Publications

To extend the signal longevity of magnetically excited spins in flowing fluids while in a state of global coherent free precession (GCFP), a refocusing radiofrequency (RF) pulse and bipolar gradient waveforms were combined with the GCFP sequence. The data demonstrate that RF refocusing in the presence of flowing blood is possible, but the improvement in signal amplitude depends on the static magnetic field homogeneity along the direction of motion and the displacement of the spins between the excitation and the RF refocusing pulse, as well as displacement during subsequent RF refocusing pulses. The least amount of phase dispersion and thus the longest lasting signal is obtained with the shortest echo spacing where only one line of data is recorded between two RF refocusing pulses. This approach was successfully used in a phantom and in vivo to image fast and slow blood flow. Depending on the experimental conditions, signal persistence is improved significantly compared to playing the same sequence without RF refocusing, but the improvement is limited by the product of blood flow velocity and the time between RF refocusing pulses.

PURPOSE

Osteonecrosis of the jaw (ONJ) has been observed recently in patients with cancer who are receiving intravenous bisphosphonate (BP) therapy. The incidence of BP-associated ONJ has not been well established. The purpose of this study was to determine the incidence of ONJ in a cohort of patients with multiple myeloma (MM), breast cancer (BC), or prostate cancer (PC) who were receiving BP therapy.

PATIENTS AND METHODS

A retrospective chart review was performed. Medical record numbers were identified by ICD-9 codes: 203.0, 203.01, 174.9, and 185.0 for active MM, MM in remission, BC, and PC, respectively. Patients were included if they were evaluated and/or treated between January 1, 2000, and December 31, 2005, and had received zoledronic acid and/or pamidronate. Patients were excluded if they had a history of radiation therapy to the jaws or of tumors or cysts. ONJ was defined as clinical evidence of "exposed necrotic bone" in the mouth.

RESULTS

Through evaluation of 1,086 patient medical records, it was determined that 447 subjects met the inclusion criteria: 11 of 292 patients with MM (3.8%; 95% confidence interval [CI], 1.6%, 6.0%) had ONJ, as did 2.5% of 81 patients with BC (0%, 6.9%) and 2.9% of 69 patients with PC (0%, 5.9%).

CONCLUSION

The incidence of ONJ associated with intravenous BPs was at least 3.8 per 100 patients with MM, 2.5 per 100 patients with BC, and 2.9 per 100 patients with PC during the 5-year study period. The next phase of this study involves assessment of risk factors that differentiate these patients from those treated with BPs who do not develop ONJ.