Prospective Randomized Trial for Image-Guided Biopsy Using Cone-Beam CT Navigation Compared with Conventional CT.

PURPOSE: To compare cone-beam computed tomography (CT) navigation vs conventional CT image guidance during biopsies. MATERIALS AND METHODS: Patients scheduled for image-guided biopsies were prospectively and randomly assigned to conventional CT guidance vs cone-beam CT navigation. Radiation dose, accuracy of final needle position, rate of histopathologic diagnosis, and number of needle repositions to reach the target (defined as pullback to adjust position) were compared. RESULTS: A total of 58 patients (mean age, 57 y; 62.1% men) were randomized: 29 patients underwent 33 biopsies with CT guidance and 29 patients with 33 lesions underwent biopsy with cone-beam CT navigation. The average body mass index (BMI) was similar between groups, at 28.8 kg/m(2) ± 6.55 (P = .18). There was no difference between groups in terms of patient and lesion characteristics (eg, size, depth). The average lesion size was 29.1 ± 12.7mm for CT group vs 32.1mm ±16.8mm for cone-beam CT group (P < 0.59). Location of lesions was equally divided between the 2 groups, 20 lung lesions, 18 renal lesions and 20 other abdominal lesions. Mean number of needle repositions in the cone-beam CT group was 0.3 ± 0.5, compared with 1.9 ± 2.3 with conventional CT (P < .001). The average skin entry dose was 29% lower with cone-beam CT than with conventional CT (P < .04 accounting for BMI). The average estimated effective dose for the planning scan from phantom data was 49% lower with cone-beam CT vs conventional CT (P = .018). Accuracy, defined as the difference between planned and final needle positions, was 4.9 mm ± 4.1 for the cone-beam CT group, compared with 12.2 mm ± 8.1 for conventional CT (P < .001). Histopathologic diagnosis rates were similar between groups, at 90.9% for conventional CT and 93.9% for cone-beam CT (P = .67). CONCLUSIONS: Cone-beam CT navigation for biopsies improved targeting accuracy with fewer needle repositions, lower skin entry dose, and lower effective dose for planning scan, and a comparable histopathologic diagnosis rate.

Positron emission tomography imaging of tumors expressing the human chemokine receptor CXCR4 in mice with the use of 64Cu-AMD3100.

PURPOSE: Expression of CXCR4 in cancers has been correlated with poor prognosis and increased metastasis. Quantifying CXCR4 expression non-invasively might aid in prognostication and monitoring therapy. We evaluated a radiolabeled antagonist of CXCR4, 64Cu-AMD3100, as a positron-emitting imaging agent. PROCEDURES: CXCR4-transfected or non-transfected cell lines were injected into mice to form xenografts. Accumulation of 64Cu-AMD3100 in tumors was analyzed by small-animal PET and biodistribution assays. RESULTS: 64Cu-AMD3100 accumulated in CXCR4-expressing, but not CXCR4-negative, tumors. For CXCR4-expressing tumors, tumor-to-blood and tumor-to-muscle ratios were 23-41 and 50-59, respectively, depending on tumor type. Excess of unlabeled Cu-AMD3100 or AMD3100 significantly reduced 64Cu-AMD3100 accumulation in CXCR4-expressing tumors. Human-absorbed dose calculations predicted a dose limit of 444 MBq. CONCLUSIONS: CXCR4 can be imaged in tumors using 64Cu-AMD3100. Dosimetry studies suggest that imaging in humans is feasible. We conclude that 64Cu-AMD3100 should be investigated as a potential agent for imaging and quantifying CXCR4 in tumors.