Predicting complete response to neoadjuvant CRT for distal rectal cancer using sequential PET/CT imaging

Autor(es)

Perez, R. O. ^{[1, 2, 3]} ; Habr-Gama, A. ^{[4, 3]} ; Juliao, G. P. Sao ^[3] ; Lynn, P. B. ^[3] ; Sabbagh, C. ^[3] ; Proscurshim, I. ^[3] ; Campos, F. G. ^[2] ; Gama-Rodrigues, J. ^{[4, 3]} ; Nahas, S. C. ^[2] ; Buchpiguel, C. A. ^{[5, 6]}

Afiliação do(s) autor(es)

^[1] Ludwig Inst Canc Res, Sao Paulo Branch, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sch Med, Dept Gastroenterol, Colorectal Surg Div, BR-1564 Sao Paulo - Brazil

^[3] Angelita & Joaquim Gama Inst, BR-1564 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Sch Med, Sao Paulo - Brazil

^[5] Univ Sao Paulo, Sch Med, Dept Radiol, Div Nucl Med, Sao Paulo - Brazil

^[6] Hosp Coracao, Dept Radiol & Nucl Med, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Techniques in Coloproctology; v. 18, n. 8, p. 699-708, AUG 2014.
• Citações Web of Science: 26

Resumo

Molecular imaging using positron emission tomography/computerized tomography (PET/CT) may add relevant incremental diagnostic information to standard structural cross-sectional imaging. Such information may allow identification of patients with rectal cancer that are more likely to develop complete tumor regression after neoadjuvant chemoradiation therapy (CRT). The objective of this report was to identify PET/CT features that are associated with a complete response after CRT. 99 cT2-4N0-2M0 distal rectal cancer patients (a parts per thousand currency sign7 cm from anal verge) were included in this prospective single center trial (NCT 00254683). Patients underwent baseline PET/CT followed by 54 Gy and 5-fluorouracil-based neoadjuvant CRT. After completion of therapy, patients underwent 6- and 12-week PET/CT. Clinical assessment of tumor response was performed at 12 weeks and was blinded to radiological information. Patients were treated according to clinical assessment. There were seven patients with a complete pathological response (pCR) and 16 with a complete clinical response (cCR) (23 complete responders). Comparison of pCR exclusively and non-pCR revealed that only baseline primary tumor standard uptake value (SUV) was a significant predictor of response. Comparison of complete responders (pCR or cCR) and non-complete responders showed that depth of rectal wall uptake at baseline PET/CT (p = 0.002) and variation between baseline and 12-week maximum standard uptake value (SUVmax) of primary tumor (p = 0.001) were independent predictors for complete response at multivariate analysis. A decrease > 67 % between baseline and 6-week or 76 % between baseline and 12-week SUVmax were associated with complete response (pCR or cCR; p = 0.02 and p < 0.001, respectively). Positron emission tomography/computerized tomography at baseline, 6 and 12 weeks, may provide information regarding patients with a higher likelihood of developing complete tumor regression following neoadjuvant CRT. (AU)

• Processo FAPESP: 07/51069-0 - Estudo do valor da tomografia computadorizada por emissão de pósitrons na avaliação da resposta do adenocarcinoma do reto e radioterapia e quimioterapia neoadjuvante
• Beneficiário: Rodrigo Oliva Perez
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado