Total Lymphoid Irradiation (TLI) for the Management of Bronchiolitis Obliterans Syndrome (BOS) Post Lung Transplant: A Single Centre Experience

Background: Chronic rejection, more commonly called bronchiolitis obliterans syndrome (BOS), is the leading cause of death beyond the first year post lung transplantation. TLI is an established treatment for the management of post lung transplant BOS. We sought to describe our experience of outcomes in the use of TLI in a single transplant centre. Methods: We identified all patients who had a clinical diagnosis of BOS and were suitable for TLI from 2009-2018. Data collection includes functional baseline of recipients presented with FEV1 pre and post TLI and survival post treatment. Results: 15 patients with BOS underwent TLI treatment. Mean age of patients was 39.26 years (range 20.75 - 57.5), with 53% being male. 13 (86.6%) received a bilateral lung transplant, with 2 (13.3%) receiving a single lung transplant. 60% of patients underwent transplant for cystic fibrosis, with 33% being for interstitial lung disease. Mean time to development of BOS was 64 months (range 14-117). 10 patients (66%) completed scheduled TLI (8 Gy, 10 fractions). The mean decline in lung function leading up to TLI was 1180 ml, with a mean of 1601ml pre treatment. There was a further decrease in lung function of 85ml immediately post treatment. A mean peak increase of 130ml was seen at an average of 3 months post treatment. Mean survival post TLI was 4.2 years (range 0.75-7.5). Conclusions: Of those patients deemed suitable for therapy, TLI was well tolerated with the majority of complications being minor and not leading to cessation of treatment. Therapy is associated with a significant slowing in the rate of decline in lung function impacting overall survival.