Background and Purpose A constant relative biological effectiveness (RBE) is used for clinical proton therapy; however, experimental evidence indicates that RBE can vary. We analyzed pediatric ependymoma patients who received proton therapy to determine if areas of normal tissue damage indicated by post-treatment image changes were associated with increased biological dose effectiveness. Material and Methods Fourteen of 34 children showed T2-FLAIR hyperintensity on post-treatment magnetic resonance (MR) images. We delineated regions of treatment-related change and calculated dose and linear energy transfer (LET) distributions with Monte Carlo. Voxel-level image change data were fit to a generalized linear model incorporating dose and LET. Cross-validation was used to determine model parameters and for receiver operating characteristic curve analysis. Tolerance dose (TD50; dose at which 50% of patients would experience toxicity) was interpolated from the model. Results Image changes showed dependence on increasing LET and dose. TD50 decreased with increasing LET, indicating an increase in biological dose effectiveness. The cross-validated area under the curve for the model was 0.91 (95% confidence interval 0.88–0.94). Conclusions Our correlation of changes on MR images after proton therapy with increased LET constitutes the first clinical evidence of variable proton biological effectiveness.

Abstract The impact of bridging therapy (BT) administered between leukapheresis and chimeric antigen receptor (CAR) T-cell therapy for large B-cell lymphoma (LBCL) is unclear. We evaluated the influence of BT (systemic therapy [ST], radiation therapy [RT], or combined-modality therapy [CMT]) on outcomes of 148 LBCL patients who underwent leukapheresis for planned axicabtagene ciloleucel (axi-cel) infusion. The 55% (n = 81) of patients who received BT were more likely to have international prognostic index (IPI) score ≥3 (P ≤ .01), bulky disease (P = .01), and elevated lactate dehydrogenase (LDH; P ≤ .01). The 1-year progression-free (PFS) and overall survival (OS) rates were 40% and 65% in non-BT patients vs 21% and 48% in BT patients (P = .01 and .05, respectively). Twenty-four patients (16%) did not receive axi-cel, most commonly because of lymphoma progression (88%), despite 80% (n = 19) receiving BT. Among 124 patients who received axi-cel, 50% (n = 62) received BT with ST (n = 45), RT (n = 11), or CMT (n = 6); 1-year PFS and OS rates were not significantly different between BT and non-BT cohorts (P = .06 and .21, respectively). There was no difference in proportion of patients with IPI ≥3, limited-stage disease, or elevated LDH between ST, RT, and CMT groups. Compared with non-BT patients, 1-year PFS was inferior for ST-bridged patients (P = .01). RT-bridged patients had improved PFS compared with ST-bridged patients (P = .05). Despite the poor prognosis associated with requiring BT, RT can be an effective bridging strategy. Future studies are necessary to identify strategies that may improve access to CAR T-cell therapy and outcomes.

We introduce a novel contrast mechanism for optical coherence tomography (OCT) whereby the optical scattering of magnetically labeled cells is modified by means of an externally applied magnetic field. This modification is made through the addition of a small electromagnet to the imaging arm of a conventional OCT interferometer. We measure the magnetomotive OCT signal by differencing pairs of axial scans (A-scans) acquired with the magnetic field on and off. Magnetomotive contrast is demonstrated in bulk three-dimensional cell scaffolds containing macrophages labeled with microparticles of iron oxide, demonstrating magnetic-specific contrast over a dynamic range of 30 dB.

HighlightsHigh H19 expression in primary tumors is an independent predictor of short overall survival in CRC patients.RB1-E2F and CDK8-β-catenin signaling are essential in mediating the oncogenic activity of H19 in CRC.Combined analysis of H19 and its targets further improved the prediction power on overall survival of CRC patients.Long noncoding RNAs (lncRNAs) are transcripts at least 200 nucleotides long that do not code for proteins. The clinical relevance of lncRNAs in colorectal cancer (CRC) is largely unknown. Here we identified that H19 expression in primary tumors is an independent prognostic predictor of poor prognosis of CRC patients and further proved its oncogenic role. To characterize the mechanisms, we profiled gene expression changes following H19 modulation in CRC cell lines and analyzed gene expression association in clinical datasets. Our data revealed important cancer-signaling pathways, including the RB1-E2F and the CDK8-β-catenin signaling, underlying H19 function.

The presence of bulky disease in Hodgkin lymphoma (HL), traditionally defined with a 1-dimensional measurement, can change a patient's risk grouping and thus the treatment approach. We hypothesized that 3-dimensional measurements of disease burden obtained from baseline F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), would more accurately risk-stratify patients. To test this hypothesis, we reviewed pretreatment PET-CT scans of patients with stage I-II HL treated at our institution between 2003 and 2013. Disease was delineated on prechemotherapy PET-CT scans by 2 methods: (1) manual contouring and (2) subthresholding of these contours to give the tumor volume with standardized uptake value ≥2.5. MTV and TLG were extracted from the threshold volumes (MTV, TLG) and from the manually contoured soft-tissue volumes. At a median follow-up of 4.96 years for the 267 patients evaluated, 27 patients were diagnosed with relapsed or refractory disease and 12 died. Both MTV and TLG were highly correlated with freedom from progression and were dichotomized with 80th percentile cutoff values of 268 and 1703, respectively. Consideration of MTV and TLG enabled restratification of early unfavorable HL patients as having low- and high-risk disease. We conclude that MTV and TLG provide a potential measure of tumor burden to aid in risk stratification of early unfavorable HL patients.