Computed tomography assessment of lung density in patients with lung cancer treated with accelerated hypofractionated radio-chemotherapy supported with amifostine.

Abstract

Lung fibrosis is a severe complication after radiotherapy in patients with nonsmall cell lung cancer and is the main undesirable late complication limiting the therapeutic ratio of thoracic radiation treatment. Here we evaluated the lung fibrosis using computed tomography scan mediated assessment of lung tissue density in long-term survivals treated with hypofractionated and accelerated radiotherapy supported with amifostine (HypoARC).
Out of 45 patients with locally advanced nonsmall cell lung cancer treated with conformal HypoARC (3.5 Gy x 15 fractions in 4 weeks) and concurrent chemotherapy, 14 are alive 16 to 47 months (median 20) after radiotherapy. Patients received 500 to 1000 mg of amifostine before each radiotherapy fraction, according to a previously described dose individualization algorithm.
Early pneumonitis was absent in all patients, whereas lung density assessed with computed tomography scan in Hounsfield units (HU), within a median of 20 months after radiotherapy, showed marked increase in 2/6 and 0/8 patients who received 500 to 750 mg and 1000 mg of amifostine, respectively. The HU in these 2 patients increased to values below -550 HU, from initial values of -700 to -800 HU. Only one of these 2 patients had mild exertional dyspnoea.
Given the good tolerance of daily high-dose amifostine administration and the encouraging very low rates of pneumonitis and lung fibrosis noted, despite the aggressiveness of the radio-chemotherapy regimen applied, it is suggested that the value of amifostine in chest radiotherapy should be re-evaluated in properly designed randomized clinical trials.