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

Significance of pulmonary nodules in patients with colorectal cancer

Objectives: Radiographically small pulmonary nodules (PNs) in patients with colorectal cancer are troublesome because their discovery raises concern about metastases. This study sought to establish the appropriate timing of radiological follow-up for PNs detected at initial staging evaluation of colorectal carcinoma patients. Methods: The medical records of 376 consecutive colorectal cancer patients who underwent curative surgery and had baseline and follow-up chest X-rays (CXR) and computed tomography (CT) were reviewed. Results: The study included 92 patients who had all CXR and chest CT available for review, at least one PN found on baseline imaging, and no synchronous neoplasms. On baseline chest CT, these 92 patients had 170 PNs altogether and 77 (45.2 %) of them were greater than 5 mm in size. Baseline CXR detected 13 PNs in 12 patients and all but 2 were larger than 5 mm. Nodule size greater than 5 mm and irregular margins were predictors of nodule growth. The mean doubling time of 24/170 (14.1 %) growing PNs was about 4 months. Conclusions: Our findings suggest that baseline and follow-up CXR are pointless, and short-interval CT follow-up is warranted when PNs larger than 5 mm with irregular margins are detected on preoperative chest CT. Key Points: \u2022 Pulmonary nodules in colorectal cancer patients raise concern about metastasis. \u2022 Baseline and follow-up chest X-ray in colorectal cancer can be abandoned. \u2022 CT is the best technique for assessing PNs in colorectal cancer. \u2022 Short-interval CT follow-up advisable for PNs larger than 5 mm with irregular margins