International Journal of Hematology and Oncology 2019, Vol 29, Num 3 Page(s): 130-138
Is There Any Prognostic Significance of the Level of Change in SUVmax after SBRT in Patients with Early Stage NSCLC?

Gokhan YAPRAK1, Alaattin OZEN2, Fuzuli TUGRUL3, Sule OZUGUR4, Naciye ISIK1

1University of Health Sciences, Kartal Dr. Lütfi Kırdar Training and Research Hospital, Department of Radiation Oncology, Istanbul, TURKEY
2Eskisehir Osmangazi University, Faculty of Medicine, Department of Radiation Oncology, Eskisehir, TURKEY
3Eskisehir City Hospital, Radiation Oncology Clinic, Eskisehir, TURKEY
4University of Health Sciences, Kartal Dr. Lütfi Kırdar Training and Research Hospital, Department of Nuclear Medicine, Istanbul, TURKEY

Keywords: Stereotactic body radiotherapy (SBRT), Early stage non-small cell lung cancer, SUVmax, Positron Emission Tomography/ Computed Tomography (PET/CT)
We aimed to evaluate the prognostic significance of the level of change in SUVmax (ΔSUVmax) on pre and post-treatment PET/ CT in early stage non-small cell lung cancer (esNSCLC) patients treated with stereotactic body radiotherapy (SBRT). Between November 2009-February 2018, pathologically proven esNSCLC patients (T1-2N0M0) treated with CyberKnife as primary treatment alone and who had pre and post-treatment PET/CT were retrospectively identified. The ΔSUVmax was calculated using formula ΔSUVmax= (PreSBRT SUVmax- PostSBRT SUVmax) / (PreSBRT SUVmax). A total of 48 patients were identified. All patients had biopsy-confirmed NSCLC. Median dose was 45 Gy / 3 fr (range: 45-60 Gy / 3-5 fr). According to EORTC metabolic response criteria at 12-16 weeks after SBRT, 8 (16.7%) patients achieved complete response, 35 (72.9%) patients achieved partial response. AUC was calculated as 0.62 for cutoff ΔSUVmax. Median PFS was 15 (range: 6-54) vs 59 (range: 10-92) months (p= 0.012) and median OS was 36 (range: 10-75) vs 70 (range: 23-92) months (p= 0.045) in patients with ΔSUVmax < 0.62 and ≥ 0.62, respectively. In both univariate and multivariate analysis, the lower ΔSUVmax (as both dichotomous and continuous variable) was determined as a negative prognostic factor on PFS and it has been showed that the lower ΔSUVmax (only as a dichotomous variable) is a negative prognostic factor on OS in multivariate analysis. In conclusion, in esNSCLC patients who were treated with SBRT, a ΔSUVmax higher than 0.62 demonstrates better PFS and OS.