Birgitta Versluijs

31 Pulmonary complications of childhood cancer treatment city of BCNU. 31,32 When BCNU is given in the HCT setting, often other potentially pul- motoxic modalities (radiotherapy and alkylating agents) have been applied, which might increase the risk for pulmonary toxicity. Mertens et al. 6 showed treatment with BCNU and CCNU to be a risk factor for supplemental oxygen use at older age, which can be a sign of lung fibrosis. Pulmonary complications of surgery Although primary lung cancer is exceedingly rare in childhood, pulmonary metastases of other malignancies do occur, and surgical resection is a key component of treatment for such pulmonary metastases. Children appear to tolerate resection better than adults, possibly due to adaptive mechanisms such as hypertrophy or hyperinflation to compen- sate for the loss of lung tissue in the long term. 11 A recent study on osteosarcoma survi- vors after metastatectomy showed abnormal PFTs in a higher number of cases (30-67%) depending on the specific tests considered and the number of thoracotomies. All of the- se survivors had received multiagent chemotherapy for osteosarcoma, but few received known pulmotoxic agents. The negative effect of chemotherapy in general on lung reco- very after surgery was suggested to cause the impaired lung function. 33 Pulmonary complications of allogeneic hematopoietic cell transplantation Children undergoing HCT are exposed to a number of injurious factors that can impair pulmonary function. Mainly non-infectious aetiologies are responsible for pulmonary complications months to years after HCT. 34 Effects of high dose chemotherapy (Busulphan, Cyclophosphamide) and irradiation (To- tal Body or Thoraco-Abdominal Irradiation, TBI/TAI) have been described above. On top of this, other contributing factors include prolonged immune suppression (with incre- ased risk of bacterial and fungal infection or viral reactivation) and immune-mediated phenomena (Graft versus Host Disease, GvHD]. Lung injury following HCT can be cate- gorized as damage to lung parenchyma (alveolar and interstitial), airway epithelium and vascular endothelium. Idiopathic pneumonia syndrome (IPS) is seen within weeks to months after HCT. It is a clinical syndrome of alveolar injury, with marked radiographic abnormalities, in the absence of an identifiable infectious cause. Interstitial pneumonia, Diffuse Alveolar Hae- morrhage and Engraftment Syndrome are considered subsets of IPS. Patients with IPS present with cough, hypoxia and progressive dyspnoea. The exact aetiology of IPS is currently being unravelled, but more and more evidence leads to the view that in IPS the 2