Local hyperthermia, hyperfractionated radiation, and cisplatin in preirradiated recurrent lymph node metastases of recurrent head and neck cancer

Large tumor size is a negative prognostic variable for attaining complete regression (CR) with local hyperthermia (HT) and radiotherapy (RT). Such poor prognosis lesions (i.e., >7 cm(2) or >14 cm(3)) have an expected CR rate of similar to 30+/-8%. To improve on this result we added cisplatin to HT and RT with standard fractionation (std Fx) in an earlier study, and observed a 19% CR rate in head and neck (H&N) patients. We now report the results of a second generation trial combining HT, cisplatin (40 mg/m(2)) and hyperfractionated RT in a series of 13 pretreated poor prognosis H&N patients. Therapy encompassed 44 triple modality sessions and was well tolerated: toxicity included one episode of grade-3 skin reaction and one grade 1 leukopenia. Although the overall remission rate was 92%, the CR rate was only 8%; this resulted in early closure of this trial concluding that hyperfractionated RT had no (over std Fx RT) benefit in this combined modality approach.

Toward online reconstruction of quantitative susceptibility maps: superfast dipole inversion

Magnetic susceptibility is an intrinsic tissue property that recently became measureable in vivo by a magnetic-resonance based technique called quantitative susceptibility mapping (QSM). Although QSM may be performed without additional acquisition time, for example, in the course of the well-established susceptibility weighted imaging, the applicability of QSM is currently hampered by the numerical complexity and computational cost associated with the reconstruction procedure. This work introduces a novel QSM framework called superfast dipole inversion which allows rapid online reconstruction of susceptibility maps from wrapped raw gradient-echo phase data. The algorithm relies on the extension and combination of several recent algorithms involving the precalculation of convolution kernels and the correction of inversion artifacts. Reconstruction of three-dimensional high resolution susceptibility maps of the human brain was achieved with superfast dipole inversion in less than 20 s on a conventional workstation computer. Thus, superfast dipole inversion opens the door to an implementation of QSM on MR scanner hardware as well as to the routine reconstruction of large cohorts of datasets.

Quantitative susceptibility mapping for investigating subtle susceptibility variations in the human brain

Quantitative susceptibility mapping (QSM) is a novel magnetic resonance-based technique that determines tissue magnetic susceptibility from measurements of the magnetic field perturbation. Due to the ill-posed nature of this problem, regularization strategies are generally required to reduce streaking artifacts on the computed maps. The present study introduces a new algorithm for calculating the susceptibility distribution utilizing a priori information on its regional homogeneity derived from gradient echo phase images and analyzes the impact of erroneous a priori information on susceptibility map fidelity. The algorithm, Homogeneity Enabled Incremental Dipole Inversion (HEIDI), was investigated with a special focus on the reconstruction of subtle susceptibility variations in a numerical model and in volunteer data and was compared with two recently published approaches, Thresholded K-space Division (TKD) and Morphology Enabled Dipole Inversion (MEDI). HEIDI resulted in susceptibility maps without streaking artifacts and excellent depiction of subtle susceptibility variations in most regions. By investigating HEIDI susceptibility maps acquired with the volunteers' heads in different orientations, it was demonstrated that the apparent magnetic susceptibility distribution of human brain tissue considerably depends on the direction of the main magnetic field.

Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study

Quantitative susceptibility mapping (QSM) is a novel technique which allows determining the bulk magnetic susceptibility distribution of tissue in vivo from gradient echo magnetic resonance phase images. It is commonly assumed that paramagnetic iron is the predominant source of susceptibility variations in gray matter as many studies have reported a reasonable correlation of magnetic susceptibility with brain iron concentrations in vivo. Instead of performing direct comparisons, however, all these studies used the putative iron concentrations reported in the hallmark study by Hallgren and Sourander (1958) for their analysis. Consequently, the extent to which QSM can serve to reliably assess brain iron levels is not yet fully clear. To provide such information we investigated the relation between bulk tissue magnetic susceptibility and brain iron concentration in unfixed (in situ) post mortem brains of 13 subjects using MRI and inductively coupled plasma mass spectrometry. A strong linear correlation between chemically determined iron concentration and bulk magnetic susceptibility was found in gray matter structures (r = 0.84, p < 0.001), whereas the correlation coefficient was much lower in white matter (r = 0.27, p < 0.001). The slope of the overall linear correlation was consistent with theoretical considerations of the magnetism of ferritin supporting that most of the iron in the brain is bound to ferritin proteins. In conclusion, iron is the dominant source of magnetic susceptibility in deep gray matter and can be assessed with QSM. In white matter regions the estimation of iron concentrations by QSM is less accurate and more complex because the counteracting contribution from diamagnetic myelinated neuronal fibers confounds the interpretation.

[Skeletal tuberculosis of the distal radius during pregnancy]

We present a case of a pregnant woman (32nd gestational week) that suffered from a chronic non-healing wound at the distal radius. Skeletal tuberculosis was finally diagnosed and treated successfully with staged surgical therapy combined with appropriate medication. One year after surgical treatment, the outcome of the mother was excellent and the baby did not suffer from any disease related to operative procedures or pharmacotherapy. Operative treatment of skeletal tuberculosis (especially osteoarticular and vertebral tuberculosis) in combination with tuberculostatic therapy during pregnancy and lactation seem to be the appropriate treatment with minimal risk for the child and excellent outcome for the mother.