Diagnostic accuracy of 18F-FDG PET/CT for detection of peritoneal carcinomatosis; a systematic review and meta-analysis

Comparison of 68 Ga-FAPI-04 PET/CT with 18 F-FDG PET/CT for diagnosis and staging of gastric and colorectal cancer

OBJECTIVE

The objective of this study is to evaluate the effectiveness of 68 Ga-FAPI-04 PET/computed tomography (CT) for the diagnosis of primary and metastatic gastric cancer and colorectal cancer lesions as compared with 18 F-FDG PET/CT.

MATERIALS AND METHODS

Fifty-nine patients who underwent both 18 F-FDG and 68 Ga-FAPI-04 for initial staging or restaging were enrolled. Histopathological findings and clinical imaging follow-up were used as the reference standard. The diagnostic performance and TNM staging of the two tracers were calculated and compared. The maximum standardized uptake value (SUV max ), tumour-to-mediastinal blood pool ratio (TBR) (lesions SUV max /ascending aorta SUV mean ), and tumour-to-normal liver parenchyma ratio (TLR) (lesions SUV max /liver SUV mean ) of primary and metastatic lesions between two imaging modalities were measured and compared using the Wilcoxon signed-rank test and paired t -test.

RESULTS

The two imaging agents are comparable for the detection of primary tumors. The sensitivity of 68 Ga-FAPI-04 PET/CT was higher than that of 18 F-FDG PET/CT for detecting lymph node metastases, peritoneal metastases, liver metastases, and bone metastases. In the patient-based analysis, the TLR for all lesions was significantly higher with 68 Ga-FAPI-04 PET/CT than with 18 F-FDG PET/CT (all P  < 0.05). The accuracy (92.2 vs. 70.3%, P  = 0.002) and sensitivity of 68 Ga-FAPI-04 were significantly higher than that of 18 F-FDG (78.6 vs. 71.4%, P  = 0.011) in determining the lymph node status. 68 Ga-FAPI-04 has a higher accuracy in staging ( P  = 0.041), which is mainly due to the ability of distant metastases detection.

CONCLUSION

68 Ga-FAPI-04 PET/CT may be superior in evaluating the diagnostic efficiency and staging accuracy of gastric and colorectal cancer.

Diagnostic accuracy and clinical value of [68Ga]Ga-FAPI-46 PET/CT for staging patients with ovarian cancer: study protocol for a prospective clinical trial

BACKGROUND

[18F]Fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) is recommended during diagnostic work-up for ovarian cancer; however, [18F]FDG PET has several inherent limitations. The novel oncologic PET-tracer fibroblast activation protein inhibitor (FAPI) has demonstrated promising results in multiple cancer types, including ovarian cancer, and could overcome the limitations of [18F]FDG PET; however, high-quality clinical studies are lacking. The primary objective of the present study is to compare the diagnostic accuracy of [68Ga]Ga-FAPI-46 PET/CT and [18F]FDG PET/CT in ovarian cancer patients and to investigate how this potential difference impacts staging and patient management.

METHODS AND DESIGN

Fifty consecutive ovarian cancer patients will be recruited from Aalborg University Hospital, Denmark. This study will be a single-center, prospective, exploratory clinical trial that adheres to the standards for reporting diagnostic accuracy studies (STARD). This study will be conducted under continuous Good Clinical Practice monitoring. The eligibility criteria for patients are as follows: (1) biopsy verified newly diagnosed ovarian cancer or a high risk of ovarian cancer and referred for primary staging with [18F]FDG PET/CT; and (2) resectable disease, i.e., candidate for primary debulking surgery or neoadjuvant chemotherapy followed by interval debulking surgery. All recruited study subjects will undergo [68Ga]Ga-FAPI-46 PET/CT at primary staging, before primary debulking surgery or neoadjuvant chemotherapy (Group A + B), in addition to conventional imaging (including [18F]FDG PET/CT). Study subjects in Group B will undergo an additional [68Ga]Ga-FAPI-46 PET/CT following neoadjuvant chemotherapy prior to interval debulking surgery. The results of the study-related [68Ga]Ga-FAPI-46 PET/CTs will be blinded, and treatment allocation will be based on common clinical practice in accordance with current guidelines. The histopathology of surgical specimens will serve as a reference standard. A recruitment period of 2 years is estimated; the trial is currently recruiting.

DISCUSSION

To our knowledge, this trial represents the largest, most extensive, and most meticulous prospective FAPI PET study conducted in patients with ovarian cancer thus far. This study aims to obtain a reliable estimation of the diagnostic accuracy of [68Ga]Ga-FAPI-46 PET/CT, shed light on the clinical importance of [68Ga]Ga-FAPI-46 PET/CT, and examine the potential applicability of [68Ga]Ga-FAPI-46 PET/CT for evaluating chemotherapy response.

TRIAL REGISTRATION

clinicaltrials.gov: NCT05903807, 2nd June 2023; and euclinicaltrials.eu EU CT Number: 2023-505938-98-00, authorized 11th September 2023.

Do PET-positive supradiaphragmatic lymph nodes predict overall survival or the success of primary surgery in patients with advanced ovarian cancer?

OBJECTIVES

Compared to conventional computed tomography (CT), fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) detects higher rates of lymph node and distant metastases in patients with ovarian cancer. However, FDG-PET/CT is not routinely performed during preoperative work-up. Therefore, we investigated the prognostic value of preoperative FDG-PET/CT in advanced epithelial ovarian cancer (EOC) and its predictive value for surgical resection in patients with no residual disease. The potential significance of PET-positive supradiaphragmatic lymph nodes (SDLNs) for these parameters was evaluated.

METHODS

All patients with FIGO IIA-IVB EOC diagnosed between March 2014 and January 2021 at our certified gynaecological cancer centre, who underwent FDG PET/CT before primary surgery were retrospectively included.

RESULTS

Fifty-three consecutive patients were included in the study. Eighteen (34 %) patients had PET-positive SDLNs. We could not demonstrate a significant correlation between PET-positive SDLNs and median overall survival (OS; SDLN-positive: 58.76 months, SDLN-negative: 60.76 months; p = 0.137) or intra- or perioperative outcomes.

CONCLUSIONS

FDG PET/CT has a higher detection rate for SDLNs in patients with ovarian cancer than CT has, as described in the literature. Moreover, PET-positive SDLNs failed to predict intraoperative outcomes or overall survival.

The OCDA-Net: a 3D convolutional neural network-based system for classification and staging of ovarian cancer patients using [18F]FDG PET/CT examinations

OBJECTIVE

To create the 3D convolutional neural network (CNN)-based system that can use whole-body [18F]FDG PET for recurrence/post-therapy surveillance in ovarian cancer (OC).

METHODS

In this study, 1224 image sets from OC patients who underwent whole-body [18F]FDG PET/CT at Kowsar Hospital between April 2019 and May 2022 were investigated. For recurrence/post-therapy surveillance, diagnostic classification as cancerous, and non-cancerous and staging as stage III, and stage IV were determined by pathological diagnosis and specialists' interpretation. New deep neural network algorithms, the OCDAc-Net, and the OCDAs-Net were developed for diagnostic classification and staging of OC patients using [18F]FDG PET/CT images. Examinations were divided into independent training (75%), validation (10%), and testing (15%) subsets.

RESULTS

This study included 37 women (mean age 56.3 years; age range 36-83 years). Data augmentation techniques were applied to the images in two phases. There were 1224 image sets for diagnostic classification and staging. For the test set, 170 image sets were considered for diagnostic classification and staging. The OCDAc-Net areas under the receiver operating characteristic curve (AUCs) and overall accuracy for diagnostic classification were 0.990 and 0.92, respectively. The OCDAs-Net achieved areas under the receiver operating characteristic curve (AUCs) of 0.995 and overall accuracy of 0.94 for staging.

CONCLUSIONS

The proposed 3D CNN-based models provide potential tools for recurrence/post-therapy surveillance in OC. The OCDAc-Net and the OCDAs-Net model provide a new prognostic analysis method that can utilize PET images without pathological findings for diagnostic classification and staging.

A novel risk model for predicting peritoneal metastasis in colorectal cancer based on the SEER database

BACKGROUND

Early detection and intervention could significantly improve the prognosis of patients with peritoneal metastasis (PM). Our main purpose was to develop a model to predict the risk of PM in patients with colorectal cancer (CRC).

METHODS

Patients from the Surveillance, Epidemiology, and End Results (SEER) database with CRC classified according to the AJCC 8th TNM staging system were selected for the study. After data pre-processing, the dataset was divided into a training set and a validation set. In the training set, univariate logistic analysis and stepwise multivariate logistic regression analysis were utilized to screen clinical features and construct a risk prediction model. Then, we validated the model using the confusion matrix, receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and calibration curves to examine its performance.

RESULTS

The model constructed using stepwise multivariate logistic regression analysis incorporated the following eight clinical features: age, tumor location, histological type, T stage, carcinoembryonic antigen (CEA) level, tumor deposits (TDs), log odds (LODDS) of metastatic lymph nodes, and extraperitoneal metastasis (EM). The areas under the curve (AUCs) of the model in the training and validation sets were 0.924 and 0.912, respectively. The accuracy and the recall ratio were higher than 0.8 in both cohorts. DCA and the calibration curves also confirmed its excellent predictive power.

CONCLUSIONS

Our model can effectively predict the risk of PM in CRC patients, which is of great significance for the timely identification of patients at high risk of PM and further clinical decision-making.

Postoperative peritoneal inflammatory granuloma mimicking peritoneal metastasis in a patient with breast cancer: a case report

Peritoneal metastasis from breast cancer is a relatively rare life-threatening condition. The gold standard for diagnosing peritoneal metastasis is a direct peritoneal biopsy. In this report, we describe an interesting case of peritoneal inflammation mimicking peritoneal metastasis in a patient with breast cancer, as confirmed by laparoscopic peritoneal biopsy. A 45-year-old woman with a history of right breast cancer presented with a peritoneal wall mass seen on an abdominal computed tomography (CT) in routine follow-up. She underwent right skin-sparing mastectomy with sentinel lymph node biopsy with direct to implant reconstruction 6 years prior and underwent right salpingo-oophorectomy 2 years before. Positron emission tomography-computed tomography (PET-CT) and abdominopelvic CT showed multiple enhancing nodules in small bowel mesentery and right peritoneal wall with a small amount of ascites, which led to a strong suspicion of peritoneal metastasis. After a multidisciplinary conference, the possibility of peritoneal seeding became doubtful. Laparoscopic biopsy was performed, and peritoneal wall mass biopsy was subsequently performed. Pathologic results showed no evidence of peritoneal metastasis of breast cancer. The peritoneal biopsy specimen revealed postoperative fibrosis and inflammation with some meal content. Although rare in breast cancer, peritoneal metastasis can produce a devastating outcome if left undiagnosed. Despite the imaging findings strongly suggesting metastasis, biopsy confirmation for the suspected lesion was necessary. This not only verifies true metastasis but also determines the treatment options available for the patient and thus unnecessary treatment can be avoided.

Unravelling Peritoneal Carcinomatosis Using Cross-Sectional Imaging Modalities

Peritoneal carcinomatosis (PC) refers to malignant epithelial cells that spread to the peritoneum, principally from abdominal malignancies. Until recently, PC prognosis has been considered ill-fated, with palliative therapies serving as the only treatment option. New locoregional treatments are changing the outcome of PC, and imaging modalities have a critical role in early diagnosis and disease staging, determining treatment decision making strategies. The aim of this review is to provide a practical approach for detecting and characterizing peritoneal deposits in cross-sectional imaging modalities, taking into account their appearances, including the secondary complications, the anatomical characteristics of the peritoneal cavity, together with the differential diagnosis with other benign and malignant peritoneal conditions. Among the cross-sectional imaging modalities, computed tomography (CT) is widely available and fast; however, magnetic resonance (MR) performs better in terms of sensitivity (92% vs. 68%), due to its higher contrast resolution. The appearance of peritoneal deposits on CT and MR mainly depends on the primary tumour histology; in case of unknown primary tumour (3-5% of cases), their behaviour at imaging may provide insights into the tumour origin. The timepoint of tumour evolution, previous or ongoing treatments, and the peritoneal spaces in which they occur also play an important role in determining the appearance of peritoneal deposits. Thus, knowledge of peritoneal anatomy and fluid circulation is essential in the detection and characterisation of peritoneal deposits. Several benign and malignant conditions show similar imaging features that overlap those of PC, making differential diagnosis challenging. Knowledge of peritoneal anatomy and primary tumour histology is crucial, but one must also consider clinical history, laboratory findings, and previous imaging examinations to achieve a correct diagnosis. In conclusion, to correctly diagnose PC in cross-sectional imaging modalities, knowledge of peritoneal anatomy and peritoneal fluid flow characteristics are mandatory. Peritoneal deposit features reflect the primary tumour characteristics, and this specificity may be helpful in its identification when it is unknown. Moreover, several benign and malignant peritoneal conditions may mimic PC, which need to be considered even in oncologic patients.

Comparison of the role of 18 F-fluorodeoxyglucose PET/computed tomography and 68 Ga-labeled FAP inhibitor-04 PET/CT in patients with malignant mesothelioma

OBJECTIVE

In this study, we aimed to compare the role of 68 Ga-labeled FAP inhibitor ( 68 Ga-FAPI)-04 PET/computed tomography (CT) and 18 F-fluorodeoxyglucose ( 18 F-FDG) PET/CT in the evaluation of primary tumor and metastases in patients diagnosed with malignant mesothelioma.

MATERIALS AND METHODS

Our prospective study included 21 patients with histopathological diagnosis of malignant mesothelioma who underwent both 68 Ga-FAPI-04 PET/CT and 18 F-FDG PET/CT imaging between April 2022 and September 2022. Maximum standardized uptake value (SUVmax), metabolic tumor volume, total lesion glycolysis, tumor-to-background ratio (TBR) and highest SUVpeak (HPeak) values and lesion numbers were calculated from primary and metastatic lesions on FDG and FAPI PET/CT images. Findings obtained from FAPI and FDG PET/CT were compared.

RESULTS

More lesions were detected in 68 Ga-FAPI-04 PET/CT compared to 18 F-FDG PET/CT in primary tumor and lymph node metastases. Statistically significantly higher SUVmax and TBR values were found with FAPI PET/CT (primary lesion SUVmax and TBR, P  = 0.001 and P  < 0.001, respectively; lymph node SUVmax and TBR, P  = 0.016 and P  = 0.005, respectively). With FAPI PET/CT, upstage was observed according to tumor-node-metastasis staging in a total of seven patients including three patients with pleural origin, three patients with peritoneal origin and one patient with pericardial origin.

CONCLUSION

In addition to the stage change with 68 Ga-FAPI-04 PET/CT in malignant mesothelioma patients, a statistically significant superiority was observed in SUVmax, TBR and volumetric parameters in primary tumors and metastases.

Head-To-Head Comparison of 68Ga-FAPI PET/CT and FDG PET/CT for the Detection of Peritoneal Metastases: Systematic Review and Meta-Analysis

BACKGROUND. FDG PET/CT has limited diagnostic performance in the detection of peritoneal metastasis (PM). Gallium-68-labeled fibroblast activation protein inhibitor (FAPI) targets tumor stroma, leading to high accumulation across cancer types. OBJECTIVE. The purpose of this study was to conduct a meta-analysis to compare the diagnostic performances of ⁶⁸Ga-FAPI PET/CT and FDG PET/CT in detecting PM on the basis of studies providing head-to-head comparisons between the two tests. EVIDENCE ACQUISITION. PubMed, Embase, and Cochrane Library databases were searched through July 2022 to identify studies reporting head-to-head comparison of ⁶⁸Ga-FAPI PET/CT and FDG PET/CT for detection of PM. The reference standard was classified as histopathology for all patients or as a combination of histopathologic, clinical, imaging, laboratory, and follow-up information (multidisciplinary reference standard). A random-effects statistical model was applied to conduct a meta-analysis of the diagnostic performances of the tests in patient-based and lesion-based analyses. The QUADAS-2 and QUADAS Comparative tools were used to assess study quality. EVIDENCE SYNTHESIS. Eleven studies were included. Patient-based analysis was reported in nine studies including 340 patients, and lesion-based analysis was reported in four studies including 222 lesions. The pooled sensitivity of ⁶⁸Ga-FAPI PET/CT was significantly higher than that of FDG PET/CT in patient-based analysis (98.2% [95% CI, 96.1-100.0%] vs 55.9% [95% CI, 33.9-77.9%]) and lesion-based analysis (99.9% [95% CI, 99.5-100.0%] vs 27.3% [95% CI, 11.2-43.4%]). Eight studies were rated at high risk of bias in the reference standard domain because the multidisciplinary reference standard was not sufficiently explained and may have included one of the two index tests, which would have artificially increased sensitivity. In three studies specificity was reported as 100.0% for both tests; these studies were considered at uncertain risk of bias in the patient selection domain because patients with benign peritoneal conditions may have been excluded, resulting in underestimation of potential false-positive results. CONCLUSION. The current evidence suggests excellent sensitivity of ⁶⁸Ga-FAPI PET/CT for the detection of PM in comparison with poorer sensitivity of FDG PET/CT. However, most included studies had high risk of bias. Further studies are needed to more convincingly characterize true- and false-positive results. CLINICAL IMPACT. The sensitivity of ⁶⁸Ga-FAPI PET/CT may be substantially greater than that of FDG PET/CT for the evaluation of PM, facilitating surgical planning and candidate selection.

Radiologic staging of peritoneal and retroperitoneal disease

Peritoneal and retroperitoneal tumors consist of a heterogenous group of benign and malignant lesions of different origin. Due to often complex multidisciplinary treatment concepts in patients with peritoneal surface malignancies radiological imaging plays a pivotal role regarding the therapeutic options. Moreover, tumor entity, abdominal tumor distribution and common as well as rare differential diagnoses have to be taken into account. Using different radiological modalities non-invasive pretherapeutic diagnostics might be significantly improved. KEY POINTS::   · Diagnostic CT is a valuable part of the initial diagnostic approach to peritoneal surface malignancies.. · Sensitivity might be increased by the additional use of dwMRI and PET/CT considering tumor entity and individual diagnostic issues.. · The Peritoneal Cancer Index (PCI) should be determined independent of radiologic modality.. CITATION FORMAT: · Glockzin G, Helmberger T. Radiologic staging of peritoneal and retroperitoneal disease. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1999-7057.

Development of the Peritoneal Metastasis: A Review of Back-Grounds, Mechanisms, Treatments and Prospects

Peritoneal metastasis is a malignant disease which originated from several gastrointestinal and gynecological carcinomas and has been leading to a suffering condition in patients for decades. Currently, as people have gradually become more aware of the severity of peritoneal carcinomatosis, new molecular mechanisms for targeting and new treatments have been proposed. However, due to the uncertainty of influencing factors involved and a lack of a standardized procedure for this treatment, as well as a need for more clinical data for specific evaluation, more research is needed, both for preventing and treating. We aim to summarize backgrounds, mechanisms and treatments in this area and conclude limitations or new aspects for treatments.

Utility of [68Ga]FAPI-04 and [18F]FDG dual-tracer PET/CT in the initial evaluation of gastric cancer

Objectives

We aimed to investigate the role of [68Ga]FAPI-04 and [18F]FDG dual-tracer PET/CT for the initial assessment of gastric cancer and to explore the factors associated with their uptake.

Methods

This study enrolled 62 patients with histopathologically confirmed gastric cancer. We compared the diagnostic performance of [68Ga]FAPI-04, [18F]FDG, and combined dual-tracer PET/CT. The standardized uptake value (SUV) and tumor-to-background ratio (TBR) were also measured, and the factors that influence tracer uptake were analyzed.

Results

[68Ga]FAPI-04 PET/CT detected more primary lesions (90.3% vs 77.4%, p = 0.008) and peritoneal metastases (91.7% vs 41.7%, p = 0.031) and demonstrated higher SUVmax and TBR values (p < 0.001) of primary lesions compared to [18F]FDG PET/CT. Dual-tracer PET/CT significantly improved the diagnostic sensitivity for the detection of distant metastases, compared with stand-alone [18F]FDG (97.1% vs 73.5%, p = 0.008) or [68Ga]FAPI-04 (97.1% vs 76.5%, p = 0.016) PET/CT. Subsequently, treatment strategies were changed in nine patients following [68Ga]FAPI-04 and [18F]FDG dual-tracer PET/CT. Nevertheless, [68Ga]FAPI-04 uptake was primarily influenced by the size and invasion depth of the tumor. Both [68Ga]FAPI-04 and [18F]FDG PET/CT showed limited sensitivity for detecting early gastric cancer (EGC) (37.5% vs 25.0%, p > 0.05).

Conclusions

In this initial study, [68Ga]FAPI-04 and [18F]FDG dual-tracer PET/CT were complementary and improved sensitivity for the detection of distant metastases pre-treatment in gastric cancer and could improve treatment stratification in the future. [68Ga]FAPI-04 had limited efficacy in detecting EGC.

Key Points

•[68Ga]FAPI-04 and[18F]FDG dual-tracer PET/CT are complementary to each other for improving diagnostic sensitivity in the initial evaluation of distant metastases from gastric cancer.

•[68Ga]FAPI-04 PET/CT showed limited sensitivity in detecting EGC.

• Need for further validation in a larger multi-centre prospective study.

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

Prospective Comparison of 68Ga-FAPI versus 18F-FDG PET/CT for Tumor Staging in Biliary Tract Cancers

Background Gallium 68-labeled fibroblast-activation protein inhibitor (⁶⁸Ga-FAPI), an imaging agent for detecting tumors, represents a promising alternative to fluorine 18 fluorodeoxyglucose (¹⁸F-FDG). Purpose To compare the potential efficacy of ⁶⁸Ga-FAPI PET/CT with that of ¹⁸F-FDG PET/CT for detecting primary tumor and nodal and distant metastases in biliary tract cancer (BTC) and to explore the impact (tumor staging) of ⁶⁸Ga-FAPI compared with ¹⁸F-FDG on clinical management of BTC. Materials and Methods This single-center prospective clinical study was performed at the Affiliated Hospital of Southwest Medical University between June 2020 and June 2021. Participants with BTC underwent both ⁶⁸Ga-FAPI and ¹⁸F-FDG PET/CT. Histopathologic examination, morphologic imaging, and/or follow-up imaging served as the reference standard. The maximum standardized uptake value (SUV_max) of the primary tumor and nodal and distant metastases between ¹⁸F-FDG and ⁶⁸Ga-FAPI PET/CT were compared using the paired-sample t test. Results Eighteen participants with primary or recurrent BTC were evaluated (mean age, 61 years ± 10 [SD]). The sensitivity of ⁶⁸Ga-FAPI PET/CT was higher than that of ¹⁸F-FDG PET/CT for detecting primary tumors (16 of 16 [100%] vs 13 of 16 [81%]), nodal metastases (41 of 42 [98%] vs 35 of 42 [83%]), and distant metastases (99 of 99 [100%] vs 78 of 99 [79%]). ⁶⁸Ga-FAPI PET/CT resulted in new oncologic findings in 10 of 18 participants and upgraded tumor staging or restaging in five of 18 participants compared with ¹⁸F-FDG PET/CT. ⁶⁸Ga-FAPI PET/CT demonstrated higher sensitivity than ¹⁸F-FDG PET/CT in inflammatory processes secondary to tumor-related obstruction (seven of eight [88%] vs one of eight [13%]). ⁶⁸Ga-FAPI showed lower average SUV_max in inflammatory processes than in oncologic lesions (4.9 ± 2.6 vs 10.0 ± 4.6, respectively; P = .003). Conclusion Gallium 68-labeled fibroblast-activation protein inhibitor PET/CT for tumor staging showed potential for more accurate staging of biliary tract cancer, thereby improving treatment decision making. Clinical trial registration no. ChiCTR2100044131 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Choyke in this issue.

Comparison of [68 Ga]Ga-DOTA-FAPI-04 PET/CT and [18F]FDG PET/CT in colorectal cancer

AIM

In this study, we aimed to evaluate the diagnostic sensitivity of [⁶⁸ Ga]Ga-DOTA-FAPI-04 PET/CT in the evaluation of primary or recurrent tumor, and nodal, peritoneal, and distant organ metastases in patients with newly diagnosed or relapsed colorectal cancer (CRC) in comparison with [¹⁸F]FDG PET/CT.

MATERIALS AND METHOD

Thirty-nine patients with histopathologically confirmed primary or relapsed CRC were included in our study. All patients underwent both [¹⁸F]FDG and [⁶⁸ Ga]Ga-DOTA-FAPI-04 PET/CT imaging in the same week. Primary lesions, lymph nodes, and metastatic lesions were recorded on both scans. SUVmax and background values were measured from the primary and metastatic lesions; tumor-to-background ratio (TBR) was calculated and compared. The results of the operation were compared with PET findings in patients who underwent surgical treatment without neoadjuvant chemotherapy (NAC).

RESULTS

The sensitivity and specificity of [⁶⁸ Ga]Ga-DOTA-FAPI-04 PET/CT in the evaluation of primary tumors were 100%, while the sensitivity of [¹⁸F]FDG PET/CT was 100% and its specificity was 85.3%. When evaluated with surgical results in the detection of lymph nodes, [⁶⁸ Ga]Ga-DOTA-FAPI-04 PET/CT had a sensitivity of 90% and a specificity of 100%, whereas [¹⁸F]FDG PET/CT had a sensitivity of 80% and a specificity of 81.8%. The sensitivity and specificity of [⁶⁸ Ga]Ga-DOTA-FAPI PET/CT for peritoneal implants were 100%, and the sensitivity of [¹⁸F]FDG PET/CT was 55%. The SUVmax of primary lesions was higher with [¹⁸F]FDG (p < 0.001), while TBR was higher in [⁶⁸ Ga]Ga-DOTA-FAPI PET/CT than [¹⁸F]FDG PET/CT (p: 0.008). SUVmax and TBR of the lymph nodes were significantly higher in [⁶⁸ Ga]Ga-DOTA-FAPI PET/CT than [¹⁸F]FDG PET/CT (p < 0.001 for both).

CONCLUSION

[⁶⁸ Ga]Ga-DOTA-FAPI-04 PET/CT achieved much higher sensitivity and specificity in the detection of primary lesions, and especially the lymph nodes and peritoneal metastases, suggesting that it can be employed in the assessment of primary tumor and metastases in patients with CRC in routine clinical practice.

Peritoneal malignancy: anatomy, pathophysiology and an update on modern day imaging

With increasing subspecialised experience in radical cytoreductive surgery and intra-abdominal chemotherapy for peritoneal malignancy, outcomes have improved significantly in selected patients. The surgery and the treatment regimens are radical and therefore correct patient selection is critical. The radiologist plays a central role in this process by estimating, as precisely as possible, the pre-treatment disease burden. Because of the nature of the disease process, accurate staging is not an easy task. Tumour deposits may be very small and in locations where they are very difficult to detect. It must be acknowledged that no form of modern day imaging has the capability of detecting the smallest peritoneal nodules, which may only be visible to direct inspection or histopathological evaluation. Nonetheless, it behoves the radiologist to be as exact and precise as possible in the reporting of this disease process. This is both to select patients who are likely to benefit from radical treatment, and just as importantly, to identify patients who are unlikely to achieve adequate cytoreductive outcomes. In this review, we outline the patterns of spread of disease and the anatomic basis for this, as well as the essential aspects of reporting abdominal studies in this patient group. We provide an evidence-based update on the relative strengths and limitations of our available multimodality imaging techniques namely CT, MRI and positron emission tomography/CT.

Performances of 18F-FDOPA PET/CT in the Preoperative Evaluation of the Peritoneal Cancer Index in Small Intestine Neuroendocrine Tumors

PURPOSE

Peritoneal carcinomatosis (PC) concerns up to 30% of patients with a neuroendocrine tumor (NET), especially of the small intestine. Aggressive management of carcinomatosis seems to be justified, especially with regard to possible mechanical complications. 18F-FDOPA PET/CT is known to be the most sensitive imaging modality for the detection of small bowel NET metastases, yet its performance in the detection of PC is not well studied. The main objective of our study is to evaluate the performances of preoperative 18F-FDOPA PET/CT in the prediction of surgical peritoneal cancer index.

METHODS

All patients referred to our center for an 18F-FDOPA PET/CT from October 2017 to January 2021 were retrospectively screened. Images were analyzed by a blinded nuclear medicine physician, and peritoneal abnormalities were reported to comply with the surgical peritoneal cancer index standard. Per patient analysis and per region analysis were then conducted.

RESULTS

Thirty-three patients were included; 6 patients (35 regions) presented a peritoneal carcinosis. Peritoneal Carcinomatosis Index (PCI) estimated on 18F-FDOPA PET/CT was significantly and strongly correlated to surgical PCI (r = 0.96, P < 0.001). Patient-based sensitivity, specificity, negative predictive value, and positive predictive value for 18F-FDOPA PET/CT were 100%, 93%, 100%, and 75%, respectively. The agreement between 18F-FDOPA and surgery regarding PC was excellent (Cohen κ = 0.82 on per patient analysis, 0.74 on per region analysis).

CONCLUSIONS

A preoperative estimation of PCI is achievable based on 18F-FDOPA PET/CT for small intestine NET and could allow to optimize surgical procedures and patient selection.

Imaging Cancer-Associated Fibroblasts (CAFs) with FAPi PET

The tumor microenvironment (TME) surrounding tumor cells is a complex and highly dynamic system that promotes tumorigenesis. Cancer-associated fibroblasts (CAFs) are key elements in TME playing a pivotal role in cancer cells’ proliferation and metastatic spreading. Considering the high expression of the fibroblast activation protein (FAP) on the cell membrane, CAFs emerged as appealing TME targets, namely for molecular imaging, leading to a pan-tumoral approach. Therefore, FAP inhibitors (FAPis) have recently been developed for PET imaging and radioligand therapy, exploring the clinical application in different tumor sub-types. The present review aimed to describe recent developments regarding radiolabeled FAP inhibitors and evaluate the possible translation of this pan-tumoral approach in clinical practice. At present, the application of FAPi-PET has been explored mainly in single-center studies, generally performed in small and heterogeneous cohorts of oncological patients. However, preliminary results were promising, in particular in low FDG-avid tumors, such as primary liver and gastro-entero-pancreatic cancer, or in regions with an unfavorable tumor-to-background ratio at FDG-PET/CT (i.e., brain), and in radiotherapy planning of head and neck tumors. Further promising results have been obtained in the detection of peritoneal carcinomatosis, especially in ovarian and gastric cancer. Data regarding the theranostics approach are still limited at present, and definitive conclusions about its efficacy cannot be drawn at present. Nevertheless, the use of FAPi-based radio-ligand to treat the TME has been evaluated in first-in-human studies and appears feasible. Although the pan-tumoral approach in molecular imaging showed promising results, its real impact in day-to-day clinical practice has yet to be confirmed, and multi-center prospective studies powered for efficacy are needed.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases: analysis of short- and long-term outcomes

Background

Peritoneal metastases carry the worst prognosis among all sites of colorectal cancer (CRC) metastases. In recent years, the advent of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has improved survival for selected patients with limited peritoneal involvement. We report the evolution of CRS and HIPEC for colorectal peritoneal metastases at a tertiary referral center over a 10-year period.

Methods

Patients with colorectal peritoneal metastases undergoing CRS and HIPEC were included and retrospectively analyzed at a tertiary referral center from January 2006 to December 2015. Main outcomes included evaluation of grade III/IV complications, mortality rate, overall and disease-free survival, and prognostic factors influencing survival on a Cox multivariate analysis.

Results

Sixty-seven CRSs were performed on 67 patients during this time for colorectal peritoneal metastases. The median patient age was 57 years with 55.2% being female. The median peritoneal carcinomatosis index (PCI) was 7, with complete cytoreduction achieved in 65 (97%) cases. Grade > 2 complications occurred in 6 cases (8.9%) with no mortality. The median overall survival for the entire cohort was 41 months, with a 3-year overall survival of 43%. In case of complete cytoreduction, median overall and disease-free survival were 57 months and 36 months respectively, with a 3-year disease-free survival of 62%. Complete cytoreduction and nonmucinous histology were key factors independently associated with improved overall survival.

Conclusions

CRS and HIPEC for limited peritoneal metastases from CRC are safe and effective, with acceptable morbidity. In selected patients, it offers a highly favorable long-term outcomes.

Performance of Multiparametric Functional Imaging to Assess Peritoneal Tumor Burden in Ovarian Cancer

PURPOSE

The aim of the study was to evaluate the clinical utility of pretreatment 18F-FDG PET/CT with quantitative evaluation of peritoneal metabolic cartography in relation to staging laparoscopy for ovarian carcinomatosis.

PATIENTS AND METHODS

A retrospective review of prospectively collected data from 84 patients with FIGO (International Federation of Gynecology and Obstetrics) stage IIIC to IV ovarian cancer was carried out. All patients had a double-blinded 18F-FDG PET/CT review. Discriminant capacity of metabolic parameters to identify peritoneal carcinomatosis in the 13 abdominal regions according to the peritoneal cancer index was estimated with area under the receiver operating characteristic curve (AUC).

RESULTS

The metabolic parameter showing the best trade-off between sensitivity and specificity to predict peritoneal extension compared with peritoneal cancer index score was the metabolic tumor volume (MTV), with a Spearman ρ equal to 0.380 (P < 0.001). The AUC of MTV to diagnose peritoneal involvement in the upper abdomen (regions 1, 2, and 3) ranged from 0.740 to 0.765. MTV AUC values were lower in the small bowel regions (9-12), ranging from 0.591 to 0.681, and decreased to 0.487 in the pelvic region 6. 18F-FDG PET/CT also improved the detection of extra-abdominal disease, upstaging 35 patients (41.6%) from stage IIIC to IV compared with CT alone and leading to treatment modification in more than one third of patients.

CONCLUSIONS

18F-FDG PET/CT metrics are highly accurate to reflect peritoneal tumor burden, with variable diagnostic value depending on the anatomic region. MTV is the most representative metabolic parameter to assess peritoneal tumor extension.

Variants and Pitfalls in PET/CT Imaging of Gastrointestinal Cancers

In the past two decades, PET/CT has become an essential modality in oncology increasingly used in the management of gastrointestinal (GI) cancers. Most PET/CT tracers used in clinical practice show some degree of GI uptake. This uptake is quite variable and knowledge of common patterns of biodistribution of various radiotracers is helpful in clinical practice. 18F-Fluoro-Deoxy-Glucose (FDG) is the most commonly used radiotracer and has quite a variable uptake within the bowel. 68Ga-Prostate specific membrane antigen (PSMA) shows intense uptake within the proximal small bowel loops. 11C-methyl-L-methionine (MET) shows high accumulation within the bowels, which makes it difficult to assess bowel or pelvic diseases. One must also be aware of technical artifacts causing difficulties in interpretations, such as high attenuation oral contrast material within the bowel lumen or misregistration artifact due to patient movements. It is imperative to know the common variants and benign diseases that can mimic malignant pathologies. Intense FDG uptake within the esophagus and stomach may be a normal variant or may be associated with benign conditions such as esophagitis, reflux disease, or gastritis. Metformin can cause diffuse intense uptake throughout the bowel loops. Intense physiologic uptake can also be seen within the anal canal. Segmental bowel uptake can be seen in inflammatory bowel disease, radiation, or medication induced enteritis/colitis or infection. Diagnosis of appendicitis or diverticular disease requires CT correlation, as normal appendix or diverticulum can show intense uptake. Certain malignant pathologies are known to have only low FDG uptake, such as early-stage esophageal adenocarcinoma, mucinous tumors, indolent lymphomas, and multicystic mesotheliomas. Response assessment, particularly in the neoadjuvant setting, can be limited by post-treatment inflammatory changes. Post-operative complications such as abscess or fistula formation can also show intense uptake and may obscure underlying malignant pathology. In the absence of clinical suspicion or rising tumor marker, the role of FDG PET/CT in routine surveillance of patients with GI malignancy is not clear.

Postoperative oxaliplatin-based hyperthermic intraperitoneal chemotherapy: an effective and safe palliative treatment option for colorectal cancer with peritoneal metastasis

Background

The prognosis of patients with colorectal cancer and peritoneal metastasis (CRC-PM) after incomplete cytoreductive surgery (CRS) or palliative surgery is poor. Novel and effective therapies are urgently needed. This study aimed to assess the effects of palliative postoperative hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with CRC-PM.

Methods

This retrospective study included patients with CRC-PM at the First Affiliated Hospital of Xi’an Jiaotong University in 05/2014–05/2019. Observation indicators included overall survival (OS), ascites-free survival, peritoneal cancer index (PCI), and completeness of cytoreduction (CC). Kaplan-Meier survival curves and multivariable Cox regression models were used to determine the factors associated with OS and ascites-free survival. The ascites-specific quality of life (QoL) was measured using the Functional Assessment of Chronic Illness Therapy-Ascites Index (FACIT-AI).

Results

Eighty-two patients were included, including 37 and 45 in the HIPEC and non-HIPEC groups, respectively. Mean OS was 10.3±3.7 (95% CI 9.5–11.2) months. Multivariable Cox proportional hazard regression suggested that PCI (HR=6.086, 95% CI 3.187–11.620, P < 0.0001) was independently associated with OS. The degree of ascites (HR=2.059, 95% CI 1.412–3.005, P < 0.0001), PCI (HR=6.504, 95% CI 2.844–14.875, P < 0.0001), and HIPEC (HR=0.328, 95% CI 0.191–0.562, P < 0.0001) were independently associated with ascites-free survival. In patients with survival >6 months, postoperative ascites-specific QoL was significantly improved after HIPEC compared with the non-HIPEC group (P < 0.001). Oxaliplatin-based HIPEC significantly increased the rates of neutropenia and peripheral neurotoxicity (both P < 0.05).

Conclusion

These data indicate that postoperative oxaliplatin-based HIPEC might help increase ascites-free survival in CRC-PM patients after incomplete CRS or palliative surgery, with improved QoL after 6 months of follow-up.

ESGO/ISUOG/IOTA/ESGE Consensus Statement on preoperative diagnosis of ovarian tumors

The European Society of Gynaecological Oncology (ESGO), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), the International Ovarian Tumour Analysis (IOTA) group and the European Society for Gynaecological Endoscopy (ESGE) jointly developed clinically relevant and evidence-based statements on the preoperative diagnosis of ovarian tumors, including imaging techniques, biomarkers and prediction models. ESGO/ISUOG/IOTA/ESGE nominated a multidisciplinary international group, including expert practising clinicians and researchers who have demonstrated leadership and expertise in the preoperative diagnosis of ovarian tumors and management of patients with ovarian cancer (19 experts across Europe). A patient representative was also included in the group. To ensure that the statements were evidence-based, the current literature was reviewed and critically appraised. Preliminary statements were drafted based on the review of the relevant literature. During a conference call, the whole group discussed each preliminary statement and a first round of voting was carried out. Statements were removed when consensus among group members was not obtained. The voters had the opportunity to provide comments/suggestions with their votes. The statements were then revised accordingly. Another round of voting was carried out according to the same rules to allow the whole group to evaluate the revised version of the statements. The group achieved consensus on 18 statements. This Consensus Statement presents these ESGO/ISUOG/IOTA/ESGE statements on the preoperative diagnosis of ovarian tumors and the assessment of carcinomatosis, together with a summary of the evidence supporting each statement.

ESGO/ISUOG/IOTA/ESGE Consensus Statement on preoperative diagnosis of ovarian tumours

The European Society of Gynaecological Oncology (ESGO), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), the International Ovarian Tumour Analysis (IOTA) group and the European Society for Gynaecological Endoscopy (ESGE) jointly developed clinically relevant and evidence-based statements on the preoperative diagnosis of ovarian tumours, including imaging techniques, biomarkers and prediction models.

ESGO/ISUOG/IOTA/ESGE nominated a multidisciplinary international group, including expert practising clinicians and researchers who have demonstrated leadership and expertise in the preoperative diagnosis of ovarian tumours and management of patients with ovarian cancer (19 experts across Europe). A patient representative was also included in the group. To ensure that the statements were evidence-based, the current literature was reviewed and critically appraised.

Preliminary statements were drafted based on the review of the relevant literature. During a conference call, the whole group discussed each preliminary statement and a first round of voting was carried out. Statements were removed when a consensus among group members was not obtained. The voters had the opportunity to provide comments/suggestions with their votes. The statements were then revised accordingly. Another round of voting was carried out according to the same rules to allow the whole group to evaluate the revised version of the statements. The group achieved consensus on 18 statements.

This Consensus Statement presents these ESGO/ISUOG/IOTA/ESGE statements on the preoperative diagnosis of ovarian tumours and the assessment of carcinomatosis, together with a summary of the evidence supporting each statement.

ESGO/ISUOG/IOTA/ESGE Consensus Statement on pre-operative diagnosis of ovarian tumors

The European Society of Gynaecological Oncology (ESGO), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), the International Ovarian Tumour Analysis (IOTA) group, and the European Society for Gynaecological Endoscopy (ESGE) jointly developed clinically relevant and evidence-based statements on the pre-operative diagnosis of ovarian tumors, including imaging techniques, biomarkers, and prediction models. ESGO/ISUOG/IOTA/ESGE nominated a multidisciplinary international group, including expert practising clinicians and researchers who have demonstrated leadership and expertise in the pre-operative diagnosis of ovarian tumors and management of patients with ovarian cancer (19 experts across Europe). A patient representative was also included in the group. To ensure that the statements were evidence-based, the current literature was reviewed and critically appraised. Preliminary statements were drafted based on the review of the relevant literature. During a conference call, the whole group discussed each preliminary statement and a first round of voting was carried out. Statements were removed when a consensus among group members was not obtained. The voters had the opportunity to provide comments/suggestions with their votes. The statements were then revised accordingly. Another round of voting was carried out according to the same rules to allow the whole group to evaluate the revised version of the statements. The group achieved consensus on 18 statements. This Consensus Statement presents these ESGO/ISUOG/IOTA/ESGE statements on the pre-operative diagnosis of ovarian tumors and the assessment of carcinomatosis, together with a summary of the evidence supporting each statement.

Approach to large adrenal tumors

PURPOSE OF REVIEW

To summarize the data concerning approach to large adrenal tumors (LAT's), since recent guidelines published in 2016 recommend individual approach rather than clear size cut-off of a tumor that should be removed.

RECENT FINDINGS

Although the risk of malignancy clearly correlates with the size of a lesion, tumor size of more than 4 cm in diameter represents only 31-61% specificity for the diagnosis of malignant tumor. Therefore, the risk of malignancy and decision about surgery should not be based only on the size of a tumor but assessed in terms of imaging studies, growth pattern during follow-up and new tool that is urine/serum steroid metabolomics.

SUMMARY

Approach to patients with LAT's should be individualized. Patients with LAT's should be managed by an expert multidisciplinary team, that includes an endocrinologist, a radiologist, a pathologist, and an adrenal surgeon.

Prediction of Pretreatment 18F-FDG-PET/CT Parameters on the Outcome of First-Line Therapy in Patients with Metastatic Breast Cancer

Objective

18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) can provide prognostic information, especially 18F-FDG uptake has been proven to be a predictor for the prognosis of various tumors. Nevertheless, the prognosis of other PET parameters in the metastatic setting remains unclear. This study was aimed at investigating pretreatment parameters based on 18F-FDG-PET/CT so as to estimate the progression-free survival (PFS) of metastatic breast cancer (MBC) patients receiving first-line treatment.

Methods

MBC patients who underwent a whole-body 18F-FDG-PET/CT prior to first-line therapy were enrolled. The heterogeneity parameter of PET/CT was analyzed, including heterogeneity index (HI) and general parameters (metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax) and mean SUV (SUVmean). PFS was used to evaluate the treatment outcome. Kaplan-Meier method was adopted to carry out survival analysis and Log rank test was conducted to make a comparison.

Results

A total of 177 MBC patients were selected, in which 68 were in De novo stage IV. Thirty patients were human epidermal growth factor receptor 2 (HER2)-positive, 60 patients were triple-negative, and 87 patients were hormone receptor (HR)-positive and HER2-negative. In the whole population, patients with high baseline SUVmax, SUVmean, MTV, TLG or HI were associated with lower PFS (P=0.028, 0.005, 0.017, 0.026 and 0.035, respectively). Among the patients in De novo stage IV, those with high HI at baseline had significantly shorter PFS (P=0.001). In HR+/HER2- and HER2+ subgroups, only baseline HI showed the predictive value of PFS (P=0.023 and 0.049, respectively). In the triple-negative subgroup, high baseline SUVmax, MTV or TLG showed the predictive value of worse PFS (P=0.030, 0.011 and 0.023, respectively).

Conclusion

Pretreatment 18F-FDG-PET/CT parameters show the predictive value of PFS in MBC patients receiving first-line treatment. However, predictive PET/CT parameters might be different in patients with different molecular subtypes and De novo stage IV.

Intraperitoneal Glucose Transport to Micrometastasis: A Multimodal In Vivo Imaging Investigation in a Mouse Lymphoma Model

Bc-DLFL.1 is a novel spontaneous, high-grade transplantable mouse B-cell lymphoma model for selective serosal propagation. These cells attach to the omentum and mesentery and show dissemination in mesenteric lymph nodes. We aimed to investigate its early stage spread at one day post-intraperitoneal inoculation of lymphoma cells (n = 18 mice), and its advanced stage at seven days post-inoculation with in vivo [18F]FDG-PET and [18F]PET/MRI, and ex vivo by autoradiography and Cherenkov luminescence imaging (CLI). Of the early stage group, nine animals received intraperitoneal injections, and nine received intravenous [18F]FDG injections. The advanced stage group (n = 3) received intravenous FDG injections. In the early stage, using autoradiography we observed a marked accumulation in the mesentery after intraperitoneal FDG injection. Using other imaging methods and autoradiography, following the intravenous injection of FDG no accumulations were detected. At the advanced stage, tracer accumulation was clearly detected in mesenteric lymph nodes and in the peritoneum after intravenous administration using PET. We confirmed the results with immunohistochemistry. Our results in this model highlight the importance of local FDG administration during diagnostic imaging to precisely assess early peritoneal manifestations of other malignancies (colon, stomach, ovary). These findings also support the importance of applying topical therapies, in addition to systemic treatments in peritoneal cancer spread.

[Radiologic Evaluation for Resectability of Pancreatic Adenocarcinoma]

Imaging studies play an important role in the detection, diagnosis, assessment of resectability, staging, and determination of patient-tailored treatment options for pancreatic adenocarcinoma. Recently, for patients diagnosed with borderline resectable or locally advanced pancreatic cancers, it is recommended to consider curative-intent surgery following neoadjuvant or palliative therapy, if possible. This review covers how to interpret imaging tests and what to consider when assessing resectability, diagnosing distant metastasis, and re-assessing the resectability of pancreatic cancer after neoadjuvant or palliative therapy.

Review of systemic chemotherapy in unresectable colorectal peritoneal carcinomatosis

Colorectal cancer remains the third most common malignancy in Australia with the peritoneum being the second most common metastatic site. Colorectal peritoneal carcinomatosis (CPC) can be treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy but this is only limited to a small subset of patients. Those with inoperable disease have a particularly poor prognosis. While the ideal systemic regimen has not been defined, 5-fluorouracil-based chemotherapy regimens appear to provide overall and progression free survival benefits. The role of targeted agents such as bevacizumab (vascular endothelial growth factor inhibitor) or cetuximab (epidermal growth factor inhibitor) in the setting of CPC is still evolving. Currently, retrospective analyses have shown promising results for the use of bevacizumab in addition to systemic chemotherapy but similar results have not been seen with cetuximab or panitumumab. However, there is significant heterogeneity in the trial data, lack of prospective randomized controlled trials and demonstrated treatment variability based on age and tumour characteristics. This review summarises the current literature in regard to treatment in the unresectable CPC setting as well as discussing issues with the current data and highlighting the need for further trials.

Role of [68Ga]Ga-DOTA-FAPI-04 PET/CT in the evaluation of peritoneal carcinomatosis and comparison with [18F]-FDG PET/CT

PURPOSE

The aim of this study was to explore the role of [⁶⁸Ga]Ga-DOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT), compared with ¹⁸F-fluorodeoxyglucose [¹⁸F]-FDG PET/CT, for evaluating peritoneal carcinomatosis in patients with various types of cancer.

METHODS

Patients with suspected peritoneal malignancy, who underwent both [¹⁸F]-FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT between October 2019 and August 2020, were retrospectively analysed. The radiotracer uptake, peritoneal cancer index (PCI) score, and diagnostic performance of [¹⁸F]-FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT were evaluated and compared.

RESULTS

Our cohort consisted of 46 patients, including 16 patients with diffuse-type peritoneal carcinomatosis, 27 with nodular-type peritoneal carcinomatosis, and 3 true-negative patients. A significant difference in standard uptake values (SUV) of lesions between [¹⁸F]-FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT examination was observed (median SUV: 3.48 vs. 9.82; P < 0.001), particularly in peritoneal carcinomatosis from gastric cancer (median SUV: 3.44 vs. 8.05; P = 0.001). Moreover, [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT showed a higher PCI score and better sensitivity than [¹⁸F]-FDG PET/CT for the detection of peritoneal carcinomatosis (6 vs. 18; P < 0.001; 72.09% vs. 97.67%; P = 0.002).

CONCLUSION

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT demonstrated superior sensitivity over [¹⁸F]-FDG PET/CT for the detection of peritoneal carcinomatosis in patients with various types of cancer, particularly gastric cancer. Furthermore, the uptake of [⁶⁸Ga]Ga-DOTA-FAPI-04 in peritoneal carcinomatosis was significantly higher than that of [¹⁸F]-FDG, demonstrating a larger extent of the lesions and yielding a higher PCI score. This could help enhance the image contrast, improve physicians' diagnostic confidence, and reduce the proportion of missed diagnoses.

Current Status and Recent Update of Imaging Evaluation for Peri-Hilar Cholangiocarcinoma

간문주변부의 해부학적 복잡성으로 인해 간문주변부 담관암은 그 진단과 치료가 어려운 질환으로 알려져 있다. 간문주변부 담관암이 의심되는 환자에 있어서, 영상 검사는 이상 소견의 발견 및 감별 진단, 종양의 종축 침범 부위의 파악, 인접 혈관 침범과 원격 전이 유무의 파악, 그리고 최종적으로 수술적 절제 가능 유무의 평가에 있어 핵심적인 역할을 하고 있다. 이 종설에서는 간문주변부 담관암의 분류 및 종양의 평가를 위해 권고되는 표준 영상 검사의 기법과 간문주변부 담관암의 전형적인 영상 소견에 대해 기술할 예정이다. 종축 방향의 종양 침범 파악, 인접 혈관 침범 및 원격 전이 유무의 평가에 있어서 각 영상 검사 소견과 그 진단능에 대해 논의할 예정이다. 이후 전통적인 절제 가능성 평가의 개념에 대해 고찰하고, 최근의 경향을 소개한다.

Survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: A systematic review and discussion of latest controversies

INTRODUCTION

Peritoneal metastases confer the worst survival amongst all sites of metastatic colorectal cancer. The adoption of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has become an option for patients with isolated colorectal peritoneal metastases (CRPM). The aim of this study was to evaluate the outcomes following CRS and HIPEC for CRPM from published high volume cohort studies and to highlight the latest controversies and future directions of CRPM treatment.

MATERIALS AND METHODS

A systematic review was performed on published studies on the treatment outcomes of CRS and HIPEC for colorectal peritoneal metastases.

RESULTS

Twenty studies met the inclusion criteria for the systematic review. The median survival for all patients ranged from 14.6 to 60.1 months. The 5-year overall survival ranged from 23.4% to 52%. For patients with complete cytoreduction, the median survival was 25 to 49 months. Major morbidity and mortality ranged from 15.1% to 47.2% and 0% to 4.5%, respectively.

CONCLUSION

CRS and HIPEC for the treatment of CRPM is safe and current evidence suggests it improves both median and disease-free survival. However, the efficacy of intraperitoneal chemotherapy, in particular oxaliplatin, has recently come under scrutiny. Accordingly, higher quality evidence is urgently required to contribute to multidisciplinary and international consensus on CRPM treatment strategies.

Diagnostic value of [18F]FDG PET/MRI for staging in patients with ovarian cancer

Purpose

To evaluate the diagnostic potential of PET/MRI with 2-[¹⁸F]fluoro-2-deoxy-d-glucose ([¹⁸F]FDG) in ovarian cancer.

Materials and methods

Participants comprised 103 patients with suspected ovarian cancer underwent pretreatment [¹⁸F]FDG PET/MRI, contrast-enhanced CT (ceCT) and pelvic dynamic contrast-enhanced MRI (ceMRI). Diagnostic performance of [¹⁸F]FDG PET/MRI and ceMRI for assessing the characterization and the extent of the primary tumor (T stage) and [¹⁸F]FDG PET/MRI and ceCT for assessing nodal (N stage) and distant (M stage) metastases was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis.

Results

Accuracy for the characterization of suspected ovarian cancer was significantly better for [¹⁸F]FDG PET/MRI (92.5%) [95% confidence interval (CI) 0.84–0.95] than for ceMRI (80.6%) (95% CI 0.72–0.83) (p < 0.05). Accuracy for T status was 96.4% (95% CI 0.96–0.96) and 92.9% (95% CI 0.93–0.93) for [¹⁸F]FDG PET/MRI and ceMRI/ceCT, respectively. Patient-based accuracies for N and M status were 100% (95% CI 0.88–1.00) and 100% (95% CI 0.88–1.00) for [¹⁸F]FDG PET/MRI and 85.2% (95% CI 0.76–0.85) and 30.8% (95% CI 0.19–0.31) for ceCT and M staging representing significant differences (p < 0.01). Lesion-based sensitivity, specificity and accuracy for N status were 78.6% (95% CI 0.57–0.91), 95.7% (95% CI 0.93–0.97) and 93.9% (95% CI 0.89–0.97) for [¹⁸F]FDG PET/MRI and 42.9% (95% CI 0.24–0.58), 96.6% (95% CI 0.94–0.98) and 90.8% (95% CI 0.87–0.94) for ceCT.

Conclusions

[¹⁸F]FDG PET/MRI offers better sensitivity and specificity for the characterization and M staging than ceMRI and ceCT, and diagnostic value for T and N staging equivalent to ceMRI and ceCT, suggesting that [¹⁸F]FDG PET/MRI might represent a useful diagnostic alternative to conventional imaging modalities in ovarian cancer.

Radiologic Evaluation and Structured Reporting Form for Extrahepatic Bile Duct Cancer: 2019 Consensus Recommendations from the Korean Society of Abdominal Radiology

Radiologic imaging is important for evaluating extrahepatic bile duct (EHD) cancers; it is used for staging tumors and evaluating the suitability of surgical resection, as surgery may be contraindicated in some cases regardless of tumor stage. However, the published general recommendations for EHD cancer and recommendations guided by the perspectives of radiologists are limited. The Korean Society of Abdominal Radiology (KSAR) study group for EHD cancer developed key questions and corresponding recommendations for the radiologic evaluation of EHD cancer and organized them into 4 sections: nomenclature and definition, imaging technique, cancer evaluation, and tumor response. A structured reporting form was also developed to allow the progressive accumulation of standardized data, which will facilitate multicenter studies and contribute more evidence for the development of recommendations.

Colorectal peritoneal metastases: pathogenesis, diagnosis and treatment options - an evidence-based update

Peritoneal metastases confer the worst survival among all sites in patients with metastatic colorectal cancer. They develop largely through transcoelomic spread, with a sequence of events that allow cells to first detach from primary tumours, survive in the peritoneal environment, attach to the peritoneal surface of organs and migrate into the submesothelial space to create a microenvironment conducive to metastatic growth. Diagnostic challenges have previously hindered early identification of peritoneal metastases. While advances in diagnostic modalities have improved our ability to identify peritoneal metastases, lesions under 0.5 cm remain challenging to detect. The advent of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) can offer selected patients with colorectal peritoneal metastases a favourable long-term survival. Recent trials, however, have cast doubts on the efficacy of HIPEC, with the recent PRODIGE 7 trial showing no benefit from oxaliplatin based HIPEC in addition to good quality cytoreductive surgery in resectable disease. While peritoneal recurrence can be reliably predicted from high-risk features in primary tumours such as a perforated cancer, ovarian metastases or T4a cancers, the use of prophylactic second look surgery with HIPEC or adjuvant HIPEC failed to demonstrate any survival benefit in high-risk cases in recent clinical trials, raising further questions about the efficacy of HIPEC. With high failure rates from systemic chemotherapy in unresectable disease, novel surgical techniques such as pressurized intraperitoneal aerolized chemotherapy are being investigated in clinical trials worldwide. Further collaborative research is needed to explore newer avenues of treatment for this poor prognostic cohort.

Evolution of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases: 8-Year Single-Institutional Experience

BACKGROUND

Colorectal cancer is the second leading cause of cancer-related mortality worldwide. Peritoneal metastases carry the worst prognosis among all sites of colorectal cancer metastases. In recent years, the advent and acceptance of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy have greatly improved survival for selected patients with low-volume peritoneal metastases.

OBJECTIVE

Here, we report the evolution of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases at a statewide tertiary referral center over an 8-year period.

DESIGN

This is a retrospective study from 2009 to 2017.

SETTING

The study was conducted at a single center over 8 years.

PATIENTS

Patients with colorectal peritoneal metastases undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were included.

MAIN OUTCOMES

Main outcomes included evaluation of grade III/IV morbidity rate, mortality rate, overall and relapse-free survival, and prognostic factors influencing survival on a Cox multivariate analysis model.

RESULTS

One hundred one cytoreductive surgeries were undertaken on 96 patients during this time for colorectal peritoneal metastases. The median patient age was 60 years with 55.2% being female. The median Peritoneal Carcinomatosis Index was 9, with complete cytoreduction achieved in 76 (75.2%) cases. Grade III or IV complications occurred in 26 cases (25.7%) with 2 (2%) perioperative mortalities. Median overall survival for the entire cohort was 32 months, with a 3-year survival of 38%. For patients who achieved a complete cytoreduction, median overall survival was 37 months, with a relapse-free survival of 13 months and a 3-year survival of 54%. Complete cytoreduction and nonmucinous histology were key factors independently associated with improved overall survival.

LIMITATIONS

The main limitation this study is its retrospective nature.

CONCLUSION

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for isolated low-volume colorectal peritoneal metastases is safe and effective, with low morbidity. It offers selected patients a highly favorable overall and relapse-free survival. See Video Abstract at http://links.lww.com/DCR/B2. EVOLUCIÓN DE LA CIRUGÍA CITORREDUCTIVA Y QUIMIOTERAPIA INTRAPERITONEAL HIPERTÉRMICA (HIPEC) PARA METÁSTASIS PERITONEALES COLORRECTALES: EXPERIENCIA INSTITUCIONAL DE 8 AÑOS: El cáncer colorrectal es la segunda causa de mortalidad relacionada con el cáncer en todo el mundo. Las metástasis peritoneales tienen el peor pronóstico entre todos los sitios de metástasis del cáncer colorrectal. En los últimos años, el advenimiento y la aceptación de la cirugía citorreductiva y la quimioterapia intraperitoneal hipertérmica ha mejorado enormemente la supervivencia de pacientes seleccionados con metástasis peritoneales de bajo volumen.

OBJETIVO

Aquí, informamos sobre la evolución de la cirugía citorreductiva y la quimioterapia intraperitoneal hipertérmica para las metástasis peritoneales colorrectales en un centro de referencia terciario para todo el estado durante un período de ocho años. DISEÑO:: Estudio retrospectivo del 2009 a 2017. CONFIGURACIÓN:: Centro único a lo largo de ocho años.

PACIENTES

Pacientes con metástasis peritoneales colorrectales sometidos a cirugía citorreductiva y quimioterapia intraperitoneal hipertérmica.

RESULTADOS PRINCIPALES

Los resultados principales incluyeron la evaluación de la tasa de morbilidad de grado III / IV, la tasa de mortalidad, la supervivencia general y libre de recaída y los factores pronósticos que influyen en la supervivencia en el modelo de análisis multivariado Cox.

RESULTADOS

Se realizaron el ciento uno cirugías citorreductivas en noventa y seis pacientes durante este tiempo por metástasis peritoneales colorrectales. La edad media de los pacientes fue de 60 años, con un 55.2% de mujeres. El Índice de Carcinomatosis Peritoneal mediano fue de 9, con una citorreducción completa lograda en 76 (75.2%) casos. Las complicaciones de grado III o IV ocurrieron en 26 casos (25.7%) con dos (2%) de mortalidad perioperatoria. La supervivencia mediana general para toda la cohorte fue de 32 meses, con una supervivencia de 3 años del 38%. Para los pacientes que lograron una citorreducción completa, la supervivencia global media fue de 37 meses, con una supervivencia sin recaída de 13 meses y una supervivencia de 3 años del 54%. La citorreducción completa y la histología no mucinosa fueron factores clave asociados de forma independiente con una mejor supervivencia general.

LIMITACIONES

La principal limitación es la naturaleza retrospectiva del estudio. CONCLUSIÓN:: La cirugía citorreductiva y la quimioterapia intraperitoneal hipertérmica para las metástasis peritoneales colorrectales aisladas de bajo volumen son seguras y eficaces, con baja morbilidad. Ofrece a los pacientes seleccionados una supervivencia global altamente favorable y libre de recaída. Vea el Resumen del video en http://links.lww.com/DCR/B2.

Colorectal peritoneal metastases: Optimal management review

The peritoneum is a common site of dissemination for colorrectal cancer, with a poorer prognosis than other sites of metastases. In the last two decades, it has been considered as a locoregional disease progression and treated as such with curative intention treatments. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is the actual reference treatment for these patients as better survival results have been reached as compared to systemic chemotherapy alone, but its therapeutic efficacy is still under debate. Actual guidelines recommend that the management of colorectal cancer with peritoneal metastases should be led by a multidisciplinary team carried out in experienced centers and consider CRS + HIPEC for selected patients. Accumulative evidence in the last three years suggests that this is a curative treatment that may improve patients disease-free survival, decrease the risk of recurrence, and does not increase the risk of treatment-related mortality. In this review we aim to gather the latest results from referral centers and opinions from experts about the effectiveness and feasibility of CRS + HIPEC for treating peritoneal disease from colorectal malignancies.

Colorectal Peritoneal Metastases: A Systematic Review of Current and Emerging Trends in Clinical and Translational Research

Colorectal peritoneal metastases (CPM) are associated with abbreviated survival and significantly impaired quality of life. In patients with CPM, radical multimodality treatment consisting of cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has demonstrated oncological superiority over systemic chemotherapy alone. In highly selected patients undergoing CRS + HIPEC, overall survival of over 60% has been reported in some series. These are patients in whom the disease burden is limited and where the diagnosis is made at an early stage in the disease course. Early diagnosis and a deeper understanding of the biological mechanisms that regulate CPM are critical to refining patient selection for radical treatment, personalising therapeutic approaches, enhancing prognostication, and ultimately improving long-term survivorship. In the present study, we outline three broad themes which represent critical future research targets in CPM: (1) enhanced radiological strategies for early detection and staging; (2) identification and validation of translational biomarkers for diagnostic, prognostic, and therapeutic deployment; and (3) development of optimized approaches for surgical cytoreduction as well as more precise strategies for intraperitoneal drug selection and delivery. Herein, we provide a contemporary narrative review of the state of the art in these three areas. A systematic review in accordance with PRISMA guidelines was undertaken on all English language studies published between 2007 and 2017. In vitro and animal model studies were deemed eligible for inclusion in the sections pertaining to biomarkers and therapeutic optimisation, as these areas of research currently remain in the early stages of development. Acquired data were then divided into hierarchical thematic categories (imaging modalities, translational biomarkers (diagnostic/prognostic/therapeutic), and delivery techniques) and subcategories. An interactive sunburst figure is provided for intuitive interrogation of the CPM research landscape.

18F-FDG PET/CT for the early prediction of the response rate and survival of patients with recurrent or metastatic breast cancer

The present study aimed to explore the value of fludeoxyglucose F 18 positron emission tomography-computed tomography (PET/CT) for the early prediction of chemotherapy remission rates and survival in patients with recurrent and metastatic breast cancer. A total of 24 patients diagnosed with recurrent or metastatic breast cancer between 2009 and 2014 were enrolled. All patients underwent a PET/CT examination prior to (PET/CT1) and following (PET/CT2) chemotherapy. Differences of PET/CT1 maximal standardized uptake values (SUV_max), PET/CT2 SUV_max, ΔSUV_max and the ΔSUV_max% between objective remission (OR) and non-OR groups were measured. Survival differences between OR and non-OR groups and the overall survival (OS) between metabolic responsive and metabolic non-responsive groups were analyzed. In the present study, it was revealed that ΔSUV_max and ΔSUV_max% were significantly higher in the OR group compared with the non-OR group (P<0.001). Overall survival was significantly prolonged in the OR and metabolic responder groups compared with their respective control groups (P<0.001 and P<0.01, respectively). ΔSUV_max% were significantly positively associated with OS (r²=0.266; P<0.01). In conclusion, PET/CT may be valuable for the early prediction of the chemotherapy efficacy and survival of patients with recurrent or metastatic breast cancer.