Long term effects of definitive chemoradiotherapy on respiratory function tests in patients with locally advanced (non) small cell lung carcinoma

Radiation induced lung injury is common in patients receiving thoracic
radiotherapy. Radiotherapy-induced pulmonary symptoms (shortness of breath and
cough) occur in approximately 5-20% of patients irradiated for breast cancer,
lymphoma or lung cancer. 50-90% of these patients have declines in pulmonary
function tests (PFTs) (8)

Radiation induced lung injury can be divided in early injury (3- 6 months after
treatment), most of the time radiation pneumonitis and late injury (from 1 year
after treatment, chronic fibrosis). Previous studies show the first decline in
PFT in 6 months and further decline beyond 1 year (3, 4). During treatment
with (chemo) radiation there is no change in PFT (1,2,6).

The change in pulmonary function is dependent on the mean lung dose (2,3, 5)
and pre-existing lung disease (3,9). Concurrent chemotherapy has an
additional negative effect on pulmonary function (5, 7,10) From previous
studies in breast cancer en lymphoma it is known that the changes in PFT values
can be estimated before treatment (6).

The aim of the study is to evaluate the change of lung function at least one
year after definitive chemoradiation (concurrent or sequential) in patients
with locally advanced (non) small cell lung carcinoma to assess late radiation
injury in our patient population (patients treated in a large non academic
teaching hospital). Our aim is to see if our results match the results found in
literature.

Patients who received either sequential or concurrent treatment with
chemoradiation in the period between November 2010 and November 2015 will be
selected restrospective from the electronical patient file (Hix) in the Haga
hospital. All patients who were treated had pulmonary lung function testing
done before start of the treatment, including both spirometry, with measurement
of forced capacity (VC) and forced expiratory volume in 1 second (FEV1), and
measurement of diffusion capacity to carbon monoxide (DLCO).
The patients who meet our in-and exclusion criteria will be asked to have
another pulmonary function test done in our pulmonary function testing
laboratory >1 year after finishing their treatment in order to study the change
in lung function due to long term radiation induced lung injury (fibrosis).

The results will be correlated with smoking history and smoking after treatment
as well. The mean lung dose will also be used by evaluating the decline of lung
function. We will also look at histology and effect of either sequential or
concurrent treatment.

Burden: one extra isit to the hospital. This will take about 60 minutes
including medical history and pulmonary function testing.