[Low-dose CT-guided transthoracic lung biopsy for evaluation of non-infectious chronic interstitial lung disease in children].

BACKGROUND: Children with interstitial pneumonitis (IP) of unknown origin often have to undergo open lung biopsy to establish a final diagnosis. Open lung biopsy is an invasive procedure with major potential complications. In the meantime, CT-guided transthoracic lung biopsy (TLB) has become a common diagnostic procedure in adults.
OBJECTIVE: The aim of this study was to retrospectively evaluate the efficacy and radiation exposure of low-dose CT-guided TLB in children with non-infectious IP of unknown origin.
METHODS: Twelve children (7-males, age range: 7 months-15 years) with non-infectious IP of unknown origin and inconclusive clinical tests underwent CT-guided TLB with a 20-gauge biopsy instrument. A low-dose protocol with acquisition of single slices was used on a 16-row CT scanner: 80 kVp, 20 mAs, slice thickness 10 mm. Biopsy specimens were processed by standard histopathological and immunohistochemical techniques and effective doses were individually calculated.
RESULTS: All biopsies were performed without major complications. Two children (17 %) developed a small pneumothorax/pulmonary haemorrhage that resolved spontaneously. A final diagnosis could be established in 9/12 patients (75 %) by CT-guided TLB. In 2 patients (17 %) the results of TLB were inconclusive; however, the clinical suspicion could be disproved. Open lung biopsy was performed in 1 patient (8 %), which demonstrated idiopathic pulmonary fibrosis. On average, the effective dose of CT-guided TLB was 0.78 mSv (0.4 - 1.1 mSv).
CONCLUSION: Low-dose CT-guided TLB can be a helpful method for investigating children with non-infectious IP of unknown origin thus making open lung biopsy unnecessary. Application of a low-dose protocol leads to a significant reduction of radiation exposure in CT-guided TLB.