Molecular imaging in the management of gynecologic malignancies

Exploration of the shared pathways and common biomarkers in cervical and ovarian cancer using integrated bioinformatics analysis

OBJECTIVE

Searching for potential biomarkers and therapeutic targets for early diagnosis of gynecological tumors to improve patient survival.

METHODS

Microarray datasets of cervical cancer (CC) and ovarian cancer (OC) were downloaded from the Gene Expression Omnibus (GEO) database, then, differential gene expression between cancerous and normal tissues in the datasets was analyzed. Weighted gene co-expression network analysis (WGCNA) was performed to screen for co-expression modules associated with CC and OC. The screened shared genes were then further analyzed for functional pathway enrichment. Next, the least absolute shrinkage and selection operator (LASSO) with tenfold cross validation is used to further screened for common diagnostic biomarkers for the two diseases, and further validation is performed using two independent GEO datasets. Finally, the CIBERSORT algorithm was used to estimate the immune infiltration levels of CC and OC, and the correlation between immune cell infiltration and common biomarkers was explored.

RESULTS

After crossing the common DEGs detected by "Limma" R package with the common module genes identified by WGCNA, 44 shared genes were obtained. Functional enrichment indicates that these shared genes are mainly related to DNA synthesis pathways. Lasso regression analysis revealed that EFNA1, TYMS, and WISP2 were co-diagnostic markers for CC and OC, and then based on their expression levels and diagnostic efficacy, EFNA1 was selected as the best co-marker for CC and OC. Immune infiltration analysis shows that the immune environment has a significant impact on the occurrence and development of CC and OC, and the expression of EFNA1 is related to changes in immune cells. Gene-drug interaction analyses identified 27 common drug compounds that interact with candidate genes.

CONCLUSION

This study adopted bioinformatics methods to investigate the common pathways and identify diagnostic markers between CC and OC, suggesting that DNA synthesis and immune environment are closely related to the occurrence and development of CC and OC. EFNA1 may be a potential diagnostic indicator and therapeutic target for patients with CC and OC.

Clinical factor-based risk stratification for precision therapy in locally advanced squamous cell carcinoma of the uterine cervix

BACKGROUND

Concurrent chemoradiotherapy (CCRT) is the standard of care for locally advanced cervical cancer. In this study, we analyzed the pretreatment clinical and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) characteristics of patients with locally advanced cervical squamous cell carcinoma (SCC) to develop a scoring prototype for risk stratification.

METHODS

Two cohorts were constructed in this study. Cohort 1 comprised patients with cervical SCC with 2009 FIGO stage III-IVA or stage I-II with positive pelvic or para-aortic lymph node (PALN) on PET/CT from AGOG09-001 trial. Cohort 2 comprised patients with similar characteristics who had received adequate therapy in our hospital between 2016 and 2021. Pretreatment patient characteristics and PET/CT parameters including maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of primary tumor and nodal SUVmax were assessed for cancer-specific survival (CSS) using multivariate Cox regression.

RESULTS

Analysis of combined data from cohorts 1 (n = 55) and 2 (n = 128) indicated age ≥ 66 years, primary tumor MTV ≥87 mL, and positive PALN on PET/CT to be independently significant adverse predictors for CSS (p < 0.001, p = 0.014, and p = 0.026, respectively) with a median follow-up duration of 51 months. Assigning a score of 1 to each adverse predictor, patients with cumulative risk scores of 0, 1, 2, and 3 were discovered to have a 5-year CSS of 86.9%, 71.0%, 32.2%, and 0%, respectively (p < 0.001).

CONCLUSION

Age, primary tumor MTV, and positive PALN on PET/CT may serve as independent predictors of poor survival in patients with locally advanced cervical SCC. Our findings indicate that patients without any adverse factors can receive standard CCRT, whereas those with at least one adverse factor can consider novel combination therapies or clinical trials.

Comparing Magnetic Resonance Fingerprinting (MRF) and the MAGiC Sequence for Simultaneous T1 and T2 Quantitative Measurements in the Female Pelvis: A Prospective Study

The aim of this study was to explore the potential of magnetic resonance fingerprinting (MRF), an emerging quantitative MRI technique, in measuring relaxation values of female pelvic tissues compared to the conventional magnetic resonance image compilation (MAGiC) sequence. The study included 32 female patients who underwent routine pelvic MRI exams using anterior and posterior array coils on a 3T clinical scanner. Our findings demonstrated significant correlations between MRF and MAGiC measured T1 and T2 values (p < 0.0001) for various pelvic tissues, including ilium, femoral head, gluteus, obturator, iliopsoas, erector spinae, uterus, cervix, and cutaneous fat. The tissue contrasts generated from conventional MRI and synthetic MRF also showed agreement in bone, muscle, and uterus for both T1-weighted and T2-weighted images. This study highlights the strengths of MRF in providing simultaneous T1 and T2 mapping. MRF offers distinct tissue contrast and has the potential for accurate diagnosis of female pelvic diseases, including tumors, fibroids, endometriosis, and pelvic inflammatory disease. Additionally, MRF shows promise in monitoring disease progression or treatment response. Overall, the study demonstrates the potential of MRF in the field of female pelvic organ imaging and suggests that it could be a valuable addition to the clinical practice of pelvic MRI exams. Further research is needed to establish the clinical utility of MRF and to develop standardized protocols for its implementation in clinical practice.

PET/MR imaging in gynecologic cancer: tips for differentiating normal gynecologic anatomy and benign pathology versus cancer

Positron emission tomography/magnetic resonance imaging (PET/MR) is used in the pre-treatment and surveillance settings to evaluate women with gynecologic malignancies, including uterine, cervical, vaginal and vulvar cancers. PET/MR combines the excellent spatial and contrast resolution of MR imaging for gynecologic tissues, with the functional metabolic information of PET, to aid in a more accurate assessment of local disease extent and distant metastatic disease. In this review, the optimal protocol and utility of whole-body PET/MR imaging in patients with gynecologic malignancies will be discussed, with an emphasis on the advantages of PET/MR over PET/CT and how to differentiate normal or benign gynecologic tissues from cancer in the pelvis.

Clinical and prognostic 18F-FDG PET/CT role in recurrent vulvar cancer: a multicentric experience

PURPOSE

The aim of this retrospective multicentric study was to investigate the diagnostic performance, the prognostic value and the impact of 18F-FDG PET/CT on treatment decision-making in patients with suspected recurrent vulvar cancer (VC).

MATERIALS AND METHODS

Sixty-three patients affected by VC performed 18F-FDG-PET/CT for restaging purposes in case of suspected clinical and/or radiological recurrence. Histopatology results if available and/or clinical-imaging follow-up for at least 12 months were considered as reference standard. The diagnostic accuracy and the clinical impact of 18F-FDG PET/CT were investigated. Progression free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier curves.

RESULTS

Fifty-two (82.5%) PET/CT showed the presence of recurrence, while the remaining 11 (17.5%) were negative. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT were 100% (95%CI 93-100%), 92% (95%CI 62-100%), 98% (95%CI 89-99%), 100% and 98% (95%CI 92-100%). A relevant impact of 18F-FDG PET/CT imaging was registered in 28 cases: in 12 cases moving from local therapy to chemotherapy due to the recognition of disseminate localizations; in 10 showing the site of recurrence in presence of negative conventional imaging, and in 6 cases confirming to be true negative and avoiding unnecessary therapies. Beside advanced age and HPV status, a positive restaging 18F-FDG PET/CT scan was significantly correlated with shorter PFS and OS compared to negative scan (p < 0.001).

CONCLUSIONS

18F-FDG PET/CT demonstrated to be an accurate tool in the assessing of recurrent VC with high sensitivity and specificity and with a significant impact on clinical decision-making. Restaging 18F-FDG PET/CT findings were associated with survival.

Initial experience with positron emission tomography/computed tomography in addition to computed tomography and magnetic resonance imaging in preoperative risk assessment of endometrial cancer patients

OBJECTIVE

Improved preoperative evaluation of lymph node status could potentially replace lymphadenectomy in women with endometrial cancer. PET/CT was routinely implemented in the preoperative workup of endometrial cancer at St Olav's University Hospital in 2016. Experience with PET/CT is limited, and there is no consensus about the use of PET/CT in the diagnostic workup of endometrial cancer. The aim of the study was to evaluate the diagnostic accuracy of PET/CT compared to standard CT/MRI in identifying lymph node metastases in endometrial cancer with histologically confirmed lymph node metastases as the standard of reference. We especially wanted to look at PET/CT as a supplement to the sentinel lymph node algorithm in the detection of paraaortic lymph nodes.

STUDY DESIGN

A retrospective study included all women undergoing surgery for endometrial cancer from January 2016 through July 2019 at St Olav's University Hospital. Clinical data, results of CT, MRI, and PET/CT, and histopathological results were analyzed.

RESULTS

Among 185 patients included, 27 patients (15 %) had lymph node metastases. 17 (63 %) had pelvic lymph node metastases, one (4 %) had isolated paraaortic lymph node metastases, and 9 (33 %) had lymph node metastases in both the pelvis and the paraaortic region. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for the detection of lymph node metastases were 63 %, 98 %, 85 %, 94 %, and 93 %, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CT/MRI were 41 %, 98 %, 73 %, 91 %, and 90 %, respectively (p = 0.07). For the 26 pelvic lymph node metastases, PET/CT had a sensitivity of 58 %, compared to 42 % for CT/MRI (p = 0.22). PET/CT detected all 10 paraaortic lymph node metastases, for a sensitivity of 100 %, compared to 50 % for CT/MRI (p = 0.06).

CONCLUSIONS

PET is superior to CT/MRI for detection of lymph node metastases in endometrial cancer, particularly in detecting paraaortic lymph node metastases. The ability of preoperative PET to exclude paraaortic lymph node metastases may strengthen the credibility of the sentinel lymph node algorithm.

Evaluation of Pre-Therapeutic Assessment in Endometrial Cancer Staging

OBJECTIVE

The aim of this retrospective cohort study is to evaluate the concordance between the preoperative MRI and histology data with the final histopathological examination.

METHOD

This is a retrospective observational study of 183 patients operated for endometrioid cancer between January 2009 and December 2019 in the surgical oncology department of the Lorraine Cancer Institute (ICL) in Vandœuvre-lès-Nancy. The patients included are all women operated on for endometrioid-type endometrial cancer over this period. The exclusion criteria are patients for whom the pre-therapy check-up does not include pelvic MRI and those who have not had first-line surgery. The final anatomopathological results were compared with preoperative imaging data and with endometrial biopsy data.

RESULTS

For the myometrial infiltration, the sensitivity of MRI was of 37% and the specificity of 54%. To detect nodal metastases, the sensitivity of MRI was of 21% and the specificity of 93%. We observed an under estimation of the FIGO classification (p = 0.001) with the MRI in 42.7% of cases (n = 76) and an overestimation in 24.2% of cases (n = 43). There was a concordance in 33.1% of cases (n = 59). We had a poor agreement between the MRI and final histopathological examination with an adjusted kappa (κ) of 0.12 [95% IC (0.02; 0.24)]. There was a moderate concordance on the grade between the pretherapeutic biopsy and the final histopathological examination on excised tissue with an adjusted kappa of 0.52 [95% IC 0.42-0.62)]. Endometrial biopsy underestimated the tumor grade in 28.9% of cases (n = 50) (p < 0.001), overestimated the tumor grade in 6.9% of cases (n = 12) and we observed a concordance in 64.2% of cases (n = 111).

CONCLUSION

The pre-operative assessment of endometrial cancer is inconsistent with the results obtained on final histopathological examination. A study with a systematic review should be done to assess the performance of MRI, only in expert centers, in order to consider a a specific care management for endometrial cancer patients: patients who have had an MRI in an outpatient center should have their imaging systematically reviewed, with the possibility of a new examination in case of incomplete sequences, by expert radiologists, and discussed in multidisciplinary concertation meeting in expert centers, before any therapeutic decision. The sentinel node biopsy must be used for low and intermediate risk endometrial cancer.

The Role of Positron Emission Tomography/Magnetic Resonance Imaging in Gynecological Malignancies

Accurate oncological staging for early detection is of utmost importance in patient care and increasing the overall patient survival outcome. Hybrid imaging in the form of positron emission tomography (PET)/computed tomography has been successfully implemented in oncological imaging and, where available, has been used consistently in patients with gynecologic malignancies. The implementation of PET/magnetic resonance imaging (MRI) enables high-quality assessment of gynecological malignancies by combining the diagnostic advantages of metabolic information of PET along with the high-resolution anatomical and functional information from the MRI to provide precise information about staging, recurrence, and metastases. This article will review the various applications of PET/MRI in gynecological cancer.

Current Status of Magnetic Resonance Imaging in Patients with Malignant Uterine Neoplasms: A Review

In this study, we summarize the clinical role of magnetic resonance imaging (MRI) in the diagnosis of patients with malignant uterine neoplasms, including leiomyosarcoma, endometrial stromal sarcoma, adenosarcoma, uterine carcinosarcoma, and endometrial cancer, with emphasis on the challenges and disadvantages. MRI plays an essential role in patients with uterine malignancy, for the purpose of tumor detection, primary staging, and treatment planning. MRI has advanced in scope beyond the visualization of the many aspects of anatomical structures, including diffusion-weighted imaging, dynamic contrast enhancement-MRI, and magnetic resonance spectroscopy. Emerging technologies coupled with the use of artificial intelligence in MRI are expected to lead to progressive improvement in case management of malignant uterine neoplasms.

Feasibility and diagnostic performance of hybrid PET/MRI compared with PET/CT for gynecological malignancies: a prospective pilot study

PURPOSE

The purpose of the study was to assess the feasibility and diagnostic performance of FDG-PET/MR imaging compared to PET/CT for staging of patients with a gynecological malignancy.

METHODS

25 patients with a gynecological malignancy were prospectively enrolled into this pilot study. Patients underwent sequential full-body PET/CT and PET/MR of the abdomen and pelvis after administration of a single dose of F-18 FDG. PET/MRI and PET/CT images were independently reviewed by two expert radiologists. Readers were blinded to the results of the other imaging procedures. Clinical and pathologic information was abstracted from medical charts.

RESULTS

18 patients were included in the final analysis with a median age of 62 years (range 31-88). 61% of patients (11/18) had cervical cancer, while the remaining patients had endometrial cancer. PET/MRI as compared to PET/CT detected all primary tumors, 7/7 patients with regional lymph nodes, and 1/1 patient with an abdominal metastasis. Two patients had additional lymph nodes outside of the abdominopelvic cavity detected on PET/CT that were not seen on PET/MRI, whereas 6 patients had parametrial invasion and one patient had invasion of the bladder seen on PET/MRI not detected on PET/CT. Five cervical cancer patients had discordant clinical vs. radiographic staging based on PET/MRI detection of soft tissue involvement. Management changed for two patients who had clinical stage IB1 and radiographic stage IIB cervical cancer.

CONCLUSIONS

PET/MRI is feasible and has at least comparable diagnostic ability to PET/CT for identification of primary cervical and endometrial tumors and regional metastases. PET/MRI may be superior to PET/CT for initial radiographic assessment of cervical cancers.

Emerging Molecular Imaging Techniques in Gynecologic Oncology

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

Positron emission tomography in the management of documented or suspected recurrent ovarian cancer

BACKGROUND

To prospectively evaluate the value of positron emission tomography (PET) or integrated computed tomography (CT) and PET (PET/CT) in the management of documented or suspected recurrent ovarian cancer.

METHODS

Patients with ovarian cancer who had completed primary cytoreductive surgery and standard adjuvant chemotherapy were studied to evaluate the following indications: (1) CA125 elevation after complete remission with negative CT or magnetic resonance imaging (MRI) result; (2) post-therapy surveillance CT/MRI-detected suspicious lesions that guided biopsy was not feasible; (3) documented relapse for restaging prior to or after curative salvage therapy. The clinical impact of PET, as compared with those of CT/MRI, was determined on a per scan basis.

RESULTS

From 2002 to 2009, 73 patients were recruited, and 92 PET scans were performed. Up to June 2015, 53 patients had died of disease, four were alive with disease, and the remaining 16 were alive without disease. Among the 92 scans, PET had positive impacts in 72.8%, no clinical impacts in 21.7%, and negative impacts in 5.4%. For indication 1, the sensitivity and positive predictive value of PET in detecting recurrence were 80.0% and 92.3%, respectively. For indication 2, the sensitivity, specificity, positive predictive value, and negative predictive value of PET were 91.2%, 62.5%, 91.2%, and 62.5%, respectively. For indication 3, PET provided positive impact in 85.3% and negative impact in 2.9% of the 34 scans.

CONCLUSION

PET has value in the management of suspected or documented recurrent ovarian cancer, with positive impacts on confirming recurrent status and offering a better treatment plan.

Is there a revision needed of the current FIGO staging system?

The FIGO staging system has undergone many modifications since it first appeared in about the middle of the previous century. Due to the use of modern diagnostic tools, namely computed tomography, magnetic resonance imaging, positron emission tomography, sentinel lymph node biopsy and neoadjuvant chemotherapy, certain gynecological cancer cases cannot be allocated to a specific stage if one wishes to adhere strictly to FIGO requirements. In these circumstances such cases actually remain unstaged. This should prompt appropriate modifications of the current FIGO staging system so that it fulfills its aims.

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

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

Hypoxia in cervical cancer: from biology to imaging

PURPOSE

Hypoxia imaging may improve identification of cervical cancer patients at risk of treatment failure and be utilized in treatment planning and monitoring, but its clinical potential is far from fully realized. Here, we briefly describe the biology of hypoxia in cervix tumors of relevance for imaging, and evaluate positron emission tomography (PET) and magnetic resonance imaging (MRI) techniques that have shown promise for assessing hypoxia in a clinical setting. We further discuss emerging imaging approaches, and how imaging can play a role in future treatment strategies to target hypoxia.

METHODS

We performed a PubMed literature search, using keywords related to imaging and hypoxia in cervical cancer, with a particular emphasis on studies correlating imaging with other hypoxia measures and treatment outcome.

RESULTS

Only a few and rather small studies have utilized PET with tracers specific for hypoxia, and no firm conclusions regarding preferred tracer or clinical potential can be drawn so far. Most studies address indirect hypoxia imaging with dynamic contrast-enhanced techniques. Strong evidences for a role of these techniques in hypoxia imaging have been presented. Pre-treatment images have shown significant association to outcome in several studies, and images acquired during fractionated radiotherapy may further improve risk stratification. Multiparametric MRI and multimodality PET/MRI enable combined imaging of factors of relevance for tumor hypoxia and warrant further investigation.

CONCLUSIONS

Several imaging approaches have shown promise for hypoxia imaging in cervical cancer. Evaluation in large clinical trials is required to decide upon the optimal modality and approach.

What Is the Best Preoperative Imaging for Endometrial Cancer?

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

Multiparametric [18F]Fluorodeoxyglucose/ [18F]Fluoromisonidazole Positron Emission Tomography/ Magnetic Resonance Imaging of Locally Advanced Cervical Cancer for the Non-Invasive Detection of Tumor Heterogeneity: A Pilot Study

Objectives

To investigate fused multiparametric positron emission tomography/magnetic resonance imaging (MP PET/MRI) at 3T in patients with locally advanced cervical cancer, using high-resolution T2-weighted, contrast-enhanced MRI (CE-MRI), diffusion-weighted imaging (DWI), and the radiotracers [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and [¹⁸F]fluoromisonidazol ([¹⁸F]FMISO) for the non-invasive detection of tumor heterogeneity for an improved planning of chemo-radiation therapy (CRT).

Materials and Methods

Sixteen patients with locally advanced cervix were enrolled in this IRB approved and were examined with fused MP [¹⁸F]FDG/ [¹⁸F]FMISO PET/MRI and in eleven patients complete data sets were acquired. MP PET/MRI was assessed for tumor volume, enhancement (EH)-kinetics, diffusivity, and [¹⁸F]FDG/ [¹⁸F]FMISO-avidity. Descriptive statistics and voxel-by-voxel analysis of MRI and PET parameters were performed. Correlations were assessed using multiple correlation analysis.

Results

All tumors displayed imaging parameters concordant with cervix cancer, i.e. type II/III EH-kinetics, restricted diffusivity (median ADC 0.80x10^-3mm²/sec), [¹⁸F]FDG- (median SUV_max16.2) and [¹⁸F]FMISO-avidity (median SUV_max3.1). In all patients, [¹⁸F]FMISO PET identified the hypoxic tumor subvolume, which was independent of tumor volume. A voxel-by-voxel analysis revealed only weak correlations between the MRI and PET parameters (0.05–0.22), indicating that each individual parameter yields independent information and the presence of tumor heterogeneity.

Conclusion

MP [¹⁸F]FDG/ [¹⁸F]FMISO PET/MRI in patients with cervical cancer facilitates the acquisition of independent predictive and prognostic imaging parameters. MP [¹⁸F]FDG/ [¹⁸F]FMISO PET/MRI enables insights into tumor biology on multiple levels and provides information on tumor heterogeneity, which has the potential to improve the planning of CRT.

Utility of (18)F-FDG PET/CT in patients with advanced squamous cell carcinoma of the uterine cervix receiving concurrent chemoradiotherapy: a parallel study of a prospective randomized trial

PURPOSE

The aim of this prospective study was to assess the usefulness of (18)F-FDG PET/CT performed before and during treatment for predicting treatment failure in patients with advanced squamous cell carcinoma of the uterine cervix treated with concurrent chemoradiotherapy (CCRT).

METHODS

Patients with cervical squamous cell carcinoma, International Federation of Gynecology and Obstetrics stage III/IVA or positive pelvic or paraaortic lymph node (LN) metastasis without other distant metastasis on PET/CT entering a randomized trial of CCRT (AGOG 09-001) were eligible. PET/CT scans were performed at baseline, during week 3 of CCRT and 2 - 3 months after CCRT. PET/CT parameters were correlated with sites of failure and overall survival (OS). The resulting predictors developed from the study cohort were validated on two independent datasets using area under the curve values, sensitivities and specificities.

RESULTS

With a median follow-up of 54 months for survivors, 20 (36 %) of the 55 eligible patients were proven to have treatment failure. Sites of failure were local in five, regional in 11, and distant in 11. Four predictors for local failure, three for regional failure, and four for distant failures were identified. After validation with two independent cohorts of 31 and 105 patients, we consider the following as clinically useful predictors: pretreatment metabolic tumour volume (MTV) and during-treatment cervical tumour MTV for local failure; during-treatment SUVnode (maximum standardized uptake value of LNs) for regional and distant failure, and during-treatment MTV for distant failure. During-treatment SUVnode (P = .001) and cervical tumour MTVratio (P = .004) were independent significant predictors of OS by stepwise Cox regression.

CONCLUSION

PET/CT imaging before and during treatment is useful for predicting failure sites and OS, making tailored therapeutic modifications feasible with potential outcome improvement during primary therapy.

Role of MR Imaging and FDG PET/CT in Selection and Follow-up of Patients Treated with Pelvic Exenteration for Gynecologic Malignancies

Pelvic exenteration (PE) is a radical surgical procedure used for the past 6 decades to treat locally advanced malignant diseases confined to the pelvis, particularly persistent or recurrent gynecologic cancers in the irradiated pelvis. The traditional surgical technique known as total PE consists of resection of all pelvic viscera followed by reconstruction. Depending on the tumor extent, the procedure can be tailored to remove only anterior or posterior structures, including the bladder (anterior exenteration) or rectum (posterior exenteration). Conversely, more extended pelvic resection can be performed if the pelvic sidewall is invaded by cancer. Preoperative imaging evaluation with magnetic resonance (MR) imaging and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is central to establishing tumor resectability and therefore patient eligibility for the procedure. These imaging modalities complement each other in diagnosis of tumor recurrence and differentiation of persistent disease from posttreatment changes. MR imaging can accurately demonstrate local tumor extent and show adjacent organ invasion. FDG PET/CT is useful in excluding nodal and distant metastases. In addition, FDG PET/CT metrics may serve as predictive biomarkers for overall and disease-free survival. This pictorial review describes different types of exenterative surgical procedures and illustrates the central role of imaging in accurate patient selection, treatment planning, and postsurgical surveillance.

(18)F-FDG PET in small-cell cervical cancer: a prospective study with long-term follow-up

PURPOSE

Small-cell cervical cancer (SCCC) is rare and prone to metastasize. We conducted a prospective study to evaluate the role of (18)F-FDG PET in the management of this aggressive malignancy.

METHODS

Patients with untreated primary, histologically confirmed SCCC were enrolled. (18)F-FDG PET (or PET/CT) was performed immediately after MRI or CT, for primary staging, monitoring response to treatment or restaging when there was suspicion of recurrence. The clinical impact of PET was determined on a scan basis.

RESULTS

A total of 25 patients were recruited and 43 PET scans were performed. The PET images were obtained for primary staging (25 patients), monitoring response (10 patients) and restaging when there was suspicion of recurrence (8 patients). The median follow-up time in event-free patients was 109.3 months (range 97.5 - 157.7 months). A positive impact of PET was found in 8 (18.6 %) of the 43 scans, which included detection of additional regions of distal lymph node (LN) metastasis (one primary staging scan, two restaging scans), bone metastasis (two primary staging scans, one monitoring response scan), and exclusion of false-positive lesions on MRI (one primary staging scan, one restaging scan). On the other hand, one negative impact was recorded as one false-positive lesion on a restaging PET scan. One positive impact was noted for monitoring response (bone metastasis). The impact of three scans was indeterminate. The positive impact of down-staging in avoiding overtreatment but finding additional distal LN (except one on restaging) or bone metastases had no beneficial effect on long-term survival.

CONCLUSION

The results of this preliminary study suggest that PET is useful in the management of SCCC. PET could have more value in detecting occult metastases if future novel therapies are able to offer better control of extensive SCCC.

Endometrial cancer

Endometrial cancer is the most common gynaecological tumour in developed countries, and its incidence is increasing. The most frequently occurring histological subtype is endometrioid adenocarcinoma. Patients are often diagnosed when the disease is still confined to the uterus. Standard treatment consists of primary hysterectomy and bilateral salpingo-oophorectomy, often using minimally invasive approaches (laparoscopic or robotic). Lymph node surgical strategy is contingent on histological factors (subtype, tumour grade, involvement of lymphovascular space), disease stage (including myometrial invasion), patients' characteristics (age and comorbidities), and national and international guidelines. Adjuvant treatment is tailored according to histology and stage. Various classifications are used to assess the risks of recurrence and to determine optimum postoperative management. 5 year overall survival ranges from 74% to 91% in patients without metastatic disease. Trials are ongoing in patients at high risk of recurrence (including chemotherapy, chemoradiation therapy, and molecular targeted therapies) to assess the modalities that best balance optimisation of survival with the lowest adverse effects on quality of life.

Computed tomography, magnetic resonance imaging and FDG positron emission tomography in the management of vulvar malignancies

OBJECTIVES

To prospectively evaluate the value of CT or MRI (CT/MRI) and PET in the management of vulvar malignancies.

METHODS

Abdominal and pelvic CT/MRI and whole-body (18) F-FDG (fluorodeoxyglucose) PET or PET/CT (collectively designated PET hereafter) were performed. Lesion status was determined by the pathological findings or clinical follow-up. The diagnostic efficacy was evaluated by receiver operating characteristic (ROC) curve analysis. The clinical impact of PET was determined on a per scan basis.

RESULTS

Twenty-three patients were enrolled, and 38 PET examinations were performed. CT/MRI and PET studies were used for primary staging (n = 17), monitoring the response (n = 7) and restaging after recurrence (n = 14). In primary staging, there was no significant difference between CT/MRI and PET in detecting metastatic inguinal lymph nodes (ILN). CT/MRI was significantly more efficacious than PET in detecting pelvic lymph node (PLN) or distant metastasis (p = 0.007 by ROC per patient basis). PET findings resulted in two positive impacts and one negative impact for both primary staging and restaging.

CONCLUSIONS

False-positive PLN or distant metastasis PET findings are not uncommon, and hence should be interpreted with caution. PET can be supportive when metastatic ILN/PLN or distant metastasis is suspected on CT/MRI.

KEY POINTS

• False-positive metastatic PLN or distant metastasis PET findings are not uncommon. • CT/MRI has value in the management of vulvar malignancies. • PET can be supportive when metastasis is suspected by CT/MRI.