Predictive performance of radiomics for peritoneal metastasis in patients with gastric cancer: a meta-analysis and radiomics quality assessment.

PURPOSE: The purpose of this meta-analysis is to systematically review the diagnostic performance of radiomic techniques in predicting peritoneal metastasis in patients with gastric cancer, and to evaluate the quality of current research. METHODS: We searched PubMed, Web of Science, EBSCO, Embase, and Cochrane databases for relevant studies up to April 3, 2023. Data extraction and quality evaluation were performed by two independent reviewers. Then we performed statistical analysis, including plotting the forest plot and summary receiver operating characteristic (SROC) curve, and source of heterogeneity analysis, through the MIDAS module in Stata 15. We performed meta-regression and subgroup analyses to analyze the sources of heterogeneity. Using the QUADAS-2 scale and the RQS scale to assess the quality of retrieved studies. RESULTS: Ten studies with 6199 patients were finally included in our meta-analysis. Pooled sensitivity and specificity were 0.77 (95% confidence interval [CI]: 0.66, 0.86), and 0.88 (95% CI 0.80, 0.93), respectively. The overall AUC was 0.89 (95% CI 0.86, 0.92). The heterogeneity of this meta-analysis was high, with I2 = 88% (95% CI 75,100). The result of meta-regression showed that QUADAS-2 results, RQS results and machine learning method led to heterogeneity in sensitivity and specificity (P < 0.05). Furthermore, the image segmentation area and the presence or absence of combined clinical factors were associated with sensitivity heterogeneity and specificity heterogeneity, respectively. CONCLUSION: Undoubtedly, radiomics has potential value in diagnosing peritoneal metastasis of gastric cancer, but the quality of current research is inconsistent, and more standardized and high-quality research is still needed in the future to achieve the transformation of radiomics results into clinical applications.

Radiological assessment of peritoneal carcinomatosis: a primer for resident.

The imaging has critical responsibility in the assessment of peritoneal lesions along with estimating the overall extent. Valuing disease burden is crucial for selection of combining cytoreductive surgery (CRS) and intraperitoneal hyperthermic chemotherapy (HIPEC) treatment. An approach that combines the strength of several imaging tools and increases diagnostic accuracy, should be chosen, even if the preferred imaging tool in patients with suspected Peritoneal Carcinomatosis (PC) is CT. The outcomes of PC are mainly correlated to tumor spread, localization, and lesion size. Accurate assessment of these features is critical for prognosis and treatment planning. These data can be evaluated by Peritoneal Cancer Index (PCI), a quantitative index suggested by Harman and Sugarbaker. Additionally, precise predictive biomarkers should be established to predict PC in patients at risk. The radiomics analysis could predict PC throughout the evaluation of cancers heterogeneity.

Assessment of the use of computed tomography colonography in early detection of peritoneal metastasis in patients with gastric cancer: A prospective cohort study.

Peritoneal metastasis (PM) is one of the most frequent forms of gastric cancer recurrence. In this study, we aimed to use computed tomography (CT) colonography (CTC) to detect signs of PM earlier in patients in whom PM was suspected but not yet diagnosed. CTC was used to evaluate patients with clinical symptoms or general CT findings that were suspicious but not sufficient to confirm PM. In total, 18 patients with suspected PM were enrolled. Ten patients (55.6%) had PM on CTC. Abnormal colonic deformities were identified at locations other than those of the lesions detected by general CT in seven patients. The sensitivity and specificity of CTC for the detection of PM were 83.3% and 100%, respectively. The median overall survival after CTC was 201 days in the CTC-positive group, which was significantly shorter than that in the CTC-negative group (945 days, p = 0.01). In the multivariate analysis, a positive CTC finding was the only factor independently associated with survival (p = 0.005). According to our experience with 18 patients, CTC can be an alternative to conventional imaging for early detection of PM. Further prospective studies with larger sample sizes are warranted to confirm and validate these findings. University hospital Medical Information Network Clinical Trials Registry (UMIN-CTR): Registration number: UMIN000044167.

Quantitative Indocyanine Green Fluorescence Imaging Assessment for Nonmucinous Peritoneal Metastases: Preliminary Results of the ICCP Study.

BACKGROUND: In selected patients with peritoneal metastases of colorectal origin, complete cytoreduction has been the main single prognostic factor influencing long-term outcomes. In these patients, indocyanine green fluorescence imaging seems to be useful in detecting small subclinical peritoneal implants. However, quantitative fluorescence analysis has not yet been established as standard. OBJECTIVE: This study aimed to evaluate the sensitivity and specificity of quantitative indocyanine green fluorescence assessment in the detection of peritoneal metastases of nonmucinous colorectal origin. DESIGN: This is a single-center, single-arm, low-intervention prospective trial. SETTINGS: A fluorescence assessment device was used for intraoperative fluorescence quantitative assessment. PATIENTS: Consecutive patients diagnosed with peritoneal metastases of colorectal origin who met the inclusion criteria were selected for curative surgery. INTERVENTIONS: Intravenous indocyanine green was administered 12 hours before surgery. Cytoreduction was performed through nodule identification under white light and then under indocyanine green. Finally, ex vivo fluorescence was assessed. MAIN OUTCOME MEASURES: The primary outcomes measured were the sensitivity and specificity of quantitative fluorescence. RESULTS: The first 11 enrolled patients were included in this preliminary analysis. In total, 52 nodules were resected, with 37 (71.1%) being diagnosed as malignant in the histopathological analysis. Of those, 5 (13.5%) were undetectable under white light and were identified only with fluorescence. A total of 15 nonmalignant nodules were detected under white light, 8 (53.3%) of which were fluorescence negative. Fluorescence greater than 181 units might be the threshold of malignancy, with a sensitivity and specificity of 89.0% and 85.0%, whereas uptake less than 100 units appears to correlate with a benign pathology. LIMITATIONS: The limited sample size, the physiological uptake, and excretion of indocyanine green might interfere with the assessment of unnoticed implants in the bowel serosa and liver. CONCLUSIONS: Quantitative indocyanine green seems to be useful for the assessment of nonmucinous colorectal peritoneal metastases. Fluorescence uptake greater than 181 units appears to correlate with malignancy, whereas uptake less than 100 units appears to correlate with a benign pathology. See Video Abstract at http://links.lww.com/DCR/B743. EVALUACIN CUANTITATIVA DE IMGENES DE FLUORESCENCIA CON VERDE DE INDOCIANINA PARA METSTASIS PERITONEALES NO MUCINOSAS RESULTADOS PRELIMINARES DEL ESTUDIO ICCP: ANTECEDENTES:En pacientes seleccionados con metástasis peritoneales de origen colorrectal, la citorreducción com-pleta ha sido el único factor pronóstico principal que influye en el resultado a largo plazo. En estos pacientes, las imágenes de fluorescencia con verde de indocianina parecen ser útiles para detectar pequeños implantes peritoneales subclínicos. Sin embargo, el análisis cuantitativo de fluorescencia aún no se ha establecido como estándar.OBJETIVO:Evaluar la sensibilidad y especificidad de la evaluación cuantitativa de fluorescencia verde de indo-cianina, en la detección de metástasis peritoneales de origen colorrectal no mucinoso.DISEÑO:Ensayo prospectivo de intervención baja de un solo brazo y un solo centro.ENTORNO CLINICO:El dispositivo se utilizó para la evaluación cuantitativa de fluorescencia intraoperatoria.PACIENTES:Pacientes consecutivos diagnosticados con metástasis peritoneales de origen colorrectal, selecciona-dos para cirugía curativa y que cumplieron con los criterios de inclusión.INTERVENCIONES:Se administró verde de indocianina por vía intravenosa 12 h antes de la cirugía. La citorreducción se realizó mediante identificación de nódulos con luz blanca y luego con verde de indocianina. Final-mente, se evaluó la fluorescencia ex vivo.PRINCIPALES MEDIDAS DE VALORACION:Sensibilidad y especificidad cuantitativa de la fluorescencia.RESULTADOS:Los primeros 11 pacientes fueron incluidos en este análisis preliminar. En total se resecaron 52 nódu-los, siendo 37 (71,1%) diagnosticados como malignos en el análisis histopatológico. De ellos, 5 (13,5%) eran indetectables bajo luz blanca y solamente se identificaron con fluorescencia. Se detec-taron un total de 15 nódulos no malignos bajo luz blanca, de los cuales 8 (53,3%) fueron fluorescen-tes negativos. La fluorescencia superior a 181 unidades podría ser el umbral de malignidad, con una sensibilidad y especificidad del 89,0% y el 85,0% respectivamente; mientras que la captación por debajo de 100 unidades parece correlacionarse con una patología benigna.LIMITACIONES:El tamaño limitado de la muestra; la captación fisiológica y la excreción de verde de indocianina pueden interferir con la evaluación de implantes inadvertidos en la serosa intestinal y el hígado.CONCLUSIONES:La cuantificación del verde de indocianina, parece ser útil en la evaluación de metástasis peritonea-les colorrectales no mucinosas. La captación de fluorescencia por encima de 181 unidades parece correlacionarse con la malignidad, mientras que la captación por debajo de 100 unidades parece co-rrelacionarse con una patología benigna. Consulte Video Resumen en http://links.lww.com/DCR/B743. (Traducción - Dr. Fidel Ruiz Healy).

Fusion imaging in preoperative assessment of extent of disease in patients with advanced ovarian cancer: feasibility and agreement with laparoscopic findings.

OBJECTIVES: Fusion imaging is an emerging technique that combines real-time ultrasound examination with images acquired previously using other modalities, such as computed tomography (CT), magnetic resonance imaging and positron emission tomography. The primary aim of this study was to evaluate the feasibility of fusion imaging in patients with suspicion of ovarian or peritoneal cancer. Secondary aims were: to compare the agreement of findings on fusion imaging, CT alone and ultrasound imaging alone with laparoscopic findings, in the assessment of extent of intra-abdominal disease; and to evaluate the time required for the fusion imaging technique. METHODS: Patients with clinical and/or radiographic suspicion of advanced ovarian or peritoneal cancer who were candidates for surgery were enrolled prospectively between December 2019 and September 2020. All patients underwent a CT scan and ultrasound and fusion imaging to evaluate the presence or absence of the following abdominal-cancer features according to the laparoscopy-based scoring model (predictive index value (PIV)): supracolic omental disease, visceral carcinomatosis on the liver, lesser omental carcinomatosis and/or visceral carcinomatosis on the lesser curvature of the stomach and/or spleen, involvement of the paracolic gutter(s) and/or anterior abdominal wall, involvement of the diaphragm and visceral carcinomatosis on the small and/or large bowel (regardless of rectosigmoid involvement). The feasibility of the fusion examination in these patients was evaluated. Agreement of each imaging method (ultrasound, CT and fusion imaging) with laparoscopy (considered as reference standard) was calculated using Cohen's kappa coefficient. RESULTS: Fifty-two patients were enrolled into the study. Fusion imaging was feasible in 51 (98%) of these patients (in one patient, it was not possible for technical reasons). Two patients were excluded because laparoscopy was not performed, leaving 49 women in the final analysis. Kappa values for CT, ultrasound and fusion imaging, using laparoscopy as the reference standard, in assessing the PIV parameters were, respectively: 0.781, 0.845 and 0.896 for the great omentum; 0.329, 0.608 and 0.847 for the liver surface; 0.472, 0.549 and 0.756 for the lesser omentum and/or stomach and/or spleen; 0.385, 0.588 and 0.795 for the paracolic gutter(s) and/or anterior abdominal wall; 0.385, 0.497 and 0.657 for the diaphragm; and 0.336, 0.410 and 0.469 for the bowel. The median time needed to perform the fusion examination was 20 (range, 10-40) min. CONCLUSION: Fusion of CT images and real-time ultrasound imaging is feasible in patients with suspicion of ovarian or peritoneal cancer and improves the agreement with surgical findings when compared with ultrasound or CT scan alone. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Assessment of peritoneal metastases with DW-MRI, CT, and FDG PET/CT before cytoreductive surgery for advanced stage epithelial ovarian cancer.

BACKGROUND: Preoperative assessment of peritoneal metastases is an important factor for treatment planning and selection of candidates for cytoreductive surgery (CRS) in primary advanced stage (FIGO stages III-IV) epithelial ovarian cancer (EOC). The primary aim was to evaluate the efficacy of DW-MRI, CT, and FDG PET/CT used for preoperative assessment of peritoneal cancer index (PCI). MATERIAL AND METHODS: In this prospective observational cohort study, 50 advanced stage EOC patients were examined with DW-MRI and FDG PET/CT with contrast enhanced CT as part of the diagnostic program. All patients were deemed amenable for upfront CRS. Imaging PCI was determined for DW-MRI, CT, and FDG PET/CT by separate readers blinded to the surgical findings. The primary outcome was agreement between the imaging PCI and PCI determined at surgical exploration (the reference standard) evaluated with Bland-Altman statistics. RESULTS: The median surgical PCI was 18 (range: 3-32). For all three imaging modalities, the imaging PCI most often underestimated the surgical PCI. The mean differences between the surgical PCI and the imaging PCI were 4.2 (95% CI: 2.6-5.8) for CT, 4.4 (95% CI: 2.9-5.8) for DW-MRI, and 5.3 (95% CI: 3.6-7.0) for FDG PET/CT, and no overall statistically significant differences were found between the imaging modalities (DW-MRI - CT, p = 0.83; DW-MRI - FDG PET/CT, p = 0.24; CT - FDG PET/CT, p = 0.06). CONCLUSION: Neither DW-MRI nor CT nor FDG PET/CT was superior in preoperative assessment of the surgical PCI in patients scheduled for upfront CRS for advanced stage EOC.

The Chicago Consensus on peritoneal surface malignancies: Standards.

The Chicago Consensus Working Group provides the following multidisciplinary recommendations for the care of patients with peritoneal surface malignancies. This article focuses on the standards of a peritoneal surface malignancy center, standards of billing and coding, standards of operative reports for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, standards of cytoreductive surgery training, and standards of intraoperative chemotherapy preparation. These guidelines are developed with input from leading experts, including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence.

Radiological assessment of Peritoneal Cancer Index on preoperative CT in ovarian cancer is related to surgical outcome and survival.

PURPOSE: To evaluate whether Peritoneal Cancer Index (PCI) assessed on preoperative CT (CT-PCI) can be used as non-invasive preoperative tool to predict surgical outcome, disease-free survival (DFS) and overall survival (OS). MATERIALS AND METHODS: This is a retrospective, observational cohort study performed in a single institution. We considered all patients with diagnosis of ovarian cancer and preoperative CT, who had undergone upfront cytoreductive surgery between 2008 and 2010 and had post-operative clinical follow-up to December 2015. Two radiologists reviewed CT scans and assessed CT-PCI using Sugarbaker's diagram. We assessed the discriminatory capacity of the CT-PCI score on the surgical outcome by ROC curve analysis. DFS and OS were assessed by Kaplan-Meier nonparametric curves and by multivariable Cox-regression analysis. RESULTS: A total of 297 patients were included in the present analysis. CT-PCI was positively correlated with post-operative residual disease [odds ratio (OR) 1.04, 95% CI 1.01-1.07, p = 0.003]. ROC curve analysis returned AUC = 0.64 for the prediction of total macroscopic tumour clearance. In multivariable analysis, patients with no peritoneal disease seen on CT had a significantly longer DFS [Hazard ratio (HR) 2.28, p = 0.007]. Radiological serosal small bowel involvement was an independent predictor for shorter OS (HR 3.01, p = 0.002). CONCLUSION: Radiological PCI assessed on preoperative CT is associated with the probability of residual disease after cytoreductive surgery; however, it has low performance as a triage test to reliably identify patients who are likely to have complete cytoreductive surgery. CT-PCI is positively correlated with both DFS and OS and may be used as an independent prognostic factor, for example in patients with high FIGO stages.

Magnetic Resonance Assessment of Peritoneal Carcinomatosis: Is There a True Benefit From Diffusion-Weighted Imaging?

PURPOSE: To assess the added value of diffusion weighted imaging (DWI) with intermediate (500 s/mm2) and high (1000 s/mm2) b values when combined to conventional contrast-enhanced magnetic resonance imaging (MRI) in identifying peritoneal neoplastic involvement. METHODS: Twenty-four patients with peritoneal carcinomatosis from gastrointestinal or gynecological tumors were retrospectively evaluated. All patients underwent peritonectomy with hyperthermic intraoperative chemotherapy and 1.5 T MRI including DWI with 500 s/mm2 and 1000 s/mm2 b values within 1 month from surgery. Images were independently reviewed by 2 radiologists with different experience in abdominal MRI in 3 separate reading sessions, the first including conventional MR images alone (T2-weighted, T1-weighted pre- and post gadolinium injection), the second conventional MRI and DWI with a b value of 500 s/mm2 (b 500-DWI), and the third conventional MRI and DWI with a b value of 1000 s/mm2 (b 1000-DWI). Apparent diffusion coefficient maps were included in the DWI analyses. Peritoneal dissemination was assessed in 9 anatomical sites, including right and left subphrenic space, paracolic gutters, small bowel mesentery, greater omentum, gastric-bowel serosa, free peritoneal surfaces, rectosigmoid-colon mesentery, and pelvis. The presence or absence of peritoneal dissemination for each patient and for each site was scored using a 5-point confidence scale. Sensitivity, specificity, and area under the curve (AUC) for identifying per-site peritoneal implants were calculated for each reader at each reading session. Interobserver agreement was evaluated using kappa statistics. RESULTS: For both readers, the sensitivity and AUC values resulting from combined interpretation of conventional MRI and DWI (both b500-DWI and b1000-DWI) were significantly higher than those of conventional MRI alone (P < 0.001). The added value of DWI was greater for the less experienced reader (sensitivity 0.55, specificity 0.73, AUC 0.64 on conventional MRI; sensitivity 0.75, specificity 0.72, AUC 0.74 on b500-DWI; sensitivity 0.87, specificity 0.72, AUC 0.80 on b1000-DWI) than for the more experienced reader (sensitivity 0.63, specificity 0.75, AUC 0.70 on conventional MRI; sensitivity 0.76, specificity 0.77, AUC 0.77 on b500-DWI; sensitivity 0.85, specificity 0.72, AUC 0.79 on b1000-DWI), although the differences between the 2 observers were not statistically significant. Interobserver agreement resulted to be fair (κ = 0.30) when dealing with conventional MRI alone. The addition of b500-DWI and b1000-DWI to conventional MRI allowed to reach a substantial agreement (κ = 0.75). CONCLUSIONS: The combined interpretation of high b value DWI and conventional MRI provides increased sensitivity and diagnostic performance in detection of peritoneal carcinomatosis in oncologic patients.

Whole-body diffusion-weighted MRI for operability assessment in patients with colorectal cancer and peritoneal metastases.

BACKGROUND: Correct staging of patients with colorectal cancer is of utmost importance for the prediction of operability. Although computed tomography (CT) has a good overall performance, estimation of peritoneal cancer spread is a known weakness, a problem that cannot always be overcome by Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT); especially in infiltrative and miliary disease spread. Due to its high spatial and contrast resolution magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) might have a better performance. Our aim was to evaluate the added value of whole-body diffusion-weighted MRI (WB-DWI/MRI) to CT for prediction of peritoneal cancer spread and operability assessment in colorectal cancer patients with clinically suspected peritoneal carcinomatosis (PC). METHODS: This institutional review board approved retrospective study included sixty colorectal cancer patients who underwent WB-DWI/MRI in addition to CT for clinically suspected peritoneal metastases. WB-DWI/MRI and CT were assessed for detecting PC following the peritoneal cancer index (PCI), determination of PCI-score categorized as PC < 12, PCI = 12-15 and PCI > 15, detection of nodal and distant metastases and estimation of overall operability. Histopathology after surgery and biopsy and/or 6 months follow-up were used as reference standard. RESULTS: For detection of PC, CT had 43.2% sensitivity, 95.6% specificity, 84.5% positive predictive value (PPV) and 75.2% negative predictive value (NPV). WB-DWI/MRI had 97.8% sensitivity, 93.2% specificity, 88.9% PPV and 98.7% NPV. WB-DWI/MRI enabled better detection of inoperable distant metastases (all 12 patients) than CT (2/12 patients) and significantly improved prediction of PCI category [WB-DWI/MRI PCI < 12: 37/39 patients (94.9%); PCI = 12-15: 4/4 patients (100%); PCI > 15: 16/17 patients (94.1%) versus CT PCI < 12: 38/39 patients (97.4%); PCI = 12-15: 0/4 patients (0%); PCI > 15: 2/17 patients (11.8%); p < 0.0001)]. WB-DWI/MRI improved prediction of inoperability over CT with 90.6% sensitivity compared to 25% (p < 0.0001). CONCLUSIONS: WB-DWI/MRI significantly outperformed CT for estimation of spread of PC, overall staging and prediction of operability. Pending validation in larger prospective trials, WB-DWI/MRI could be used to guide surgical planning and minimize unnecessary exploratory laparotomies.

Preoperative assessment of peritoneal carcinomatosis of colorectal origin.

The goal of preoperative assessment of patients with peritoneal carcinomatosis (PC) from colorectal origin is to select candidates for curative surgery by evaluating the possibility of complete resection, and to plan the surgical procedure. Quantitative and qualitative evaluation of lesional localization remains difficult even with current technical progress in imaging. Computed tomography (CT), the reference imaging technique, allows detection of both peritoneal and extra-peritoneal lesions. Sensitivity and specificity for detecting PC are 83% (95%CI: 79-86%) and 86% (95%CI: 82-89%), respectively. Functional imaging, with diffusion-weighted magnetic resonance imaging (MRI) and positron emission tomography PET-CT allows efficient exploration of peritoneal lesions. MRI is operator-dependent, with a long learning curve, and is, at present, essentially used only in expert centers. A standardized protocol provided by the radiologists working with the French National Center for rare peritoneal tumors RENA-RAD (http://www.renape-online.fr/fr/espace-professionnel/rena-rad.html) is however available on line. PET-CT is particularly useful for identifying and defining extra-peritoneal disease. Combining imaging techniques, particular CT with MRI, seems to improve the calculation of the Peritoneal Cancer Index compared to CT alone. Surgical exploration is the reference technique to evaluate PC. Currently, the literature cannot confirm whether laparoscopy performs as well as laparotomy, but laparoscopy is, de facto, the fundamental tool to decrease the number of unnecessary laparotomies in these patients. To optimize the pre-, intra- and postoperative reporting of the extent of PC, the French National Network for management of PC (RENAPE and BIG-RENAPE: http://www.e-promise.org/) has offered on-line a free-of-charge, standardized, multidisciplinary and transversal software.

Computed Tomography Follow-Up Assessment of Patients with Low-Grade Appendiceal Mucinous Neoplasms: Evaluation of Risk for Pseudomyxoma Peritonei.

BACKGROUND: Low-grade appendiceal mucinous neoplasms are rare. Both classification and management vary. This study aimed to follow up on patients with a diagnosis of LAMN after primary surgery with computer tomography (CT) scans to examine the risk for the development of pseudomyxoma peritonei (PMP). METHODS: This population-based prospective study investigated patients who underwent appendectomy between 2007 and 2013 and had histology results demonstrating the presence of LAMN. The patients were followed up with a CT scan every 6 months for 2 years, until December 2015. RESULTS: The study investigated 41 patients (20 females) with a median age of 65 years (range 20-87 years). The entire appendix was processed and examined, with results showing that 12 were perforated, and 3 had a positive margin. Extra-appendiceal mucin on the surface of the appendix was found in ten cases, and in two cases, extra-mucinous epithelial cells were detected. During a median follow-up period of 5.1 years (range 2-8.6 years), none of the patients experienced the development of PMP. CONCLUSIONS: These data suggest that for patients with LAMN confined to the appendix, involvement of the appendectomy margin or perforation with mucin locally, even with epithelial cells, did not predict the development of PMP, and a conservative approach seems justified. No reoperation was needed, and regular follow-up evaluation with CT scans was sufficient.

External Validation of the Simplified Preoperative Assessment for Low-Grade Mucinous Adenocarcinoma of the Appendix.

BACKGROUND: MD Anderson Cancer Center developed a computed tomography (CT)-based preoperative assessment tool simplified preoperative assessment for appendix tumor (SPAAT) for predicting incomplete cytoreduction (IC) in low-grade mucinous adenocarcinoma (LGMA) of the appendix, based on preoperative CT scans. This study independently evaluates the tool's performance. METHODS: Seventy-six preoperative CT scans of LGMA patients were evaluated by two surgeons unfamiliar with the patients' medical history. Scores were assigned based on SPAAT criteria, with a SPAAT ≥3 predictive of IC. Binary regression analyses and area under the receiver operating characteristic (AUROC) curve analyses were performed. Patients with splenic resection were excluded due to the structure of the SPAAT assessment tool. RESULTS: Seventy-six LGMA patients underwent attempted cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). Of 68 patients, 58 had complete cytoreduction and 10 had IC; 8 patients were ineligible due to prior splenectomy. The mean SPAAT score was 0.8, with six patients having SPAAT scores ≥3. SPAAT scores ≥3 were predictive of IC, with a hazard ratio (HR) of 19 (95% confidence interval 2.8-124.1) (p = 0.002). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value were 40, 97, 50, and 90%, respectively. A SPAAT score ≥3 was not associated with worse survival prognosis. Median follow-up was 2.4 years and AUROC curve was 71%. SPAAT components with respective HR and p-values were foreshortening of the bowel mesentery (29.5; p = 0.004), and scalloping of the pancreas (9; p = 0.008), spleen (4.3; p = 0.04), portal vein (3.1; p = 0.4), and liver (2.1; p = 0.3). CONCLUSION: A SPAAT score ≥3 predicted IC based on a binary regression model. The clinical value of this score is controversial due to low sensitivity and PPV.

Fluid retention associated with imatinib treatment in patients with gastrointestinal stromal tumor: quantitative radiologic assessment and implications for management.

OBJECTIVE: We aimed to describe radiologic signs and time-course of imatinib-associated fluid retention (FR) in patients with gastrointestinal stromal tumor (GIST), and its implications for management. MATERIALS AND METHODS: In this Institutional Review Board-approved, retrospective study of 403 patients with GIST treated with imatinib, 15 patients with imaging findings of FR were identified by screening radiology reports, followed by manual confirmation. Subcutaneous edema, ascites, pleural effusion, and pericardial effusion were graded on a four-point scale on CT scans; total score was the sum of these four scores. RESULTS: The most common radiologic sign of FR was subcutaneous edema (15/15, 100%), followed by ascites (12/15, 80%), pleural effusion (11/15, 73%), and pericardial effusion (6/15, 40%) at the time of maximum FR. Two distinct types of FR were observed: 1) acute/progressive FR, characterized by acute aggravation of FR and rapid improvement after management, 2) intermittent/steady FR, characterized by occasional or persistent mild FR. Acute/progressive FR always occurred early after drug initiation/dose escalation (median 1.9 month, range 0.3-4.0 months), while intermittent/steady FR occurred at any time. Compared to intermittent/steady FR, acute/progressive FR was severe (median score, 5 vs. 2.5, p = 0.002), and often required drug-cessation/dose-reduction. CONCLUSION: Two distinct types (acute/progressive and intermittent/steady FR) of imatinib-associated FR are observed and each type requires different management.

A Simplified Preoperative Assessment Predicts Complete Cytoreduction and Outcomes in Patients with Low-Grade Mucinous Adenocarcinoma of the Appendix.

BACKGROUND: Complete cytoreduction with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has been shown to improve survival in patients with low-grade mucinous adenocarcinoma (LGMA). However, incomplete cytoreduction exposes patients to significant morbidity without a similar survival benefit. Preoperative assessment of the ability to achieve CRS is therefore a critical step in selecting patients for CRS/HIPEC. OBJECTIVE: The aim of this study was to develop and validate a preoperative scoring system to accurately predict the ability to achieve complete cytoreduction in patients with LGMA of the appendix. METHODS: A simplified preoperative assessment for appendix tumor (SPAAT) score was developed based on computed tomography scan findings thought to predict incomplete cytoreduction. We applied the SPAAT score to patients with LGMA to determine the ability of the score to predict complete cytoreduction. This scoring system was then applied to a separate cohort of patients from a different institution. Sensitivity and specificity were determined for the SPAAT score. Survival was calculated and correlated with the SPAAT score and the completeness of cytoreduction score. RESULTS: A SPAAT score of <3 is a significant predictor of complete cytoreduction in the derivation cohort. In the validation cohort, 40 of 42 patients with a SPAAT score <3 achieved a complete cytoreduction, for a positive predictive value of 95.2 % and a negative predictive value of 100 %. Additionally, the SPAAT score was a significant predictor of disease-free survival. CONCLUSIONS: The SPAAT score is a useful tool in the preoperative assessment of patients with LGMA who are under consideration for cytoreductive surgery. Prospective analysis of this scoring system is warranted to appropriately select patients who will benefit from CRS/HIPEC.

Assessment of surgical resectability of pancreatic adenocarcinomas with multidetector computed tomography: what are the possibilities and problems?

BACKGROUND/AIMS: To investigate the accuracy of multidetector computed tomography (MDCT) in preoperatively determining the surgical resectability of pancreatic adenocarcinomas. MATERIALS AND METHODS: Multidetector computed tomography, surgery, and pathological results of 274 patients with pancreatic adenocarcinoma were evaluated retrospectively. MDCT findings were compared with surgical and pathological findings to determine the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MDCT in determining surgical resectability. RESULTS: A total of 124 of 274 (56%) patients (83 males, mean age: 60 years) underwent laparoscopy and/or laparotomy. The sensitivity, specificity, PPV, NPV, and accuracy of MDCT in determining the surgical resectability of pancreatic adenocarcinomas were 100%, 72%, 78%, 100%, and 86%, respectively. Liver metastases in 9 cases, peritoneal metastases in 3 cases, and vascular invasion in 5 cases, which were determined during surgery, were not reported by MDCT. On re-review of the MDCT images of these 17 patients, no metastatic lesions could be seen in 9 patients with liver metastases and in 2 of 3 patients with peritoneal metastases. In 1 patient, a peritoneal implant of a diameter of 8 mm was missed on MDCT. There was no vascular invasion according to Lu criteria on the MDCT images in the 5 cases that had vascular invasion in the surgical exploration. CONCLUSION: The accuracy of MDCT is high in the preoperative determination of surgical resectability of pancreatic adenocarcinomas, but the detection of small liver and peritoneal metastases and accurate determination of vascular invasion are still major problems. Surgeons should be aware of the limitations of preoperative MDCT.

Preoperative assessment of peritoneal carcinomatosis: intraindividual comparison of 18F-FDG PET/CT and MRI.

OBJECTIVE: Exact determination of localization and extent of peritoneal carcinomatosis (PC) before peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) is crucial for the clinical outcome. Our study compares dynamic contrast enhanced 3D MRI (T1wDCE) and 18F-FDG PET/CT regarding diagnostic accuracy in correlation with surgical exploration (SE) and histological (HI) results. MATERIALS AND METHODS: 15 patients with PC were examined on a 1.5T MRI and 16 slice PET/CT. MRI: coronal T1wDCE covering the complete abdomen (0.15 mmol Gd-chelate/kg BW, 2000 mL mannitol solution p.o., 40 mg buscopan i.v.). PET-CT: contrast enhanced 16slice CT (120 mL ultravist 370 i.v., 1000 mL mannitol solution p.o., 40 mg buscopan i.v.), PET: 350 MBq 18-FDG i.v., 3 min acquisition time/bed, 60 min after tracer injektion). Assessment by two independent, experienced observers in correlation with results of SE and HI for each abdominal segment based on the peritoneal cancer index (PCI) proposed by Sugarbaker and co-authors. RESULTS: MRI and PET/CT provided reliable detection of PC. One patient had to be excluded from statistical analysis. In summary, 182 segments were assessed (13/patient, 14 patients, one patient excluded from statistical analysis). PC was found in 118 by MRI, 124 by PET/CT. 4 segments were classified false positive for MRI, 2 for PET/CT. False negative segments (MRI: 17, PET/CT: 9) did not result in irresectability. Positive predictive value for PC/segment was 97/98%, negative predictive value 73/84%, sensitivity 87/93%, specificity 92/96%, and diagnostic accuracy 88/94% (MRI/PET/CT). CONCLUSION: With high diagnostic accuracy for PC of both, MRI and PET/CT, PET/CT provides better diagnostic accuracy and especially better NPV.

CT-Enteroclysis in the preoperative assessment of the small-bowel involvement in patients with peritoneal carcinomatosis, candidates for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

PURPOSE: To assess the performance of CT-Enteroclysis (CTE) in the preoperative evaluation of the small bowel (SB) involvement in patients with peritoneal carcinomatosis (PC), candidates for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). MATERIAL AND METHODS: In this prospective study, 48 consecutive patients (37 women, 11 men, mean age: 57.02 years) with PC of different primaries, eligible for cytoreductive surgery and HIPEC underwent CTE before surgery. Lesions were gathered according to their location (SB wall or mesentery), distribution (jejunum/ileum, proximal/distal) and lesion size (LS, where LS0 is the absence of disease, LS1 < 1 cm, LS < 1-5 cm, and LS3 > 5 cm in maximal diameter). The preoperative CTE classification was correlated with surgical scoring of PC in the SB. RESULTS: CTE was found to have sensitivity 92%, specificity 96%, PPV 97%, NPV 91%, in assessing PC in the SB/mesentery. CTE exhibited "excellent" agreement with surgical classification of disease extent (overall kappa-weighted coefficient of agreement (κ (w)) was 0.962). Patients (n = 6) found inoperable at surgery manifested extensive plaque-like cover of the SB wall/mesentery on CTE. CONCLUSIONS: CTE may be considered a reliable imaging technique for the preoperative evaluation of the extent and distribution of PC in the SB/mesentery in order to assist surgical planning or to prevent unnecessary surgery.

Recurrent endometrial cancer: patterns of recurrent disease and assessment of prognosis.

AIM: To evaluate patterns of disease and identify factors predicting outcome in patients presenting with recurrent endometrial adenocarcinoma following primary surgery. MATERIALS AND METHODS: A retrospective review was performed of the imaging and clinical data in 86 patients (median age 66 years, range 42-88 years) presenting with recurrent endometrial adenocarcinoma following primary surgery. RESULTS: Following primary surgery recurrent disease occurred within 2 years in 64% and within 3 years in 87%. Relapse was seen within lymph nodes in 41 (46%), the vagina in 36 (42%) the peritoneum in 24 (28%) and the lung in 21 (24%). Unusual sites of disease included spleen, pancreas, rectum, muscle and brain. Univariate survival analysis showed the factors significant for poor outcome were: multiple sites of disease, liver and splenic disease, haematogenous, peritoneal and nodal spread, poorly differentiated tumour, and early relapse. The presence of disease within the vagina, bladder or lung was not associated with poor prognosis. Multivariate analysis identified multiple sites of disease, liver and splenic metastases to be independent predictors of poor outcome. CONCLUSION: The most frequently observed sites of relapse are: lymph nodes, vagina, peritoneum and lung. Significant predictors of poor outcome in recurrent disease are multiple sites of disease and liver and splenic metastases.

Abdominal and pelvic CT for detection and volume assessment of peritoneal sarcomatosis.

OBJECTIVE: Peritoneal sarcomatosis is a common finding in patients with recurrent abdominal or pelvic sarcoma. CT of the abdomen and pelvis is the standard radiological examination for evaluation of tumor volume and location in the peritoneal cavity; however data regarding the reliability of recurrent sarcoma detection has not been available. The purpose of this study was to evaluate the sensitivity of CT in detecting recurrent peritoneal sarcomatosis. METHODS: Abdominal and pelvic CT scans of 33 patients with abdominal or pelvic sarcoma recurrence were retrospectively reviewed. Subsequently all patients underwent surgery at which time complete exploration of the abdomen and pelvis was performed. Twenty-five CT parameters were evaluated and statistically analyzed using the findings at surgery as a standard. RESULTS: Among the anatomic sites, the lesser omentum and the Douglas pouch showed a sensitivity of 100%. In the nine abdominopelvic regions sensitivity was greater than 85% in the central region, the left lower quadrant and the pelvis. In all regions and sites, the pelvis and Douglas pouch showed the highest accuracy (91%). The volume of tumor present within an abdominopelvic region influenced the sensitivity. A sensitivity of 72.5% was recorded when tumor nodules were less than 0.5 cm in diameter. This increased to 90% when tumor diameter was greater than 5 cm. CONCLUSIONS: Abdominal and pelvic CT is a reliable test to evaluate recurrent sarcoma. The nodules in the pelvis were most accurately detected. Even small nodules of 0.5 cm were detected; the sensitivity increased as the nodules became greater than 5 cm.