Total FDG lesion number on PET/CT predicts survival of esophageal carcinoma patients with recurrence following curative surgery.

BACKGROUND: Total lesion number is a prognostic determinant in recurrent esophageal cancer, but this requires multiple tests. Here, we investigated the prognostic value of total FDG lesion number obtained from a single PET/CT study. METHODS: Subjects were 153 esophageal squamous cell carcinoma patients with loco-regional or distant recurrence following curative surgery. FDG PET/CT performed within 30 days was inspected for abnormal FDG uptake lesions using a SUVmax of 3.0 as threshold for significance. Prognostic associations were assessed by Cox proportional hazards regression and Kaplan-Meier analysis. RESULTS: PET/CT showed significant local FDG lesions in 49.0%, regional lesions in 78.4%, and distant lesions in 44.4% of patients. Among 73 patients with loco-regional recurrence, 54 had 0-3 and 19 had ≥4 FDG lesions. Among 80 patients with distant recurrence, 31 had 0-3 and 49 had ≥4 FDG lesions. During a median follow-up of 11.8 months, 99 deaths occurred. Univariate variables associated with poor survival included ≥4 FDG lesions and no treatment for loco-regional recurrence and no treatment for distant recurrence. Kaplan Meier analysis showed worse survival for ≥4 than 0-3 FDG lesions in patients with loco-regional recurrence (15.6 vs. 32.1 months; P=0.009), but not in those with distant recurrence. Significant independent predictors of poor survival were ≥4 FDG lesions and no treatment for loco-regional recurrence and no treatment for distant recurrence. CONCLUSIONS: Total FDG lesion number assessed by PET/CT is a significant independent prognostic factor in esophageal cancer patients with loco-regional recurrence following curative surgery.

Incidental 99mTc MDP uptake in the intestines and intravenous CT contrast.

AIM: We evaluated the association between intestinal visualization on bone scintigraphy and IV CT contrast in patients with breast cancer. PATIENTS, METHODS: 452 patients with breast cancer underwent a 99mTc methylene diphosphonate (MDP) bone scan for surveillance of bone metastasis. Presence, site and intensity of intestinal uptake were visually assessed. For patients with intestinal visualization, medical records were reviewed to identify the alleged potential causes. When IV CT contrast was administrated on the same day as bone scan, the time between IV CT contrast injection, 99mTc MDP administration and bone scan was assessed. RESULTS: Intestinal 99mTc MDP uptake was observed in 44 of the 452 patients (9.7%). Bone scans showed no thyroid or gastric uptake that suggested free pertechnetate. There were no patients with documented causes of intestinal uptake except for one patient with vesicoenteric fistula. Of the 452 patients, 149 (33.0%) underwent IV contrast-enhanced CT on the same day as bone scan. Forty of the 44 patients (90.9%) with intestinal uptake on bone scan underwent IV contrast-enhanced CT on the same day, whereas 109 of 408 (26.7%) patients without intestinal uptake on bone scintigraphy underwent IV contrast-enhanced CT on the same day (p < 0.001). The patients who underwent IV contrast injection between Tc-99m MDP administration and acquisition of bone scans had significantly more frequent intestinal uptake than patients who underwent IV contrast injection either before 99mTc MDP administration or after bone scanning (42.4% vs. 1.8%, p < 0.001). CONCLUSIONS: IV CT contrast injection administered on the same day as bone scintigraphy is significantly associated with 99mTc MDP uptake in the intestines among patients with breast cancer.

Anaerobic bio-hydrogen production from ethanol fermentation: the role of pH.

Hydrogen was produced by an ethanol-acetate fermentation at pH of 5.0 +/- 0.2 and HRT of 3 days. The yield of hydrogen was 100-200 ml g Glu(-1) with a hydrogen content of 25-40%. This fluctuation in the hydrogen yield was attributed to the formation of propionate and the activity of hydrogen utilizing methanogens. The change in the operational pH for the inhibition of this methanogenic activity induced a change in the main fermentation pathway. In this study, the main products were butyrate, ethanol and propionate, in the pH ranges 4.0-4.5, 4.5-5.0 and 5.0-6.0, respectively. However, the activity of all the microorganisms was inhibited below pH 4.0. Therefore, pH 4.0 was regarded as the operational limit for the anaerobic bio-hydrogen production process. These results indicate that the pH plays an important role in determining the type of anaerobic fermentation pathway in anaerobic bio-hydrogen processes.

Removal of headspace CO2 increases biological hydrogen production.

For biological hydrogen production by fermentation to be a useful method of hydrogen generation, molar yields of hydrogen must be increased. While heat treatment of a soil inoculum increases hydrogen yields by preventing loss of hydrogen to methanogenesis, hydrogen is still lost to acetic acid generation from hydrogen and CO2. To reduce hydrogen losses via acetogenesis, CO2 concentrations in the headspace were substantially reduced during hydrogen production using a chemical scavenger (KOH). CO2 in the headspace was decreased from 24.5% (control) to a maximum of 5.2% during the highest gas production phase, resulting in a hydrogen partial pressure of 87.4%. This reduction in CO2 increased the hydrogen yield by 43% (from 1.4 to 2.0 mol of H2/mol of glucose). The soluble byproducts in all tests consisted primarily of acetate and ethanol. Higher concentrations of ethanol (10.9 mM) remained in solution from bottles with CO2 removal than in the control (1.2 mM), likely as a result of hydrogen inhibition of biological ethanol conversion to acetic acid. These results show that hydrogen production can be increased by removing CO2 in the reactor vessel, likely as a result of suppression of acetogenesis.