Buscar en
Revista Española de Medicina Nuclear e Imagen Molecular (English Edition)
Toda la web
Inicio Revista Española de Medicina Nuclear e Imagen Molecular (English Edition) Comparison of 18F-FDG PET/CT and DW-MRI in assessment of neoadjuvant radiochemot...
Journal Information
Vol. 40. Issue 1.
Pages 19-29 (January - February 2021)
Share
Share
Download PDF
More article options
ePub
Visits
3
Vol. 40. Issue 1.
Pages 19-29 (January - February 2021)
Original Article
Comparison of 18F-FDG PET/CT and DW-MRI in assessment of neoadjuvant radiochemotherapy response in locally advanced rectal cancer patients
Comparación de la PET/TC 18F-FDG y la DW-MRI en la evaluación de la respuesta a la radioquimioterapia neoadyuvante en pacientes con cáncer rectal localmente avanzado
Visits
...
Lebriz Uslu-Beşlia,b,
Corresponding author
lebriz.uslu@istanbul.edu.tr

Corresponding author.
, Özlem Mermutc, Aytul Hande Yardimcid, Cihan Gündoğanb, Rıza Umar Gürsue, Tevfik Fikret Çermikb
a Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Department of Nuclear Medicine, Istanbul, Turkey
b University of Health Sciences, Istanbul Training and Research Hospital, Clinic of Nuclear Medicine, Istanbul, Turkey
c University of Health Sciences, Istanbul Training and Research Hospital, Clinic of Radiation Oncology, Istanbul, Turkey
d University of Health Sciences, Istanbul Training and Research Hospital, Clinic of Radiology, Istanbul, Turkey
e University of Health Sciences, Istanbul Training and Research Hospital, Clinic of Medical Oncology, Istanbul, Turkey
Article information
Abstract
Full Text
Bibliography
Download PDF
Statistics
Figures (3)
Show moreShow less
Tables (3)
Table 1. Inclusion and exclusion criteria of patients who were included in the prospective study.
Table 2. Demographic data and post-operative histopathology results of patients included in the analysis (TRG: tumor regression grade).
Table 3. Change in PET parameters and MRI apparent diffusion coefficient (ADC) values in interim or post-therapy imaging compared to initial imaging in responders and non-responders.
Show moreShow less
Abstract
Objective

Our aim is to evaluate if different metabolic parameters obtained by 18F-FDG PET/CT and diffusion weighted magnetic resonance imaging (DW-MRI) can aid in neoadjuvant radiochemotherapy (RCT) response assessment in locally advanced rectal cancer (LARC) patients.

Methods

Out of 20 LARC patients, who were planned to receive neoadjuvant RCT, 19 were included in this prospective study. Patients had 18F-FDG PET/CT and DW-MRI at initial staging, interim (2 weeks after onset of RCT) and after completion of RCT (post-therapy). Standardized uptake value (SUV) parameters (SUVmax, SUVmean, SUVpeak, SULpeak), metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) detected on PET images and apparent diffusion coefficient (ADC) values (for b=400 and b=1000s/mm2) obtained from DW-MRI were recorded. Postoperative tumor regression grade (TRG) was used as gold-standard, except for 2 patients who were under complete remission with non-operative management 19 months post-therapy and scored as responders.

Results

On interim PET/CT, no significant difference was found among PET parameters between responders and non-responders, whereas post-therapy SUVmax, SUVpeak, MTV, SULpeak, TLG (p=0.02, p=0.014, p=0.025, p=0.007, p=0.02, respectively) and initial MTV (p=0.034) were significantly lower in responders. ADC response index (RI) was higher in responders (interim p=0.026; post-therapy: p=0.018) and ROC analysis revealed that a threshold of ADC RI>41.6% for interim MRI and >44.6% for post-therapy MRI had sensitivity and specificity of 75.0% and 90.9%, respectively.

Conclusions

While interim 18F-FDG PET/CT failed to predict therapy response during RCT, post-therapy PET could accurately differentiate responders. DW-MRI was found to be more promising in interim detection of RCT response.

Keywords:
Rectal neoplasms
Fluorodeoxyglucose F18
Positron emission tomography computed tomography
Diffusion magnetic resonance imaging
Resumen
Objetivo

El objetivo fue evaluar si diferentes parámetros metabólicos obtenidos con PET-TC 18F-FDG y la RM con técnica de difusión (DW-RM), pueden ayudar a evaluar la respuesta a la radioquimioterapia neoadyuvante en pacientes con cáncer de recto localmente avanzado.

Métodos

De 20 pacientes con cáncer rectal localmente avanzado que se planificaron para recibir radioquimioterapia neoadyuvante, 19 fueron incluidos en este estudio prospectivo. Se les realizó PET-TC 18F-FDG y RM de difusión en la estadificación inicial, interim PET (a las dos semanas de inicio de tratamiento) y al finalizar el tratamiento (post-tratamiento). Se calcularon valores de Standardized Uptake Value (SUVmax, SUVmean, SULpeak, volumen tumoral metabólico (MTV) y tasa de glicólisis (TLG) y valores de coeficiente de difusión aparente (ADC) obtenidos de la RM (para b=400 y para b=1000s/mm2). El grado de regresión tumoral tras la cirugía fue el patrón oro, excepto para dos pacientes que alcanzaron la remisión completa con manejo no operatorio, tras 19 meses de tratamiento y se consideraron respondedores.

Resultados

En interim PET-TC no se encontraron diferencias significativas en los parámetros de PET entre respondedores y no respondedores, mientras que en el PET post-tratamiento, el SUVmax, SUVpeak, MTV, SULpeak, TLG (p=0.02, p=0.014, p=0.025, p=0.007, p=0.02, respectivamente) y MTV inicial (p=0.034) fueron significativamente inferiores en los respondedores. El índice de respuesta ADC fue mayor en los respondedores (interim p=0.026, post-tratamiento p=0.018) y el análisis de curvas ROC mostró que un valor umbral de ADC RI>41.6% para interim RM y >44.6% para la RM post-tratamiento, presentaban una sensibilidad y especificidad del 75 y 90.9%, respectivamente.

Conclusiones

Si bien el interim PET-TC 18F-FDG no logra predecir la respuesta al tratamiento durante la quimiorradioterapia, el PET post-tratamiento podría diferenciar adecuadamente a los respondedores. La RM de difusión parece más prometedora en la respuesta precoz al tratamiento.

Palabras clave:
Neoplasias rectales
Fluordesoxiglucosa 18F
Tomografía por emisión de positrones-Tomografía computarizada
RM de difusión

Article

These are the options to access the full texts of the publication Revista Española de Medicina Nuclear e Imagen Molecular (English Edition)
Subscriber
Subscriber

If you already have your login data, please click here .

If you have forgotten your password you can you can recover it by clicking here and selecting the option “I have forgotten my password”
Subscribe
Subscribe to

Revista Española de Medicina Nuclear e Imagen Molecular (English Edition)

Purchase
Purchase article

Purchasing article the PDF version will be downloaded

Price 19.34 €

Purchase now
Contact
Phone for subscriptions and reporting of errors
From Monday to Friday from 9 a.m. to 6 p.m. (GMT + 1) except for the months of July and August which will be from 9 a.m. to 3 p.m.
Calls from Spain
932 415 960
Calls from outside Spain
+34 932 415 960
E-mail
Article options
Tools
es en pt

¿Es usted profesional sanitario apto para prescribir o dispensar medicamentos?

Are you a health professional able to prescribe or dispense drugs?

Você é um profissional de saúde habilitado a prescrever ou dispensar medicamentos