Multidetector computed tomography pulmonary angiography: does arm position affect pulmonary artery enhancement?

OBJECTIVE: To evaluate whether arm position affects pulmonary artery enhancement in computed tomographic pulmonary angiography (CTPA). METHODS: Study protocol had local ethics committee approval. Eighty-six patients who received 16 detector row CTPA for suspected pulmonary embolism were scanned with their contrast-injected arm resting at their side and compared with 94 patients who were scanned with both arms resting above their head. Two radiologists assessed pulmonary artery enhancement with a region-of-interest measurement of the main pulmonary artery density, scored the degree of beam-hardening artifact arising from the superior vena cava (SVC) and from the dependent arm that crossed the pulmonary arteries (1 = no artifact, 5 = artery obscured), and measured the degree of central venous compression of the injected veins at the thoracic inlet. A 2-tailed t test was performed to compare pulmonary artery density and central venous compression. RESULTS: There was no difference in pulmonary artery enhancement between the 2 arm positions. Mean density of contrast in the main pulmonary artery was 329 Hounsfield units (HU) (95% confidence interval (CI), 310-350) in the arm-down group, compared with 325 HU (95% CI, 306-346) in the arm-up group (P = 0.65). Greater compression of the central veins occurred in the arm-up group (48.5%; 95% CI, 42.3%-54.8%) than in the arm-down group (22.3%; 95% CI, 16.8%-27.8%) (P < 0.05). There was also more beam hardening arising from contrast in the SVC in the arm-up group (P < 0.0001). CONCLUSIONS: Arm position does not affect pulmonary arterial enhancement during CTPA. There was greater central venous compression and more beam-hardening artifact arising from the SVC when the arm was held above the head.

Erlotinib and chemoradiation followed by maintenance erlotinib for locally advanced pancreatic cancer: a phase I study.

OBJECTIVES: A phase I trial was conducted to determine the maximally tolerated dose of erlotinib with concurrent gemcitabine, paclitaxel, and radiation for patients with locally advanced pancreatic cancer and to gather preliminary data on maintenance erlotinib after chemoradiation. METHODS: Patients received gemcitabine, 75 mg/m2, and paclitaxel, 40 mg/m, weekly for 6 weeks with 50.4 radiation to the primary tumor and draining lymph nodes with a 2- to 3-cm margin. Erlotinib was administered over 3-dose levels (50-100 mg/d) with chemoradiation then all patients received 150 mg/d maintenance until disease progression. RESULTS: Seventeen patients were assessable for toxicity; 13 with locally advanced disease and 4 who had undergone resection but had positive margins. At erlotinib dosages > or =75 mg/d with chemoradiation the dose-limiting toxicities were diarrhea, dehydration, rash, myelosuppression, and small bowel stricture. Maintenance erlotinib, 150 mg/d, was well tolerated. The median survival of the 13 patients with locally advanced disease was 14.0 months and 6 of 13 (46%) had a partial response. CONCLUSIONS: The maximum tolerated dose of erlotinib with gemcitabine, paclitaxel and concurrent radiation is 50 mg/d for patients with locally advanced pancreatic cancer. Full dose maintenance erlotinib is well tolerated. Promising preliminary activity and overall survival were demonstrated.