gms | German Medical Science

Purpose: To assess the toxicity and efficacy of Intensity-modulated Radiotherapy (IMRT) of lung tumors.

Patients and Methods: Between 01/2004 and 10/2005, 50 patients with lung tumors treated with IMRT were analysed retrospectively. 35 patients (70%) had non small cell lung cancer, 8 patients (16%) small cell lung cancer, 7 patients (14%) other or not histologically proven tumors. Most patients suffered from advanced disease (stage 4: 50%, stage 3B: 36%, stage 3A: 12%, stage I: 2%). Depending on tumor histology, tumor stage and performance status patients received radiation treatment of the lung with median 65 Gy (37-70 Gy) and single doses of 2 Gy (1,5-3 Gy). In 6 patients (12%) simultaneous chemotherapy was given.

Results: Dose-volume-histograms of the lung showed a V20Gy of mean 27% (11-41%) and a V30Gy of 15% (5-33%), respectively. Mean lung dose was 15 Gy (8-23 Gy). IMRT was performed according to treatment plan in all patients and was very well tolerated as only 1 patient displaying a V20Gy of 31%, a V30Gy of 21% and mean lung dose of 16 Gy developed a symptomatic pneumonitis. No other grade 3 to 4 toxicity was observed. Transient esophagitis was mild and occurred in 27 patients (grade 1: 12 patients (24%), grade 2: 15 patients (30%)). An overall complete remission rate of 10% was achieved, whereas partial remission was observed in 70% and minimal response in 10% of the patients. Progressive disease occured in 10% of the patients.

Conclusion: IMRT of lung cancer is safe, feasible in clinical routine and effective. IMRT allows to protect normal lung tissue, as mean lung dose and even high-dose volume are reduced. Even though IMRT causes an increase of low-dose volume no increase of lung toxicity was observed. The treatment resulted in an encouragingly very low pneumonitis rate and low toxicity in the esophagus.