A Clinical Study of Shrinking Field Radiation Therapy Based on ¹⁸F-FDG PET/CT for Stage III Non-Small Cell Lung Cancer

Abstract

The aim is to investigate the feasibility of shrinking field technique after 40 Gy for stage III nonsmall cell lung cancer (NSCLC) during radiation therapy. Eighty-seven consecutive patients treated with intensity-modulated radiation therapy or three-dimensional conformal radiation therapy were enrolled in this study. months, ranging from 5 to 46 months, and the 1-and 2-year overall survival rates in our study were 74.7% and 34.6%. The response rate was 79.5%, and radiation toxicity was acceptable. Tumor progression occurred in 67.8% (59/87) patients. Numbers of patients who had outfield, infield and both infield and outfield recurrences were 3 (3.4%), 26 (29.5%), and 3 (3.4%), respectively. In conclusion, significant tumor regression was observed after 40 Gy, and radiation dose escalated after shrinking field with acceptable toxicity and outfield relapse. Shrinking field radiotherapy based on 18 F-FDG PET/CT after 40 Gy was safe and feasible for stage III NSCLC.

Late-Course Adaptive Adjustment Based on Metabolic Tumor Volume Changes during Radiotherapy May Reduce Radiation Toxicity in Patients with Non-Small Cell Lung Cancer

“…In a previous study, Mahasittiwat et al[ 22 ] found that the mean PET-MTVs were 43.4 cc (28.2–58.5 cc) and 17.9 cc (10.0–25.7 cc) on pre-RT and during-RT (approximately 45 Gy) scans, respectively, and the mean reduction in PET-MTVs was 32.2 cc (20.8–43.7 cc, p<0.001). In the course of RT (40 Gy~50 Gy), FDG-PET/CT activity decreased[ 20 ], and the tumor volume was significantly reduced[ 7 , 23 , 24 , 25 , 26 ]. Similar results have been obtained in previous studies.…”

“…A study by Fox et al[ 27 ] indicated that the GTV had a median reduction during RT (24.7% at 30 Gy, 44.3% at 50 Gy). Ding et al[ 25 ] carried out an analogous study that demonstrated that the tumor volumes regressed in 84 (96.6%) patients and increased in 3 (3.4%) patients after 40 Gy; the mean GTV and PTV reduction was 38% (range, 213–95%) and 30% (range, 25–95%). Guckenberger et al[ 28 ] studied the tumor changes in 13 patients with NSCLC, and they found continuous tumor regression by 1.2% per day as measured by CT images, which was in good agreement with the results presented by Kupelian’s research[ 29 ] and Everitt’s research[ 26 ].…”

An assessment of cone beam CT in the adaptive radiotherapy planning process for non-small-cell lung cancer patients

“…Some groups have evaluated serial 18 F-FDG PET scans taken during treatment. Ding et al 28 report significant change to avidity using PET/CT after 40 Gy. Their study included patients receiving chemotherapy and RT.…”

Study of the Cumulative Dose Between Fractions of Lung Cancer Radiotherapy Based on CT and CBCT Image Deformable Registration Technology

“…Replanning should be done only at the right time. Ding et al [7] studied 87 patients with IMRT and three-dimensional adaptive radiotherapy, followed by 18F-FDG PET/CT scans after 40 Gy irradiation, and mapped the target. Zhang et al [8] studied 40 cases of NSCLC radiotherapy target volume changes.…”