Imaging of Peritoneal Metastases in Ovarian Cancer Using MDCT, MRI, and FDG PET/CT: A Systematic Review and Meta-Analysis

This review aims to compare the diagnostic performance of multidetector CT (MDCT), MRI, including diffusion-weighted imaging, and FDG PET/CT in the detection of peritoneal metastases (PMs) in ovarian cancer (OC). A comprehensive search was performed for articles published from 2000 to February 2023. The inclusion criteria were the following: diagnosis/suspicion of PMs in patients with ovarian/fallopian/primary peritoneal cancer; initial staging or suspicion of recurrence; MDCT, MRI and/or FDG PET/CT performed for the detection of PMs; population of at least 10 patients; surgical results, histopathologic analysis, and/or radiologic follow-up, used as reference standard; and per-patient and per-region data and data for calculating sensitivity and specificity reported. In total, 33 studies were assessed, including 487 women with OC and PMs. On a per-patient basis, MRI (p = 0.03) and FDG PET/CT (p < 0.01) had higher sensitivity compared to MDCT. MRI and PET/CT had comparable sensitivities (p = 0.84). On a per-lesion analysis, no differences in sensitivity estimates were noted between MDCT and MRI (p = 0.25), MDCT and FDG PET/CT (p = 0.68), and MRI and FDG PET/CT (p = 0.35). Based on our results, FDG PET/CT and MRI are the preferred imaging modalities for the detection of PMs in OC. However, the value of FDG PET/CT and MRI compared to MDCT needs to be determined. Future research to address the limitations of the existing studies and the need for standardization and to explore the cost-effectiveness of the three imaging modalities is required.

Imaging of Peritoneal Carcinomatosis in Advanced Ovarian Cancer: CT, MRI, Radiomic Features and Resectability Criteria

PC represents the most striking picture of the loco-regional spread of ovarian cancer, configuring stage III. In the last few years, many papers have evaluated the role of imaging and therapeutic management in patients with ovarian cancer and PC. This paper summed up the literature on traditional approaches to the imaging of peritoneal carcinomatosis in advanced ovarian cancer, presenting classification systems, most frequent patterns, routes of spread and sites that are difficult to identify. The role of imaging in diagnosis was investigated, with particular attention to the reported sensitivity and specificity data-computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT)-and to the peritoneal cancer index (PCI). In addition, we explored the therapeutic possibilities and radiomics applications that can impact management of patients with ovarian cancer. Careful staging is mandatory, and patient selection is one of the most important factors influencing complete cytoreduction (CCR) outcome: an accurate pre-operative imaging may allow selection of patients that may benefit most from primary cytoreductive surgery.

Prognostic role of the peritoneal cancer index in ovarian cancer patients who undergo cytoreductive surgery: a meta-analysis

Advanced-stage ovarian cancer is usually associated with peritoneal carcinomatosis. This study evaluates the prognostic role of the Peritoneal Cancer Index (PCI) in predicting the survival of patients with ovarian cancer. A literature search was conducted in electronic databases (Google Scholar, PubMed, Ovid, and Science Direct) and study selection was based on precise eligibility criteria. Random-effects meta-analyses were performed to estimate survival with low and high PCI scores and to pool hazard ratios (HR) of survival between lower and higher PCI scores. A total of 20 studies (2588 patients) were included. Median follow-up was 39 months [95%CI: 25, 54]. Complete cytoreduction rate was 80% [95% CI: 73, 87]. The median PCI score was 11.3 [95% CI: 9.9, 12.7]. Median survival was 56.7 months [95% CI: 45.2, 68.2] with below and 28.8 months [95% CI: 23.0, 34.6] with above any PCI cutoff. Most studies used PCI cutoffs between 10 and 20. The median progression-free survival was 23.7 months [95% CI: 16.5, 30.8] with below and 11.9 months [95% CI: 5.9, 17.9] with above any PCI cutoff. 5-year survival rates were 61.3% [95% CI: 49.9, 72.8] with PCI<10 cutoffs, 21.7% [95% CI: 11.6, 31.8] with PCI>10 cutoffs, 50.1% [95% CI: 39.0, 61.2] with PCI<20 cutoffs, and 21.7% [95% CI: 16.2, 27.1] with PCI>20 cutoffs. Pooled analysis of HRs showed that a higher PCI score was associated with worse survival in both univariate (HR 2.14 [95%CI: 1.63, 2.66]) and multivariate (HR 1.10 [95% CI: 1.02, 1.18]) analyses. In a set of studies that used varying PCI cutoffs, the PCI has been found to have a significant inverse association with the survival of patients with advanced ovarian cancer who underwent cytoreductive surgery.

[Peritoneal carcinomatosis secondary to CUP syndrome : Diagnosis and indications for multimodal treatment]

CLINICAL PROBLEM

Peritoneal carcinomatosis secondary to cancer of unknown primary (CUP) syndrome is a rare entity for which there are no uniform treatment recommendations or guidelines. The median survival time is 3 months.

DIAGNOSIS

Computed tomography (CT), magnetic resonance imaging (MRI), and ¹⁸F‑FDG positron emission tomography (PET)/CT are valid imaging modalities for the detection of peritoneal carcinomatosis. The sensitivity of all techniques is highest for large, macronodular peritoneal carcinomatosis manifestations. A limitation of all imaging techniques is limited and small-nodular peritoneal carcinomatosis. Also, peritoneal metastasis in the small bowel mesentery or diaphragmatic domes can only be visualized with low sensitivity. Therefore, exploratory laparoscopy should be considered as the next diagnostic step. In half of these cases an unnecessary laparotomy can be avoided, because the laparoscopy revealed diffuse, small-nodule involvement of the small bowel wall and thus an irresectable situation.

TREATMENT

In selected patients, performing complete cytoreduction followed by hyperthermic intra-abdominal chemotherapy (HIPEC) is a good therapeutic option. Therefore, the identification of the extent of peritoneal tumor manifestation as accurately as possible is important for the definition of the increasingly complex oncological therapy strategies.

FDG PET/CT for Staging and Restaging Malignant Mesothelioma

Malignant mesothelioma is an aggressive tumor originating from the mesothelial cells and presenting in general with a very poor prognosis. The pleural localization represents the prevailing disease site, while peritoneal involvement is commonly rare. The WHO classifies mesotheliomas into epithelioid, biphasic, and sarcomatoid histotypes, having diverse outcome with the sarcomatoid or biphasic forms showing the poorest prognosis. Given the peculiar rind-like pattern of growth, mesothelioma assessment is rather challenging for medical imagers. Conventional imaging is principally based on contrast-enhanced CT, while the role of functional and metabolic imaging is regarded as complementary. By focusing essentially on the staging and restaging role of [18F]FDG PET/CT in malignant mesotheliomas, the present review will summarize the available data present in literature and provide some hints on alternative imaging and future perspectives. Given the prevailing incidence of pleural disease, the majority of the information will be addressed on malignant pleural mesothelioma, although a summary of principal characteristics and imaging findings in patients with peritoneal mesothelioma will be also provided.

Prospective Comparison of the Performance of MRI Versus CT in the Detection and Evaluation of Peritoneal Surface Malignancies

Background: The performance of MRI versus CT in the detection and evaluation of peritoneal surface malignancies (PSM) remains unclear in the current literature. Our study is the first prospective study in an Asian center comparing the two imaging modalities, validated against intra-operative findings. Methods: A total of 36 patients with PSM eligible for CRS-HIPEC underwent both MRI and CT scans up to 6 weeks before the operation. The scans were assessed for the presence and distribution of PSM and scored using the peritoneal cancer index (PCI), which were compared against PCI determined at surgery. Results: Both MRI and CT were 100% sensitive and specific in detecting the overall presence of PSM. Across all peritoneal regions, the sensitivity and specificity for PSM detection was 49.1% and 93.0% for MRI, compared to 47.8% and 95.1% for CT (p = 0.76). MRI was more sensitive than CT for small bowel disease, although the difference did not reach statistical significance. Comparing PCI on imaging with intra-operative PCI, the mean difference was found to be −3.4 ± 5.4 (p < 0.01) for MRI, and −3.9 ± 4.1 (p < 0.01) for CT. The correlation between imaging and intra-operative PCI was poor, with a concordance coefficient of 0.76 and 0.79 for MRI and CT, respectively. Within individual peritoneal regions, there was also poor agreement between imaging and intra-operative PCI for both modalities, other than in regions 1 and 3. Conclusion: MRI and CT are comparable in the detection and evaluation of PSM. While sensitive in the overall detection of PSM, they are likely to underestimate the true disease burden.

Synopsis of a clinical practice guideline for pancreatic ductal adenocarcinoma with peritoneal dissemination in Japan; Japan Peritoneal Malignancy Study Group

Patients with pancreatic ductal adenocarcinoma (PDAC) with peritoneal dissemination have a dismal prognosis because discontinuation of systemic chemotherapy is required for massive ascites or poor performance status. The natural history, diagnosis and treatment of PDAC with peritoneal dissemination have not been fully investigated. We systematically reviewed published information on the clinical diagnosis and treatment of PDAC with peritoneal dissemination using the PubMed database (2000-2020) and provided recommendations in response to clinical questions. This guideline was created according to the "Minds Clinical Practice Guideline Development Guide 2017". The literature quality and body of evidence were evaluated with the GRADE System and classified into four levels ("strong", "medium", "weak", "very weak"). The strength of each final recommendation was decided by a vote of committee members based on the GRADE Grid method. These guidelines address three subjects: diagnostic, chemotherapeutic, and surgical approaches. They include nine clinical questions and statements with recommendation strengths, evidence levels, and agreement rates, in addition to one "column". This is the English synopsis of the 2021 Japanese clinical practice guideline for PDAC with peritoneal dissemination. It summarizes the clinical evidence for the diagnosis and treatment of PDAC with peritoneal dissemination and provides future perspectives.

The role of imaging in diagnosis and management of malignant peritoneal mesothelioma: a systematic review

PURPOSE

Imaging of the peritoneum and related pathology is a challenge. Among peritoneal diseases, malignant peritoneal mesothelioma (MPeM) is an uncommon tumor with poor prognosis. To date, there are no specific guidelines or imaging protocols dedicated for the peritoneum and MPeM. The objective of this study was to analyze the literature describing imaging modalities used for MPeM to determine their relative clinical efficacy and review commonly reported imaging features of MPeM to promote standardized reporting.

METHODS

We performed a systematic review of original research articles discussing imaging modalities in MPeM from 1999 to 2020. Effectiveness measures and common findings were compared across imaging modalities.

RESULTS

Among 582 studies analyzed, the most-used imaging modality was CT (54.3%). In the differentiation of MPeM from peritoneal carcinomatosis, one study found CT had a diagnostic sensitivity of 53%, specificity of 100%, and accuracy of 68%. Two studies found fluorodeoxyglucose positron emission tomography (FDG-PET) had sensitivity of 86-92%, specificity of 83-89%, and accuracy of 87-89%. Another study found magnetic resonance imaging (MRI) was the best predictor of the peritoneal carcinomatosis index. Characteristics shown to best differentiate MPeM from other diseases included ascites, peritoneal thickening, mesenteric thickening, pleural plaques, maximum tumor dimension, and number of masses.

CONCLUSION

Most published MPeM imaging studies utilized CT. PET/CT or MRI appear promising, and future studies should compare effectiveness of these modalities. MPeM imaging reports should highlight ascites, number of and maximum tumor dimension, peritoneal/mesenteric thickening, and associated pleural plaques, allowing for better aggregation of MPeM imaging data across studies.

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.

Treatment for Peritoneal Metastasis of Patients With Colorectal Cancer

From the perspective of survival outcomes, the cancer survival of colorectal cancer (CRC) in the whole stage has improved. Peritoneal metastasis (PM) is found in approximately 8% to 15% of patients with CRC, with a poorer prognosis than that associated with other sites of metastases. Randomized controlled trials and up-to-date meta-analyses provide firm evidence that cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) could significantly improve overall survival compared with systemic chemotherapy alone in selected patients with CRC-PM. Practical guidelines recommend that the management of CRC-PM should be led by a multidisciplinary team carried out in experienced centers and consider CRS plus HIPEC for selected patients. In this review, we aim to provide the latest results of land mark studies and an overview of recent insights with regard to the management of CRC-PM.

Characterizing omental PET/CT findings for differentiating tuberculous peritonitis from peritoneal carcinomatosis

PURPOSE

To characterize and investigate PET/CT findings in the omentum in the differentiation of tuberculous peritonitis (TBP) and peritoneal carcinoma (PC).

METHODS

Thirty-nine patients with TBP and 113 patients with PC who underwent PET/CT were retrospectively enrolled. The omental uptake intensity, distribution characteristics, contracture, size and boundary of soft-tissue lesions, and CT patterns were reviewed.

RESULTS

Absent and focal FDG uptake in the lesser omentum was more common in the PC patients (P = 0.034 and P = 0.017, respectively), and diffuse FDG uptake in the lesser omentum was more common in the TBP patients (P < 0.001). An apron-like pattern in the greater omentum commonly occurred in the TBP patients (P = 0.004). Micronodules (< 5 mm) were more common in the TBP patients (P < 0.001), and masses (> 3 cm) were more common in the PC patients (P = 0.001). Smudged and nodular patterns occurred more frequently in the TBP patients than in the PC patients (P < 0.001 and P = 0.003, respectively), and the caked pattern occurred more frequently in the PC patients (P < 0.001). There was no significant difference in the FDG uptake intensity and the boundary of soft-tissue lesions between the TBP and PC patients (P = 0.191 and P = 0.061, respectively).

CONCLUSION

Diffuse FDG uptake, an apron-like pattern, micronodules, and a smudged and nodular pattern might be significant differential features of TBP. Absent and/or focal FDG uptake, mass, and a caked pattern might be significant differential features of PC.

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.

To Enhance or Not to Enhance? The Role of Contrast Medium 18F-FDG PET/CT in Recurrent Ovarian Carcinomas

Background and Objectives: ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/X-ray computed tomography (PET/CT) represents the mainstay diagnostic procedure for suspected ovarian cancer (OC) recurrence. PET/CT can be integrated with contrast medium and in various diagnostic settings; however, the effective benefit of this procedure is still debated. We aimed to compare the diagnostic capabilities of low-dose and contrast-enhanced PET/CT (PET/ldCT and PET/ceCT) in patients with suspected ovarian cancer relapse. Materials and Methods: 122 OC patients underwent both PET/ldCT and PET/ceCT. Two groups of nuclear medicine physicians and radiologists scored the findings as positive or negative. Clinical/radiological follow-up was used as ground truth. Sensitivity, specificity, negative/positive predictive value, and accuracy were calculated at the patient and the lesion level. Results: A total of 455 and 474 lesions were identified at PET/ldCT and PET/ceCT, respectively. At the lesion level, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were not significantly different between PET/ldCT and PET/ceCT (98%, 93.3%, 97.4%, 94.9%, and 96.9% for PET/ldCT; 99%, 95.5%, 98.3%, 97%, and 98% for PET/ceCT, p = ns). At the patient level, no significant differences in these parameters were identified (e.g., p = 0.22 and p = 0.35 for accuracy, in the peritoneum and lymph nodes, respectively). Smaller peritoneal/lymph node lesions close to physiological FDG uptake sources were found in the cases of misidentification by PET/ldCT. PET/ceCT prompted a change in clinical management in four cases (3.2%) compared to PET/ldCT. Conclusions: PET/ceCT does not perform better than PET/ldCT but can occasionally clarify doubtful peritoneal findings on PET/ldCT. To avoid unnecessary dose to the patient, PET/ceCT should be excluded in selected cases.

Development of a high payload, cancer-targeting liposomes of methyl aminolevulinate for intraoperative photodynamic diagnosis/therapy of peritoneal carcinomatosis

Methyl aminolevulinate (MAL) is a photosensitizer topically used for photodynamic diagnosis (PDD) and photodynamic therapy (PDT) of skin pre-cancers and cancers. In this study, our goal is to expand the application of MAL to dual intraoperative PDD and PDT of peritoneal carcinomatosis. A new liposomal MAL formulation (lipMAL) designed for systemic or intraperitoneal administration was developed. LipMALs prepared by ammonium sulfate gradient technique achieved MAL payload up to 18% (w/w) with drug encapsulation efficiency in the range of 15.1-31.5%. All lipMALs demonstrated controlled MAL release behavior, and achieved strong fluorescence in cancer cells (SKOV3) but minimal fluorescence in non-cancer peritoneal cells (B14FAF28-G3). LipMALs led to significantly higher fluorescence levels than free MAL groups (P < 0.05), up to 6.8-fold of the free MAL fluorescence levels in SKOV3 cells. The PDD performance of lipMALs was also compared with free MAL in SKOV3/ B14FAF28-G3 co-cultures simulating ovarian cancer micrometastases on peritoneal surface. The lipMAL-treated cancer colonies glew more brightly than the free MAL treated colonies and were clearly distinguishable from the dim peritoneum background with unaided eyes. LipMAL also achieved significantly stronger anticancer PDT effects than free MAL both in terms of cell viability and colony-formation (P < 0.05) while demonstrating minimal dark toxicity. To conclude, a new promising aid for the surgeons to achieve more complete resection of tumors and PC micrometastases and clean up any residual cancer cells undetected was developed.

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.

Peritoneal cancer index (PCI) based patient selecting strategy for complete cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy in gastric cancer with peritoneal metastasis: A single-center retrospective analysis of 125 patients

OBJECTIVE

The role of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in gastric cancer with peritoneal metastasis (GCPM) is still controversial, mainly due to the limited survival benefit and uncertain patient selection. This study aims to construct a selecting strategy in GCPM for CRS + HIPEC.

METHODS

From a prospective established database, 125 patients were enrolled. All these patients were pathologically confirmed as GCPM and treated with CRS + HIPEC with or without preoperative or postoperative chemotherapy. The clinical documents and follow-up results were collected and analyzed with the primary endpoint of overall survival (OS) and the secondary endpoint of perioperative serious adverse events (SAEs).

RESULTS

The median OS of 125 GCPM patients treated with CRS + HIPEC was 10.7 months, with 1-, 2-, 3-, and 5-year survival rates of 43.8%, 24.7%, 18.6%, and 15.7%, respectively. The multivariate analysis identified completeness of cytoreduction (CC), SAEs, HIPEC drugs, and adjuvant chemotherapy as independent prognostic factors on OS. The median OS was 30.0 (95%CI: 16.8-43.3) months in CC-0 group, significantly better than 7.3 (95%CI: 5.8-8.8) months in CC1-3 group (P < 0.001). The median OS showed no significant difference among CC-1 (8.5, 95%CI: 6.7-10.2, months), CC-2 (5.6, 95%CI: 3.0-8.2, months) and CC-3 (6.5, 95%CI: 5.2-7.7, months) groups (P > 0.05 for all pairwise comparations). The nomogram based on peritoneal metastasis timing, preoperative tumor marker (TM), and peritoneal cancer index (PCI), with AUC of 0.985, showed a good accuracy and consistency between actual observation and prediction of the probability of complete CRS. The cutoffs of PCI were 16 for synchronous GCPM with normal TM, 12 for synchronous GCPM with abnormal TM, 10 for metachronous GCPM with normal TM, and 5 for metachronous GCPM with abnormal TM, setting the probability to achieve complete CRS as 50%.

CONCLUSIONS

Only complete CRS + HIPEC (CC-0) could improve survival for high selected GCPM patients with acceptable safety. An incomplete CRS (CC1-3) should be avoided for GCPM patients. Synchronous GCPM with PCI ≤16 and normal TM, synchronous GCPM with PCI ≤12 and abnormal TM, metachronous GCPM with PCI ≤10 and normal TM, or metachronous GCPM with PCI ≤5 and abnormal TM maybe potential indications for complete CRS + HIPEC treatment.

Accuracy of peritoneal carcinomatosis extent diagnosis by initial FDG PET CT in epithelial ovarian cancer: A multicentre study of the FRANCOGYN research group

INTRODUCTION

Peritoneal carcinomatosis extent in ovarian cancer is difficult to evaluate by imaging techniques even though it determines the surgical complexity and survival. The aim of this study was to estimate the accuracy of 2-[18F]-fluoro-2-deoxy-d-glucose (FDG)-PET CT (Positron-emission tomography coupled with Computerised Tomography) performed before any treatment, in the diagnosis of the extent of peritoneal carcinomatosis. We compared these results to per-operative observations/ histology samples obtained during surgery (laparotomy/ laparoscopy).

MATERIAL AND METHODS

All women managed for an epithelial ovarian cancer between 1st January 2000 and 30th June 2016 were included if they had a FDG PET CT, before initiation of any treatment (neoadjuvant chemotherapy or frontline cytoreductive surgery). The extent of disease on histology samples from cytoreductive surgery/observations during exploratory laparoscopy were compared with the PET CT results.

RESULTS

Over the study period, 980 women were managed for epithelial ovarian cancer, among them 90 (9.2 %) had a PET CT before any treatment. The diagnostic reliability of an ovarian lesion was 67.8 %, a colon lesion was 61.25 %, a small intestine lesion was 50.6 %, an epiploic lesion was 41.7 %, a pelvic ganglionic invasion was 62.9 % and a paraortic lymph node invasion was 61.5 %. PET CT was less effective than a standard CT examination.

CONCLUSION

PET CT is not the most effective imaging examination to estimate the extent of peritoneal carcinomatosis during the initial management of an epithelial ovarian cancer.

Molecular Imaging of Peritoneal Carcinomatosis in Ovarian Carcinoma

OBJECTIVE. This article discusses the emerging roles of ¹⁸F-FDG PET/CT and DWI in the assessment of peritoneal carcinomatosis in ovarian carcinoma from diagnostic accuracy to disease prognostication with gross pathologic correlation. CONCLUSION. PET/CT and DWI have incremental clinical values over conventional modalities with high predictive values of incomplete cytoreduction in ovarian carcinoma. The respective quantitative metrics offer evaluation of tumor burden with prognostic value in ovarian carcinoma.

Metabolic active peritoneal sites affect tumor debulking in ovarian and peritoneal cancers

Rationale and objectives

To evaluate the impact of metabolic parameters in the peritoneal cavity on the likelihood of achieving complete tumor debulking in patients with ovarian and peritoneal cancers.

Materials and methods

Forty-nine patients with ovarian and peritoneal cancers were included, who underwent pre-operative ¹⁸F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (¹⁸F-FDG PET/CT). The immediate surgical outcome was dichotomized into complete and incomplete tumor debulking. ¹⁸F-FDG PET/CT was qualitatively and quantitatively assessed by scrutinizing 15 anatomical sites for the presence of peritoneal carcinomatosis (PC). Patient-based and site-based diagnostic characteristics were described. Metabolic parameters (SUVmax, metabolic tumor volume and total lesion glycolysis) and the number of ¹⁸F-FDG avid peritoneal sites were evaluated between the two groups. Receiver operating curve (ROC) analysis was performed to determine the optimal cut-off value in predicting incomplete tumor debulking.

Results

Twenty-seven out of the 49 patients had PC and 11 had incomplete debulking. Patient-based and site-based accuracies for detection of PC were 87.8 and 97.6%, respectively. The number of ¹⁸F-FDG avid peritoneal sites was significantly different between complete and incomplete debulking groups (0.6 ± 0.8 versus 2.3 ± 1.7 sites respectively, p = 0.001), and the only independent significant risk factor among other metabolic parameters tested (odd ratio = 2.983, 95% CI 1.104–8.062) for incomplete tumor debulking with an optimal cut-off value of ≥4 (AUC = 0.816).

Conclusion

The number of ¹⁸F-FDG avid peritoneal sites increased the risk of incomplete tumor debulking after surgery and potentially useful in assisting treatment stratification in patients with ovarian and peritoneal cancers.

Can [18F]F-FDG PET/CT be used to assess the pre-operative extent of peritoneal carcinomatosis in patients with colorectal cancer?

PURPOSE

To evaluate whether PET/CT could be used to assess the extent of colorectal peritoneal metastases.

METHODS

All patients who underwent a PET/CT scan before a CRS-HIPEC procedure between January 1, 2010 and December 31, 2013 were retrospectively included (n = 35). Two nuclear medicine physicians (observer 1 and observer 2) separately reviewed the scans on intraperitoneal abnormalities. A simplified PCI was used to compare the extent of rPCI versus sPCI.

RESULTS

Included patients had a median age of 60.6 years. Histology of primary tumors were 51.5% adenocarcinomas, 37.1% mucinous adenocarcinoma, and 11.4% SRCC. Median sPCI was 9.5 (5.0-11.8) and median rPCI was 5.0 (3.0-7.0) for observer 1 and 4.0 (3.0-6.0) for observer 2 (p = 0.02 and p = 0.01, respectively). When compared to the surgical data, PET/CT showed a poor correlation for assessing the extent of PC for both adenocarcinoma (observer 1 rho - 0.17, p = 0.51 and observer 2 rho 0.13, p = 0.61) as well as mucinous carcinoma or SRCC (observer 1 rho 0.44, p = 0.08 and observer 2 rho 0.38, p = 0.14).

CONCLUSION

PET/CT underestimates the extent of PC during surgery in both mucinous and non-mucinous CRC and is not recommended for intraperitoneal tumor scoring.

The role of single-incision laparoscopic peritoneal exploration in the management of patients with peritoneal metastases

BACKGROUND

The outcome of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) depends on the extent of peritoneal metastases (PM) and the completeness of cytoreduction (CCR). The role of preoperative assessment of PM is to identify potential candidates for CRS/HIPEC and to prevent unwarranted laparotomy for those who are not. Laparoscopy has been utilized for that purpose but with concerns related to technical difficulties and risk of trocar site metastases. Single-incision laparoscopic peritoneal exploration (SILPE) has not yet been evaluated in this setting.

METHODS

This single-center retrospective study examined patients from January 2011 to December 2015 who underwent SILPE for diagnosis and staging of PM. Preoperative, intraoperative, and postoperative data were collected. For the patients who underwent subsequent laparotomy, a comparison between SILPE and laparotomy findings was made.

RESULTS

A total of 183 SILPE were performed. Primary sites were mostly colorectal in 72 cases (39.3%) and gastric in 47 (25.7%). Overall, 157 patients (85.8%) had at least one prior abdominal surgery and 48 (26.2%) had 3 or more. SILPE was successfully achieved in 90.2% of the cases. Two (1.2%) intraoperative complications and five (3%) postoperative complications were observed. Eighty-one patients had laparotomy, with a median of 27 days between SILPE and laparotomy (4-162 days). The peritoneal carcinomatosis index PCI was 9.7 ± 7.5 at SILPE, and 13.5 ± 9.6 at laparotomy. The positive predictive value of SILPE to predict CCR was 79.5%. SILPE sensitivity was 75% and specificity 97%. The lowest sensitivity was in regions 9-12 ranging from 44 to 53%.

CONCLUSION

SILPE can be safely incorporated in the management of patients with PM. It is a safe and feasible staging tool, allowing for preventing unwarranted laparotomy for patients not deemed candidate for CRS/HIPEC. Even though it may underestimate PCI, SILPE accurately predicts the possibility of CCR.

Improved Peritoneal Cavity and Abdominal Organ Imaging Using a Biphasic Contrast Agent Protocol and Spectral Photon Counting Computed Tomography K-Edge Imaging

OBJECTIVES

To validate in vitro the capability of a high-spatial-resolution prototype spectral photon-counting computed tomography (SPCCT) scanner to differentiate between 2 contrast agents and to assess in vivo the image quality and the feasibility to image the peritoneal cavity in rats using the 2 contrast agents simultaneously within the vascular and peritoneal compartments.

MATERIALS AND METHODS

The authors performed SPCCT imaging (100 mAs, 120 kVp) with energy bin thresholds set to 30, 51, 64, 72, and 85 keV in vitro on a custom-made polyoxymethylene cylindrical phantom consisting of tubes with dilutions of both contrast agents and in vivo on 2 groups of adult rats using 2 injection protocols. Approval from the institutional animal ethics committee was obtained. One group received macrocylic gadolinium chelate intraperitoneal (IP) and iodine intravenous (IV) injections (protocol A, n = 3), whereas the second group received iodine IP and gadolinium IV (protocol B, n = 3). Helical scans were performed 35 minutes after IP injection and 20 seconds after IV injection. The SPCCT and contrast material images, that is, iodine and gadolinium maps, were reconstructed with a field of view of 160 mm, an isotropic voxel size of 250 μm, and a matrix size of 640 × 640 pixels using a soft reconstruction kernel. The SPCCT images were reconstructed with 2 different spatial resolutions to compare the image quality (sharpness, diagnostic quality, and organ visualization) of SPCCT (250 μm) with single-energy computed tomography (CT) (600 μm). Two radiologists evaluated the peritoneal opacification index in 13 regions (score = 0-3 per region) on each type of image. Concentrations of contrast agents were measured in the organs of interest.

RESULTS

In vitro, the concentration measurements correlated well with the expected concentrations. The linear regressions both had R values of 0.99, slopes of 0.84 and 0.87, and offsets at -0.52 and -0.38 mg/mL for iodine and gadolinium, respectively. In vivo, the SPCCT images were of better diagnostic quality, with increased sharpness compared with the CT-like images (P < 0.0001). Intraperitoneal diffusion was excellent, with similar peritoneal opacification index on SPCCT images and overlay of contrast material maps (P = 1) without a significant difference between protocol A (37.0 ± 1.7) and protocol B (35.3 ± 1.5) (P = 0.34). Only the contrast material maps demonstrated clear visual separation of the contrast agents, allowing specific quantification of the physiological enhancement in the liver, spleen, and kidney and the urinary clearance in the renal pelvis and bladder. Renal excretion of the contrast agents injected IP was observed and was consistent with blood diffusion.

CONCLUSIONS

Spectral photon-counting CT can be used to perform a complete peritoneal dual-contrast protocol, enabling a good assessment of the peritoneal cavity and abdominal organs in rats.

Can machine learning predict resecability of a peritoneal carcinomatosis?

BACKGROUND

Approximately 20% of initially eligible patients in a HIPEC procedure eventually underwent a simple surgical exploration. These procedures are called 'open & close' (O & C) representing up to 48% of surgery. The objective of this study was to predict the resecability of peritoneal carcinomatosis using a machine-learning model for decision-making support, for eligible patients of HIPEC.

METHODS

The study was conducted as an intention to treat based on three databases including a prospective, between January 2000 and December 2015. A propensity score allowed us to obtain two groups of comparable and matched patients. Subsequently, several algorithm models of classification were studied (simple classification, conditional tree, support vector machine, random forest) to determine the model having the best performance and accuracy.

RESULTS

Two groups of 155 patients were obtained: one group without resection and one group with resection. Nine criteria of non-resecability reflecting the organ involvement have been retained. They were coded according to their importance. Five classification algorithms were tested. The training data included 218 patients and 92 test data. The random forest model exhibited the best performance with an accuracy of close to 98%. Only two errors of predictions were observed.

DISCUSSION

The largest number of patients will allow us to improve the precision prediction. Gathering more data such as biologic, radiologic, and even laparoscopic features, should improve the knowledge of the disease and decrease the number of 'O & C' procedures.

Mucinous appendiceal neoplasms: classification, imaging, and HIPEC

Recent advances, specifically cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), offer advantages compared to the traditional therapeutic approach of systemic chemotherapy in the treatment of peritoneal carcinomatosis from mucinous appendiceal neoplasms (MAN). This review provides an up-to-date, comprehensive summary of the histologic classification of MAN, reviews common imaging findings of mucoceles and pseudomyxoma peritonei, and describes the radiologist's role in the multidisciplinary care team in quantifying disease and in helping select patients for definitive surgery.

ACR Appropriateness Criteria® Staging and Follow-Up of Ovarian Cancer

In the management of epithelial ovarian cancers, imaging is used for cancer detection and staging, both before and after initial treatment. The decision of whether to pursue initial cytoreductive surgery for ovarian cancer depends in part on accurate staging. Contrast-enhanced CT of the abdomen and pelvis (and chest where indicated) is the current imaging modality of choice for the initial staging evaluation of ovarian cancer. Fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT and MRI may be appropriate for problem-solving purposes, particularly when lesions are present on CT but considered indeterminate. In patients who achieve remission, clinical suspicion for relapse after treatment prompts imaging evaluation for recurrence. Contrast-enhanced CT is the modality of choice to assess the extent of recurrent disease, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT is also usually appropriate, as small metastatic foci may be identified. If imaging or clinical examination confirms a recurrence, the extent of disease and timing of disease recurrence then determines the choice of treatments, including surgery, chemotherapy, and radiation therapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Peritoneal MRI in patients undergoing cytoreductive surgery and HIPEC: History, clinical applications, and implementation

MR imaging provides considerable advantages in the evaluation of patients with peritoneal metastases. A standardized peritoneal MRI protocol, including diffusion-weighted and gadolinium-enhanced sequences, allows an efficient exploration of small peritoneal tumors that are often missed on other imaging tests. In experienced hands, a dedicated reading allows producing a quantitative and qualitative evaluation of lesional localization to better assist surgeons in the selection of candidates for curative surgery by evaluating the possibility of complete resection, and to plan the surgical procedure. Based on a close collaboration between oncologic surgeon and radiologist, MRI provides a powerful tool for accurate preoperative imaging in patients being considered for curative surgery but also in their surveillance to detect an early recurrence.

History of Peritoneal Surface Malignancy Treatment in Japan

In this review, Japanese experience of cytoreductive surgery and perioperative chemotherapy is described. The new concept of peritoneal metastasis (PM) type, i.e., trans-mesothelial, trans-lymphatic, and superficial growing metastasis type was proposed in 2012. Surgeons should perform peritonectomy according to the type of PM. Since 1980, Japanese surgical oncologists have been spearheading the use of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemoperfusion (HIPEC) as treatment for PM from gastric cancer. Two RCTs were conducted to verify the effect of HIPEC for the prophylaxis of peritoneal recurrence after curative resection of advanced gastric cancer. These two studies indicated that HIPEC is effective in preventing peritoneal recurrence of gastric cancer with serosal invasion. In 2002, intraperitoneal chemotherapy using taxans was developed for the treatment of PM from gastric cancer and led to the development of neoadjuvant intraperitoneal/systemic chemotherapy (NIPS), which was reported in 2006. In 2009, extensive intra-operative peritoneal lavage (EIPL) was developed, and contributed to the remarkable improvement in survival of patients with positive lavage cytology as demonstrated by prospective randomized clinical trials. In 2017, the Peritoneal Surface Oncology Group International proposed the value of complete cytoreduction and peritoneal cancer index cut-off as independent prognostic factors after CRS for gastric cancer with PM. Founded in 2016, the Japanese/Asian School of Peritoneal Surface Oncology (JASPSO) trains beginners to perform CRS and HIPEC safely. Sixteen students have already graduated from JASPSO and started to perform the treatment in their home countries.

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.

Imaging for Peritoneal Metastases

MRI provides considerable advantages for imaging of patients with peritoneal tumor. Its inherently superior contrast resolution compared with computed tomography allows MRI to more accurately depict small peritoneal tumors that are often missed on other imaging tests. Combining different contrast mechanisms, including diffusion-weighted MRI and gadolinium-enhanced MRI, provides a powerful tool for preoperative and surveillance imaging in patients being considered for cytoreductive surgery and heated intraperitoneal chemotherapy.

Positron emission tomography (PET) and magnetic resonance imaging (MRI) for assessing tumour resectability in advanced epithelial ovarian/fallopian tube/primary peritoneal cancer

BACKGROUND

Ovarian cancer is the leading cause of death from gynaecological cancer in developed countries. Surgery and chemotherapy are considered its mainstay of treatment and the completeness of surgery is a major prognostic factor for survival in these women. Currently, computed tomography (CT) is used to preoperatively assess tumour resectability. If considered feasible, women will be scheduled for primary debulking surgery (i.e. surgical efforts to remove the bulk of tumour with the aim of leaving no visible (macroscopic) tumour). If primary debulking is not considered feasible (i.e. the tumour load is too extensive), women will receive neoadjuvant chemotherapy to reduce tumour load and subsequently undergo (interval) surgery. However, CT is imperfect in assessing tumour resectability, so additional imaging modalities can be considered to optimise treatment selection.

OBJECTIVES

To assess the diagnostic accuracy of fluorodeoxyglucose-18 (FDG) PET/CT, conventional and diffusion-weighted (DW) MRI as replacement or add-on to abdominal CT, for assessing tumour resectability at primary debulking surgery in women with stage III to IV epithelial ovarian/fallopian tube/primary peritoneal cancer.

SEARCH METHODS

We searched MEDLINE and Embase (OVID) for potential eligible studies (1946 to 23 February 2017). Additionally, ClinicalTrials.gov, WHO-ICTRP and the reference list of all relevant studies were searched.

SELECTION CRITERIA

Diagnostic accuracy studies addressing the accuracy of preoperative FDG-PET/CT, conventional or DW-MRI on assessing tumour resectability in women with advanced stage (III to IV) epithelial ovarian/fallopian tube/primary peritoneal cancer who are scheduled to undergo primary debulking surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles and abstracts for relevance and inclusion, extracted data and performed methodological quality assessment using QUADAS-2. The limited number of studies did not permit meta-analyses.

MAIN RESULTS

Five studies (544 participants) were included in the analysis. All studies performed the index test as replacement of abdominal CT. Two studies (366 participants) addressed the accuracy of FDG-PET/CT for assessing incomplete debulking with residual disease of any size (> 0 cm) with sensitivities of 1.0 (95% CI 0.54 to 1.0) and 0.66 (95% CI 0.60 to 0.73) and specificities of 1.0 (95% CI 0.80 to 1.0) and 0.88 (95% CI 0.80 to 0.93), respectively (low- and moderate-certainty evidence). Three studies (178 participants) investigated MRI for different target conditions, of which two investigated DW-MRI and one conventional MRI. The first study showed that DW-MRI determines incomplete debulking with residual disease of any size with a sensitivity of 0.94 (95% CI 0.83 to 0.99) and a specificity of 0.98 (95% CI 0.88 to 1.00) (low- and moderate-certainty evidence). For abdominal CT, the sensitivity for assessing incomplete debulking was 0.66 (95% CI 0.52 to 0.78) and the specificity 0.77 (95% CI 0.63 to 0.87) (low- and low-certainty evidence). The second study reported a sensitivity of DW-MRI of 0.75 (95% CI 0.35 to 0.97) and a specificity of 0.96 (95% CI 0.80 to 1.00) (very low-certainty evidence) for assessing incomplete debulking with residual disease > 1 cm. In the last study, the sensitivity for assessing incomplete debulking with residual disease of > 2 cm on conventional MRI was 0.91 (95% CI 0.59 to 1.00) and the specificity 0.97 (95% CI 0.87 to 1.00) (very low-certainty evidence). Overall, the certainty of evidence was very low to moderate (according to GRADE), mainly due to small sample sizes and imprecision.

AUTHORS' CONCLUSIONS

Studies suggested a high specificity and moderate sensitivity for FDG-PET/CT and MRI to assess macroscopic incomplete debulking. However, the certainty of the evidence was insufficient to advise routine addition of FDG-PET/CT or MRI to clinical practice..In a research setting, adding an alternative imaging method could be considered for women identified as suitable for primary debulking by abdominal CT, in an attempt to filter out false-negatives (i.e. debulking, feasible based on abdominal CT, unfeasible at actual surgery).

Phase I Study of Oncolytic Vaccinia Virus GL-ONC1 in Patients with Peritoneal Carcinomatosis

Purpose: Peritoneal carcinomatosis is common in advanced tumor stages or disease recurrence arising from gastrointestinal cancers, gynecologic malignancies, or primary peritoneal carcinoma. Because current therapies are mostly ineffective, new therapeutic approaches are needed. Here, we report on a phase I study designed to assess safety, MTD, and antitumor activity of intraperitoneal administration of oncolytic vaccinia virus GL-ONC1 in advanced stage peritoneal carcinomatosis patients.Patients and Methods: GL-ONC1 was administered intraperitoneally every 4 weeks for up to four cycles at three different dose levels (10⁷-10⁹ pfu) following a standard 3+3 dose escalation design. GL-ONC1 was infused via an indwelling catheter that enabled repetitive analyses of peritoneal fluid biopsies. The primary study objective was safety of GL-ONC1 according to Common Terminology Criteria for Adverse Events, version 4.0 (CTCAEv4.0).Results: Patients with advanced-stage peritoneal carcinomatosis (n = 7) or advanced peritoneal mesothelioma (n = 2) received 24 doses of GL-ONC1. Adverse events were limited to grades 1-3, including transient flu-like symptoms and increased abdominal pain, resulting from treatment-induced peritonitis. No DLT was reported, and the MTD was not reached. Furthermore, no signs of viral shedding were observed. Importantly, in 8 of 9 study patients, effective intraperitoneal infections, in-patient replication of GL-ONC1, and subsequent oncolysis were demonstrated in cycle 1. All patients developed neutralizing activities against GL-ONC1.Conclusions: GL-ONC1 was well tolerated when administered into the peritoneal cavity of patients with advanced stage peritoneal carcinomatosis. Efficient tumor cell infection, in-patient virus replication, and oncolysis were limited to treatment cycle 1 (ClinicalTrials.gov number, NCT01443260). Clin Cancer Res; 24(18); 4388-98. ©2018 AACR.

Diagnostic value of contrast-enhanced CT combined with 18-FDG PET in patients selected for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC)

PURPOSE

Aim of the study is to assess the reliability and correlation with surgical peritoneal cancer index (PCI) of combined PET/CT and ceCT scans (PET/ceCT) performed in a session in patients with peritoneal carcinomatosis candidates for cytoreductive surgery (CS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

We retrospectively analyzed data collected from 27 patients with different types of peritoneal carcinomatosis candidates to CS + HIPEC who underwent FDG PET/ceCT in a single session. Two nuclear medicine physicians and two radiologists independently and blindly evaluated PET/CT and ceCT imaging, respectively. In the case of discordance, the consensus was reached by a discussion between the specialists. Moreover, the combined images were evaluated by all the specialists in consensus. The PCIs obtained from surgical look, PET/CT, ceCT, and PET/ceCT were compared with each other. The coefficients of correlation (r) were calculated. The study was conducted after approval of local ethics committee.

RESULTS

Surgical PCI was available in 21 patients. The coefficient of correlation between PCI of PET/CT and surgery was 0.528, while it resulted higher between PET/ceCT and surgery (r = 0.878), very similar to ceCT and surgery (r = 0.876). The r coefficient between surgical PCI and PET/CT was higher in patients with a non-mucinous cancer (n = 12) than the counterpart (0.601 vs. 0.303) and the addition of ceCT significantly increases the correlation (r = 0.863), which is anyway similar to ceCT alone (r = 0.856).

CONCLUSIONS

PET/ceCT as single examination is more accurate than PET/CT but not than ceCT alone for the definition of PCI in a selected group of patients candidates to CS + HIPEC.

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.

Treatment of peritoneal metastases from gastric carcinoma

Patients with advanced gastric cancer and positive peritoneal cytology and/or peritoneal dissemination are deemed to be incurable and to hold dismal prognosis. So far, the only treatment option for these patients has been palliative systemic (chemo)therapy. However, for the last three decades, great progress has been made in attempts to treat (potential) peritoneal dissemination by means of complete cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) after preoperative systemic therapy. This review is focused on the recent achievements of this multimodal strategy. Additionally, the review stands as background for the 4th International Conference “Advances in Surgical Oncology” that was held at the Medical University of Lublin (Poland) in November 2017, and dedicated to cytoreductive surgery and HIPEC for advanced gastric cancer.

A case of advanced gastric cancer achieved a pathological complete response by chemotherapy

BACKGROUND

Although chemotherapy is the first recommended treatment of unresectable gastric cancer, a pathological complete response is a rare event.

CASE PRESENTATION

A 58-year-old male was diagnosed as gastric cancer with a bulky tumor, lymphadenopathy, and suspicious peritoneal dissemination. The patient underwent chemotherapy with S-1 and cisplatin. After three courses of chemotherapy, a computed tomography showed dramatic improvements in gastric wall thickening, shrinkage of lymphadenopathy, and disappearance of disseminated peritoneal lesion. The patient underwent potentially curative resection by total gastrectomy with D2 lymph node dissection. Histological examination revealed the absence of malignant cells not only in the resected specimen but also in the harvested lymph nodes. At present, more than 7 years after the initial surgery, the patient is still alive without any recurrence.

CONCLUSIONS

We obtained a pathological complete response by chemotherapy with S-1 and cisplatin for advanced gastric cancer. Although a pathological complete response is a rare event, it would be associated with the long-term survival of patients with advanced gastric cancer.

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

OBJECTIVE

The current review aimed to investigate the performance of the diagnostic accuracy of ¹⁸F- fludeoxyglucose positron emission tomography/CT (PET/CT) in detecting peritoneal carcinomatosis (PC) through a systematic review and meta-analysis.

METHODS

The MEDLINE via PubMed and EMBASE from the earliest available date of indexing to 31 March 2017, were searched for studies evaluating the diagnostic performance of ¹⁸F-FDG PET/CT in detecting PC. We evaluated the pooled sensitivities and specificities across included studies, calculated positive and negative likelihood ratios (LR+ and LR-), and plotted summary receiver operating characteristic curves. Deek's funnel plot asymmetry tests were used to assess the possible underlying publication bias.

RESULTS

The current meta-analysis demonstrated no significant publication bias (p = 0.21). Across 14 studies (671 patients), the overall sensitivity of ¹⁸F-FDG PET/CT was 0.87 [95% CI (0.77-0.93)] with heterogeneity (χ² = 94.2, p = 0.00) and a pooled specificity of 0.92 [95% CI; (0.89-0.94)] with heterogeneity (χ² = 20.6, p = 0.08). LR syntheses gave an overall LR+ of 10.4 [95% CI (7.5-14.5)] and LR- of 0.14 [95% CI (0.08-0.26)]. The pooled diagnostic odds ratio was 73 [95% CI (34-159)]. In univariate meta-regression analysis, publication year and cohort homogeneity were the potent sources of heterogeneity. However, in multivariate meta-regression, no definite variable was the source of the study heterogeneity.

CONCLUSION

¹⁸F-FDG PET/CT demonstrated good sensitivity and specificity for the detection of PC. Further large multicentre studies would be necessary to substantiate the diagnostic accuracy of ¹⁸F-FDG PET/CT for the diagnosis of PC in various cancers. Advances in knowledge: ¹⁸F-FDG PET/CT showed good diagnostic performance in the evaluation of PC and could provide additional information for that purpose in various cancers.

1st Evidence-based Italian consensus conference on cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal carcinosis from ovarian cancer

Ovarian cancer (OC) remains relatively rare, although it is among the top 4 causes of cancer death for women younger than 50. The aggressive nature of the disease and its often late diagnosis with peritoneal involvement have an impact on prognosis. The current scientific literature presents ambiguous or uncertain indications for management of peritoneal carcinosis (PC) from OC, both owing to the lack of sufficient scientific data and their heterogeneity or lack of consistency. Therefore, the Italian Society of Surgical Oncology (SICO), the Italian Society of Obstetrics and Gynaecology, the Italian Association of Hospital Obstetricians and Gynaecologists, and the Italian Association of Medical Oncology conducted a multidisciplinary consensus conference (CC) on management of advanced OC presenting with PC during the SICO annual meeting in Naples, Italy, on September 10-11, 2015. An expert committee developed questions on diagnosis and staging work-up, indications, and procedural aspects for peritonectomy, systemic chemotherapy, and hyperthermic intraperitoneal chemotherapy for PC from OC. These questions were provided to 6 invited speakers who answered with an evidence-based report. Each report was submitted to a jury panel, representative of Italian experts in the fields of surgical oncology, gynecology, and medical oncology. The jury panel revised the reports before and after the open discussion during the CC. This article is the final document containing the clinical evidence reports and statements, revised and approved by all the authors before submission.

Recommendations and consensus on the treatment of peritoneal metastases of colorectal origin: a systematic review of national and international guidelines

AIM

This systematic review aimed to provide an overview of (inter)national guidelines on the treatment of peritoneal metastases of colorectal cancer origin (PMCRC) and to determine the degree of consensus and available evidence with identification of topics for future research.

METHOD

A systematic search of MEDLINE, Embase, PubMed as well as Tripdatabase, National Guideline Clearinghouse, BMJ Best Practice and Guidelines International Network was performed to identify (inter)national guidelines and consensus statements from oncological or surgical societies on PMCRC. The quality of guidelines was assessed using the AGREE-II score. Topics followed by recommendations were extracted from the guidelines. The recommendations, highest level of supporting evidence and the degree of consensus were determined for each topic.

RESULTS

Twenty-one guidelines were included, in most (15) of which cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) was recommended in selected patients based on level 1b evidence. Substantial consensus was also reached on the benefit of multidisciplinary team discussion and the achievability of a (near) complete cytoreduction (CC0-1) without supporting evidence. Both evidence and consensus were lacking regarding other aspects including preoperative positron emission tomography/CT, second look surgery in high risk patients, the optimal patient selection for CRS/HIPEC, procedural aspects of HIPEC and (perioperative) systemic therapy.

CONCLUSION

In currently available guidelines, evidence and consensus on the treatment strategy for PMCRC are lacking. Updates of guidelines are ongoing and future (randomized) clinical trials should contribute to multidisciplinary and international consensus on treatment strategies for PMCRC.

What the Radiologist Should Know About Treatment of Peritoneal Malignancy

OBJECTIVE

The purpose of this article is to discuss the role of the radiologist in the treatment of peritoneal cancer, with focus placed on advanced treatment options and selection of patients with resectable disease for whom complete cytoreduction can be achieved.

CONCLUSION

Peritoneal cancers traditionally have been associated with significant morbidity and universal mortality; however, the management of such cancers has evolved substantially. Advanced treatment options, including cytoreductive surgery and intraperitoneal chemotherapy, are associated with significantly improved long-term patient survival. To ensure that patients benefit from aggressive multimodality treatments, the radiologist plays a pivotal role in the multidisciplinary team to ensure careful patient selection, identifying individuals with resectable disease for whom complete cytoreduction can be achieved.

Survival and Prognostic Factors for Metachronous Peritoneal Metastasis in Patients with Colon Cancer

BACKGROUND

The clinical course of metachronous peritoneal metastasis of colorectal origin is poorly understood. In this retrospective study, we aimed to elucidate survival and prognostic factors for metachronous peritoneal metastasis.

METHODS

Patients with metachronous peritoneal metastasis after curative resection for stage I-III colon cancer were retrospectively reviewed, and the incidence and prognosis of metachronous peritoneal metastasis were investigated. Prognostic factors were identified by univariate and multivariate analyses.

RESULTS

Among 1582 surgically resected stage I-III colon cancer patients, 65 developed metachronous peritoneal metastasis. The 5-year cumulative incidence rate was 4.5%, and the median survival after diagnosis of peritoneal metastasis was 29.6 months. None of the patients underwent peritonectomy or intraperitoneal chemotherapy. Independent prognostic factors included right colon cancer [hazard ratio (HR) 2.69, 95% confidence interval (CI) 1.26-5.64; p = 0.011], time to metachronous peritoneal metastasis of <1 year (HR 2.02, 95% CI 1.04-3.87; p = 0.040), Peritoneal Cancer Index (PCI) >10 (HR 3.68, 95% CI 1.37-8.99; p = 0.012), concurrent metastases (HR 4.09, 95% CI 2.02-8.23; p < 0.001), and peritoneal nodule resection (HR 0.31, 95% CI 0.13-0.65; p = 0.002).

CONCLUSIONS

A proportion of colon cancer patients with metachronous peritoneal metastasis may benefit from combined peritoneal nodule resection and systemic chemotherapy. Right colon cancer, early peritoneal metastasis, a high PCI, and concurrent metastases negatively affected prognosis in patients with metachronous peritoneal metastasis.

Cytoreductive surgery and intraperitoneal chemotherapy for peritoneal carcinomatosis of colorectal cancer: 2-year follow-up results at a single institution in Korea

Purpose

The purpose of this study was to examine 2-year follow-up results of cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) for peritoneal carcinomatosis (PC) of colorectal cancer.

Methods

We performed 54 cases of CRS and IPC in 53 patients with PC of colorectal cancer from December 2011 to December 2013. We collected data prospectively and analyzed the grade of PC, morbidity and mortality, and short-term follow-up (median, 10 months; range, 2–47 months) results.

Results

Mean peritoneal cancer index (PCI) was 15 (range, 1–35), and complete cytoreduction was possible in 35 patients (64.8%). Complications occurred in 25 patients (46.3%) and mortality occurred in 4 patients (7.4%). Excluding the 4 mortalities, 17 patients out of 49 patients (31.5%) were alive at the time of the last follow-up and the overall median survival was 10.3 months. Patients with complete cytoreduction had a median survival of 22.6 months, which was significantly longer than the median survival of 3.5 months for patients without complete cytoreduction (P < 0.001). PCI grade, CCR grade, cell type, and postoperative chemotherapy were significant prognostic factors by univariate analysis. Positive independent prognostic factors by multivariate analysis included PCI grade and postoperative chemotherapy.

Conclusion

CRS and IPC increased the survival of patients with low PCI and postoperative systemic chemotherapy was mandatory. However, this combined therapeutic approach showed high rate of complications and mortality. Therefore, this aggressive treatment should be performed in only selected patients by considering the general condition of the patient and the extent of PC.