Participants and Setting
We included all patients diagnosed and treated at CHEO between January
1994 and December 2014 for a diagnosis of Hodgkin Lymphoma (HL), Wilms
Tumour (WT) or extracranial germ cell tumour (GCT). WT and GCT are two
types of embryonal tumours. CHEO is a tertiary care pediatric hospital
in Ottawa, Canada with a medium-sized pediatric oncology program,
treating approximately 70 new oncology patients per year. Included
patients were <18 years at diagnosis and received both
pulmonary function testing and pulmonary toxic treatment. We limited
inclusion to children with a minimum of two acceptable pulmonary
function tests (PFT), with at least one test performed within 90 days
following treatment completion and prior to any relapse, in order to
capture the onset of pulmonary function changes related to initial
treatment. Our centre only performs pulmonary function testing on
children 6 and older, so children below this age cut-off were excluded.