science.

SELECTION CRITERIA

All studies reporting data on the FDG PET/CT and FDG PET MRI in the management of gynecological cancer, performed anywhere in the world and published exclusively in the English language, were included in the present study.

DATA COLLECTION AND ANALYSIS

We used the EndNote software (EndNote X8.1, Thomson Reuters) to list the studies and screen them on the basis of the inclusion criteria. Data, including first author, publication year, sample size, clinical application, imaging type, and main result, were extracted and tabulated in Excel. The sensitivity, specificity, and diagnostic accuracy of the modalities were extracted and summarized.

MAIN RESULTS

After screening 988 records, 166 studies published between 2004 and 2022 were included, covering various methodologies. Studies were divided into the following five categories: the role of FDG PET/CT and FDG-PET/MRI in the management of: (a) endometrial cancer (n = 30); (b) ovarian cancer (n = 60); (c) cervical cancer (n = 50); (d) vulvar and vagina cancers (n = 12); and (e) gynecological cancers (n = 14).

CONCLUSIONS

FDG PET/CT and FDG PET/MRI have demonstrated potential as non-invasive imaging tools for enhancing the management of gynecological malignancies. Nevertheless, certain associated challenges warrant attention.

Novel prognostic nomograms in cervical cancer based on analysis of 1075 patients

OBJECTIVE

To explore the factors affecting the prognosis of cervical cancer (CC), and to construct and evaluate predictive nomograms to guide individualized clinical treatment.

METHODS

The clinicopathological and follow-up data of CC patients from June 2013 to December 2019 in Sun Yat-sen Memorial Hospital of Sun Yat-sen University were retrospectively analyzed. Log-rank test was used for univariate survival analysis, and Cox multivariate regression was used to identify independent prognostic factors, based on which nomogram models were established and evaluated in multiple aspects.

RESULTS

Patients were randomly assigned into the training (n = 746) and validation sets (n = 329). Survival analysis of the training set identified cervical myometrial invasion, parametrial involvement, and malignant tumor history as prognosticators of postoperative DFS and pathological type, cervical myometrial invasion, and history of STD for OS. C-index was 0.799 and 0.839 for the nomograms for DFS and OS, respectively. Calibration curves and Brier scores also indicated high performance. Importantly, decision curve analysis suggested great clinical applicability of these nomograms.

CONCLUSIONS

In this study, we analyzed a cohort of 1075 CC patients and identified DFS- or OS-associated clinicohistologic characteristics. Two nomograms were subsequently constructed for DFS and OS prognostication, respectively, and showed high performance in terms of discrimination, calibration, and clinical applicability. These models may facilitate individualized treatment and patient selection for clinical trials. Future investigations with larger cohorts and prospective designs are warranted for validating these prognostic models.

[F18]FDG PET/CT-Derived Metabolic and Volumetric Biomarkers Can Predict Response to Treatment in Locally Advanced Cervical Cancer Patients

Simple Summary

Carcinoma of the uterine cervix is one of the most common and severe malignancies in women. Up to 40% of locally advanced cervical cancer patients treated with definitive chemoradiation therapy will not respond or will develop disease recurrence. The aim of this retrospective study was to evaluate the relationship between quantitative metabolic and volumetric parameters extracted from FDG PET/CT imaging data and the response rate to definitive chemoradiation therapy in this group of patients. FDG PET/CT studies of 90 cervical cancer patients were analyzed, and it was found that quantitative metabolic and volumetric parameters such as SUVmax, SUVmean, MTV, and TLG are higher in locally advanced cervical cancer patients who will not respond to definitive chemoradiation therapy. Specifically, in patients who are not metastatic at staging, MTV and TLG values can serve as a predictor for treatment response and thus may alter treatment strategy.

Abstract

(1) Purpose: Current study aimed at evaluating the relationship between quantitative metabolic and volumetric FDG PET/CT parameters and the response to definitive chemoradiation therapy in locally advanced cervical cancer patients; (2) Methods: Ninety newly diagnosed locally advanced cervical cancer patients (FIGO IB2-IVA) were investigated. All patients underwent PET/CT at staging and after treatment. Metabolic and volumetric parameters, including SUVmax, SUVmean, Total Lesion Glycolysis (TLG), and Metabolic Tumor Volume (MTV) of the primary tumor and metastatic lymph nodes were measured and compared between patients with and without complete metabolic response (CMR). A similar analysis was performed in a subgroup of FIGO IB2-IIB patients; (3) Results: SUVmax and SUVmean of the primary tumor as well as those of metastatic lymph nodes, MTV, and TLG were found to be significantly different between CMR and non-CMR patients. In a subgroup of patients with FIGO IB2-IIB disease, MTV and TLG identified women who will achieve CMR with a threshold of 31.1 cm³ for MTV and 217.8 for TLG; (4) Conclusions: PET/CT-derived quantitative metabolic and volumetric parameters are higher in locally advanced cervical cancer patients who will not respond to definitive chemoradiation therapy. Specifically, in patients who are not metastatic at staging, MTV and TLG values can serve as a predictor for treatment response and thus may alter treatment strategy.

Squamous Cell Carcinoma Antigen: Clinical Application and Research Status

The squamous cell carcinoma antigen (SCCA) is a tumor marker that has gained increasing attention for its biological functions and significance in normal physiological and pathological processes. Not only SCCA but also circulating immune complexes of SCCA and immunoglobulin M (IgM) are involved in normal physiological and pathological processes, providing a background for numerous clinical studies aimed at assessing the potential role of SCCA, SCCA–IgM, and SCCA isoform complexes in clinical practice. Previous studies support the clinical value of SCCA as a tumor marker for either diagnosing squamous cancers or monitoring the response to radiotherapy or chemotherapy, tumor relapse, and treatment failure. However, these studies show contrasting results, making the diagnostic or prognostic value of SCCA controversial. To reduce clinical heterogeneity across studies and achieve a more accurate and reliable comparison of results, a standardized detection method, scoring system, and cutoff level need to be established. Moreover, despite the fact that performances of different methods are comparable, the dynamic observation of tumor marker kinetics should be conducted under the same method.

First experiences with PET-MRI/CT in radiotherapy planning for cervical cancer

Purpose

PET-CT has recently been included in the NCCN staging recommendations for cervical cancer stages II–IV and is already routinely applied to radiotherapy planning for other malignancies, as it is expected to provide higher accuracy for the detection of areas with tumor cell spread. In this study, we report on our first experiences of PET-based radiotherapy planning for cervical cancer.

Methods

19 patients with cervical cancer that underwent pre-therapeutic PET imaging treated at our institution between January 2016 and April 2019 were included in the study. Information on the primary tumor, lymph node involvement, metastatic spread and changes in the radiotherapy procedure based on the PET findings are described.

Results

A previously unknown primary tumor extension that was detected by PET imaging in one patient. In patients who underwent a PET before the systematic pelvic and paraaortic lymphonodectomy (n = 2), PET was false negative for pelvic lymph node metastases in 50%. In patients who underwent a PET after the systematic LNE (n = 13), additional lymph node metastases were detected in seven patients (53.80%). Distant metastases were suspected in three patients (15.7%) based on PET imaging. The suspicion was confirmed in one patient (peritoneal spread) and excluded in two patients (supra-diaphragmatic lymph nodes). In 13 patients (68.4%), RT procedures were altered due to findings in PET imaging.

Conclusion

PET-based radiochemotherapy planning may improve control rates by identifying areas of tumor cell spread eligible for dose escalation. False positivity, however, should be excluded in patients with findings that lead to major modifications of the therapeutic strategy.

Differences between [18F]FLT and [18F]FDG Uptake in PET/CT Imaging in CC Depend on Vaginal Bacteriology

This study aims to investigate if vaginal bacteriology obtained prior to treatment influences the 3′-deoxy-3 18F-fluorothymidine (FLT) [¹⁸F]FLT and 2-deoxy-2-[¹⁸F]fluoro-d-glucose (2-[¹⁸F]FDG) [¹⁸F]FDG parameters in positron emission tomography (PET/CT) in cervical cancer (CC) patients. Methods: Retrospective analysis was performed on 39 women with locally advanced histologically confirmed cervical cancer who underwent dual tracer PET/CT examinations. The [¹⁸F]FLT and [¹⁸F]FDG PET parameters in the primary tumor, including SUVmax, SUVmean, MTV, heterogeneity, before radiotherapy (RT) were analyzed, depending on the bacteriology. The p-values < 0.05 were considered statistically significant. Results: In the vaginal and/or cervical smears, there were 27 (79.4%) positive results. In seven (20.6%) cases, no opportunistic pathogen growth was observed (No Bacteria Group). In positive bacteriology, eleven (32%) Gram-negative bacilli (Bacteria group 2) and fifteen (44%) Gram-positive bacteria (Bacteria group 1) were detected. Five patients with unknown results were excluded from the analysis. Data analysis shows a statistically significant difference between the SUV_max, and SUV_min values for three independent groups for the [¹⁸F]FLT. Conclusions: The lowest values of SUV_max and SUV_min for [¹⁸F]FLT are registered in Gram-negative bacteria, higher are in Gram-positive, and the absence of bacteria causes the highest [¹⁸F]FLT values.

Differences between TNM classification and 2-[18F]FDG PET parameters of primary tumor in NSCLC patients

Background

The aim of the study was to compare the TNM classification with 2-[¹⁸F]FDG PE T biological parameters of primary tumor in patients with NSCLC.

Materials and methods

Retrospective analysis was performed on a group of 79 newly diagnosed NSCLC patients. PET scans were acquired on Gemini TF PET/CT scanner 60–70 min after injection of 2-[¹⁸F]FDG with the mean activity of 364 ± 75 MBq, with the area being examined from the vertex to mid-thigh. The reconstructed PET images were evaluated using MIM 7.0 Software for SUV_max, MTV and TLG values.

Results

The analysis of the cancer stage according to TNM 8^th edition showed stage IA2 in 8 patients, stage IA3 — 6 patients, stage IB — 4 patients, IIA — 3 patients, 15 patients with stage IIB, stage IIIA — 17 patients, IIIB — 5, IIIC — 5, IVA in 7 patients and stage IVB in 9 patients. The lowest TLG values of primary tumor were observed in stage IA2 (11.31 ± 15.27) and the highest in stage IIIC (1003.20 ± 953.59). The lowest value of primary tumor in SUV_max and MTV were found in stage IA2 (6.8 ± 3.8 and 1.37 ± 0.42, respectively), while the highest SUV_max of primary tumor was found in stage IIA (13.4 ± 11.4) and MTV in stage IIIC (108.15 ± 127.24).

Conclusion

TNM stages are characterized by different primary tumor 2-[¹⁸F]FDG PET parameters, which might complement patient outcome.

Cervical Cancer Diagnosis: Insights into Biochemical Biomarkers and Imaging Techniques

Cervical malignancy is known as one of the important cancers which is originated from cervix. This malignancy has been observed in women infected with papillomavirus who had regular oral contraceptives, multiple pregnancies, and sexual relations. Early and fast cervical cancer diagnosis is known as two important aspects of cervical cancer therapy. Several investigations indicated that early and fast detection of cervical cancer could be associated with better treatment process and increasing survival rate of patients with this malignancy. Imaging techniques are very important diagnosis tools that could be employed for diagnosis and following responses to therapy in various cervical cancer stages. Multiple lines of evidence indicated that utilization of imaging techniques is related to some limitations (i.e. high cost, and invasive effects). Hence, it seems that along with using imaging techniques, finding and developing new biomarkers could be useful in the diagnosis and treatment of subjects with cervical cancer. Taken together, many studies showed that a variety of biomarkers including, several proteins, mRNAs, microRNAs, exosomes and polymorphisms might be introduced as prognostic, diagnostic and therapeutic biomarkers in cervical cancer therapy. In this review article, we highlighted imaging techniques as well as novel biomarkers for the diagnosis of cervical cancer.

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.

Fluorodeoxyglucose positron-emission tomography-magnetic resonance hybrid imaging: An emerging tool for staging of cancer of the uterine cervix

Positron-emission tomography-magnetic resonance imaging (PET-MRI) is an emerging hybrid imaging modality that utilizes the superior soft tissue resolution of MR with the metabolic data from PET. In this study, we sought to assess the clinical value of fluorodeoxyglucose (FDG) PET-MRI with dedicated pelvic PET-MR in the initial staging of cervical cancer. In this institutional-approved study, we identified 23 adult females who underwent FDG PET-MRI on hybrid camera for staging of primary uterine cervical cancer that included a dedicated PET-MR of the pelvis. A nuclear medicine physician and a radiologist reviewed the PET, MRI, and fusion-body and pelvis images alone and then with consensus read characterizing PET and MR abnormal findings. There were 23 patients who underwent FDG PET-MRI for initial staging of cervical cancer with an average age of 52.2 ± 14.0 years. A total of 23 suspected lymph nodes in eight different patients were detected within the pelvis with increased metabolic activity on PET. Both the dedicated pelvis and whole-body PET imaging detected the same corresponding pelvic lymph nodes, although the pelvic PET imaging had better lymph node uptake delineation due to longer acquisition time. Using a 10-mm short-axis criterion, MRI identified only 43.5% of the FDG avid lymph nodes. The average SUVmax on the pelvis PET sequences was higher with SUV 8.9 ± 5.2 compared to the whole-body PET with SUV 7.8 ± 5.4 but was not statistically significant (P > 0.05). Primary cervical cancer was identified in 18 patients on both PET imaging and MRI with dedicated MR pelvis providing better characterization. Based on our results of the patients with cervical cancer evaluated for initial staging, combining dedicated pelvic PET-MRI with whole-body PET/MR provides the most complete status of malignant disease in reference to delineation of primary tumor, involvement of surrounding tissues, and regional lymph nodes.

Parametric Response Mapping of Coregistered Positron Emission Tomography and Dynamic Contrast Enhanced Computed Tomography to Identify Radioresistant Subvolumes in Locally Advanced Cervical Cancer

PURPOSE

To identify subvolumes that may predict treatment response to definitive concurrent chemoradiation therapy using parametric response mapping (PRM) of coregistered positron emission tomography (PET) and dynamic contrast-enhanced (DCE) computed tomography (CT) in locally advanced cervical carcinoma.

METHODS AND MATERIALS

Pre- and midtreatment (after 23 ± 4 days of concurrent chemoradiation therapy) DCE CT and PET imaging were performed on 21 patients with cervical cancer who were enrolled in a pilot study to evaluate the prognostic value of CT perfusion for primary cervical cancer (NCT01805141). Three-dimensional coregistered maps of PET/CT standardized uptake value (SUV) and DCE CT blood flow (BF) were generated. PRM was performed using voxel-wise joint histogram analysis to classify voxels within the tumor as highly metabolic and perfused (SUV^hiBF^hi), highly metabolic and hypoxic (SUV^hiBF^lo), low metabolic activity and hypoxic (SUV^loBF^lo), or low metabolic activity and perfused (SUV^loBF^hi) tissue based on thresholds determined from population means of pretreatment PET SUV and DCE CT BF. Relationships between baseline pretreatment imaging metrics and relative changes in metabolic tumor volume (ΔMTV), calculated from before treatment and during treatment imaging, were determined using univariable and multivariable linear regression models.

RESULTS

The relative volume of three PRM subvolumes significantly changed during treatment (SUV^hiBF^hi: P = .04; SUV^hiBF^lo: P = .0008; SUV^loBF^hi: P = .02), whereas SUV^loBF^lo did not (P = .9). Pretreatment PET SUV_max (r = -.58, P = .006), PET SUV_mean (ρ = -.59, P = .005), DCE CT BF_mean (r = -.50, P = .02), tumor volume (ρ = -.65, P = .001) and PRM SUV^hiBF^hi (ρ = -.59, P = .004) were negatively correlated with ΔMTV, whereas PRM SUV^loBF^lo was positively related to ΔMTV (r = .77, P < .0001). In a multivariable model that predicted ΔMTV, PRM SUV^loBF^lo, which combines both PET/CT and DCE CT, was the only significant variable (β = 1.825, P = .03), dominating both imaging modalities independently.

CONCLUSIONS

PRM was applied in locally advanced cervical carcinoma treated definitively with chemoradiation, and radioresistant subvolumes were identified that correlated with changes in MTV and predicted treatment response. Identification of these subvolumes may assist in clinical decision making to tailor therapies, such as brachytherapy, in an effort to improve patient outcomes.

Influence of Biological Parameters Assessed in [18F]FDG PET/CT on Overall Survival in Cervical Cancer Patients

AIM

The aim of this study was to estimate the influence of biological parameters assessed in [F]FDG PET/CT on overall survival (OS) in cervical cancer patients.

METHODS

Retrospective analysis was performed on a group of 371 patients with newly diagnosed and histologically confirmed cervical cancer. PET biological parameters in primary tumor including SUVmax, SUVmean, total lesion glycolysis (TLG), metabolic tumor volume (MTV), heterogeneity, and parameters referring both to primary tumor and metastatic lesions: SUVtotal, TLGtotal, and MTVtotal, were analyzed.

RESULTS

Based on PET/CT results, 3 subgroups were identified: cervical only-with disease limited only to the cervix (38%), +regional nodes-where increased glucose accumulation in addition to the cervical area was also observed in regional lymph nodes (36%), and +distal metastases-where PET scan showed a disseminated disease (26%). Depending on the stage of the disease, in the cervical-only group, 5-year survival rate was 86%; in the +regional nodes group, it was 80%; whereas in the +distal metastases group, 5-year survival rate was only 55%. However, based on Cox regression model, significant influence on OS was found only in heterogeneity of primary tumor; more inhomogeneous tumors suggest worse prognosis (0.25 ± 0.04 vs 0.16 ± 0.09, P < 0.001), SUVtotal (76.6 ± 130.1 vs 45.4 ± 73.4, P = 0.002), and MTVtotal (79.03 ± 88.27 vs 63.00 ± 83.80 cm, P = 0.03). For heterogeneity, cutoff point suggesting worse prognosis was 0.18; for SUVtotal, 52.3; and for MTVtotal, 66.55 cm.

CONCLUSIONS

Stage of disease assessed in [F]FDG PET/CT significantly influences survival rate in patients with cervical cancer. SUVtotal, MTVtotal, and heterogeneity of primary tumor are independent prognostic factors on OS in cervical cancer patients.

Evaluation of SUV normalized by lean body mass (SUL) in 68Ga-PSMA11 PET/CT: a bi-centric analysis

Introduction

The aim of this analysis was to investigate whether the standardized uptake value (SUV) normalized by lean body mass (SUL) is a more appropriate quantitative parameter compared to the commonly used SUV normalized by patient’s weight in ⁶⁸Ga-PSMA11 PET/CT.

Material and methods

⁶⁸Ga-PSMA11 PET/CT scans of 121 patients with prostate cancer from two institutions were evaluated. Liver SUV was measured within a 3-cm volume-of-interest (VOI) in the right hepatic lobe and corrected for lean body mass using the Janmahasatian formula. SUV and SUL repeatability between baseline and follow-up scans of the same patients were assessed.

Results

SUV was significantly positively correlated with body weight (r = 0.35, p = 0.02). In contrast, SUL was not correlated with body weight (r = 0.23, p = 0.07). No significant differences were found between baseline and follow-up scan (p = 0.52).

Conclusion

The Janmahasatian formula annuls the positive correlations between SUV and body weight, suggesting that SUL is preferable to SUV for quantitative analyses of ⁶⁸Ga-PSMA11 PET/CT scans.

A Review of Viral-Related Malignancies and the Associated Imaging Findings

OBJECTIVE. Imaging plays an important role in the diagnosis and staging of malignancies. Many common lymphoproliferative and other solid tumor malignancies can be viral-related. CONCLUSION. This review discusses the imaging findings that can be associated with common viral-induced malignancies. Knowledge of these imaging presentations can help narrow the differential diagnosis to reach a specific diagnosis through a precise workup and proper management.

Positron emission tomography for staging locally advanced cervical cancer and assessing intensity modulated radiotherapy approach

AIMS

To evaluate toxicity and outcome of concomitant chemotherapy and intensity modulated radiotherapy (IMRT) with 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) based simultaneous integrated boost (SIB) of locally advanced cervical cancer (LACC).

METHODS

Patients with LACC underwent chemo-radiation with IMRT and SIB. Staging and follow-up were performed with clinical evaluation and CT, MRI, ¹⁸FDG-PET/CT. SIB was done on positive nodes with ¹⁸FDG-PET/CT based planning. CT-based planning high-dose-rate brachytherapy (HDR-BT) was delivered as subsequent boost to the primary tumor. Cisplatin concomitant chemotherapy was administered during IMRT.

RESULTS

Fourteen patients with cervical cancer were prospectively recruited between August 2014 and June 2017, 13 (93%) had a LACC, one (7%) patient was not evaluable because ¹⁸FDG-PET/CT evidenced metastases to the liver undetected by previous CT/MRI. Patients had a median age of 59 years, a median Karnofsky performance status of 100%, and a prevalence of squamous cell carcinoma histology (85%). SIB was delivered on 23 positive lymph nodes. IMRT median dose to the pelvis was 48.6 Gy in 27 fractions, SIB median dose 54 Gy in 27 fractions, HDR-BT boost median dose 21 Gy in 3 fractions. After a median follow-up of 30 months, 2-year local control and distant control were 86% and 86%, respectively. There were no grade 4 acute and/or late toxicities.

CONCLUSIONS

The ¹⁸FDG-PET/CT influenced stage assessment and RT treatment planning due to its high specificity in distant metastases and nodal involvement detection. The IMRT with SIB for positive nodes was an effective therapy with acceptable toxicity in LACC.

Incidence of mesorectal node metastasis in locally advanced cervical cancer: its therapeutic implications

OBJECTIVE

To evaluate the incidence and risk factors for mesorectal node metastasis (MRNM) in locally advanced cervical cancer.

METHODS/MATERIALS

We performed an observational retrospective cohort study of 122 patients with cervical cancer who received definitive chemo-radiation treatment between December 2013 and June 2017 to evaluate the incidence of MRNM. Three diagnostic radiologists assessed all available pre-treatment images. In this study, the pelvic node metastasis was defined as ≥ 1.0 cm and MRNM as ≥ 0.5 cm for CT and MRI scans and as a maximum standardized uptake value of > 2.5 for PET/CT. The relationship of MRNM with FIGO stage, pelvic node metastasis, and mesorectal fascia involvement was evaluated.

RESULTS

The incidence of MRNM in all 122 patients was 8 (6.6%). However, in advanced stage (III- IV) patients, MRNM occurred in 4 of 39 (10.3%) compared with 4 of 83 (4.8%) in early stage (IB1-IIB) patients (p = 0.27). In patients with a positive pelvic node, MRNM occurred in 7 of 55 (12.7%) and 1 of 67 (1.5%) in those with negative pelvic node (p = 0.02). In addition, the incidence of MRNM was 3 of 9 (33.3%) in the presence of mesorectal fascia involvement and 5 of 113 (4.4%) among those without mesorectal fascia involvement (p = 0.013).

CONCLUSION

This study indicates that pelvic node metastasis and mesorectal fascia involvement are high-risk factors for MRNM. Therefore, vigilance of reviewing images in the mesorectum for MRNM is necessary for high-risk patients.

Amide proton transfer imaging to evaluate the grading of squamous cell carcinoma of the cervix: A comparative study using 18 F FDG PET

BACKGROUND

Amide proton transfer (APT) imaging has shown great potential value in the diagnosis of cancer, but has yet not been applied in cervical carcinoma patients.

PURPOSE

To investigate the utility of APT imaging in estimating histologic grades of squamous cell carcinoma of the cervix (SCCC), compared with the standardized uptake value (SUV).

STUDY TYPE

Prospective.

POPULATION

Thirty-one patients with SCCC (median age 51 years) were included.

FIELD STRENGTH/SEQUENCE

Ingenia 3.0 T CX, Axial T₁ -weighted imaging (T₁ WI), Axial T₂ WI, 3D turbo spin echo sequence for APT imaging.

ASSESSMENT

Patient pathology was confirmed by surgery and the patients were divided into three groups based on histologic grades: Grade 1 (n = 9), Grade 2 (n = 12), and Grade 3 (n = 10). The APT signal intensity (APT SI), maximum SUV (SUV_max ) and mean SUV (SUV_mean ) for each grade were assessed by experienced radiologists in a blinded manner.

STATISTICAL TESTS

The obtained parameters were compared by one-way analysis of variance with Tukey honest significant difference post-hoc test. The correlations between the parameters and histologic grades were analyzed by Spearman's correlation coefficient. The Pearson correlation coefficients of the APT SI with the SUV_max and SUV_mean were also calculated.

RESULTS

The APT SIs for the three grades were significantly different (P = 0.0002). The APT SIs of Grade 2 and Grade 3 had significant differences (P = 0.009). The Spearman correlation coefficients for the correlations between the parameters and histological grade were as follows: APT SI: 0.684 (P = 0.00002), SUV_max : 0.318 (P = 0.082), and SUV_mean : 0.261 (P = 0.157). The Pearson correlation coefficients of the APT SI with the SUV_max and SUV_mean were 0.108 (P = 0.564) and 0.178 (P = 0.337), respectively.

DATA CONCLUSION

The APT SI was positively correlated with the SCCC grades. APT imaging maybe a promising method for predicting SCCC histologic grades.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:261-268.

Evaluation of 18F-FDG PET/CT parameters for reflection of aggressiveness and prediction of prognosis in early-stage cervical cancer

PURPOSE

The aim of this study was to investigate the value of five typical fluorine-18-fluorodeoxyglucose PET/computed tomography (CT) parameters (including SUVmax, SUVmean, SUVpeak, MTV and TLG) in the reflecting aggressiveness and predicting prognosis in patients with early-stage cervical cancer.

PATIENTS AND METHODS

Our study enrolled 85 primary cervical cancer patients who underwent preoperative fluorine-18-fluorodeoxyglucose PET/CT scans. We investigated the association of five parameters derived from PET/CT with clinicopathological characteristics. Immunohistochemistry was utilized to evaluate the expression of glucose transporter protein-1 (GLUT-1), TP53-induced glycolysis and apoptosis regulator (TIGAR), and vascular endothelial growth factor (VEGF), and the correlation between PET/CT parameters and the expression of GLUT-1, TIGAR, and VEGF was analyzed. In addition, we also investigated the correlation between disease-free survival of cervical cancer patients and PET/CT parameters.

RESULTS

The mean peak standardized uptake value (SUV)peak showed significant differences between all three International Federation of Gynecology and Obstetrics stages (P<0.001-0.032). The patients with lymph node metastasis had significantly higher SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) compared with those with the absence of lymph node metastasis (P=0.038, 0.024, and 0.010, respectively). All the five parameters showed an association with tumor size and cervical stromal invasion depth. Immunohistochemistry results indicated that the SUVpeak showed the highest association with the expression of GLUT-1, TIGAR, and VEGF (rs=0.705, P<0.001, rs=-0.466, P<0.001, rs=0.580, P<0.001, respectively) in these five parameters. The survival analysis showed that SUVpeak, MTV, and TLG were correlated with disease-free survival (P=0.042, P<0.001, and P=0.004, respectively).

CONCLUSION

Early-stage cervical cancer with high SUVpeak may reflect more aggressive behavior, and SUVpeak, MTV, and TLG can be used to predict the prognosis of early-stage cervical cancer patients. It may help with the choice of individualized treatment options.

Prognostic value of posttreatment 18F-FDG PET/CT and predictors of metabolic response to therapy in patients with locally advanced cervical cancer treated with concomitant chemoradiation therapy: an analysis of intensity- and volume-based PET parameters

PURPOSE

To investigate the prognostic value of posttreatment 18F-FDG PET/CT in patients with locally advanced cervical cancer (LACC) treated with concomitant chemoradiation therapy (CCRT). The secondary aim was to assess the possible role of intensity-based and volume-based PET parameters including SUVmax, SUVmean, MTV and TLG, and clinical parameters including age, pathology, FIGO stage and nodal involvement as factors predicting response to treatment.

METHODS

This retrospective study included 82 patients affected by LACC treated with CCRT. All patients underwent 18F-FDG PET/CT both before and after treatment. The posttreatment PET/CT scans were used to classify patients as complete metabolic responders (CMR) or non-complete metabolic responders (N-CMR) according to the EORTC criteria. Kaplan-Meier analysis was used to evaluate differences in overall survival (OS) between the CMR and N-CMR groups. Student's t test, Pearson's chi-squared test and logistic regression were used to investigate the possible value of PET and clinical parameters as predictors of metabolic response to therapy.

RESULTS

Kaplan-Meier analysis showed a highly significant difference in OS between the CMR and N-CMR groups (log-rank test p < 0.0001). Significant independent predictors of response to therapy were MTV (p = 0.019, odds ratio = 1.015, 95% CI = 1.002-1.028, Nagelkerke R2 = 0.110), TLG (p = 0.045, odds ratio = 1.001, 95% CI = 1.000-1.002, Nagelkerke R2 = 0.081) and nodal involvement (p = 0.088, odds ratio = 2.361, 95% CI = 0.879-6.343, Nagelkerke R2 = 0.051).

CONCLUSION

18F-FDG PET/CT-based response assessment using the EORTC criteria reliably predicts OS in LACC patients treated with CCRT. In our cohort of patients, pretreatment MTV and TLG and nodal involvement were predictors of response to therapy. MTV was the best predictor of response. However, its additional risk value seems to be low (MTV odds ratio = 1.015).

18F-FDG PET/CT in the evaluation of cancer cervix: Where do we stand today?

The incidence of gynecological malignancies is on the rise partly because of the availability of screening programmes, awareness, higher technological advancements, and availability of better medical care. Early diagnosis of any malignancy leads to prompt treatment. Use of 18Fluorine-Fluorodeoxyglucose (F-FDG) PET/CT in the treatment and follow-up of patients with Ca cervix considerably improves patient management. The primary diagnosis of Ca cervix is made either by biopsy of a visible tumor on the cervix or by a cone biopsy of a nonvisible malignant cervical focus. The staging procedure is purely clinical (i.e. gynecologic examination under general anesthesia) according to the International Federation of Gynaecology and Obstetrics classification. Earlier, with the nonavailability of sophisticated medical equipment and imaging specialists, oncologists relied heavily on clinical examination. However, anatomical and functional imaging has been proven to be considerably superior in understanding parametrial involvement and nodal/distant metastases in the cancer cervix than clinical examination alone. Data are evolving on the usage of F-FDG PET/CT in initial staging, treatment planning, and monitoring therapy response for gynecological malignancies. Prognostic information derived from the primary lesion such as the maximum standardized uptake value, metabolic tumor volume, and extent of para-aortic nodal metastatic disease plays a critical role in tailoring therapy on the basis of patient tumor-specific factors rather than on International Federation of Gynaecology and Obstetrics stage alone. Thus, F-FDG PET/CT needs to be listed not only under the panel of pretherapy investigations for Ca cervix but also for recurrence and therapy response assessments. It allows a more confident approach to patient management at initial staging, especially in terms of the decision to choose surgical versus palliation measures.

18F-FDG-PET/CT guided external beam radiotherapy volumes in inoperable uterine cervical cancer

BACKGROUND

In patients with advanced stage cancer of the uterine cervix who undergo irradiation with curative intent, there is the necessity to treat all suspicious nodes on imaging. Our hypothesis was that adding fluorodeoxyglucose positron emission computer tomography/computer tomography (FDG-PET/CT) to the imaging workup would alter the external beam radiotherapy (EBRT) treatment plan, either resulting in an extended external beam radiotherapy (EBRT) field to the para-aortal region or an additional boost to suspicious nodes. Since extended field radiotherapy or additional boost can cause toxicity, our secondary aim was to assess the incidence of severe late bowel toxicity in patients treated with extended para-aortal EBRT-field and boost compared to elective pelvic radiotherapy.

METHODS

Eighty-eight patients were enrolled. First, the optimal radiation treatment plan (EBRT and boost) was retrospectively determined based on magnetic resonance imaging (MRI) or FDG-PET/CT. Second, the severe bowel toxicity caused by the extended para-aortal field was assessed, based on the executed radiotherapy.

RESULTS

Based on MRI 8/88 patients would receive EBRT with para-aortic extension, this was 21/88 for FDG-PET/CT. Based on MRI 47/704 lymph node regions would receive additional boost, while based on PET/CT 91/704. Late severe bowel toxicity was seen in 12/84 patients, 6/65 in the group who received elective pelvic irradiation and 6/19 with para-aortal EBRT and boost at common iliac and/or para-aortal lymph nodes. Significant worse overall survival was seen of patients who needed para-aortal irradiation.

CONCLUSIONS

Addition of FDG-PET/CT leads to an extension of the elective EBRT volume and more suspicious lymph nodes receive a boost. However, when deciding to intensify radiation therapy, late severe bowel toxicity has to be taken into account.

Construction and Evaluation of the Tumor-Targeting, Cell-Penetrating Multifunctional Molecular Probe iCREKA

A novel tumor stroma targeting and membrane-penetrating cyclic peptide, named iCREKA, was designed and labeled by fluorescein isothiocyanate (FITC) and positron emitter ¹⁸F to build the tumor-targeting tracers. The FITC-iCREKA was proved to have significantly higher cellular uptake in the glioma U87 cells in the presence of activated MMP-2 than that in absence of activated MMP-2 by cells fluorescence test in vitro. The tumor tissue fluorescence microscope imaging demonstrated that FITC-iCREKA accumulated in the walls of the blood vessels and the surrounding stroma in the glioma tumor at 1 h after intravenous injection. While at 3 h after injection, FITC-iCREKA was found to be uptaken in the tumor cells. However, the control FITC-CREKA can only be found in the tumor stroma, not in the tumor cells, no matter at 1 h or 3 h after injection. The whole-animal fluorescence imaging showed that the glioma tumor could be visualized clearly with high fluorescence signal. The microPET/CT imaging further demonstrated that 18F-iCREKA could target U87MG tumor in vivo from 30 min to 2 h after injection. The present study indicated the iCREKA had the capacity of tumor stroma targeting and the membrane-penetrating. It was potential to be developed as the fluorescent and PET tracers for tumor imaging.

[18F]-2-Fluoro-2-Deoxy-D-glucose-PET Assessment of Cervical Cancer

This article provides an overview of PET in cervical cancer, primarily with regard to the use of ¹⁸F-2-fluoro-2-deoxy-d-glucose-PET/computed tomography. A brief discussion of upcoming technologies, such as PET/MR imaging, is presented.

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.

The value of advanced MRI techniques in the assessment of cervical cancer: a review

OBJECTIVES

To assess the value of new magnetic resonance imaging (MRI) techniques in cervical cancer.

METHODS

We searched PubMed and MEDLINE and reviewed articles published from 1990 to 2016 to identify studies that used MRI techniques, such as diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM) and dynamic contrast enhancement (DCE) MRI, to assess parametric invasion, to detect lymph node metastases, tumour subtype and grading, and to detect and predict tumour recurrence.

RESULTS

Seventy-nine studies were included. The additional use of DWI improved the accuracy and sensitivity of the evaluation of parametrial extension. Most studies reported improved detection of nodal metastases. Functional MRI techniques have the potential to assess tumour subtypes and tumour grade differentiation, and they showed additional value in detecting and predicting treatment response. Limitations included a lack of technical standardisation, which limits reproducibility.

CONCLUSIONS

New advanced MRI techniques allow improved analysis of tumour biology and the tumour microenvironment. They can improve TNM staging and show promise for tumour classification and for assessing the risk of tumour recurrence. They may be helpful for developing optimised and personalised therapy for patients with cervical cancer.

TEACHING POINTS

• Conventional MRI plays a key role in the evaluation of cervical cancer. • DWI improves tumour delineation and detection of nodal metastases in cervical cancer. • Advanced MRI techniques show promise regarding histological grading and subtype differentiation. • Tumour ADC is a potential biomarker for response to treatment.

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.

Correlation between histological grade and positron emission tomography parameters in cervical carcinoma

The aim of the present study was to evaluate the changes in cervical cancer glucose metabolism for different levels of cellular differentiation. The metabolic activity was measured by standardized uptake value (SUV), SUV normalized to lean body mass, metabolic tumor volume and total lesion glycolysis using fluorine-18 fluorodeoxyglucose positron emission tomography (PET). A correlation study of these values could be used to facilitate therapeutic choice and to improve clinical practice and outcome. This study considered 32 patients with diagnosed cervical cancers, at different International Federation of Gynecology and Obstetrics stages. Glucose metabolism was assessed by PET examination, and histological specimens were examined to determine their initial grade of differentiation. A correlation study of these values was evaluated. Histological examination showed that all cases were of squamous cell carcinoma. Regarding the differentiation of the tumor, 19 well- to moderately-differentiated tumors and 13 poorly-differentiated tumors were determined. Negative findings for correlations between metabolic parameters and initial grade of histological differentiation were found, and considering that histological grade has been shown to have no consistent prognostic value in cervical cancer treatment, PET imaging could play a significant role in cervical cancer prognosis.

Current imaging strategies for the evaluation of uterine cervical cancer

Uterine cervical cancer still remains an important socioeconomic issue because it largely affects women of reproductive age. Prognosis is highly depended on extent of the disease at diagnosis and, therefore, accurate staging is crucial for optimal management. Cervical cancer is clinically staged, according to International Federation of Gynecology and Obstetrics guidelines, but, currently, there is increased use of cross sectional imaging modalities [computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT)] for the study of important prognostic factors like tumor size, parametrial invasion, endocervical extension, pelvic side wall or adjacent/distal organs involvement and lymph node status. Imaging indications also include cervical cancer follow-up, evaluation of tumor response to treatment and selection of suitable candidates for less radical surgeries like radical trachelectomy for fertility preservation. The preferred imaging method for local cervical cancer evaluation is MRI; CT is equally effective for evaluation of extrauterine spread of the disease. PET-CT shows high diagnostic performance for the detection of tumor relapse and metastatic lymph nodes. The aim of this review is to familiarize radiologists with the MRI appearance of cervical carcinoma and to discuss the indications of cross sectional imaging during the course of the disease in patients with cervical carcinoma.

FDG PET/CT in the management of colorectal and anal cancers

OBJECTIVE

CT remains the imaging modality of choice in the diagnosis of colorectal cancer (CRC) and anal cancer. However, advances in imaging have expanded the role of MRI and PET/CT. This article focuses on the evolving role of FDG PET/CT in the diagnosis, radiation therapy planning, therapy assessment, and posttherapy monitoring of CRC and anal cancer.

CONCLUSION

FDG PET/CT is a valuable imaging modality that impacts the clinical management of patients with CRC and those with anal cancer.

Positron emission tomography image-guided drug delivery: current status and future perspectives

Positron emission tomography (PET) is an important modality in the field of molecular imaging, which is gradually impacting patient care by providing safe, fast, and reliable techniques that help to alter the course of patient care by revealing invasive, de facto procedures to be unnecessary or rendering them obsolete. Also, PET provides a key connection between the molecular mechanisms involved in the pathophysiology of disease and the according targeted therapies. Recently, PET imaging is also gaining ground in the field of drug delivery. Current drug delivery research is focused on developing novel drug delivery systems with emphasis on precise targeting, accurate dose delivery, and minimal toxicity in order to achieve maximum therapeutic efficacy. At the intersection between PET imaging and controlled drug delivery, interest has grown in combining both these paradigms into clinically effective formulations. PET image-guided drug delivery has great potential to revolutionize patient care by in vivo assessment of drug biodistribution and accumulation at the target site and real-time monitoring of the therapeutic outcome. The expected end point of this approach is to provide fundamental support for the optimization of innovative diagnostic and therapeutic strategies that could contribute to emerging concepts in the field of “personalized medicine”. This review focuses on the recent developments in PET image-guided drug delivery and discusses intriguing opportunities for future development. The preclinical data reported to date are quite promising, and it is evident that such strategies in cancer management hold promise for clinically translatable advances that can positively impact the overall diagnostic and therapeutic processes and result in enhanced quality of life for cancer patients.

Recent Trends in PET Image Interpretations Using Volumetric and Texture-based Quantification Methods in Nuclear Oncology

Image quantification studies in positron emission tomography/computed tomography (PET/CT) are of immense importance in the diagnosis and follow-up of variety of cancers. In this review we have described the current image quantification methodologies employed in (18)F-fluorodeoxyglucose ((18)F-FDG) PET in major oncological conditions with particular emphasis on tumor heterogeneity studies. We have described various quantitative parameters being used in PET image analysis. The main contemporary methodology is to measure tumor metabolic activity; however, analysis of other image-related parameters is also increasing. Primarily, we have identified the existing role of tumor heterogeneity studies in major cancers using (18)F-FDG PET. We have also described some newer radiopharmaceuticals other than (18)F-FDG being studied/used in the management of these cancers. Tumor heterogeneity studies are being performed in almost all major oncological conditions using (18)F-FDG PET. The role of these studies is very promising in the management of these conditions.