Radiologic Assessment of Groin Lymph Nodes in Pelvic Malignancies.

INTRODUCTION: Metastatic involvement of groin nodes can alter radiation therapy planning for pelvic tumors. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) can identify nodal metastases; however, interpretation of PET/CT-positive nodes can be complicated by non-malignant processes. We evaluated quantitative metrics as methods to identify groin metastases in patients with pelvic tumors by comparison with standard subjective interpretive criteria, with pathology as the reference standard. METHODS: We retrospectively identified patients with vulvar, vaginal, or anal cancers who underwent 18F-FDG PET/CT before pathologic evaluation of groin nodes between 2007 and 2017. Because patho-radiologic correlation was not possible for every node, one index node identified on imaging was selected for each groin. For each index node, standardized uptake value measurements, total lesion glycolysis, metabolic tumor volume, CT-based volume, and short and long axes were measured. Multivariate logistic regression was used to identify metrics predictive for pathologically positive groins and generate a probabilistic model. Area under the receiver-operating characteristic curves (AUCs) for the model were compared with clinical interpretation from the diagnostic report via a Wald's χ2 test. RESULTS: Of 55 patients identified for analysis, 75 groins had pathologic evaluation resulting in 75 index groin nodes for analysis with 35 groins pathologically positive for malignancy. Logistic regression identified mean standardized-uptake-value (50% threshold) and short-axis length as the most predictive imaging metrics for metastatic nodal involvement. The probabilistic model performed better at predicting pathologic involvement compared with standard clinical interpretation on analysis (AUC 0.91, 95% CI 0.84 to 0.97 vs 0.80, 95% CI 0.71 to 0.89; p<0.01). DISCUSSION: Accuracy of 18F-FDG PET/CT for detecting groin nodal metastases in patients with pelvic tumors may be improved with the use of quantitative metrics. Improving prediction of nodal metastases can aid with appropriate selection of patients for pathologic node evaluation and guide radiation volumes and doses.

Ultrasound morphometric and cytologic preoperative assessment of inguinal lymph-node status in women with vulvar cancer: MorphoNode study.

OBJECTIVE: To assess the accuracy of preoperative ultrasound examination for predicting lymph-node (LN) status in patients with vulvar cancer. METHODS: This was a single-institution retrospective observational study of all women with a histological diagnosis of vulvar cancer triaged to inguinal surgery within 30 days following ultrasound evaluation between December 2010 and January 2016. For each groin examined, 15 morphological and dimensional sonographic parameters associated with suspicion for LN involvement were examined. A morphometric ultrasound pattern (MUP) was expressed for each groin, classifying the inguinal LN status into five groups (normal; reactive-but-negative; minimally suspicious/probably negative; moderately suspicious; and highly suspicious/positive) according to subjective judgment, followed by stratification as positive or negative for metastasis according to morphometric binomial assessment (MBA). In cases of positive MBA, fine-needle aspiration cytology was performed. Combining the information obtained from MUP and cytologic results, a binomial final overall assessment (FOA) was assigned for each groin. The final histology was considered as the reference standard. Comparison was performed between patients with negative and those with positive LNs on histology, and receiver-operating-characteristics curves were generated for statistically significant variables on univariate analysis, to evaluate their diagnostic ability to predict negative LN status. RESULTS: Of 144 patients included in the analysis, 87 had negative inguinal LNs and 57 had positive LNs on histology. A total of 256 groins were analyzed, of which 171 were negative and 85 showed at least one metastatic LN on histology. The following parameters showed the greatest accuracy, with the best balance between specificity and sensitivity, in predicting negative LN status: cortical (C) thickness of the dominant LN (cut-off, 2.5 mm; sensitivity, 90.0%; specificity, 77.9%); short-axis (S) length of the dominant LN (cut-off, 8.4 mm; sensitivity, 63.9%; specificity, 90.6%); C/medulla (M) thickness ratio of the dominant LN (cut-off, 1.2 mm; sensitivity, 70.4%; specificity, 91.5%), the combination of S length and C/M thickness ratio (sensitivity, 88.9%; specificity, 82.4%); and the FOA analysis (sensitivity, 85.9%; specificity, 84.2%). CONCLUSIONS: Preoperative ultrasound assessment, with or without the addition of cytology, has a high accuracy in assessing inguinal LN status in patients with vulvar cancer. In particular, the combination of two ultrasound parameters (S length and C/M thickness ratio) provided the greatest accuracy in discriminating between negative and positive LNs. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

FDG-PET for Assessment of Endometrial and Vulvar Cancer.

Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) provides a comprehensive whole body evaluation in patients with endometrial and vulvar cancer. Here, we discuss the role of FDG-PET/CT in defining the disease extent in patients presenting with these cancers. Detection of lymph node and distant metastases has implications for staging, treatment planning, and patient prognosis. Procedures for image acquisition and interpretation for optimum accuracy and essential elements that should be included in the PET-CT report are described. Common imaging pitfalls are presented and illustrated with examples.

FDG-PET Assessment of Other Gynecologic Cancers.

PET and PET/computed tomography play a role in the staging, monitoring of response to therapy, and surveillance for cervical and ovarian cancers. Currently, it is also an integral part of the assessment of patients with endometrial cancer and other gynecologic malignancies, such as vaginal and vulvar cancers and uterine sarcomas. In this article, we discuss in detail and highlight the potential role of PET and PET/computed tomography in evaluating these gynecologic malignancies using illustrative cases with relevant imaging findings.

Groin sentinel node biopsy and 18F-FDG PET/CT-supported preoperative lymph node assessment in cN0 patients with vulvar cancer currently unfit for minimally invasive inguinal surgery: The GroSNaPET study.

OBJECTIVE: The study aims were: 1) to verify the role of sentinel node biopsy (SNB) in a subset of patients with clinical N0 (cN0) invasive vulvar cancer (VC) who were still candidates for radical inguinal surgery according to the current guidelines; 2) to investigate whether a preoperative 18F-FDG PET/CT (PET/CT) evaluation could improve the selection of node negative patients. METHODS: From July 2013 to July 2016, all patients with VC admitted to our Division were evaluated by standard imaging and clinical exam. Among the patients assessed as cN0 we enrolled those unsuitable for SNB, due to: T > 4 cm, multifocal tumors, complete tumor diagnostic excision, contralateral nodal involvement and local recurrence. A preoperative PET/CT was performed. For each patient surgery included SNB, performed using a combined technique (radiotracer plus blue dye), followed by standard inguino-femoral lymphadenectomy. The reference standard was histopathology. RESULTS: Forty-seven patients entered the study for a total of 73 groins. Histopathology revealed 12 metastatic SNs in 9 groins. No false negative SNs were found (NPV 100%). PET/CT showed a negative predictive value of 93%. CONCLUSIONS: Our data suggest that SNB is accurate and safe even in cN0 patients currently excluded from this procedure, providing that a careful preoperative selection is performed. PET/CT allows a reliable assessment of LN status and may be an effective support for the selection of patients who are safe candidates for SNB.

Assessment of the sentinel lymph node in patients with invasive squamous carcinoma of the vulva.

OBJECTIVE: This study aims to evaluate the feasibility and diagnostic validity of the sentinel lymph node technique in detecting inguinal lymph node metastases in patients with invasive squamous cancer of the vulva. DESIGN: Retrospective analysis of the in-house tumor registry. SETTING: Dr. Horst Schmidt Klinik, a tertiary gynecologic oncology unit in Wiesbaden, Germany, June 2000-May 2008. POPULATION: All consecutive operated patients with primary envisaged diagnosis were included. METHODS: The sentinel node identification technique was performed and patients were informed accordingly. Patients who consented and were found eligible underwent preoperative lymphscintigraphy on the day before surgery. MAIN OUTCOME MEASURES: Sentinel node detection in specimen from sentinel lymph node biopsy and from full lymphadenectomy (LNE); sentinel lymph node biopsy as a sole surgical groin procedure in patients with histological negative sentinel node; benefit with respect to side effects for sentinel lymph node biopsy compared to full LNE; complication rates; and recurrences of vulvar cancer. RESULTS: In all, 46 of 59 patients with vulvar malignancy underwent inguinofemoral LNE, sentinel lymph node biopsy (SLB) of the groin followed by LNE, or SLB alone. Most patients had been diagnosed in the early stages of the disease. Since no false positive or false negative results were recorded, the sensitivity, specificity, positive predictive value and negative predictive value of the sentinel lymph node were 100%. However, in 6%, a sentinel lymph node could not be detected intraoperatively indicating a feasibility of 94%. CONCLUSION: The implementation of sentinel lymph node technique for groin staging in squamous cell vulvar cancer seems to provide a feasible and safe technique in tertiary gynecologic oncology.