Produção Nacional
Revisado por pares
Optimal Timing for Assessment of Tumor Response to Neoadjuvant Chemoradiation in Patients With Rectal Cancer: Do All Patients Benefit From Waiting Longer Than 6 Weeks?
2012; Elsevier BV; Volume: 84; Issue: 5 Linguagem: Inglês
10.1016/j.ijrobp.2012.01.096
ISSN1879-355X
AutoresRodrigo Oliva Perez, Angelita Habr‐Gama, Guilherme Pagin São Julião, Joaquim Gama‐Rodrigues, Afonso Henrique Silva e Sousa, Fábio Guilherme Campos, Antônio Rocco Imperiale, Patricio B. Lynn, Igor Proscurshim, Sérgio Carlos Nahas, Carla Rachel Ono, Carlos Alberto Buchpiguel,
Tópico(s)Colorectal and Anal Carcinomas
ResumoPurpose To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-d-glucose-labeled positron emission tomography/computed tomography ([18FDG]PET/CT) imaging and correlate with response to CRT. Methods and Materials Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials.org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks from CRT completion). Clinical assessment was at 12 weeks. Maximal standard uptake value (SUVmax) of the primary tumor was measured and recorded at each PET/CT study after 1 h (early) and 3 h (late) from 18FDG injection. Patients with an increase in early SUVmax between 6 and 12 weeks were considered “bad” responders and the others as “good” responders. Results Ninety-one patients were included; 46 patients (51%) were “bad” responders, whereas 45 (49%) patients were “good” responders. “Bad” responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; P=.001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; P=.008) and exhibited greater final tumor dimension (4.3 cm vs. 3.3 cm; P=.03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CT was a significant predictor of “good” response (accuracy of 67%). Conclusions Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients. To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-d-glucose-labeled positron emission tomography/computed tomography ([18FDG]PET/CT) imaging and correlate with response to CRT. Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials.org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks from CRT completion). Clinical assessment was at 12 weeks. Maximal standard uptake value (SUVmax) of the primary tumor was measured and recorded at each PET/CT study after 1 h (early) and 3 h (late) from 18FDG injection. Patients with an increase in early SUVmax between 6 and 12 weeks were considered “bad” responders and the others as “good” responders. Ninety-one patients were included; 46 patients (51%) were “bad” responders, whereas 45 (49%) patients were “good” responders. “Bad” responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; P=.001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; P=.008) and exhibited greater final tumor dimension (4.3 cm vs. 3.3 cm; P=.03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CT was a significant predictor of “good” response (accuracy of 67%). Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients.
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