MRI characteristics of proctitis in Crohn’s disease on perianal MRI

Purpose

Multiple features have been described for assessing inflammation in Crohn’s disease (CD) in MR enterography, but have not been validated in perianal magnetic resonance imaging (MRI). Retrospectively, we studied which MRI features are valuable in assessing proctitis.

Materials and methods

CD patients (≥18 years) who underwent colonoscopy (reference standard) and perianal fistula MRI within 8 weeks were included. Seventeen MRI features were blindly scored by three observers and correlated to endoscopy (regression analysis). Reproducibility (multirater kappa, intraclass correlation coefficient) was determined for all three observer pairs. MRI features were considered relevant when significantly correlated to endoscopy for ≥2 observers, and reproducibility was ≥0.40 for ≥2 observer pairs.

Results

Perianal MRI of 58 CD patients were included. Wall thickness, rectal mural fat, creeping fat, and size of mesorectal lymph nodes showed a significant correlation with endoscopy for ≥2 observers (p = 0.000–0.023, p = 0.011–0.172, p = 0.007–0.011 and p = 0.000–0.005, respectively) with a kappa/intraclass correlation coefficient of ≥0.60 for ≥2 observer pairs. Perimural T2 signal and perimural enhancement significantly correlated to endoscopy (all p values ≤0.05) for all three observers and the reproducibility was ≥0.40 for ≥2 observer pairs. Mural T2 signal and degree and pattern of T1 enhancement showed significant correlation to endoscopy for two observers, but with poor to moderate reproducibility.

Conclusion

Wall thickness, mural fat, and mesorectal features (perimural T2 signal, perimural enhancement, creeping fat, and size of mesorectal lymph nodes) had significant correlation to endoscopy and were reproducible in diagnosing proctitis. Some established luminal features in MRE were considered not useful.

     

Accuracy and reproducibility of 3D-CT measurements for early response assessment of chemoradiotherapy in patients with oesophageal cancer

Background

Chemoradiotherapy is increasingly applied in patients with oesophageal cancer. The aim of the present study was to determine whether 3D-CT volumetry is able to differentiate between responding and non-responding oesophageal tumours early in the course of neoadjuvant chemoradiotherapy.

Patients and methods

Serial CT before and after two weeks of neoadjuvant chemoradiotherapy was performed in the multimodality treatment arm of a randomised trial including patients with oesophageal carcinoma. CT response was measured with the change in tumour volume between baseline and after 14 days of neoadjuvant therapy. Receiver Operating Characteristic (ROC) analysis was used to evaluate the ability of 3D-CT as an early imaging marker of response.

Results

CT response analysis was performed in 39 patients, of whom 26 patients were histopathological responders. Median tumour volume increased between baseline and after 14 days of chemoradiotherapy in histopathological responders as well as in non-responders, though changes were not statistically significant. The area under the ROC curve was 0.71.

Conclusion

Tumour volume changes after 14 days of neoadjuvant chemoradiotherapy as measured by 3D-CT were not associated with histopathological tumour response. CT volumetry should not be used for early response assessment in patients with potentially curable oesophageal cancer treated with neoadjuvant chemoradiotherapy.     

Irrigation of port sites: prevention of port site metastases?

INTRODUCTION: Port site metastases can occur when free viable tumor cells implant at trocar wounds. Irrigation of port sites with cytotoxic agents has been suggested to prevent port site metastases. The objective of this study is to assess whether tumor growth at port sites can be reduced by irrigation of these port sites. METHODS: WAG rats were insufflated with CO(2) for 20 minutes and 5 x 10(5) CC531 tumor cells were injected intraperitoneally. Port sites were irrigated after completion of the pneumoperitoneum with povidone-iodine, a mixture of taurolidine and heparin, or sodium chloride. Controls did not undergo any irrigation of port sites. In experiment 1, all 16 rats had all 4 irrigation modalities. In experiment 2, four groups of 20 rats had one type of irrigation on two trocar wounds. Tumor growth was evaluated 4 weeks after the procedure. RESULTS: No difference in tumor growth at trocar wounds was found between any type of irrigation and controls in both experiments. CONCLUSION: In this experimental model, no beneficial or adverse effects of irrigation of port sites could be shown.     

Effects of somatostatin on proximal gastric motor function and visceral perception

Background:

Somatostatin affects gastrointestinal motility and secretion and visceral sensation, but little is known about its effects on the proximal stomach.

Aim:

To evaluate the effects of somatostatin on proximal gastric motor function and perception of symptoms.

Methods:

Six healthy subjects participated in two experiments performed in random order during continuous intravenous infusion of saline or somatostatin (250 μg/h). Proximal gastric motor function was evaluated using a barostat. We performed pressure and volume distensions and a barostat procedure (minimal distending pressure + 2 mmHg). Symptoms were evaluated at regular intervals using visual analogue scales (VAS).

Results:

Neither minimal distending pressure nor gastric fundal tone were significantly different between somatostatin and saline. Pressure–volume curves during distensions were not influenced by somatostatin. However, phasic volume waves were significantly (P < 0.001) reduced by somatostatin, and somatostatin significantly (P < 0.05) reduced symptom perception of fullness and abdominal pressure during stepwise distensions.

Conclusions:

Continuous infusion of somatostatin does not influence gastric compliance but it inhibits phasic volume waves and significantly reduces visceral perception.

     

Urologic evaluation of megacystis-microcolonintestinal hypoperistalsis syndrome

The seventh case of megacystis-microcolon-intestinal hypoperistalsis syndrome is presented with its urologic aspects. In contrast to the bowel conditions, the urologic problems were tractable.     

Decrease of CD117 expression as possible prognostic marker for recurrence in the resected specimen after imatinib treatment in patients with initially unresectable gastrointestinal stromal tumors: a clinicopathological analysis

Gastrointestinal stromal tumors (GIST) are the most common malignant mesenchymal tumors of the gastrointestinal tract. The principal treatment modality for primary GIST is surgery whereas for metastatic GIST, imatinib has an established role. In patients with locally advanced and metastatic GIST, the role of surgery in the imatinib era is still unclear. Fifteen patients with locally advanced (n=9) and/or metastatic GIST (n=6) were treated with imatinib followed by resection. Detailed histopathological examination was performed before and after treatment with imatinib, which was given for a median of 11 months before surgery. Ten patients showed a radiographic partial response, four patients had stable disease, and one patient progressed. At the time of surgery, the median tumor diameter was 6.5 cm. In all the nine patients with locally advanced GIST, a R0 resection could be performed. Histopathological examination showed imatinib effects in all tumors, including the case with progressive disease. All patients with locally advanced disease (n=9) were alive after a median follow-up of 40 months (range: 18-59), of which seven patients were free of disease. Four of the six patients treated for metastatic GIST died of disease after 30, 45, 50, and 74 months of follow-up. Remarkably, in five of six patients in whom CD117 expression was diminished or lost in the resection specimen, disease recurrence was observed. In patients with retained CD117 expression, one of the nine patients had recurrent disease. In conclusion, preoperative imatinib treatment in patients with locally advanced GIST resulted in a decrease of tumor load in most patients, enabling complete surgical resection. For patients with metastatic GIST, the role of surgery remains less clear. Loss or decrease of CD117 expression in the resected specimen after imatinib treatment may be associated with disease recurrence.     

Effect of Intraduodenal and Intravenous Amino Acids on Proximal Gastric Motor Function in Man

The present study was performed to investigate the effect of amino acids during the intestinal and postabsorptive phase of digestion on proximal gastric motor function measured with an electronic barostat. Eight healthy volunteers participated in three experiments performed during continuous infusion of: (1) intravenous and intraduodenal saline, (2) intraduodenal amino acids, and (3) intravenous amino acids. Both intraduodenal and intravenous amino acids induced gastric relaxation and increased gastric compliance. Only during intraduodenal amino acids did plasma CCK levels increase significantly. Correlation between intragastric volume measurements (with pressure set at MDP + 2 mm Hg) and plasma CCK levels was 0.90 (P < 0.001) during the early intestinal phase. Relaxation of the proximal stomach is related to plasma CCK in the early intestinal phase, whereas in the postabsorptive phase of amino acids other mechanisms play a role in proximal gastric relaxation.     

Somatostatin receptor gene therapy combined with targeted therapy with radiolabeled octreotide: a new treatment for liver metastases

OBJECTIVE: To evaluate the effect of peptide receptor radionuclide therapy (PRRT) on somatostatin receptor (SSR)-transfected colon carcinoma cells in a rat liver metastases model.SUMMARY BACKGROUND DATA: Previously the authors have shown highly effective therapy with PRRT of SSR-positive tumors. This treatment is SSR-mediated; successful treatment is seen only in SSR-positive tumors, with no effect in SSR-negative tumors. As many tumors lack this receptor, the idea arose to transfect SSR-negative tumor cells with an SSR gene to apply PRRT on these SSR-transfected tumor cells. METHODS: CC531 colon carcinoma cells (SSR-negative) were transfected in vitro with an SSR (subtype 2) gene (CC2B). Liver metastases were produced after intraportal injection of these tumor cells in rats. On day 7, animals were treated with 185 or 370 MBq [177 Lu-DOTA0, Tyr3 ]octreotate. After 21 days rats were killed and liver metastases were counted. RESULTS: Treatment with 370 MBq [177 Lu-DOTA0, Tyr3 ]octreotate showed a significant antitumor response in rats with CC2B liver metastases (SSR-positive) in comparison with controls. No significant antitumor effect was seen in PRRT-treated rats with CC531 liver metastases (SSR-negative). Also, a dose-dependent tumor response was seen in rats with CC2B liver metastases treated with 185 MBq [ 177Lu-DOTA0, Tyr3 ]octreotate compared with controls. In addition, rats with mixed liver metastases treated with 185 MBq [177 Lu-DOTA0, Tyr3 ]octreotate had significantly fewer metastases compared with controls. CONCLUSIONS: The authors showed an impressive antitumor effect of SSR (subtype 2)-transfected colon carcinoma cells with PRRT in a rat liver metastasis model. Moreover, rats with mixed liver metastases had significantly fewer liver metastases compared with control rats, which may be due to a radiologic bystander effect of [177 Lu-DOTA0, Tyr3 ]octreotate. This phenomenon is beneficial in the concept of in vivo gene therapy.     

Increased tumor growth after high pressure pneumoperitoneum with helium and air

BACKGROUND: Tumor growth appears proportional to the pressure of carbon dioxide insufflation during laparoscopic surgery. Air and helium are alternative insufflation gases. The objective of this study is to assess tumor growth after air and helium insufflation at different pressures. METHOD: Ninety-six WAG rats were allocated to either air or helium. In both arms, rats were randomly exposed to a one hour gasless procedure, or to 4 mm Hg, 10 mm Hg, or 16 mm Hg insufflation. At the start of the procedure, 500,000 CC531 tumor cells were injected intraperitoneally. After three weeks, intraperitoneal tumor growth was assessed. RESULTS: Higher insufflation pressures were associated with greater tumor growth. No difference of tumor growth between air and helium insufflation was found. CONCLUSION: In this experimental model, insufflation pressure appeared to have a greater impact on tumor growth than the type of gas. Further studies are necessary but it seems prudent to recommend employment of lower insufflation pressures in laparoscopic oncologic surgery.