Added value of para-aortic surgical staging compared to 18F-FDG PET/CT on the external beam radiation field for patients with locally advanced cervical cancer: An ONCO-GF study

Robotic-Assisted Pelvic Exenteration for Cervical Cancer: A Systematic Review and Novel Insights into Compartment-Based Imaging

Background: Patients with persistent or recurrent cervical cancer, following primary treatment with concurrent chemoradiation, represent a subgroup eligible for pelvic exenteration. In light of the substantial morbidity associated with open pelvic exenterations, minimally invasive surgical techniques have been introduced. This systematic review aims to analyze and discuss the current literature on robotic-assisted pelvic exenterations in cervical cancer. In addition, novel aspects of compartment-based magnetic resonance imaging (MRI) are highlighted. Methods: This systematic review followed the PRISMA guidelines, and a comprehensive literature search on robotic-assisted pelvic exenterations in cervical cancer was conducted to assess, as main objectives, early and late postoperative complications as well as oncological outcomes. Inclusion and exclusion criteria were applied to select eligible studies. Results: Among the reported cases of robotic-assisted pelvic exenterations in cervical cancer, 79.4% are anterior pelvic exenterations. Intraoperative complications are minimal and early/late major complications averaged between 30-35%, which is lower compared to open pelvic exenterations. Oncological outcomes are similar between robotic and open pelvic exenterations. Sensitivity for locoregional invasion increases up to 93% for compartment-based MRI in colorectal cancer. A refined delineation of the seven pelvic compartments for cervical cancer is proposed here. Conclusions: Robotic-assisted pelvic exenterations have demonstrated feasibility and safety, with reduced rates of major complications compared to open surgery, while maintaining surgical efficiency and oncological outcomes. Compartment-based MRI holds promise for standardizing the selection and categorization of pelvic exenteration procedures.

[18F]FDG-PET/CT-based risk stratification in women with locally advanced uterine cervical cancer

BACKGROUND

[18F]FDG-PET/CT is used for staging and treatment planning in patients with locally advanced cervical cancer (LACC). We studied if a PET-based prediction model could provide additional risk stratification beyond International Federation of Gynaecology and Obstetrics (FIGO) staging in our population with LACC to aid treatment decision making.

METHODS

In total, 183 patients with LACC treated with chemoradiation between 2013 and 2018 were included. Patients were treated according to FIGO 2009 and retrospectively reclassified according to FIGO 2018 staging system. After validation of an existing PET-based prediction model, the predicted recurrent free survival (RFS), disease specific survival (DSS) and overall survival (OS) at 1, 3, and 5 years, based on metabolic tumor volume (MTV), maximum standardized uptake value (SUVmax) and highest level of [18F]FDG-positive node was calculated. Then the observed survival was compared to the predicted survival. An area under the curve (AUC) close to or higher than 0.7 was considered adequate for accurate prediction. The Youden (J) index defined survival chance cutoff values for low and high risk groups.

RESULTS

All AUC values for the comparison between predicted and observed outcomes were > 0.7 except for 5-year RFS and for 5-year OS which were close to 0.7 (0.684 and 0.650 respectively). Cutoff values for low and high risk survival chance were 0.44 for the 3-year RFS and 0.47 for the 5-year OS. The FIGO 2009 system could not differentiate between the risk profiles. After reclassification according to FIGO 2018, all patients with stage IIIC2 and IVB fell in the high risk and almost all patients with stages IB2-IIIB and IVA in the low risk group. In patients with stage IIIC1 disease the FIGO stage cannot discriminate between the risk profiles.

CONCLUSIONS

Low and high risk patients with LACC can be identified with the PET-based prediction model. In particular patients with stage IIIC1 need additional risk stratification besides the FIGO 2018 staging. The Kidd model could be a useful tool to aid treatment decision making in these patients. Our results also support the choice of [18F]FDG-PET/CT imaging in patients with LACC.

Robotic para-aortic sentinel lymph node mapping in endometrial, cervical, and ovarian cancer

The concept of pelvic sentinel lymph node mapping has been well-investigated in endometrial and cervical cancer. A variety of tracers have been used including blue dye, technetium-99-m (Tc-99 m), and fluorescent tracer indocyanine green. Pelvic sentinel lymph node mapping has shown its safety, efficacy, and diagnostic accuracy, with high sensitivity and negative predictive value of more than 90%, in retrospective cohort studies as well as in prospective trials for robotic surgery. The concept of pelvic sentinel lymph node biopsy has been incorporated in several international guidelines in early-stage endometrial cancer and a subgroup of early-stage cervical cancer, although survival data are still needed to confirm its standard use. The application of para-aortic sentinel lymph node mapping is still in a development phase, but its detection rate and diagnostic accuracy seem to be promising in initial studies. Here, an overview is given of the recent developments in the different methodologies used for identifying para-aortic sentinel lymph nodes in endometrial, cervical, and ovarian cancer.

Curative treatment for stage IIIC2 cervical cancer: what to expect?

Background

Since the GOG125 study, treating radically patients with positive para-aortic lymph nodes has been a valid approach. Nevertheless, literature lacks data on how to better treat these patients since they are usually excluded from trials. In this study, we aimed to report the outcomes of patients with advanced cervical cancer and positive para-aortic lymph nodes (PAN) treated in a single tertiary/academic institution and try to identify variables that may impact survival.

Materials and methods

We retrospectively reviewed patients with positive para-aortic lymph nodes treated in our institution. Demographic variables and treatment options were assessed and their impact on overall survival (OS), locorregional control, distant metastasis free survival, and para-aortic lymph node progression was analyzed.

Results

We assessed 65 patients treated from April 2010 to May 2017. Median OS was 38.7 months. Median locorregional and para-aortic progression free survivals were not reached. Median distant metastasis progression-free survival was 64.3 months. Better ECOG performance status (p > 0.001), concurrent chemotherapy (p = 0.031), and brachytherapy (p = 0.02) were independently related to better overall survival.

Conclusion

Patients with current stage IIIC2 cervix cancer may present long term survival. Treating positive PAN cervical cancer patients with concurrent chemoradiation including brachytherapy with curative intent should be standard. Poor PS and more advanced pelvic disease may represent a higher risk for worse outcomes. Distant metastases are still a challenge for disease control.

Pattern of Care of Recurrent Cervical Cancer in Low-resource Settings: Challenges and Patient-initiated Follow-up as a Novel Opportunity

Introduction

The availability of optimum diagnostic strategies remains a major problem in resource-constraint countries. This technique of patient-initiated follow-up (PIFU) has been recently adopted in the UK for gynecological cancers and has proven cost benefits. However, no study from the Indian subcontinent has ever been reported.

Aims and Objectives

The primary objective was to study the pattern of care of recurrent cervical cancer in low-resource settings. The secondary objective was to compare the reliability of symptomatology/clinical evaluation and imaging methods on follow-up to detect recurrence and thus explore the feasibility of symptom-based PIFU.

Materials and Methods

This was a single-institutional retrospective analysis of recurrent cervical cancer cases for a period of 3 years from January 2019 to January 2022. Patients who followed up for minimum of 6 months were included in the study.

Results

In 57 of the total 69 patients, symptoms alone were the index diagnostic method. Interestingly, neither of the methods of recurrence detection had impact on overall survival (OS). Cox regression analysis revealed adverse impact of erratic/lost to follow-up (hazard ratio [HR] = 3.8) and pelvic side wall disease (HR = 1.33) on survival. Patients with positive para-aortic nodes had significantly shorter disease-free interval of 11 months, so adding systemic therapy to adjuvant treatment in this cohort needs to be further investigated.

Conclusion

Our analysis showed that patients with recurrence who were diagnosed with clinical manifestations alone vis-à-vis the ones who were diagnosed primarily on routine follow-up visit by some imaging or diagnostic test had comparable oncologic outcomes. PIFU can be a "practice changing modality" in patient management system, especially in low-resource settings. It will prove to be a simple cost-effective method to detect recurrence and prevent fallouts. Our study points to the feasibility of PIFU in Indian scenario.

Multicentric development and evaluation of 18F-FDG PET/CT and MRI radiomics models to predict para-aortic lymph node involvement in locally advanced cervical cancer

PURPOSE

To develop machine learning models to predict para-aortic lymph node (PALN) involvement in patients with locally advanced cervical cancer (LACC) before chemoradiotherapy (CRT) using 18F-FDG PET/CT and MRI radiomics combined with clinical parameters.

METHODS

We retrospectively collected 178 patients (60% for training and 40% for testing) in 2 centers and 61 patients corresponding to 2 further external testing cohorts with LACC between 2010 to 2022 and who had undergone pretreatment analog or digital 18F-FDG PET/CT, pelvic MRI and surgical PALN staging. Only primary tumor volumes were delineated. Radiomics features were extracted using the Radiomics toolbox®. The ComBat harmonization method was applied to reduce the batch effect between centers. Different prediction models were trained using a neural network approach with either clinical, radiomics or combined models. They were then evaluated on the testing and external validation sets and compared.

RESULTS

In the training set (n = 102), the clinical model achieved a good prediction of the risk of PALN involvement with a C-statistic of 0.80 (95% CI 0.71, 0.87). However, it performed in the testing (n = 76) and external testing sets (n = 30 and n = 31) with C-statistics of only 0.57 to 0.67 (95% CI 0.36, 0.83). The ComBat-radiomic (GLDZM_HISDE_PET_FBN64 and Shape_maxDiameter2D3_PET_FBW0.25) and ComBat-combined (FIGO 2018 and same radiomics features) models achieved very high predictive ability in the training set and both models kept the same performance in the testing sets, with C-statistics from 0.88 to 0.96 (95% CI 0.76, 1.00) and 0.85 to 0.92 (95% CI 0.75, 0.99), respectively.

CONCLUSIONS

Radiomic features extracted from pre-CRT analog and digital 18F-FDG PET/CT outperform clinical parameters in the decision to perform a para-aortic node staging or an extended field irradiation to PALN. Prospective validation of our models should now be carried out.

PARa-aOrtic LymphAdenectomy in locally advanced cervical cancer (PAROLA trial): a GINECO, ENGOT, and GCIG study

BACKGROUND

Positron emission tomography/computed tomography (PET/CT) fails to detect approximately 25% of aortic lymph node metastasis in patients with PET/CT stage IIIC1 cervical cancer. Surgical staging could lead to treatment modification and to improved para-aortic and distant control.

PRIMARY OBJECTIVES

To demonstrate if chemoradiation with tailored external beam radiation field based on surgical staging and pathologic examination of the para-aortic lymph node is associated with improved 3-year disease-free survival compared with patients staged with PET/CT staging only.

STUDY HYPOTHESIS

Surgical staging followed by tailored chemoradiation will improve disease-free survival while avoiding unnecessary prophylactic extended-field chemoradiation in patients with International Federation of Gynecology and Obstetrics (FIGO) stage IIIC1 cervical cancer.

TRIAL DESIGN

This is an international multicenter, randomized, phase III study. Eligible patients will be randomized 1:1 between PET/CT staging followed by chemoradiation (control arm), or surgical staging followed by tailored chemo-radiation (experimental arm). Randomization will be stratified by tumor stage according to TNM classification, center, and adjuvant treatment.

MAJOR INCLUSION/EXCLUSION CRITERIA

Main inclusion criteria are histologically proven PET/CT FIGO stage IIIC1 cervical cancer. Main exclusion criteria include unequivocal positive common iliac or para-aortic lymph node at pre-therapeutic imaging PET/CT.

PRIMARY ENDPOINTS

The primary endpoint is disease-free survival defined as the time from randomization until first relapse (local, regional, or distant), or death from any cause.

SAMPLE SIZE

510 eligible patients ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: The estimated date for completing accrual will be Q2 2027. The estimated date for presenting results will be Q4 2030.

TRIAL REGISTRATION NUMBER

NCT05581121.

Robotic Staging of Cervical Cancer With Simultaneous Detection of Primary Pelvic and Secondary Para-Aortic Sentinel Lymph Nodes: Reproducibility in a First Case Series

Objective

Discrepancies exist among international guidelines on the surgical staging of para-aortic lymph nodes in locally advanced cervical cancer (LACC), varying from considering a para-aortic lymph node dissection, at least up to the inferior mesenteric artery, to a complete para-aortic lymph node dissection. In this study, we aim to assess the reproducibility of our recently reported robotic technique using indocyanine green for identifying besides primary pelvic sentinel lymph nodes (SLNs), secondary para-aortic SLNs in a first case-cohort of cervical cancer patients.

Methods

A retrospective case series of LACC patients with/without suspicious pelvic lymph nodes (LNs) on imaging (including two patients with an additional suspicious para-aortic LN) is reported. All patients underwent a robotic pelvic SLN and para-aortic sentinel/nonsentinel LN dissection using the da Vinci Xi platform. Indocyanine green was used as a fluorescent tracer, at a concentration of 1.9 mg/mL, and injected as 0.5 mL in each quadrant of the cervix.

Results

In a total of 10 cases, primary pelvic SLNs (90% bilateral) with subsequent secondary para-aortic SLNs were identified in all cases. Lower para-aortic SLNs were present in all cases, and upper para-aortic SLNs were found in 9 out of 10 cases. The mean age of the cervical cancer patients was 49.8 years (SD ± 6.89), and the mean body mass index (BMI; kg/m²) was 23.96 (SD ± 4.60). The median total operative time was 105.5 min (range: 89–141 min). The mean numbers of primary pelvic SLNs and secondary lower and upper para-aortic SLNs were 3.10 (SD ± 1.10), 2.90 (SD ± 0.74), and 2.30 (SD ± 1.57), respectively. The median number of total para-aortic LNs (PALNs) dissected per patient was 11.5. Six patients had positive primary pelvic SLNs, and two had secondary positive para-aortic SLNs. The nonsentinel para-aortic LNs were negative in all cases. There were no intra- or postoperative complications.

Conclusion

Our preliminary experience demonstrates the reproducibility of identifying, besides primary pelvic SLNs, secondary lower and upper para-aortic SLNs during robotic staging in LACC. A surgical approach limiting a complete para-aortic LN dissection could reduce the potential risks and morbidity associated with this procedure. To determine the sensitivity and negative predictive value of this new surgical approach, and whether the lower para-aortic SLNs under the inferior mesenteric artery are representative of the whole para-aortic region, large prospective observational studies are needed in LACC and/or those with suspicious pelvic LNs but apparent normal para-aortic LNs on imaging.

Stereotactic radiotherapy for oligometastases in the lymph nodes

Even though systemic therapy is standard treatment for lymph node metastases, metastasis-directed stereotactic radiotherapy (SRT ) seems to be a valid option in oligometastatic patients with a low disease burden.

Positron emission tomography-computed tomography (PET-CT ) is the gold standard for assessing metastases to the lymph nodes; co-registration of PET-CT images and planning CT images are the basis for gross tumor volume (GTV ) delineation. Appropriate techniques are needed to overcome target motion. SRT schedules depend on the irradiation site, target volume and dose constraints to the organs at risk (OARs) of toxicity. Although several fractionation schemes were reported, total doses of 48–60 Gy in 4–8 fractions were proposed for mediastinal lymph node SRT, with the spinal cord, esophagus, heart and proximal bronchial tree being the dose limiting OAR s. Total doses ranged from 30 to 45 Gy, with daily fractions of 7–12 Gy for abdominal lymph nodes, with dose limiting OARs being the liver, kidneys, bowel and bladder. SRT on lymph node metastases is safe; late side effects, particularly severe, are rare.

Upstaging by para-aortic lymph node dissection in patients with locally advanced cervical cancer: A systematic review and meta-analysis

BACKGROUND

Accurate staging of para-aortic nodal status in cervical cancer is of great importance for individualizing treatment and impacting outcomes. Three-dimensional imaging (i.e. PET, CT, MRI) may miss para-aortic lymph node (PALN) metastases. The aim of this study was to systematically review and meta-analyze the proportion of upstaging by PALN dissection in patients with locally advanced cervical cancer without suspicious PALNs on imaging.

METHODS

PubMed/MEDLINE and Embase were systematically searched. The analysis included diagnostic studies that reported on 3D imaging and pre-therapeutic surgical assessment of PALN status in patients with cervical cancer. An overall pooled upstaging rate was calculated using a random-effects model.

RESULTS

The search identified 16 eligible studies including 18 cohorts with a total of 1530 patients. Pooling of 12 cohorts demonstrated an upstaging rate of 12% (95% confidence interval [CI] 10-15%) by PALN dissection after negative PET or PET-CT. Pooling of 6 cohorts demonstrated a pooled upstaging rate of 11% (95% CI: 8-16%) by PALN dissection after negative MRI or CT. No significant heterogeneity in upstaging proportions across cohorts was observed (I² = 0% and 27%, respectively). In 7 cohorts including only patients with pelvic nodal metastases on imaging (but no suspicion of PALN involvement) a pooled upstaging rate by PALN dissection of 21% (95% CI: 17-26%) was found (I² = 0%).

CONCLUSIONS

This meta-analysis demonstrates that in case of no suspicious PALN on PET-CT or MRI, PALN dissection still identifies lymph node metastases in a considerable amount of patients with locally advanced cervical cancer and especially in those patients with confirmed pelvic nodal metastases.

The Diagnosis, Treatment, and Aftercare of Cervical Carcinoma

BACKGROUND

Approximately 4380 cases of cervical carcinoma were diagnosed in Germany in 2016. In women who had not participated in early detection programs, cervical carcinoma was usually already in an advanced stage at the time of diagnosis. Certified structures for care in conformity with the existing guidelines are available.

METHODS

The new German clinical practice guideline was revised with the participation of 50 medical societies under the expert guidance of the Guideline Program in Oncology, which includes the German Association of the Scientific Medical Societies (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). A systematic literature review was conducted. Systematic reviews, meta-analyses, and randomized controlled trials (RCTs) were considered.

RESULTS

The histologic tumor stage and lymph-node stage are essential determinants of the treatment strategy. The main innovation regarding surgical treatment is the revival of open hysterectomy (overall survival [minimally invasive vs open hysterectomy]: 94.04% vs 99.4%; hazard ratio [HR]: 6.00; 95% confidence interval [1.77; 20.30]). In addition, for tumors measuring 2 cm or less, sentinel node biopsy is recommended rather than radical pelvic lymphadenectomy. MRI-guided brachytherapy is an obligatory component of radiochemotherapy (overall survival [radiochemotherapy with vs without brachytherapy]: 58.2% vs 46.2%, p<0.001). The standard palliative treatment consists of bevacizumab combined with a platinum-containing agent (overall survival: HR: 0.77 [0.62; 0.95]; p = 0.007).

CONCLUSION

Despite the introduction of new treatments, the outcome of patients with advanced cervical carcinoma has not much improved. In the surgical treatment of cervical carcinoma, the open approach is now favored. The sentinel node biopsy technique has become well established for the surgical staging of small tumors. Controlled trials are needed so that the outcome of women with cervical carcinoma, particularly in its advanced and metastatic stages, can be improved.

How to predict para-aortic node involvement in advanced cervical cancer? Development of a predictive score. A FRANCOGYN study

INTRODUCTION

Node involvement is one of the main prognostic factors for cervical cancer. Para-aortic lymph node (PALN) assessment is crucial for treating advanced cervical cancer, to define irradiation fields. Objective of this study was to develop a score predicting para-aortic lymph node involvement in patients with advanced cervical cancer.

PATIENTS AND METHOD

We performed a multicenter, retrospective, study on 9 French centers from 2000 to 2015, including patients with advanced squamous cell cervix carcinoma who had PALN status assessed by imaging and/or by surgery. Factors associated with a risk of PALN involvement were determined by univariate and multivariate analysis using a logistic regression model. A score was then developed and validated.

RESULTS

A total of 1446 patients treated for cervical cancer were included. Of these, 498 had an advanced squamous cell cervical cancer. Ninety-one patients (18.3%) had positive PALN. After univariate and multivariate analysis, tumor size on pelvic MRI, initial SCC, and suspected pelvic node involvement on PET-CT were included in our score. This model allowed the population to be divided into 3 risk groups. Area under the ROC curve of the score was 0.81 (95%CI = 0.72-0.90). In the low-risk group, 9% (28/287) had PALN involvement, whereas in the high-risk group, 43% (22/51) had PALN involvement.

CONCLUSION

We developed a simple score predicting PALN involvement in advanced cervical cancers. Three risk groups can be defined, and patients considered to be at low risk may avoid para-aortic staging as well as extensive field irradiation.

Optimal treatment in locally advanced cervical cancer

Introduction: Locally advanced cervical cancer (LACC) (International Federation of Gynecology and Obstetrics (FIGO) 2009/2018 - stages IB2-IVA/IB3-IVA, respectively) is treated using a multimodal approach that includes chemoradiotherapy followed by brachytherapy.Areas covered: This review provides an overview of the progress made over the past decade in the treatment of LACC. Prognostic factors, FIGO classification and the role of imaging staging will be discussed. Efficacy of external-beam radiotherapy, brachytherapy and chemotherapy will be detailed. Indications for para-aortic staging lymphadenectomy and adjuvant hysterectomy, as well as follow-up and special population, will be covered.Expert opinion: The initial workup is one of the most crucial steps in the optimal care of patients, which should be realized by a multidisciplinary expert team. With the implementation of modern conformal radiotherapy techniques, the local control rate has been optimized. Nevertheless, 40% of patients experience recurrence with distant metastasis and a dismal prognosis. Currently, a clear benefit of neo- and adjuvant chemotherapy has not been established. The future likely involves (1) improved selection of patients for whom treatment intensification is justified, (2) a combination of new drugs with chemoradiation that are currently being tested in trials, and (3) the development of tailored treatment based on molecular characteristics.

False negative rate at 18F-FDG PET/CT in para-aortic lymphnode involvement in patients with locally advanced cervical cancer: impact of PET technology

Background

The identification of factors responsible for false negative (FN) rate at ¹⁸F- Fluorodeoxyglucose (FDG) Positron Emission Tomography /Computed Tomography (PET/CT) in para-aortic (PA) lymph nodes in the presurgical staging of patients with locally advanced cervical cancer (LACC) is challenging. The aim of this study was to evaluate the impact of PET/CT technology.

Methods

A total of 240 consecutive patients with LACC (International Federation of Gynecology and Obstetrics, FIGO, stage IB2-IVA) and negative Magnetic Resonance Imaging (MRI) and/or Computed Tomography (CT) and negative ¹⁸F-FDG PET/CT in the PA region, undergoing laparoscopic PA lymphadenectomy before chemoradiotherapy were included. The FN rate in patients studied with Time of flight (TOF) PET/CT (TOF PET) or non-Time of flight PET/CT (no-TOF PET) technology was retrospectively compared.

Results

Patients presented with FIGO stage IB (n = 78), stage IIA-B (n = 134), stage III (n = 18) and stage IVa (n = 10), squamous cell carcinoma (n = 191) and adenocarcinoma (n = 49). 141/240 patients were evaluated with no-TOF PET/CT and 99/240 with TOF PET/CT. Twenty-two patients (9%) had PA nodal involvement at histological analysis and considered PET/CT FN findings. The FN rate was 8.5% for no-TOF PET and 10% for TOF PET subgroup respectively (p = 0.98). Ninety patients (38%) presented with pelvic node uptakes at PET/CT. The FN rate in the PA region was 18% (16/90) and 4% (6/150) in patients with and without pelvic node involvement at PET/CT respectively (19 vs 3% for no-TOF PET and 17 vs 5% for TOF PET subgroup).

Conclusions

In LACC, FN rate in PA lymph nodes detection is a clinical issue even for modern PET/CT, especially in patients with pelvic uptake. Surgical lymphadenectomy should be performed in case of negative PET/CT at PA level in these patients, while it could be discussed in the absence of pelvic uptake.

Prophylactic Extended-Field Irradiation in Patients With Cervical Cancer: A Literature Review

Currently, the standard radiation field for locally advanced cervical cancer patients without evidence of para-aortic lymph node (PALN) metastasis is the pelvis. Due to the low accuracy of imaging in the diagnosis of PALN metastasis and the high incidence of PALN failure after pelvic radiotherapy, prophylactic pelvic and para-aortic irradiation, also called extended-field irradiation (EFI), is performed for patients with cervical cancer. In the era of concurrent chemoradiotherapy, randomized controlled trials are limited, and whether patients with cervical cancer can benefit from prophylactic EFI is still controversial. With conformal or intensity-modulated radiation therapy, patients tolerate prophylactic EFI very well. The severe toxicities of prophylactic EFI are not significantly higher than those of pelvic radiotherapy. We recommend delivering prophylactic EFI to cervical cancer patients with common iliac lymph nodes metastasis. Clinical trials are needed to investigate whether patients with ≥3 positive pelvic lymph nodes and FIGO stage IIIB disease can benefit from prophylactic EFI. According to the distribution of PALNs, it is reasonable to use the renal vein as the upper border of the radiation therapy field for patients treated with prophylactic EFI. The clinical target volume expansion of the node from the vessel should be smaller in the right para-caval region than in the left lateral para-aortic region. The right para-caval region above L2 or L3 may be omitted from the PALN target volume to reduce the dose to the duodenum. More clinical trials on prophylactic EFI in cervical cancer are needed.

[18F]FDG-PET or PET/CT in the evaluation of pelvic and para-aortic lymph nodes in patients with locally advanced cervical cancer: A systematic review of the literature

PURPOSE

Imaging is essential in detecting lymph node metastases for radiotherapy treatment planning in locally advanced cervical cancer (LACC). There are not many data on the performance of [¹⁸F]FDG-PET(CT) in showing lymph node metastases in LACC. We pooled sensitivity and specificity of [¹⁸F]FDG-PET(CT) for detecting pelvic and/or para-aortic lymph node metastases in patients with LACC. Also, the positive and negative posttest probabilities at high and low levels of prevalence were determined.

METHODS

MEDLINE and EMBASE searches were performed and quality characteristics assessed. Logit-sensitivity and logit-specificity estimates with corresponding standard errors were calculated. Summary estimates of sensitivity and specificity with corresponding 95% confidence intervals (CIs) were calculated by anti-logit transformation. Positive and negative likelihood ratios (LRs) were calculated from the mean logit-sensitivity and mean logit-specificity and the corresponding standard errors. The posttest probabilities were determined by Bayesian approach.

RESULTS

Twelve studies were included with a total of 778 patients aged 10-85 years. For pelvic nodes, summary estimates of sensitivity, specificity, LR+ and LR- were: 0.88 (95%CI: 0.40-0.99), 0.93 (95%CI: 0.85-0.97), 11.90 (95%CI: 5.32-26.62) and 0.13 (95%CI: 0.01-1.08). At the lowest prevalence of 0.15 the positive predictive value (PPV) and negative predictive value (NPV) were 0.68 and 0.98, at the highest prevalence of 0.65, 0.96 and 0.81. For the para-aortic nodes, the summary estimates of sensitivity, specificity LR+ and LR- were: 0.40 (95%CI: 0.18-0.66), 0.93 (95%CI: 0.91-0.95), 6.08 (95%CI: 2.90-12.78) and 0.64 (95%CI: 0.42-0.99), respectively. At the lowest prevalence of 0.17 the PPV and NPV were 0.55 and 0.88, at the highest prevalence of 0.50, 0.86 and 0.61.

CONCLUSION

The PPV and NPV of [¹⁸F]FDG-PET(CT) showing lymph node metastases in patients with LACC improves with higher prevalence. Prevalence and predictive values should be taken into account when determining therapeutic strategies based on [¹⁸F]FDG-PET(CT).

How should we stage and tailor treatment strategy in locally advanced cervical cancer? Imaging versus para-aortic surgical staging

Para-aortic lymph node status at initial assessment is the most important prognostic factor and a key point for the therapeutic strategy in patients with locally advanced cervical cancer. Undiagnosed lymph node metastasis is a major clinical problem as the finding of positive para-aortic lymph nodes leads to treatment modification, with a possible impact on disease free survival. When aortic lymph node disease is discovered, radiotherapy is extended to the para-aortic area, and other treatment modalities may be considered. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is the most accurate imaging examination to assess para-aortic extension in patients with locally advanced cervical cancer. The gold standard to identify para-aortic extension remains histologic evaluation of the lymph nodes. Indeed, PET/CT fails to detect approximately 10-15% of patients with negative PET/CT aortic nodes who have lymph node metastasis on pathologic staging. Patients with positive pelvic lymph nodes have para-aortic extension in 25-30% of cases, and surgical staging will lead to treatment modification and probably to improved para-aortic and distant control. Surgical staging also avoids unnecessary toxicity associated with extended field radiation in approximately 75% of patients with pelvic lymph node metastasis. The best modality to identify para-aortic extension is histological evaluation of the lymph nodes, but the survival benefit of surgical staging remains controversial. On the other hand, current studies include a majority of patients without pelvic lymph node spread, who are likely to be those who will benefit the least from surgical staging.