3-D conformal radiation therapy for postradiation recurrent non-small cell lung cancer:a clinical phase I trial

Objective To evaluate the feasibility of reirradiation for postradiation recurrent non small cell lung cancer(NSCLC) using 3 dimensional conformal radiotherapy (3 D CRT) and to assess the immediate responses and acute side effects.Methods Between Oct. 2000 and Feb. 2001,12 NSCLC patients with local recurrence after their initial radiotherapy received retreatment with 3 D CRT. Radiotherapy was designed by the US CMS 2.6.1 3 D treatment planning system and dose volume histography (DVH) was used to verify and optimize the radiation plan. Multileaf collimation technique and immobilization devices for treatment position were used to achieve validity and accuracy of radiotherapy. The planning target volume (PTV) encompassed 1.0 1.5?cm safety margin beyond the clinical target volume (CTV). The total irradiation dose, ranging from 40 Gy to 60 Gy ,was delivered at 2.5 3.0 Gy once daily,5 days per week. The median PTV volume was 295 cm 3 (range:76.4 512.4 cm 3). The immediate responses and acute side effects were evaluated according to the WHO and RTOG criterion system. Results All 12 patients completed their second course radiotherapy. The median period between the courses was 19 months(12 32). The median radiation therapy dose to the gross tumor volume(GTV) was 51.2?Gy(42.0 67.5?Gy). The overall immediate response rate(CR+PR) was 75.0%(9/12).According to the RTOG criterion,Grade 1 2 acute radiation esophagitis occurred in 16.7%(1/12) and Grade 1 2 acute radiation pneumonitis occurred in 16.7%(2/12) patients.Grade 1 2 bone marrow suppression occurred in 8.3%(1/12) of patients and Grade 1 2 myocardial injury was present in 16.7% (2/12) of patients. The median follow up duration was 5 months.Conclusions 3 D conformal radiotherapy can be considered as an effective and feasible approach to re treat postradiation local recurrence of NSCLC with good responses and without any early serious complications. Long term survival and possible specific injury should await further study.