%0 Journal Article %A Maja Guberina %A Christoph Pöttgen %A Martin Metzenmacher %A Marcel Wiesweg %A Martin Schuler %A Clemens Aigner %A Till Ploenes %A Lale Umutlu %A Thomas Gauler %A Kaid Darwiche %A Georgios Stamatis %A Dirk Theegarten %A Hubertus Hautzel %A Walter Jentzen %A Nika Guberina %A Ken Herrmann %A Wilfried E.E. Eberhardt %A Martin Stuschke %T Prognostic Value of Postinduction Chemotherapy Volumetric PET/CT Parameters for Stage IIIA or IIIB Non–Small Cell Lung Cancer Patients Receiving Definitive Chemoradiotherapy %D 2021 %R 10.2967/jnumed.120.260646 %J Journal of Nuclear Medicine %P 1684-1691 %V 62 %N 12 %X The aim of this follow-up analysis of the ESPATUE phase 3 trial was to explore the prognostic value of postinduction chemotherapy PET metrics in patients with stage III non–small cell lung cancer who were assigned to receive definitive chemoradiotherapy. Methods: All eligible stage IIIA (cN2) and stage IIIB patients in the trial received an induction doublet chemotherapy consisting of 3 cycles with cisplatin and paclitaxel, and subsequent combined chemoradiotherapy with a cumulative dose of up to 45 Gy (1.5 Gy per fraction twice a day), followed by a radiation boost (2 Gy once per day) with concurrent continuation of doublet chemotherapy with cisplatin and vinorelbine. The protocol definition prescribed a total dose of 65–71 Gy. 18F-FDG PET/CT was performed at study entry and before concurrent chemoradiotherapy. Interim PET metrics and known prognostic clinical parameters were correlated in uni- and multivariable survival analyses. Leave-one-out cross-validation was used to show internal validity. Results: Ninety-two patients who underwent 18F-FDG PET/CT after induction chemotherapy were enrolled. Median posttreatment MTV was 5.9 cm3. Altogether, 85 patients completed the whole chemoradiation with the planned total dose of 60–71 Gy. In univariable proportional-hazards analysis, each of 3 parameters—posttreatment MTV, posttreatment SUVmax, and posttreatment maximum total lesion glycolysis (TLGmax(post))—was associated with overall survival (P < 0.05). Multivariable survival analysis, including clinical and postinduction PET parameters, found TLGmax(post) (hazard ratio, 1.032 [95% CI, 1.013–1.052] per 100 cm3 increase) and total radiation dose (hazard ratio, 0.930 [95% CI, 0.902–0.959] per 1 Gy increase) was significantly related to overall survival in the whole group of patients and in patients receiving a total dose of at least 60 Gy. The best leave-one-out cross-validated 2-parameter classifier was TLGmax(post) and total radiation dose. TLGmax(post) was associated with time to distant metastases (P = 0.0018), and posttreatment SUVmax was associated with time to locoregional relapse (P = 0.039), in multivariable analysis of patients receiving a total dose of at least 60 Gy. Conclusion: Postinduction chemotherapy PET parameters demonstrated prognostic significance. Therefore, interim 18F-FDG PET/CT is a promising diagnostic modality for guiding individualized treatment intensification. %U https://jnm.snmjournals.org/content/jnumed/62/12/1684.full.pdf