Assessment of response to neoadjuvant radiochemotherapy with F-18 FLT and F-18 FDG PET/CT in patients with rectal cancer

• Published in: Annals of nuclear medicine Vol. 29; no. 3; pp. 284 - 294
• Main Authors: Rendl, Gundula, Rettenbacher, Lukas, Holzmannhofer, Johannes, Datz, Lidwina, Hauser-Kronberger, Cornelia, Fastner, Gerd, Öfner, Dietmar, Sedlmayer, Felix, Pirich, Christian
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.04.2015; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Chemoradiotherapy; Dideoxynucleosides; Female; Fluorodeoxyglucose F18; Follow-Up Studies; Humans; Imaging; Immunohistochemistry; Male; Medicine; Medicine & Public Health; Middle Aged; Multimodal Imaging; Neoadjuvant Therapy; Nuclear Medicine; Original; Original Article; Positron-Emission Tomography - methods; Prospective Studies; Radiology; Radiopharmaceuticals; Rectal Neoplasms - diagnostic imaging; Rectal Neoplasms - pathology; Rectal Neoplasms - therapy; Tomography, X-Ray Computed - methods; Treatment Outcome; 18F-FLT; 18F-FDG; Rectal cancer; PET/CT; Radiochemotherapy
• ISSN: 0914-7187; 1864-6433; 1864-6433
• DOI: 10.1007/s12149-014-0938-2

Objective The comparison of 2-deoxy-2-[18F]fluoro- d -glucose (F-18 FDG) and 3′-deoxy-3′-[18F]fluorothymidine (F-18 FLT) imaging in patients with rectal cancer before and after neoadjuvant radiochemotherapy (RCT) in relation to histopathology and immunohistochemistry obtained from surgery. Methods 20 consecutive patients (15 m, 5 f), mean age of 65 ± 10 years were included into this prospective study with a mean follow-up of 4.1 ± 0.8 years. Results Among histopathological responders ( n  = 8 out of 20), posttreatment F-18 FLT and F-18 FDG scans were negative in 75 % ( n  = 6) and 38 % ( n  = 3), respectively. The mean response index (RI) was 61.0 % ± 14.0 % for F-18 FLT and 58.7 % ± 14.6 % for F-18 FDG imaging. Peritumoral lymphocytic infiltration (CD3 positive cells) was significantly related to posttreatment SUV max in F-18 FDG but not F-18 FLT studies. Conclusion A significant decrease of SUV max in F-18 FDG and F-18 FLT studies could be seen after RCT. Negative posttreatment F-18 FLT studies identified more histopathological responders.