Statistical analysis
The statistical software packages SPSS
version 22.0 (Chicago, IL, USA) and
GraphPad Prism version 5.00 for Windows (San Diego California USA) were
used to analyze the data. To determine the value of interim and
post-treatment PET/CT in the prediction of the outcomes of pediatric and
adolescent HL patients, we calculated the sensitivity, specificity,
positive likelihood (+LH), negative likelihood (-LH), area under the
curve (AUC), positive predictive value (PPV), negative predictive value
(NPV) and accuracy for the IHPC, DC-3, and DC-4 models. Survival curves
were estimated using the Kaplan-Meier
method with Rothman’s 95% confidence intervals (CIs) and log-rank
tests. PFS was defined as the interval from the diagnosis to the first
clinical or radiological progression or the date of the last follow-up
visit for those without events. Factors with A P value of less than 0.05
were introduced into multivariate analysis, performed by the Cox
proportional hazard model using the forward procedure. A P value of less
than 0.05 was considered statistically significant.