Radiation pneumonitis following twice-daily radiotherapy with concurrent carboplatin and paclitaxel in patients with stage III non-small-cell lung cancer.

OBJECTIVE To examine the effects of dose-volume factors on the development of radiation pneumonitis in patients with non-small-cell lung cancer who received twice-daily radiotherapy concurrently with carboplatin and paclitaxel chemotherapy. METHODS Radiotherapy consisted of twice-daily fractionation of 1.2 Gy, to a total dose of 60 Gy. Weekly carboplatin and paclitaxel were used as a concurrent chemotherapy. Effects of radiotherapy parameters on the development of radiation pneumonitis were retrospectively analyzed. RESULTS Fourteen of 37 patients developed Grade 2 or worse (> or = G2) radiation pneumonitis. Grade 2 or worse radiation pneumonitis occurred in all 5 patients with V5 >40%, all 4 patients with V10 >35%, all 4 patients with V13 >32%, 9 of 14 patients with V20 >24% and 8 of 11 patients with V30 >22%, whereas 9 of 32 patients with V5 <40%, 10 of 33 patients with V10 <35%, 10 of 33 patients with V13 <32%, 5 of 23 patients with V20 <24% and 6 of 26 patients with V30 <22%, with respective P values of 0.0045, 0.015, 0.015, 0.015 and 0.008. Eight of 11 patients with a mean lung dose of >14 Gy developed > or = G2 radiation pneumonitis in contrast to 6 of 26 patients with a mean lung dose of <14 Gy (P = 0.008). CONCLUSIONS Several cut-off values in the V(dose) and the mean lung dose differentiating probabilities of developing > or = G2 radiation pneumonitis were identified in this combination therapy.