Peritoneal carcinomatosis

Clinical and Radiological Parameters to Discriminate Tuberculous Peritonitis and Peritoneal Carcinomatosis

It is challenging to differentiate between tuberculous peritonitis and peritoneal carcinomatosis due to their insidious nature and intersecting symptoms. Computed tomography (CT) is the modality of choice in evaluating diffuse peritoneal disease. We conducted an ambispective analysis of patients suspected as having tuberculous peritonitis or peritoneal tuberculosis between Jan 2020 to Dec 2021. The study aimed to identify the clinical and radiological features differentiating the two entities. We included 44 cases of tuberculous peritonitis and 45 cases of peritoneal carcinomatosis, with a median age of 31.5 (23.5-40) and 52 (46-61) years, respectively (p ≤ 0.001). Fever, past history of tuberculosis, and loss of weight were significantly associated with tuberculous peritonitis (p ≤ 0.001, p = 0.038 and p = 0.001). Pain in the abdomen and history of malignancy were significantly associated with peritoneal carcinomatosis (p = 0.038 and p ≤ 0.001). Ascites was the most common radiological finding. Loculated ascites, splenomegaly and conglomeration of lymph nodes predicted tuberculous peritonitis significantly (p ≤ 0.001, p = 0.010, p = 0.038). Focal liver lesion(s) and nodular omental involvement were significantly associated with peritoneal carcinomatosis (p = 0.011, p = 0.029). The use of clinical features in conjunction with radiological findings provide better diagnostic yields because of overlapping imaging findings.

Rectal metastasis of gastric cancer: a case report

The most common metastatic sites of gastric cancer include the liver, peritoneum, lung, and bone. However, there is a lack of relevant clinical reports regarding rectal metastasis. Herein, we report the rare case of a patient with gastric cancer who developed rectal metastasis. A 57-year-old male patient was diagnosed with gastric cancer and underwent a radical gastrectomy in January 2016, followed by eight cycles of adjuvant chemotherapy. The patient subsequently developed a rectal mass in March 2021. He was diagnosed with rectal adenocarcinoma and underwent surgical resection of the rectal tumor. A mass was then found in the abdominal wall in September 2021 and was resected. Specimens obtained from the three surgeries were reviewed, and the rectal tumor and the mass in the abdominal wall were both found to be metastatic tumors from the gastric cancer. Metastasis of gastric cancer to the rectum is rare, but it is important to differentiate between rectal metastasis and primary rectal cancer to help avoid unnecessary treatment.

Intraperitoneal anatomy with the aid of pathologic fluid and gas: An imaging pictorial review

The peritoneum is a large serosal membrane enveloping the abdomen and pelvic organs and forming the peritoneal cavity. This complex relationship forms many named abdominopelvic spaces, which are frequently involved in infectious, inflammatory, neoplastic, and traumatic pathologies. The knowledge of this anatomy is essential to the radiologist to localize and describe the extent of the disease accurately. This manuscript provides a comprehensive pictorial review of the peritoneal anatomy to describe pathologic fluid and gas.

Lymphomatosis as a Cause of Abdominal Pain and Distension in Two Adult Horses

Two equine patients presented separately with severe abdominal distention, colic, lethargy, and decreased appetite. An ante-mortem diagnosis of lymphoma was reached in each case based on peritoneal fluid cytology. Due to a poor prognosis, the horses were humanely euthanized. Post-mortem examination with histology and immunohistochemistry confirmed both cases as lymphoma: alimentary B-cell lymphoma of the distal jejunum and cecum in one case, and T-cell lymphoma of the cecum in the second case. Both cases exhibited extensive metastasis with peritoneal and pleural serosae covered in small nodules and plaque like masses consistent with lymphomatosis. These cases document a unique presentation of lymphoma in equine patients presenting as peritoneal lymphomatosis with ascites.

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.

Role and usefulness of mr imaging in the assessment of peritoneal carcinomatosis

BACKGROUND

For many years, peritoneal carcinomatosis (PC) entitled poor prognosis until the development of the cytoreductive surgery technique associated with hyperthermic intraperitoneal chemotherapy. Imaging of peritoneal carcinomatosis plays an essential role in the diagnosis and management of the patients being considered for cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC).

MAIN BODY

The key role of imaging in patients with peritoneal malignancy is to aid surgical decision making. A standardized peritoneal magnetic resonance (MR) imaging protocol, including T2-weighted fat suppressed, diffusion-weighted and gadolinium-enhanced sequences, allows to detect small peritoneal tumours that are often missed on other imaging. A systematic approach to MR imaging and a close collaboration between the radiologist and the oncologic surgeon are key elements for an accurate evaluation of candidate patients for CRS and HIPEC.

CONCLUSION

MR imaging provides a powerful tool for accurate preoperative imaging in patients considered for curative surgery and assists the surgeon in evaluating patients for CRS and HIPEC.

Primary peritoneal serous carcinoma: a primer for radiologists

Primary peritoneal serous carcinoma (PPSC) is a rare primary peritoneal tumor characterized by a unique range of clinical features and imaging findings. Though it shares many clinical, histologic, and imaging features with serous ovarian carcinoma, it remains a distinct clinical entity. Although less common than its primary ovarian counterpart, PPSC is characterized by a prognosis that is often equally poor with presentations common in late stages of disease. Key imaging modalities used in the evaluation of PPSC include ultrasound, CT, MRI, and PET/CT. For radiologists, an understanding of the pertinent imaging findings, pathologic correlations, and clinical features of PPSC is essential for arriving at the correct diagnosis and guiding the subsequent appropriate management of this complex malignancy.

The pattern of peritoneal colorectal metastasis predicts survival after cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy

BACKGROUND

Peritoneal cancer index (PCI) has been used reliably to prognosticate patients with peritoneal metastasis, however, it fails to describe the patterns of peritoneal spread and to correlate these patterns to survival outcomes. We aim to define the scattered peritoneal spread (SPS) as a pattern associated with worse survival in colorectal peritoneal metastasis.

METHODS

A retrospective analysis of metastatic colorectal cancer patients from a prospectively maintained database of peritoneal surface malignances (n = 280) between 2015 and 2020. SPS was defined by the presence of at least two distant and non-contiguous PCI regions. We compared patients with SPS (n = 73) and clustered peritoneal spread (CPS) (n = 88) for demographics, perioperative and survival outcomes.

RESULTS

No difference in demographics or post-operative course was noted between the groups. The median follow-up was 15.4 months (0.4-70.8 months). Worse disease-free survival (DFS) in the SPS group with an estimated median of 8.2 months compared to 22.5 months in the CPS spread group, (p = 0.001). The estimated median overall survival (OS) for SPS group was 35.7 months whereas in the CPS group the median was not reached (p = 0.025). The same effect of SPS was preserved even after stratification of PCI.

CONCLUSIONS

We defined and described the association of the peritoneal spread pattern to survival outcomes. SPS patients exhibit worse DFS and OS independent of the PCI level. Integration of malignant spread pattern into prognostication models along with PCI may aid in predicting oncological outcomes.

Prevalence and Clinical Implications of Ascites in Gastric Cancer Patients after Curative Surgery

We aimed to determine the frequency and clinical significance of ascites that developed during the follow-up period in patients who underwent curative resection for gastric cancer. The study included 577 patients with gastric cancer who underwent curative gastrectomy. Among them, 184 showed ascites in postoperative follow-up images. Benign ascites was observed in 131 of 490 patients without recurrence, 48 patients (of 87) with recurrence had malignancy-related ascites, and the remaining 5 patients had ascites only prior to recurrence. In most patients without recurrence (97.7%) and in 50% of patients with malignancy-related ascites, the ascites was small in volume and located in the pelvic cavity at the time that it was first identified. However, with the exception of nine patients, malignancy-related pelvic ascites occurred simultaneously or after obvious recurrence. Of those nine patients who had minimal pelvic ascites before obvious recurrence, only one had a clear association with a malignancy-related ascites. In the multivariate analysis, an age of ≤45 was the only independent risk factor for the occurrence of benign ascites. A small volume of pelvic ascites fluid is common in young gastric cancer patients who do not have recurrence after gastrectomy, regardless of sex. It is rare for ascites to be the first manifestation of recurrence.

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.

Palliative treatment for malignant gastrointestinal obstruction with peritoneal carcinomatosis: enteral stenting versus surgery

Background and study aims  Management of malignant gastrointestinal obstruction (MGIO) is more challenging in the presence of peritoneal carcinomatosis (PC). Outcomes data to guide the management of MGIO with PC are lacking. We aimed to compare the clinical outcomes and adverse events between endoscopic and surgical palliation and identify predictors of stent success in patients with MGIO with PC. Patients and methods  Consecutive inpatients with MGIO with PC between 2000 and 2018 who underwent palliative surgery or enteral stenting were included. Clinical success was defined as relief of obstructive symptoms. Results  Fifty-seven patients with enteral stenting and 40 with palliative surgery were compared. The two groups did not differ in rates of technical success, 30-day mortality, or recurrence. Clinical success from a single intervention (63.2 % versus 95 %), luminal patency duration (27 days vs. 145 days), and survival length (148 days vs. 336 days) favored palliative surgery (all P  < 0.05) but the patients in the surgery group had a trend toward better Eastern Cooperative Oncology Group (ECOG) status. The rate of adverse events (AEs) (10.5 % vs. 50 %), the severity of AEs, and length of hospital stay (4.5 days vs. 9 days) favored enteral stenting ( P  < 0.05). The need for more than one stent was associated with a higher likelihood of stent failure. Conclusions  Our study suggests that enteral stenting is safer and associated with a shorter hospital stay than palliative surgery, although unlike other MGIOs, clinical success is lower in MGIO with PC. Identification of the right candidates and potential predictors of clinical success in ECOG-matched large-scale studies is needed to validate these results.

Non-neoplastic conditions mimicking peritoneal carcinomatosis at CT imaging

The general appearance of peritoneal carcinomatosis at abdominal CT and other cross-sectional imaging modalities consists of varying amounts of peritoneal-based soft tissue implants (mass-forming or infiltrative), peritoneal fluid, and occasionally calcification. However, a wide variety of common and uncommon neoplastic and non-neoplastic conditions can closely mimic peritoneal carcinomatosis at imaging. Neoplastic mimics of peritoneal carcinomatosis include primary peritoneal and sub peritoneal tumors, as well as peritoneal lymphomatosis and sarcomatosis.Broad categories of non-neoplastic mimics of peritoneal carcinomatosis include tumor-like conditions, systemic processes, atypical infections, and fat-based conditions. For many entities, suggestive or specific patient information and/or CT imaging findings exist that may allow the radiologist to narrow the differential diagnosis. In this article, we review the salient clinical and cross-sectional imaging features of non-neoplastic mimics of peritoneal carcinomatosis and malignancy, with emphasis on the CT findings and the additional clues that may suggest the correct benign diagnosis.

Plasma DNA as a "liquid biopsy" incompletely complements tumor biopsy for identification of mutations in a case series of four patients with oligometastatic breast cancer

PURPOSE

Circulating tumor DNA in plasma may present a minimally invasive opportunity to identify tumor-derived mutations to inform selection of targeted therapies for individual patients, particularly in cases of oligometastatic disease where biopsy of multiple tumors is impractical. To assess the utility of plasma DNA as a "liquid biopsy" for precision oncology, we tested whether sequencing of plasma DNA is a reliable surrogate for sequencing of tumor DNA to identify targetable genetic alterations.

METHODS

Blood and biopsies of 1-3 tumors were obtained from 4 evaluable patients with advanced breast cancer. One patient provided samples from an additional 7 tumors post-mortem. DNA extracted from plasma, tumor tissues, and buffy coat of blood were used for probe-directed capture of all exons in 149 cancer-related genes and massively parallel sequencing. Somatic mutations in DNA from plasma and tumors were identified by comparison to buffy coat DNA.

RESULTS

Sequencing of plasma DNA identified 27.94 ± 11.81% (mean ± SD) of mutations detected in a tumor(s) from the same patient; such mutations tended to be present at high allelic frequency. The majority of mutations found in plasma DNA were not found in tumor samples. Mutations were also found in plasma that matched clinically undetectable tumors found post-mortem.

CONCLUSIONS

The incomplete overlap of genetic alteration profiles of plasma and tumors warrants caution in the sole reliance of plasma DNA to identify therapeutically targetable alterations in patients and indicates that analysis of plasma DNA complements, but does not replace, tumor DNA profiling.

TRIAL REGISTRATION

Subjects were prospectively enrolled in trial NCT01836640 (registered April 22, 2013).

Diagnostic performance of CT for differentiating peritoneal tuberculosis from peritoneal carcinomatosis: a systematic review and meta-analysis

AIM

To undertake a systematic review and meta-analysis of the diagnostic performance of CT for differentiating peritoneal tuberculosis (PTB) from peritoneal carcinomatosis (PC).

MATERIAL AND METHODS

PubMed, Embase, the Web of Science, and the Cochrane Library were searched for papers published before 23 July 2019. The methodological quality of the studies was analysed. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Sensitivity, specificity, and positive and negative likelihood ratios were pooled. A summary receiver operating characteristic curve (sROC) was constructed and the area under the curve (AUC) of the included studies was calculated when possible.

RESULTS

Six studies were included and 17 CT features were analysed. The pooled sensitivity and specificity of smooth peritoneal thickening were 59% (95% CI: 52-66%) and 84% (95% CI: 79-88%), respectively. The AUC of smooth peritoneal thickening was 0.83. Omentum line/rim, lymph node necrosis or calcification, and mesenteric macro nodules had a pooled specificity ranging from 95% to 100% and a pooled sensitivity ranging from 12% to 67%. The other 12 signs had a pooled sensitivity ranging from 21% to 79% and a pooled specificity ranging from 19% to 81%. Omentum involvement (cake-like pattern) showed a threshold-effect, so only the AUC (=0.70) was calculated.

CONCLUSIONS

Smooth peritoneal thickening shows fairly good diagnostic accuracy, while omentum rim/line, lymph nodes necrosis or calcification, mesenteric macro nodules have good specificity but limited sensitivity. The informative features summarised in this study may aid clinical practice and future studies.

P.R.O.P.S. - A novel Pre-Operative Predictive Score for unresectability in patients with colorectal peritoneal metastases being considered for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)

Background

Twenty to thirty percent of planned cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS and HIPEC) procedures are abandoned intra-operatively. Pre-operative factors associated with unresectability identified previously were used to develop a Pre-Operative Predictive Score (PROPS), which was compared with current selection criteria—Peritoneal Surface Disease Severity Score (PSDSS), Verwaal’s Prognostic Score (PS) and Colorectal Peritoneal Metastases Prognostic Surgical Score (COMPASS), to determine which score provides the best prediction for unresectability.

Methods

Fifty-six patients with peritoneal metastases of colorectal origin were included. Beta-coefficient values of significant variables (p < 0.05) were determined from multivariate analysis to develop PROPS. PROPS, PSDSS, PS and COMPASS were compared using a receiver operating characteristic curve to calculate its accuracy, sensitivity and specificity.

Results

PROPS consisted of nine patient and tumour factors which were categorised into three groups: (i) poor tumour biology: previous inadequate resection, underwent multiple lines of chemotherapy and poorly differentiated or signet cell histology; (ii) heavy tumour burden: abdominal distension, palpable abdominal mass and computed tomography findings of ascites, small bowel disease and/or omental thickening; and (iii) active tumour proliferation: elevated tumour markers. Overall, PROPS achieved 86% accuracy with 100% sensitivity and 68% specificity, PSDSS achieved 85% accuracy with 100% sensitivity and 63% specificity, PS achieved 73% accuracy with 100% sensitivity and 68% specificity and COMPASS achieved 61% accuracy with 27% sensitivity and 100% specificity.

Conclusions

PROPS is more effective in predicting unresectability as compared to PSDSS, PS and COMPASS, and has the added advantage of using solely pre-operative factors.

FOLFIRINOX in patients with peritoneal carcinomatosis from pancreatic adenocarcinoma: a retrospective study

Background

Peritoneal carcinomatosis (pcm) in metastatic pancreatic ductal adenocarcinomas (mpdac) is frequently encountered in day-to-day practice, but rarely addressed in the literature. The objective of the present study was to describe the management and outcome of patients diagnosed with pcm.

Methods

Data for all consecutive patients with mpdac treated in our centre between 1 January 2014 and 31 August 2015 were analyzed retrospectively. Computed tomography imaging was centrally reviewed by a dedicated radiologist to determine the date of pcm diagnosis.

Results

The analysis included 48 patients. Median age in the group was 61 years, and 41 patients had an Eastern Cooperative Oncology Group performance status (ecog ps) of 0-1. All patients presented with pcm either synchronously (group 1) or metachronously (group 2). Those groups differed significantly by baseline ecog ps and neutrophil-to-lymphocyte ratio (nlr), with ecog ps being poorer and nlr being higher in group 1. In addition to pcm, the main sites of metastasis were liver (62.5%) and lungs (31.3%). First-line chemotherapy in 36 patients (75%) was folfirinox (fluorouracil-irinotecan-leucovorin-oxaliplatin). The median overall survival for the entire population was 10.81 months [95% confidence interval (ci): 7.16 months to 14.16 months]; it was 13.17 months (95% ci: 5.9 months to 15.4 months) for patients treated with folfirinox. Median overall survival was 7.13 months (95% ci: 4.24 months to 10.41 months) for patients in group 1 and 14.34 months (95% ci: 9.79 months to 19.91 months) for patients in group 2, p = 0.1296.

Conclusions

Compared with other metastatic sites, synchronous pcm seems to be a poor prognostic factor. It could be more frequently associated with a poor ecog ps and a nlr greater than 5 in this group of patients. In patients with mpdac and pcm, either synchronous or metachronous, folfirinox remains an efficient regimen.

Unicentric or Multicentric Castleman disease? A case report of a pelvic intraperitoneal mass in a middle aged woman

Castleman Disease is a lymphoid disorder characterized by the presence of an enlarged or abnormal lymph node/lymphatic tissue. The disease is classified into unicentric or multicentric variants. The unicentric form is a benign disorder that is usually asymptomatic and consists of a single lymphoid mass that is predominantly located in the mediastinum, but can also rarely develop in the neck or abdomen. The multicentric type involves more than one lymphatic station and is related to the presence of type B symptoms (fevers, night sweats and weight loss), HIV/HHV8 infection and increased serum IL-6 levels. We present the case of an unusual pelvic intraperitoneal manifestation of Castleman Disease in a 52-year-old caucasian woman who showed clinical, radiological, histological and laboratory findings common to both Unicentric and Multicentric Castleman Disease.

Ultrasonographic features of colonic B-cell lymphoma with mesenteric lymphomatosis in a cat

A 10-year-old male neutered Domestic Shorthair cat was referred for chronic inappetence, weight loss, and hematochezia and an abdominal mass. Abdominal ultrasonography revealed a heterogeneously hypoechoic transmural colonic mass, which extended beyond the serosa and into the adjacent mesentery. Cytology and clonality assays of fine needle aspirates of the mass and mesenteric nodules yielded a diagnosis of B-cell lymphoma. Colonic lymphoma with mesenteric involvement can have a similar appearance to carcinomatosis, therefore a definitive diagnosis requires sampling and further testing of the mesenteric lesions.

Precise integrin-targeting near-infrared imaging-guided surgical method increases surgical qualification of peritoneal carcinomatosis from gastric cancer in mice

Peritoneal carcinomatosis from gastric cancer represents a common recurrent gastric cancer that seriously affects the survival, prognosis, and quality of life of patients at its advanced stage. In recent years, complete cytoreduction surgery in combination with hyperthermic intraperitoneal chemotherapy has been demonstrated to improve the survival and prognosis of patients with malignant tumors including peritoneal carcinomatosis from gastric cancer. Establishing viable methods of accurately assessing the tumor burden in patients with peritoneal carcinoma and correctly selecting suitable patients in order to improve cytoreduction surgical outcomes and reduce the risk of postoperative complications has become a challenge in the field of peritoneal carcinoma research. Here, we investigated peritoneal carcinomatosis from gastric cancer in a mouse model by using our self-developed surgical navigation system that combines optical molecular imaging with an integrin-targeting Arg-Gly-Asp-indocyanine green (RGD-ICG) molecular probe. The results showed that our diagnostic method could achieve a sensitivity and specificity of up to 93.93% and 100%, respectively, with a diagnostic index (DI) of 193.93% and diagnostic accuracy rate of 93.93%.Furthermore, the minimum tumor diameter measured during the surgery was 1.8 mm and the operative time was shortened by 3.26-fold when compared with the conventionally-treated control group. Therefore, our surgical navigation system that combines optical molecular imaging with an RGD-ICG molecular probe, could improve the diagnostic accuracy rate for peritoneal carcinomatosis from gastric cancer, shorten the operative time, and improve the quality of the cytoreduction surgery for peritoneal carcinomatosis from gastric cancer, thus providing a solid foundation for its future clinical development and application.

Development of Peritoneal Carcinomatosis in Epithelial Ovarian Cancer: A Review

Epithelial ovarian cancer (EOC) metastasizes intra-abdominally with often numerous, superficial, small-sized lesions. This so-called peritoneal carcinomatosis is difficult to treat, and peritoneal recurrences are frequently observed, leading to a poor prognosis. Underlying mechanisms of interactions between EOC and peritoneal cells are incompletely understood. This review summarizes and discusses the development of peritoneal carcinomatosis from a cell-biological perspective, focusing on characteristics of EOC and peritoneal cells. We aim to provide insight into how peritoneum facilitates tumor adhesion but limits size of lesions and depth of invasion. The development of peritoneal carcinomatosis is a multistep process that requires adaptations of EOC and peritoneal cells. Mechanisms that enable tumor adhesion and growth involve cadherin restructuring on EOC cells, integrin-mediated adhesion, and mesothelial evasion by mechanical forces driven by integrin-ligand interactions. Clinical trials targeting these mechanisms, however, showed only limited effects. Other factors that inhibit tumor growth and deep invasion are virtually unknown. Future studies are needed to elucidate the exact mechanisms that underlie the development and limited growth of peritoneal carcinomatosis. This review on development of peritoneal carcinomatosis of EOC summarizes the current knowledge and its limitations. Clarification of the stepwise process may inspire future research to investigate new treatment approaches of peritoneal carcinomatosis.

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.

PET/CT for differentiating between tuberculous peritonitis and peritoneal carcinomatosis: The parietal peritoneum

OBJECTIVES

Tuberculous peritonitis (TBP) mimics peritoneal carcinomatosis (PC). We aimed to investigate the discriminative use of PET/CT findings in the parietal peritoneum.

MATERIALS AND METHODS

Parietal peritoneal PET/CT findings from 76 patients with TBP (n = 25) and PC (n = 51) were retrospectively reviewed. The lesion locations were noted as right subdiaphragmatic, left subdiaphragmatic, right paracolic gutters, left paracolic gutters, and pelvic regions. The distribution characteristic consisted of a dominant distribution in the pelvic and/or right subdiaphragmatic region (susceptible area for peritoneal implantation, SAPI) (SAPI distribution), a dominant distribution in the remaining regions (less-susceptible area for peritoneal implantation, LSAPI) (LSAPI distribution), or a uniform distribution. PET morphological patterns were classified as F18-fluorodeoxyglucose (F-FDG) uptake in a long beaded line (string-of-beads F-FDG uptake) or in a cluster (clustered F-FDG uptake) or focal F-FDG uptake. CT patterns included smooth uniform thickening, irregular thickening, or nodules.

RESULTS

More common findings in the parietal peritoneum corresponding to TBP as opposed to PC were (a) ≥4 involved regions (80.0% vs 19.6%), (b) uniform distribution (72.0% vs 5.9%), (c) string-of-beads F-FDG uptake (76.0% vs 7.8%), and (d) smooth uniform thickening (60.0% vs 7.8%) (all P < 0.001), whereas more frequent findings in PC compared with TBP were (a) SAPI distribution (78.4% vs 28.0%), (b) clustered F-FDG uptake (56.9% vs 20.0%), (c) focal F-FDG uptake (21.6% vs 4.0%), (d) irregular thickening (51.0% vs 12.0%), and (e) nodules (21.6% vs 4.0%) (P < 0.001, P < 0.05, P > 0.05, P < 0.05, P > 0.05, respectively).

CONCLUSION

Our data show that PET/CT findings in the parietal peritoneum are useful for differentiating between TBP and PC.

CT differentiation of diffuse malignant peritoneal mesothelioma and peritoneal carcinomatosis

BACKGROUND AND AIM

Diffuse malignant peritoneal mesothelioma (DMPM) and peritoneal carcinomatosis (PC) have similar imaging in computer tomography (CT). We aimed to distinguish them.

METHODS

Computer tomography findings were evaluated in 48 DMPM and 47 PC for the peritoneal, mesenteric, omentum, lymph nodes, viscera infiltration, ascites and pleural plaques.

RESULTS

Two groups had no difference in terms of thickness, clinical manifestation, diameter of lymph nodes, ascites, and viscera infiltration. But they showed differences in the following: Ratio of asbestos exposure in DMPM group was higher. Smooth and irregular peritoneal thickening were more seen in DMPM group; peritoneal nodules were more commonly detected in PC group. Forty-eight cases of peritoneum in DMPM showed mild enhanced, while 14 patients in PC showed severe enhanced. Nodular type of omentum was more common in PC group than in DMPM group; omental cake was more commonly detected in DMPM group. Mesentery involvement was more commonly seen in DMPM group. Location of enlarged lymph nodes in cardiophrenic region was more frequently identified in DMPM, whereas location of enlarged lymph nodes in retroperitoneal region was more frequently identified in PC. Lymph nodes fusion was more frequently visualized in PC. Fixation of the intestinal wall was more common in DMPM. Pleural plaque was more common in DMPM. PC had distant metastasis except primary foci and peritoneum. In PC, tumor origins were ovary in 10, digestive system in 21, breast in one.

CONCLUSION

Using a combination of CT findings may increase our ability to distinguish PC from DMPM.

Primary and secondary disease of the peritoneum and mesentery: review of anatomy and imaging features

The largest and most complex serosal membrane in the body, the peritoneum, lines the abdominal cavity, and the abdominopelvic viscera. It is frequently involved in a variety of benign and malignant processes. While secondary involvement of the peritoneum is more common, primary tumors can be a diagnostic challenge. Knowledge of the anatomy is crucial in understanding the various pathologic processes. Cross-sectional imaging plays an important role in diagnosing and evaluating the extent of the disease processes. This article reviews the imaging anatomy of the peritoneum and mesentery and the common pathologies involving it.

Spermatic Cord and Peritoneal Metastases from Unruptured Hepatocellular Carcinoma

Extrahepatic metastases are not uncommon in patients with late-stage hepatocellular carcinoma (HCC). These extrahepatic lesions are most commonly found in the lungs, lymph nodes and bones. The authors report the case of a patient with chronic liver disease who presented with left inguinal swelling which was thought to be incarcerated hernia on clinical examination. Further evaluation revealed that the patient had HCC with spermatic cord metastasis which was masquerading as inguinal hernia. He also had extensive peritoneal dissemination. Awareness and accurate detection of these unusual sites of extrahepatic dissemination of HCC is of paramount importance for radiologists to avoid unnecessary surgery as well as after loco regional therapy to assess for recurrence. Details of the case are discussed with a review of the relevant literature.

Recommendations for bowel obstruction with peritoneal carcinomatosis

This article reports on the clinical practice guidelines developed by a multidisciplinary group working on the indications and uses of the various available treatment options for relieving intestinal obstruction or its symptoms in patients with peritoneal carcinomatosis. These guidelines are based on a literature review and expert opinion. The recommended strategy involves a clinical and radiological evaluation, of which CT of the abdomen is a crucial component. The results, together with an analysis of the prognostic criteria, are used to determine whether surgery or stenting is the best option. In most patients, however, neither option is feasible, and the main emphasis, therefore, is on the role and administration of various symptomatic medications such as glucocorticoids, antiemetic agents, analgesics, and antisecretory agents (anticholinergic drugs, somatostatin analogues, and proton-pump inhibitors). Nasogastric tube feeding is no longer used routinely and should instead be discussed on a case-by-case basis. Recent studies have confirmed the efficacy of somatostatin analogues in relieving obstruction-related symptoms such as nausea, vomiting, and pain. However, the absence of a marketing license and the high cost of these drugs limit their use as the first-line treatment, except in highly selected patients (early recurrence). When these medications fail to alleviate the symptoms of obstruction, venting gastrostomy should be considered promptly. Rehydration is needed for virtually every patient. Parenteral nutrition and pain management should be adjusted according to the patient needs and guidelines.

Research on the diagnosis of peritoneal micrometastases in tumors of the subdiaphragmatic digestive tract

This presentation is aimed at analyzing the possibility of detecting the peritoneal micrometastases through multiple peritoneal biopsies to the patients with tumors of the subdiaphragmatic digestive tract.

Nowadays, detection of the micrometastases is performed indirectly through cytological analysis and / PCR analysis of the peritoneal liquid, through the histopathological study of the peritoneal fragments intraoperatively collected and the immunohistochemical study.

This presentation is aimed at analyzing the possibility of detecting the peritoneal micrometastases through multiple peritoneal biopsies and to correlate this with various factors such us: staging neoplasia, the affected organ, histopathological type, tumoral grading.

Inclusion of the patients that find themselves in the early stage of peritoneal carcinomatosis - of peritoneal micrometastases - would allow for the application of an adequate treatment and could greatly increase the patient’s survival chances

The first case of omental metastasis from primary choroidal melanoma

Choroidal melanoma is the most common intraocular malignancy and can be fatal in half of the patients because of metastatic disease. Metastasis of choroidal melanoma to the omentum is extremely rare and, to our knowledge, no such case has ever been described in the literature. Here we present a 41-year-old Chinese man with an omental metastasis, 5 years after he was diagnosed with a spindle-cell-type malignant melanoma of the choroid and had his left eye enucleated. The patient demonstrated some uncommon symptoms, but the diagnosis was confirmed histopathologically. The cells were positive for S-100, HMB-45 and Melan-A proteins. He underwent a complete tumor resection and concomitantly received chemotherapy, biological treatment and traditional Chinese medicine. At 2-year follow-up, this patient continues to do well.

Mesenterial, omental, and peritoneal disorders in antiretroviral-treated HIV/AIDS patients: spectrum of cross-sectional imaging findings

In the era of highly active antiretroviral therapy, radiologists are increasingly confronted with a progressively aging HIV-infected population with improved immune function and survival, in whom a wide spectrum of infectious and neoplastic opportunistic disorders may be encountered. Furthermore, HIV / AIDS patients commonly have unspecific symptoms and physical signs, multicentric or coexisting diseases, so that diagnostic imaging studies are crucial to correctly identify and stage HIV-related abnormalities. Currently, volumetric multidetector CT (MDCT) provides comprehensive assessment and confident post-treatment follow-up of opportunistic abnormalities involving the mesentery, omentum, and peritoneum. In this pictorial essay, the cross-sectional imaging appearances of opportunistic disorders involving the mesentery, peritoneum, or both compartments in HIV / AIDS patients are reviewed, with emphasis on those MDCT findings that may be helpful for differential diagnosis along with knowledge of the degree of immune suppression as measured by the CD4 lymphocyte count. Familiarity with the varied spectrum of HIV-related opportunistic disorders encountered in antiretroviral - treated patients and their imaging appearances should allow radiologists to improve their confidence in the characterization of abnormal findings observed on abdominal cross-sectional imaging studies.

Extraovarian primary peritoneal carcinoma: staging with 18F-FDG PET/CT

A 69-year-old woman who presented with left lower quadrant abdominal pain and elevated serum cancer antigen 125 (CA-125) levels was referred for an MRI and an (18)F-FDG PET/CT to evaluate a suspicious abdominal mass seen on ultrasound. PET/CT showed extensive, intensely FDG-avid, omental and pelvic peritoneal thickening with no suspicious ovarian or colon masses. Based on the PET/CT results, the patient had extensive debulking surgery and histopathological evaluation revealed an extraovarian primary peritoneal carcinoma (EOPPC). (18)F-FDG PET/CT may be useful in differentiating EOPPC from other types of peritoneal carcinomatosis, and in determining the extent of the disease to better guide surgical management and improve long term outcomes.

Prognostic significance of computed tomography defined ascites in advanced gastric cancer

PURPOSE

The aim of this study was to investigate the clinicopathologic features and prognosis in patients with computed tomography (CT) findings of ascites, with a focus on the correlation with peritoneal carcinomatosis.

METHODS

This study included a total of 157 patients who underwent surgery for advanced gastric cancer from 2003 to 2008 at the Department of Surgery, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea, which were analyzed retrospectively.

RESULTS

Fourteen patients (8.9%) presented ascites on their CT scan. Among them, 10 patients had peritoneal carcinomatosis, and showed significant difference with CT ascites positive group in the incidence of peritoneal carcinomatosis. The presence of CT ascites was significantly correlated with pathologic T stage, tumor size, histologic type, CT T and N stages, CT peritoneal nodularity and curability of surgery, statistically. The prognosis of CT ascites positive group was much poorer in the total advanced gastric cancer patients (P < 0.001), as well as in patients with pathologic T4 (P = 0.002). Also in patients without peritoneal carcinomatosis, CT ascites positive subgroup tended to have a worse prognosis than CT ascites negative subgroup (P = 0.086). Tumor size, CT T and N stages and the presence of CT peritoneal nodularity and ascites influenced the prognosis significantly; among which, if a tumor size larger than 5 cm, CT T4 stage and the presence of CT ascites were identified as independent prognostic factors.

CONCLUSION

The presence of ascites was closely associated with peritoneal metastasis, and was the most significant independent prognostic factor in advanced gastric cancer in the present study.

Optimizing of preoperative computed tomography for diagnosis in patients with peritoneal carcinomatosis

Background and Objective

This study evaluates whether Computer Tomography is an effective procedure for preoperative staging of patients with Peritoneal Carcinomatosis.

Method

A sample of 37 patients was analyzed with contrast enhanced abdominal Computer Tomography, followed by surgical staging. All Computer Tomography scans were evaluated 3 times by 2 radiologists with one radiologist reviewing 2 times. The efficacy of Computer Tomography was evaluated using the Spearman correlation coefficient. Correlations were analyzed by abdominopelvic region to assess results of the Peritoneal Carcinomatosis Index (PCI) aggregating the 13 regions. Surgical findings were compared to radiological findings.

Results

Results indicate high correlations between the surgical and radiological Peritoneal Carcinomatosis Indices. Analyses of the intra-class correlation between the first and second reading of one radiologist suggest high intra-observer reliability. Correlations by abdominopelvic region show higher values in the upper and middle regions and relatively lower values in the lower regions and the small bowel (correlation coefficients range between 0.418 and 0.726, p < 0.010; sensitivities range between 50% and 96%; and specificities range between 62% and 100%).

Conclusion

Computer Tomography represents an effective procedure in the preoperative staging of patients with PC. However, results by abdominopelvic region show lower correlation, therefore suggest lower efficacy. These results are supported by analyses of sensitivity and accuracy by lesion size. This suggests that Computer Tomography is an effective procedure for pre-operative staging but less for determining a tumor's accurate extent.

Intraperitoneal therapy for peritoneal cancer

Cancers originating from organs in the peritoneal cavity (e.g., ovarian, pancreatic, colorectal, gastric and liver) account for approximately 250,000 new cancer cases annually in the USA. Peritoneal metastases are common owing to locoregional spread and distant metastases of extraperitoneal cancers. A logical treatment is intraperitoneal therapy, as multiple studies have shown significant targeting advantage for this treatment, including significant survival benefits in stage III, surgically debulked ovarian cancer patients. However, the clinical use of intraperitoneal therapy has been limited, in part, by toxicity, owing to the use of indwelling catheters or high drug exposure, by inadequate drug penetration into bulky tumors (>1 cm) and by the lack of products specifically designed and approved for intraperitoneal treatments. This article provides an overview on the background of peritoneal metastasis, clinical research on intraperitoneal therapy, the pharmacokinetic basis of drug delivery in intraperitoneal therapy and our development of drug-loaded tumor-penetrating microparticles.

Peritoneal metastasis: detection with 16- or 64-detector row CT in patients undergoing surgery for gastric cancer

PURPOSE

To retrospectively measure the diagnostic performance of prospective computed tomographic (CT) results obtained by using 16- or 64-detector row scanners in the detection of peritoneal metastases (PMs) in patients with advanced gastric cancer.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and waived the need to obtain patient consent. In 498 patients with gastric cancer (stage >or= T2) who were undergoing surgery, the presence of PM was prospectively rated as grade 0 (absent), grade 1 (equivocal), or grade 2 (present) on CT scans (0.67 or 2 mm thick) that were interpreted by interactively adjusting the viewing thickness and viewing plane. The CT readings were retrospectively compared with surgical and pathologic findings. In patients in whom the presence of PM was rated as grade 1 or less, factors predictive of PM were identified by testing variables, including patient and tumor characteristics, with univariate tests and multivariate logistic regression analysis.

RESULTS

Fifty-three patients (10.6%) had confirmed PM. When only grade 2 was considered to indicate a positive CT reading, sensitivity and specificity were 28.3% (15 of 53) and 98.9% (440 of 445), respectively. With the threshold of grade 1 or greater indicating a positive reading, sensitivity and specificity were 50.9% (27 of 53) and 96.2% (428 of 445), respectively. In the patients with grades of 1 or less, the significant factors predictive of PM were greater tumor size and T stage.

CONCLUSION

The sensitivity of PM detection is limited, even with modern CT techniques. In patients whose CT results are not definitely positive for PM, staging laparoscopy is still recommended if the aforementioned two predictive factors (greater tumor size and T stage) are suspected.

Multi-detector CT in peritoneal carcinomatosis: diagnostic role of thin slices and multiplanar reconstructions

BACKGROUND

In order to investigate whether 1-mm thin slices and multiplanar reconstructions (MPRs) of multi-detector computed tomography (CT) datasets interpreted in addition to isotropic 5-mm thick slices in one session improve the detection of peritoneal carcinomatosis.

METHODS

The abdominal CT datasets of 44 patients with histologically proven tumors of the abdomen or pelvis were retrospectively evaluated for peritoneal carcinomatosis by four radiologists with variable experience (radiologist 1: >or=10 years, radiologists 2 and 3: 1.5 years, radiologist 4: 0.5 years). In three successive steps, the radiologists evaluated first the axial 5-mm slices, second the 1-mm slices, and third the MPRs and rated their diagnostic confidence.

RESULTS

Specificity was nearly unchanged for all the four radiologists. Sensitivity improved for the most experienced and the least experienced radiologists and was unchanged for the two readers with intermediate skills. Except for the third step of radiologist 4, no statistically significant differences in diagnostic performance were detected. The diagnostic confidence of all the four readers benefited to variable degrees from interpretation of the 1-mm slices and MPRs.

CONCLUSIONS

While 5-mm slices are sufficient for the detection of peritoneal carcinomatosis, 1-mm slices and MPRs can improve sensitivity and diagnostic confidence.

Preoperative investigations in the management of peritoneal surface malignancy with cytoreductive surgery and perioperative intraperitoneal chemotherapy: Expert consensus statement

At the Fifth International Workshop on Peritoneal Surface Malignancy, in Milan, the consensus on preoperative investigations for peritoneal surface malignancy was obtained through the Delphi process. The results showed that 100% of the voters considered that contrast-enhanced multi-sliced CT was the fundamental imaging modality, whereas MRI, PET, laparoscopy and serum tumor markers were regarded as useful, but not fundamental investigational modalities.

Plasminogen activator, but not systemic antibiotic therapy, prevents abscess formation in an experimental model of secondary peritonitis

Background

Intra-abdominal abscesses are sources of recurrent or ongoing abdominal sepsis. They are an important target for prevention and treatment during or after surgical treatment of peritonitis. Experimental data suggest that fibrinolytic therapy may be effective when antibiotics are not.

Methods

Peritonitis was induced via intra-abdominal injection of a faeces and bacteria mixture in male Wistar rats. Surgical debridement was performed after 1 h. Next to untreated controls, animals were treated with antibiotics (ceftriaxone plus metronidazole), recombinant tissue plasminogen activator (rtPA) or both. Abdominal fluid samples were taken at 24, 72 and 120 h for interleukin 6, interleukin 10 and tumour necrosis factor α measurements and cell counts. After 5 days the abdomen was inspected for the presence of abscesses.

Results

Antibiotics did not significantly affect abscess formation. However, giving rtPA significantly reduced the number of rats with abscesses and the abscess load per rat, both in the absence and presence of concomitant antibiotic therapy. No adverse side-effects were observed and no meaningful differences in the local inflammatory response were found.

Conclusion

In this rat model, rtPA consistently reduced abscess formation after surgical treatment of secondary peritonitis. It therefore represents a promising adjuvant to conventional therapy.