Intraoperative Peritoneal Cancer Index Research Articles

Prognostic role of body composition in peritoneal carcinomatosis patients undergoing cytoreduction and hyperthermic intraperitoneal chemotherapy

BackgroundBioelectric impedance analysis (BIA)-measured body composition and nutritional status have been used as prognostic indicators in various cancer cohorts. This study investigated whether BIA could provide information on prognosis in peritoneal carcinomatosis patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).MethodsWe retrospectively analyzed the data of 99 patients with preoperative BIA data among those who underwent CRS and HIPEC. The association between BIA-derived parameters and intraoperative peritoneal cancer index (PCI) score was assessed. Predictive analysis for the occurrence of postoperative morbidities including major complications (Clavien–Dindo classification 3–4) and re-admission within 30 days after surgery as well as 1 year mortality was also performed.ResultsBIA-derived mineral (r = 0.224, p = 0.027), fat (r = − 0.202, p = 0.048), and total body water (TBW)/fat-free mass (FFM) (r = − 0.280, p = 0.005) showed significant associations with intraoperative PCI score. Lower TBW/FFM was an independent predictor of major postoperative complications (OR 0.047, 95% CI 0.003–0.749, p = 0.031) and re-admission (OR 0.094, 95% CI 0.014–0.657, p = 0.017) within 30 days after surgery. Higher fat mass was also independently associated with a higher risk of major postoperative complications (OR 1.120, 95% CI 1.006–1.248, p = 0.039) and re-admission (OR 1.123, 95% CI 1.024–1.230, p = 0.013). Intraoperative PCI score > 20 (OR 4.489, 95% CI 1.191–16.917, p = 0.027) and re-admission within 30 days after surgery (OR 5.269, 95% CI 1.288–21.547, p = 0.021) independently predicted postoperative 1-year mortality.ConclusionsWe demonstrate that preoperative BIA-derived TBW/FFM and fat mass were significantly correlated with metastatic extent, assessed by PCI score, in patients with peritoneal carcinomatosis. In addition, BIA-derived TBW/FFM and fat mass showed independent predictability for postoperative 30-day major complications and re-admission in patients undergoing CRS and HIPEC. Our findings suggest that assessment of BIA may improve discrete risk stratification in patients who are planned to receive CRS and HIPEC.

Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Gastric Cancer with Peritoneal Carcinomatosis: Additional Information Helps to Optimize Patient Selection before Surgery

(1) Background: The prognosis of gastric cancer-associated peritoneal carcinomatosis (GCPC) is poor, with a median survival time of less than six months, and current systemic chemotherapy, including targeted therapy, is ineffective. Despite growing evidence that cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for GCPC improves overall survival (OS), optimal patient selection remains unclear. We aimed to evaluate preoperative clinical factors and identify indicative factors for predicting postoperative OS in patients with GCPC undergoing CRS-HIPEC. (2) Methods: We retrospectively reviewed 44 consecutive patients with GCPC who underwent CRS-HIPEC between May 2015 and May 2021. Data on demographics and radiologic assessment were collected and analyzed. (3) Results: Elevated preoperative serum neutrophil-to-lymphocyte ratio > 4.4 (p = 0.003, HR = 3.70, 95% CI = 1.55-8.79) and number of computed tomography risks > 2 (p = 0.005, HR = 3.26, 95% CI = 1.33-7.98) were independently indicative of OS post-surgery. A strong correlation was observed between intraoperative peritoneal cancer index score and number of computed tomography risks (r = 0.534, p < 0.0001). Two patients after CRS-HIPEC ultimately achieved disease-free survival for more than 50 months. (4) Conclusions: Our experience optimizes GCPC patients' selection for CRS-HIPEC, may help to improve outcomes in the corresponding population, and prevent futile surgery in inappropriate patients.

Molecular Classification of Appendiceal Adenocarcinoma.

Appendiceal adenocarcinomas (ACs) are rare, histologically diverse malignancies treated as colorectal cancers despite having distinct biology and clinical behavior. To guide clinical decision making, we defined molecular subtypes of AC associated with patient survival, metastatic burden, and chemotherapy response. A comprehensive molecular analysis was performed in patients with AC to define molecular subtypes. Associations between molecular subtype and overall survival, intraoperative peritoneal cancer index, and first-line chemotherapy response were assessed adjusting for histopathologic and clinical variables using multivariable Cox proportional hazards, linear regression, and logistic regression models. We defined distinct molecular lineages of mucinous appendiceal adenocarcinoma (MAAP) from co-occurring mutations in GNAS, RAS, and TP53. Of 164 MAAP tumors, 24 were RAS-mutant (mut) predominant (RAS-mut/GNAS-wild-type [wt]/TP53-wt) with significantly decreased mutations and chromosomal alterations compared with tumors with GNAS mutations (GNAS-mut predominant) or TP53 mutations (TP53-mut predominant). No patient with RAS-mut predominant subtype metastatic MAAP died of cancer, and overall survival in this subgroup was significantly improved compared with patients with GNAS-mut (P = .05) and TP53-mut (P = .004) predominant subtypes. TP53-mut predominant subtypes were highly aneuploid; increased tumor aneuploidy was independently (P = .001) associated with poor prognosis. The findings retained significance in patients with any metastatic AC. RAS-mut predominant metastases exhibited reduced peritoneal tumor bulk (P = .04) and stromal invasion (P < .001) compared with GNAS-mut or TP53-mut predominant tumors, respectively. Patients with RAS-mut predominant MAAP responded more to first-line chemotherapy (50%) compared with patients with GNAS-mut predominant tumors (6%, P = .03). AC molecular patterns identify distinct molecular subtypes: a clinically indolent RAS-mut/GNAS-wt/TP53-wt subtype; a chemotherapy-resistant GNAS-mut predominant subtype; and an aggressive, highly aneuploid TP53-mut predominant subtype. Each subtype exhibits conserved clinical behavior irrespective of histopathology.

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

Simple SummaryEarly diagnosis, evaluation, and appropriate treatment of peritoneal surface malignancies remains difficult. While computed tomography and magnetic resonance imaging are commonly used for these purposes, it remains unknown whether one is superior to the other. The aim of the current study was therefore to prospectively compare the two imaging modalities, using intra-operative evaluation as a reference standard. Our findings indicate that they are comparable in the detection and evaluation of peritoneal surface malignancies. Thus, either imaging modality may be appropriate, depending on clinical indications and resource management. It should however be noted that both modalities are likely to underestimate the true burden of disease, which may negatively impact treatment decisions.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.

Adding Value of MRI over CT in Predicting Peritoneal Cancer Index and Completeness of Cytoreduction.

Background: This study aimed to investigate the adding value of MRI over CT for preoperative cytoreductive surgery with hyperthermic intraperitoneal chemotherapies (CRS/HIPEC). Methods: Imaging and intraoperative peritoneal cancer index (PCI) were calculated in 62 patients with peritoneal metastasis. Predictive models for the completeness of cytoreductive score using PCI data were established using decision tree algorithms. Results: In gastric cancer patients, a large discrepancy and poor agreement was appreciated between CT and surgical PCI, and a nonsignificant difference was noted between MRI and surgical PCI. In colon cancer patients, a better agreement and higher correlation with a smaller error was observed in PCI score using MRI than in that using CT. However, the addition of MRI to CT was limited for appendiceal and ovarian cancer patients. For predicting incomplete cytoreduction, CT models yielded inadequate accuracy while MRI models were more accurate with fair discrimination ability. Conclusions: CT was suitable for estimating PCI and surgery outcome in appendiceal and ovarian cancer patients, while further MRI in addition to CT was recommended for colon and gastric cancer patients. However, for classifying patients with peritoneal carcinomatosis into complete and incomplete cytoreduction, MRI was more effective than CT.

Small Bowel PCI Score as a Prognostic Factor of Ovarian Cancer Patients Undergoing Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC), a Retrospective Analysis of 130 Patients.

Ovarian cancer is the leading cause of death among gynecologic malignancies. Combining cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) can benefit patients with advanced ovarian cancer. We evaluate the role of small bowel peritoneal cancer index (sb-PCI) score as a prognostic factor. We retrospectively analyzed characteristics and clinical outcomes of patients that underwent intermediate cytoreductive surgery combined with HIPEC after neoadjuvant chemotherapy and patient's characteristics underwent debulking surgery plus HIPEC for recurrence disease. One hundred thirty patients were included. Eighty-five of them (65.4%) were treated for recurrent ovarian cancer, while 45 (34.6%) underwent intermediate cytoreductive surgery after neoadjuvant chemotherapy with a mean age of 52years. Mean intraoperative peritoneal cancer index (PCI) was 11.84 with a mean sb-PCI score of 5.57. Univariate analysis revealed that PCI, sb-PCI, and completeness of cytoreduction (CC) were parameters that correlated significantly with overall survival, while after multivariate analysis sb-PCI and CC were identified as independent prognostic factors of survival. A statistically significant correlation between sb-PCI score and overall survival of patients with advanced ovarian cancer was revealed. Further larger future studies are required to confirm our conclusion in order to change the treatment of advanced ovarian cancer patients.

Pre-operative serum CA125, peritoneal cancer index and intra-operative mapping score as predictors of surgical results in primary epithelial ovarian cancer

ObjectivePrediction of post-operative residual disease after ovarian cancer cytoreductive surgery remains a topic of interest to gynecologic oncologists. The aim of this study was to explore the correlation between serum...

Correlation Between Intraoperative and Pathological Findings for Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

This study aimed to examine the correlation between intraoperative and pathological findings for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) and to determine their prognostic significance. Pathological reports of all colorectal cancer (CRC) patients undergoing CRS/HIPEC between 2009 and 2016 were retrospectively reviewed. Pathological specimens lacking tumor cells were defined as negative pathological specimens (NPS). The intraoperative peritoneal cancer index (PCI) and pathological PCI (excluding NPS) were calculated separately. Receiver operating characteristic (ROC) curves were applied to compare the prognostic value of intraoperative and pathological scoring systems. For 108 CRC patients, 113 CRS/HIPEC procedures were performed. Of 959 pathological specimens examined, 178 (18.6%) were NPS. Overall, 78 procedures (69%) showed NPS. In 52 procedures (46%), the pathological PCI differed from the intraoperative PCI (∆PCI > 0). The ROC areas for intraoperative PCI and pathological PCI were similar in predicting 1-year overall survival (OS), 2-year OS, and 1-year disease-free survival (all p values not significant). However, for the patients with NPS, the number of positive specimens (containing tumor tissue) was superior to intraoperative PCI in predicting 2-year OS (ROC under the curve areas, 0.69 vs. 0.58, respectively; p = 0.012). In addition, a subgroup of 15 patients with a high ∆PCI (≥ 3) had a more favorable median OS than a matched group of 30 patients with similar intraoperative PCI and a ∆PCI of 0 (median survival not reached vs. 21.6months, respectively; p = 0.05). In the majority of CRC CRS/HIPEC procedures, NPS may be found. Among patients with NPS, pathological correlation may have a prognostic significance.

Conversion to Complete Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Malignant Peritoneal Mesothelioma After Bidirectional Chemotherapy.

This report aims to describe preliminary results concerning secondary resectability after bidirectional chemotherapy for initially unresectable malignant peritoneal mesothelioma (MPM). Between January 2013 and January 2016, 20 consecutive patients treated for diffuse MPM not suitable for upfront surgery received bidirectional chemotherapy associating intraperitoneal and systemic chemotherapy. Evaluation of the response to chemotherapy was assessed clinically and by laparoscopy. The median peritoneal cancer index (PCI) score at staging laparoscopy was 27 (range 15-39). Altogether, 118 intraperitoneal chemotherapy cycles were administered without any specific adverse catheter-related event. Concerning tolerance, 85% of the patients experienced no pain or mild pain during chemotherapy administration. The clinical response rate was 60% after a median of three chemotherapy cycles. At laparoscopic reevaluation, the median PCI was 18 (range 0-35), and a secondary resectability was considered for 55% of the patients. Complete cytoreduction surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) was finally achieved for 10 patients (50%), with a median intraoperative PCI score of 14 (range 6-30). After a median follow-up period of 18months, the 2-year overall survival rate was 83.3% for the patients treated by CRS followed by HIPEC and 44% for the patients treated by bidirectional chemotherapy. Bidirectional chemotherapy is a promising, well-tolerated treatment capable of increasing the resection rate for selected patients with diffuse MPM initially considered as unresectable or borderline resectable. For patients with definitively unresectable disease, bidirectional chemotherapy achieves a higher clinical response rate.

Inflammation-Based Prognostic Scores: Utility in Prognostication and Patient Selection for Cytoreduction and Perioperative Intraperitoneal Chemotherapy in Patients with Peritoneal Metastasis of Colonic Origin.

Tumor-associated systemic inflammatory response has been correlated with prognosis. Our aim was to analyze the utility of inflammation-based prognostic scores for prognostication and patient selection for cytoreduction and perioperative intraperitoneal chemotherapy (POIC) in patients diagnosed with peritoneal metastasis of colonic origin. A retrospective analysis of a prospectively maintained database for all patients treated for peritoneal metastasis of colonic origin from February 2001 to April 2015. Inflammation-based prognostic scores including neutrophil-lymphocyte ratio, platelet-lymphocyte ratio (PLR) and Onodera's prognostic nutritional index (ONI) were calculated. Of 123 patients, 70 (56.9%) were men and 53 (43.1%) were women. Mean age at diagnosis was 49.9years. Significant prognosticators in univariate analysis included intraoperative peritoneal cancer index (p<0.000), tumor marker CA19-9 (p<0.000), PLR (p=0.020), POIC regimen (p<0.003), and completeness of cytoreduction (p<0.000). Multivariate Cox analysis identified CA19-9 (hazard ratio [HR] 1.0; 95% confidence interval [CI] 1.00-1.01, p=0.031), ONI (HR 0.86; 95% CI 0.79-0.94, p<0.000), PLR (HR 1.0; 95% CI 0.90-1.01, p=0.041), incompleteness of cytoreduction CC2 and CC3, and mucinous adenocarcinoma histology as significant independent prognosticators. The inflammation-based prognostic scores PLR and ONI and tumor marker CA19-9 are significant prognosticators of survival. They are useful in patient selection and prognostication for cytoreductive surgery and POIC in patients with peritoneal carcinomatosis of colonic origin.

Proposed radiological criteria for pre-operative determination of resectability in peritoneal-based malignancies.

The selection of patients for cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy infusion (HIPEC) is important, and relies heavily on imaging. However, it has been reported that Computer Tomographic (CT) scans may only achieve a low sensitivity of 33% for peritoneal disease. We propose a set of radiological criteria for pre-operative determination of resectability of peritoneal disease in peritoneal-based malignancies and validate this in our cohort of patients. A retrospective review of all patients who underwent laparotomy with a view for CRS and HIPEC, at the National Cancer Centre Singapore from January 2000 to April 2010, was performed. Intra-operative Peritoneal Cancer Index (PCI) scores were recorded. The pre-operative imaging was reviewed with a senior radiologist who was blinded, and recorded the radiological PCI scores (CT-PCI) and eight additional CT prognostic factors (CT-PF). The CT-PCI and CT-PF scores were then compared with the intra-operative findings to determine the radiological accuracy. The scores and the individual prognostic factors were then evaluated for their predictive ability for unresectability. Comparison of the CT-PCI and PCI scores showed a concordance correlation coefficient at 0.52 (95% CI 0.34-0.7). Accuracy was increased with the addition CT-PF. The presence of omental caking and ascites were predictors of unresectability. We propose a scoring system which is able to predict for unresectable disease with a specificity of 80% and a sensitivity of 62%. With our proposed criteria, and scoring system, the selection of patients for CRS and HIPEC can be improved, and unnecessary exploratory operations avoided.

Preoperative computed tomography does not predict resectability in peritoneal carcinomatosis

BackgroundObtaining a complete cytoreduction in patients with peritoneal carcinomatosis (PC) is one of the most significant prognostic variables for long-term survival. This study explored features on preoperative computed tomography (CT) to predict unresectability. MethodsA retrospective case–control study was conducted of 15 patients with unresectable PC and 15 patients with completely resected PC matched by intraoperative peritoneal cancer index (PCI) and pathology type. Two surgical oncologists blindly analyzed all abdominopelvic CT scans. ResultsPCI estimated on imaging was not higher in unresectable patients (P = .851) and significantly underestimated intraoperative PCI measurement (P = .003). No single concerning feature was associated with unresectability. However, patients with 2 or more concerning features were more likely to be unresectable (87.5% vs 36.4%, P = .035). ConclusionsTwo or more concerning CT imaging features appear to be associated with a higher risk of unresectability in patients with PC. However, no specific imaging feature should exclude a patient from an attempted cytoreduction.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis: Outcomes from a Single Tertiary Institution

BackgroundCytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC) is an effective but morbid procedure in the treatment of peritoneal carcinomatosis. We report our outcomes at a single tertiary institution. MethodA total of 170 consecutive patients underwent CRS-HIPEC for peritoneal carcinomatosis between July 2007 and August 2012. The peritoneal cancer index (1–39) was used for peritoneal carcinomatosis (PC) staging. Mitomycin C (88.8 %) was administered intraperitoneally at 42°C for 90 mins. Risk factors associated with major morbidities were analyzed. The Kaplan-Meier method was used for survival analyses. ResultsThe mean age was 55.1 (±11.3) years, and the majority (77.1 %) of patients had complete cytoreduction (CC0-1). Tumor types included colorectal (n = 51, 30.0 %), appendiceal (n = 50, 29.4 %), pseudomyxoma peritonei (n = 16, 9.4 %), and other (n = 53, 31.2 %). Factors associated with major complications were estimated blood loss (>400 ml), length of stay (>1 week), intraoperative blood transfusion, operative time (>6 h), and bowel anastomosis. Intraoperative blood transfusion was the only independent prognostic factor on multivariate analysis (p = 0.031). Median follow-up was 15.7 months (±1.2). The recurrence rates for colorectal and appendiceal carcinoma at 1 and 3 years were 40 %, 53.5 % and 68 %, 79.1 %, respectively. The 1- and 3-year overall survival for colorectal and appendiceal carcinomatosis was 74.0 %, 32.5 % and 89.4 %, 29.3 %, respectively. Intraoperative peritoneal cancer index (PCI) score (>16) and need for blood transfusion were factors independently associated with poor survival (p < 0.05). ConclusionOur single institution experience of CRS/HIPEC procedures for peritoneal carcinomatosis demonstrates acceptable perioperative outcome and long-term survival. Optimal cytoreduction was achieved in the majority of cases. Intraoperative PCI > 16 was associated with poor survival. This series supports the safety of CRS-HIPEC in selected patients.

Genitourinary Resection at the Time of Cytoreductive Surgery and Heated Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis Is Not Associated with Increased Morbidity or Worsened Oncologic Outcomes: A Case-matched Study

Cytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC) has gained acceptance in the treatment of peritoneal carcinomatosis with reported morbidity and mortality rates of 27-56 and 0-11 %, respectively. The safety and oncologic outcome of genitourinary repair at the time of CRS and HIPEC remains unclear. We identified 170 patients who underwent CRS-HIPEC at our institution between July 2007 and August 2011 with a minimum follow-up of 6 months. Thirty-four (20 %) underwent concomitant urologic reconstruction at the time of CRS-HIPEC and were matched by disease burden (intraoperative peritoneal cancer index [PCI]) and extent of surgery (ΔPCI) with a cohort of 38 (22.3 %) subjects without genitourinary involvement. The primary end points considered for this analysis included the development of major surgical (Clavien-Dindo Class III-V) complications and overall survival. Median follow-up was 9.4 months. The most commonly performed urologic interventions included partial cystectomy with primary repair in 23 (65.7 %) and segmental ureteral resection and repair in 11 (31.4 %). Patients with genitourinary reconstruction had more total organ involvement (6.5 vs. 4.3, p < 0.001) and more commonly underwent enteric anastomoses (82.4 vs. 57.9 %, p = 0.025). No significant differences were observed with regard to major morbidity, need for transfusion, operative time, intensive care unit admission, or length of stay. Among patients with appendiceal or colonic tumors (n = 46), overall survival was similar between genitourinary reconstruction and matched cohorts: 22.5 versus 15.1 months, respectively (p = 0.66). Genitourinary reconstruction at the time of CRS-HIPEC occurs more commonly in patients with extensive disease burden undergoing radical debulking, yet does not adversely influence surgical morbidity or survival.

Determining the Association Between Preoperative Computed Tomography Findings and Postoperative Outcomes After Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei

This study evaluates the accuracy of computed tomography (CT) scoring of the peritoneal cancer index (PCI) and examines its association with surgical morbidity and outcomes in pseudomyxoma peritonei. Forty-seven patients with pseudomyxoma peritonei had preoperative evaluation of CT scans and were treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy. Their radiological PCI and intraoperative PCI were scored for determination of accuracy and for correlation with morbidity and outcomes. Accuracy in detecting peritoneal lesions regardless of size ranged from 51% to 85% in the abdominopelvic regions and 21% to 25% in the small intestinal regions. The sensitivity of CT detection of peritoneal implants ranged from 67% to 84% in the abdominopelvic regions and from 56% to 57% in the small intestinal regions. The specificity of CT detection of peritoneal lesions was 100% in all regions. Preoperative CT identification of larger peritoneal lesions in the right upper quadrant (P=0.016), epigastrium (P=0.003), left upper quadrant (P=0.019), proximal jejunum (P=0.022), distal jejunum (P=0.022), and proximal ileum (P=0.022) predicted development of severe complications. Similarly, larger peritoneal lesions in the right upper quadrant (P=0.039), epigastrium (P=0.024), right flank (P=0.005), and right lower quadrant (P=0.034) were negatively associated with disease-free survival, and the right upper quadrant (P=0.037) was negatively associated with overall survival. Preoperative CT scan depicting extensive upper abdominal and small bowel disease predicts the presence of severe complications after cytoreduction. Extensive disease in the right upper quadrant seems to be associated with a poorer survival outcome.

18F-FDG-PET/CT to Select Patients with Peritoneal Carcinomatosis for Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with significantly longer survival in patients with peritoneal carcinomatosis (PC). So far, no morphological imaging method has proven to accurately assess the intra-abdominal tumor spread. This study was designed to predict tumor load in patients with PC using dual-modality (18)FDG-PET/CT and to compare the results with those of PET and CT alone by correlating imaging findings with intraoperative staging. Twenty-two patients with PC from gastrointestinal (n = 13), ovarian cancer (n = 8), and mesothelioma (n = 1) underwent contrast-enhanced (18)FDG-PET/CT before surgery and HIPEC. In a retrospective analysis PET, CT, and fused PET/CT were separately and blindly reviewed for the extent of peritoneal involvement using the Peritoneal Cancer Index (PCI). Imaging results were correlated with the intraoperative PCI using Pearson's correlation coefficient and linear regression analysis. There was a strong correlation between the PCI obtained with PET/CT and the surgical PCI with respect to the total score (r = 0.951) as well as in the regional analysis (small bowel, r = 0.838; other, r = 0.703). The correlation was slightly lower for CT alone (total score, r = 0.919; small bowel, r = 0.754; other, r = 0.666) and significantly lower (p = 0.002) for PET alone (total score, r = 0.793; small bowel, r = 0.553, other, 0.507). Contrast-enhanced CT is superior compared with PET alone to predict the extent of PC. In our patient group, the combination of both modalities (contrast enhanced PET/CT) yielded the best results and proved to be a useful tool for selecting candidates for peritonectomy and HIPEC.

Evaluation of Preoperative Computed Tomography in Estimating Peritoneal Cancer Index in Colorectal Peritoneal Carcinomatosis

Peritoneal Cancer Index (PCI) has been recognized as an independent prognostic indicator for long-term outcomes. It also influences the likelihood of complete cytoreduction, another principal determinant of long-term survival. The objective of this study was to evaluate the utility of preoperative CT in estimating PCI during the patient selection process. The efficacy of CT in demonstrating peritoneal disease was evaluated by comparing the radiological and intraoperative lesion size and PCI scores using the Wilcoxon signed-rank test. Tumor distribution was assessed in each abdominopelvic region as tumor present versus absent. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated in each abdominopelvic region. Overall, where CT identifies the presence of disease, it portrayed lesion size accurately in 60%, underestimated in 33%, and overestimated in 7% of cases. Analysis of individual abdominopelvic regions demonstrated a statistically significant difference between radiologically and intraoperatively visualized lesion sizes (P < 0.05) except in the epigastrium, left upper, and left flank regions. The sensitivity of CT in detecting peritoneal implants was influenced by lesion size. Small nodules (<0.5 cm) were visualized on CT with only a sensitivity of 11%, which is in contrast to 94% with nodules exceeding 5 cm. Radiological PCI scores significantly underestimated intraoperative PCI (P < 0.001). This study demonstrated that the sensitivity of CT in detecting peritoneal implants was influenced by lesion size and CT PCI significantly underestimated clinical PCI. The role of CT in refining patient selection and improving prognosis remains to be closely evaluated.