The split scar sign as an indicator of sustained complete response after neoadjuvant therapy in rectal cancer.
Eur Radiol
; 30(1): 224-238, 2020 Jan.
Article
en En
| MEDLINE
| ID: mdl-31350587
ABSTRACT
OBJECTIVES:
To measure the diagnostic performance of a new radiologic pattern on restaging magnetic resonance (MR) high-resolution T2-weighted imaging (T2-WI)-the split scar sign-for the identification of sustained complete response (SCR) after neoadjuvant therapy in rectal cancer.METHODS:
Institutional review board approval was obtained for this retrospective study and the informed consent requirement was waived. Fifty-eight consecutive patients with rectal cancer who underwent neoadjuvant therapy were enrolled. Two radiologists blindly and independently reviewed restaging pelvic MR imaging and recorded the presence/absence of the split scar sign (mrSSS). On a second round, they also assessed the relative proportion of intermediate signal intensity on T2-WI (mrT2) and of high signal intensity on high b-value diffusion-weighted imaging (mrDWI). Endoscopic response grading records were retrieved. Qui-square test was employed in search for associations between SCR, defined as pathologic complete response or long-term recurrence-free clinical follow-up, and mrSSS, mrT2, mrDWI and endoscopy. Interobserver agreement for imaging parameters was estimated using Cohen's kappa (k).RESULTS:
mrSSS was significantly associated with SCR, with specificity = 0.97/0.97, sensitivity = 0.52/0.64, PPV = 0.93/0.94, NPV = 0.73/0.78, and AuROC = 0.78/0.83, for observers 1/2, respectively. mrDWI was significantly associated with SCR for observer 2, with specificity = 0.76, sensitivity = 0.60, PPV = 0.65, NPV = 0.71, and AuROC = 0.69. mrT2 and endoscopy were not discriminative. Interobserver agreement was substantial for mrSSS (k = 0.69), moderate for mrDWI (k = 0.46), and poor for mrT2 (k = 0.17).CONCLUSION:
The split scar sign is a simple morphologic pattern visible on restaging T2-WI which, although not sensitive, is very specific for the identification of sustained complete responders after neoadjuvant therapy in rectal cancer. KEY POINTS ⢠The split scar sign is a morphologic pattern visible on high-resolution T2-weighted MR imaging in rectal cancer patients after neoadjuvant therapy. It therefore does not require any changes to standard protocol. ⢠At first restaging pelvic MR imaging (mean 9.1 weeks after the end of radiotherapy), the split scar sign identified patients who sustained a complete response with very high specificity (0.97) and positive predictive value (0.93-0.94). ⢠The split scar sign has the potential to improve patient selection for "watch-and-wait" after neoadjuvant therapy in rectal cancer.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Neoplasias del Recto
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Imagen de Difusión por Resonancia Magnética
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Quimioradioterapia Adyuvante
Tipo de estudio:
Diagnostic_studies
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Guideline
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Límite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Eur Radiol
Asunto de la revista:
RADIOLOGIA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Portugal