TY - JOUR
T1 - Assessing tumor response to neoadjuvant chemoradiation in rectal cancer with rectoscopy and 18f-fdg pet/ct
T2 - Results from a prospective series
AU - López-López, Víctor
AU - Abrisqueta, Jesús
AU - Luján, Juan
AU - Lynn, Patricio B.
AU - Frutos, Laura
AU - Ono, Akiko
AU - Ortiz, Eduardo
AU - López-Espín, José J.
AU - Gil, José
AU - Parrilla, Pascual
N1 - Publisher Copyright:
© 2021 ARAN Ediciones S.A.. All rights reserved.
PY - 2021/5
Y1 - 2021/5
N2 - Introduction: Rectoscopy and 18F-FDG PET/CT as a diagnostic algorithm for the assessment of tumor response in rectal cancer after neoadjuvant chemoradiation therapy (CRT) is very useful. Material and methods: This was a prospective longitudinal study in patients with locally advanced rectal cancer treated with neoadjuvant CRT. Patients were assessed after CRT completion with a digital rectal examination, proctoscopy and 18F-FDG PET/CT. Patients were subdivided as clinical (cCR) or radiologic (rCR) responders and non-responders according to tumor response. Clinical and radiological re-assessment was compared with the surgical specimen. Pathological tumor regression (pCR) grade was determined according to Mandard's classification. Results: Of the 68 patients included, 15 (22 %) presented pCR in the surgical specimen and tumor persistence (non- PCR) was detected in the remaining 53 (78 %). Clinical assessment (DRE+ rectoscopy) identified 15 patients as cCR and 53 as non-cCR, two were false positives and two were false negatives. The overall accuracy was 94 %. 18F-FDG PET/CT identified 18 patients as rCR and 50 as non-rCR, one was a false positive and four were false negatives. The overall accuracy was 92 %. A combination of clinical findings and 18F-FDG PET/CT resulted in an accuracy of 96 %. The combination of clinical findings + 18F-FDG PET/CT was able to correctly identify all cases of pCR, with the exception of one case that presented a tumor regression of 80 %. Conclusion: In this series, 18F-PET-CT and clinical assessment had excellent accuracies in differentiating PCR from non-PCR after CRT completion. PET-CT combined with clinical assessment had a better accuracy than both modalities independently. 18F-FDG PET/CT is a valid tool that complements the clinical assessment of tumor response.
AB - Introduction: Rectoscopy and 18F-FDG PET/CT as a diagnostic algorithm for the assessment of tumor response in rectal cancer after neoadjuvant chemoradiation therapy (CRT) is very useful. Material and methods: This was a prospective longitudinal study in patients with locally advanced rectal cancer treated with neoadjuvant CRT. Patients were assessed after CRT completion with a digital rectal examination, proctoscopy and 18F-FDG PET/CT. Patients were subdivided as clinical (cCR) or radiologic (rCR) responders and non-responders according to tumor response. Clinical and radiological re-assessment was compared with the surgical specimen. Pathological tumor regression (pCR) grade was determined according to Mandard's classification. Results: Of the 68 patients included, 15 (22 %) presented pCR in the surgical specimen and tumor persistence (non- PCR) was detected in the remaining 53 (78 %). Clinical assessment (DRE+ rectoscopy) identified 15 patients as cCR and 53 as non-cCR, two were false positives and two were false negatives. The overall accuracy was 94 %. 18F-FDG PET/CT identified 18 patients as rCR and 50 as non-rCR, one was a false positive and four were false negatives. The overall accuracy was 92 %. A combination of clinical findings and 18F-FDG PET/CT resulted in an accuracy of 96 %. The combination of clinical findings + 18F-FDG PET/CT was able to correctly identify all cases of pCR, with the exception of one case that presented a tumor regression of 80 %. Conclusion: In this series, 18F-PET-CT and clinical assessment had excellent accuracies in differentiating PCR from non-PCR after CRT completion. PET-CT combined with clinical assessment had a better accuracy than both modalities independently. 18F-FDG PET/CT is a valid tool that complements the clinical assessment of tumor response.
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U2 - 10.17235/reed.2020.6954/2020
DO - 10.17235/reed.2020.6954/2020
M3 - Article
C2 - 33054291
AN - SCOPUS:85107064238
SN - 1130-0108
VL - 113
SP - 307
EP - 312
JO - Revista Espanola de Enfermedades Digestivas
JF - Revista Espanola de Enfermedades Digestivas
IS - 5
ER -