551 Background: CBCs decrease during standard 3D-conformal pelvic RT for rectal cancer. We evaluated RT plans and CBCs to determine if this decrease is due to RT or only concurrent chemotherapy. Methods: Pelvic bones were contoured for 69 patients who had CT-based treatment plans and CBCs 3 months pre and during RT. CBCs included white blood cells (WBC), hemoglobin (Hgb) and platelets (PLT). The pelvic bones included the bilateral femoral heads and innominate bones, sacrum and L5. Dose volume histograms (DVH) for the pelvic bones were encoded as volumes (Vol) receiving 10 (V10) to 50 Gy (V50) in cc, and percent (Perc) (P10 to P50). The paired t-test was used to compare CBCs pre and during RT. CBCs were analyzed with a repeated measures general linear model for uneven time intervals (R 2.15.1). Results: Median age was 60 y, with 40 men (58%) and preoperative RT in 32 (46%). The median RT dose was 50.4 Gy (range 25.2-60.4 Gy), with all but 2 patients receiving ≥45 Gy. Among 677 CBCs, there were 675 WBC, 677 Hgb, and 672 PLT. The average WBC pre and during RT were 7.7 vs 5.4 bil/L (p<0.001), Hgb 12.9 vs 12.5 g/dL (p=0.005), and PLT 271 vs 227 bil/L (p<0.001). A statistical model with variables for time, the 3-week chemotherapy cycle, the pre-RT average CBC, and 1st and 2nd-order interactions of time with Vol and Perc was constructed. All Vol and Perc for all bones as one structure were significant predictors of the PLT timecourse during RT, with the first-order time-dose interaction encoding a decrease over time, and the second-order time-dose interaction a recovery towards the end of RT. For WBC, V40 and P40 were most predictive (p<0.001), with P40 more so. There were no time-dependent interactions for Hgb. All models had a significant effect of pre RT average CBC and the 3-week chemo cycle. Conclusions: Whereas chemotherapy acts systemically, RT affects a circumscribed area. As such, bone marrow outside the RT field can compensate for lost hematopoiesis over time. Pelvic bone RT dose correlates with PLT and WBC (circulation half-life 1-3 d) but not Hgb (half-life 120 d) supporting an effect of RT in decreased CBC during treatment. Research of approaches that minimize bone marrow dose during pelvic radiotherapy is warranted.
Parametric response mapping (PRM) is a novel computed tomography (CT) technology that has shown potential for assessment of bronchiolitis obliterans syndrome (BOS) after hematopoietic stem cell transplantation (HCT). The primary aim of this study was to evaluate whether variations in image acquisition under real-world conditions affect the PRM measurements of clinically diagnosed BOS. CT scans were obtained retrospectively from 72 HCT recipients with BOS and graft-versus-host disease from Fred Hutchinson Cancer Research Center, Karolinska Institute, and the University of Michigan. Whole lung volumetric scans were performed at inspiration and expiration using site-specific acquisition and reconstruction protocols. PRM and pulmonary function measurements were assessed. Patients with moderately severe BOS at diagnosis (median forced expiratory volume at 1 second [FEV1] 53.5% predicted) had similar characteristics between sites. Variations in site-specific CT acquisition protocols had a negligible effect on the PRM-derived small airways disease (SAD), that is, BOS measurements. PRM-derived SAD was found to correlate with FEV1% predicted and FEV1/ forced vital capacity (R = -0.236, P = .046; and R = -0.689, P < .0001, respectively), which suggests that elevated levels in the PRM measurements are primarily affected by BOS airflow obstruction and not CT scan acquisition parameters. Based on these results, PRM may be applied broadly for post-HCT diagnosis and monitoring of BOS.
We aimed to describe the incidence, risk factors, and clinical outcomes of pericardial effusions within 6 months after pediatric heart transplantation (HT).A single-center retrospective cohort study was performed on all pediatric HT recipients from 2004 to 2018. Logistic regression was used to identify factors associated with pericardial effusions post-HT, and survival was compared using log-rank test.During the study period, 97 HTs were performed in 93 patients. Fifty patients (52%) had a ≥small pericardial effusion within 6 months, 16 of which were, or became, ≥moderate in size. Pericardial drain was placed in 8 patients. In univariate analysis, larger recipient body surface area (p = .01) and non-congenital heart disease (p = .002) were associated with pericardial effusion development. Donor/recipient size ratios, post-HT hemodynamics, and rejection did not correlate with pericardial effusion development. In multivariable analysis, non-congenital heart disease (adjusted odds ratio 3.3, p = .01) remained independently associated with development of pericardial effusion. There were no significant differences in post-HT survival between patients with and without ≥small (p = .68) or ≥moderate pericardial effusions (p = .40).Pericardial effusions are common after pediatric HT. Patients with cardiomyopathy, or non-congenital heart disease, were at higher risk for post-HT pericardial effusions. Pericardial effusions increased morbidity but had no effect on mortality in our cohort. The risk factors identified may be used for anticipatory guidance in pediatric HT.
Introduction: Multisystem Inflammatory Syndrome in Children (MIS-C) associated with COVID-19 can cause cardiovascular dysfunction. We aimed to determine if strain abnormalities persist in MIS-C patients 3-10 weeks post-discharge, and whether acute markers of clinical severity are associated with lower strain at subacute follow-up. Methods: We performed a retrospective cohort study of MIS-C patients admitted at a single center from 3/2020-3/2021. Demographic and clinical variables during hospitalization were obtained. Global longitudinal strain (GLS), 4-chamber longitudinal strain (4C-LS), mid-papillary circumferential strain (CS), and left atrial strain (LAS) at 3-10 week follow-up were compared to age matched controls (n=10). Bivariate analyses were performed using Spearman rank correlation and two-sample t-test or Wilcoxon rank sum test. Results: Sixty MIS-C patients were identified (age 8.9 +/- 4 years, 35/60 male, 39% Hispanic, 29% African American). Hypotension (65%), ICU admission (57%), and inotropic support (45%) were common; 7% received mechanical ventilation. No deaths or need for ECMO were reported. Median length of stay (LOS) was 7 days. LVEF was <55% in 28% during hospitalization (median 57% [52-61]) and 6% at follow-up (median 65% [61-67]). Peak NT-proBNP (median 5321 pg/ml [IQR 1712, 17400]) and peak CRP (median 17 mg/dl [12, 22]) were significantly associated with hypotension, ICU admission, and total ICU days. Forty-five patients had available follow-up imaging for strain. CS (mean -26.0 vs -28.6; p=0.009) and LAS (mean -34.5 vs -51.2; p=0.001) were lower in MIS-C vs controls, but not GLS or 4C-LS. Lower CS (-24.2 +/- 3.1 vs -26.7 +/- 2.7; p=0.04) and lower 4C-LS (-19.1 +/- 1.9 vs -21.2 +/- 3.3; p=0.04) were associated with abnormal EF (<55%) during acute illness. CS was lower in those admitted to ICU (-25.1 +/- 2.6 vs -27.5 +/- 2.9; p=0.03). Peak CRP correlated with lower CS (r= -0.41, p=0.03) and GLS (r= -0.55, p=0.01) at follow-up. Conclusions: MIS-C patients show abnormal strain during subacute follow-up despite improvement in EF. Lower CS, GLS, and 4C-LS were associated with in-hospital markers of clinical severity. This data may allow for identification of at-risk MIS-C patients and help guide outpatient cardiology follow-up.
