FDG-PET and stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer

• Published in: Lung cancer (Amsterdam, Netherlands) Netherlands), 2007-05, Vol.56 (2), p.229-234
• Main Authors: Hoopes, David J, Tann, Mark, Fletcher, James W, Forquer, Jeffrey A, Lin, Pei-Fen, Lo, Simon S, Timmerman, Robert D, McGarry, Ronald C
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Biological and medical sciences; Carcinoma, Non-Small-Cell Lung - diagnostic imaging; Carcinoma, Non-Small-Cell Lung - mortality; Carcinoma, Non-Small-Cell Lung - surgery; Female; Fluorodeoxyglucose F18; Hematology, Oncology and Palliative Medicine; Humans; Hypofractionation; Isolated nodal recurrence; Kaplan-Meier Estimate; Lung cancer; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - mortality; Lung Neoplasms - surgery; Male; Medical sciences; Middle Aged; Non-small-cell; Persistent hypermetabolic activity; PET; Pneumology; Positron-Emission Tomography; Pulmonary/Respiratory; Radiopharmaceuticals; Radiosurgery; Stereotactic body radiotherapy; Tomography, X-Ray Computed; Tumors; Tumors of the respiratory system and mediastinum
• ISSN: 0169-5002; 1872-8332
• DOI: 10.1016/j.lungcan.2006.12.009

Summary Purpose To investigate the utility of positron emission tomography (PET) in patients treated with stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer (NSCLC) on prospective institutional trials. Patients and methods Fifty-eight patients with medically inoperable stage I NSCLC who participated in prospective phase I and II trials of SBRT, had ≥2 years of follow-up, and received FDG-PET imaging are the focus of this evaluation. Fifty-seven of 58 patients received pre-SBRT FDG-PET to confirm stage I status. All patients received stereotactic body frame immobilization and treatment with 7–10 photon beams. SBRT total doses ranged from 24 to 72 Gy in three fractions. No elective nodal irradiation was undertaken. Regular follow-up with planned CT imaging was performed on all patients. Post-SBRT FDG-PET was not mandated by protocol and was typically ordered upon concern for disease recurrence. Thirty-eight post-SBRT PET studies were performed in 28 patients at a median 17.3 months following SBRT. Results With a median follow-up of 42.5 months, the 3-year actuarial overall survival and local control for this select subset of our SBRT experience were 48.9% and 74.8%, respectively. Pre-SBRT FDG-PET SUV did not predict 3-year overall survival or local control. Fourteen of 57 patients eventually failed in nodal stations by CT and/or PET. Isolated first site of failure was nodal in 6 patients (10%). Out of 28 patients with post-SBRT PET, 4 (14%) had delayed PET imaging (22–26 months after SBRT) showing moderate hypermetabolic activity (SUV 2.5–5.07), but no evidence of local, nodal, or distant recurrence by clinical examination and conventional imaging performed 20–26 months following these concerning PET findings. Conclusions Isolated nodal recurrence following PET-staged I NSCLC treated with SBRT is uncommon. Moderate post-SBRT PET hypermetabolic activity may persist 2 years following treatment without definite evidence of recurrence. Further study is needed to confirm these results in larger populations with longer follow-up.