No abstract

Background. Onboard magnetic resonance imaging (OB-MRI) for daily localization and adaptive radiotherapy has been under development by several groups. However, no clinical studies have evaluated whether OB-MRI improves visualization of the target and organs at risk (OARs) compared to standard onboard computed tomography (OB-CT). This study compared visualization of patient anatomy on images acquired on the MRI-60 Co ViewRay system to those acquired with OB-CT. Material and methods. Fourteen patients enrolled on a protocol approved by the Institutional Review Board (IRB) and undergoing image-guided radiotherapy for cancer in the thorax (n ϭ 2), pelvis (n ϭ 6), abdomen (n ϭ 3) or head and neck (n ϭ 3) were imaged with OB-MRI and OB-CT. For each of the 14 patients, the OB-MRI and OB-CT datasets were displayed side-by-side and independently reviewed by three radiation oncologists. Each physician was asked to evaluate which dataset offered better visualization of the target and OARs. A quantitative contouring study was performed on two abdominal patients to assess if OB-MRI could offer improved inter-observer segmentation agreement for adaptive planning. Results. In total 221 OARs and 10 targets were compared for visualization on OB-MRI and OB-CT by each of the three physicians. The majority of physicians (two or more) evaluated visualization on MRI as better for 71% of structures, worse for 10% of structures, and equivalent for 14% of structures. 5% of structures were not visible on either. Physicians agreed unanimously for 74% and in majority for Ͼ 99% of structures. Targets were better visualized on MRI in 4/10 cases, and never on OB-CT. Conclusion. Low-fi eld MR provides better anatomic visualization of many radiotherapy targets and most OARs as compared to OB-CT. Further studies with OB-MRI should be pursued.

The physiological relevance of naturally occurring IgM-ALA remains to be elucidated. These autoantibodies are present from birth and increase in diverse inflammatory states that are both infectious and noninfectious. Clinical observations showing significantly less acute allograft rejections in recipients having high IgM-ALA levels, led us to investigate whether IgM-ALA could have a functional role in attenuating T cell mediated inflammatory responses. In pursuit of this hypothesis, we did studies using IgM purified from the serum of normal individuals, patients with end stage renal disease, and HIV-1 infection. All preparations of IgM immunoprecipitated certain receptors e.g., CD3, CD4, CCR5, and CXCR4 from whole cell lysates but failed to immunoprecipitate IL-2R and HLA Ags. In physiological doses IgM down-regulated CD4, CD2 and CD86 but not CD8 and CD28, inhibited T cell proliferation, decreased production of certain proinflammatory cytokines e.g., TNF-α, IL-13 and IL-2, but not IFN- γ, IL-1β, GM-CSF, IL-6 and IL-8 and inhibited leukocyte chemotaxis. These inhibitory effects were more pronounced when using IgM from patients with high levels of IgM-ALA and these inhibitory effects were significantly reduced after using IgM preabsorbed with leukocytes. IgM-ALA binding to leukocytes was found to be highly specific, as <10% of IgM secreting B cell clones had IgM-ALA specificity with some clones having specificity for either T cells or monocytes. These findings support the concept that IgM-ALA provides an innate mechanism to regulate T cell mediated inflammatory responses.

IPSI radiation therapy demonstrated excellent locoregional control with no adverse effect on disease-free survival or overall survival.

Unilateral IMRT appears to reduce acute toxicity and achieves oncological outcomes similar to those of bilateral IMRT in selected patients with lateralized palatine tonsillar cancer with a neck classification of N0 to N2b. Cancer 2017;123:4594-4607. © 2017 American Cancer Society.