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Title: Repeated Positron Emission Tomography-Computed Tomography and Perfusion-Computed Tomography Imaging in Rectal Cancer: Fluorodeoxyglucose Uptake Corresponds With Tumor Perfusion

Abstract

Purpose: The purpose of this study was to analyze both the intratumoral fluorodeoxyglucose (FDG) uptake and perfusion within rectal tumors before and after hypofractionated radiotherapy. Methods and Materials: Rectal cancer patients, referred for preoperative hypofractionated radiotherapy (RT), underwent FDG-positron emission tomography (PET)-computed tomography (CT) and perfusion-CT (pCT) imaging before the start of hypofractionated RT and at the day of the last RT fraction. The pCT-images were analyzed using the extended Kety model, quantifying tumor perfusion with the pharmacokinetic parameters K{sup trans}, v{sub e}, and v{sub p}. The mean and maximum FDG uptake based on the standardized uptake value (SUV) and transfer constant (K{sup trans}) within the tumor were correlated. Also, the tumor was subdivided into eight subregions and for each subregion the mean and maximum SUVs and K{sup trans} values were assessed and correlated. Furthermore, the mean FDG uptake in voxels presenting with the lowest 25% of perfusion was compared with the FDG uptake in the voxels with the 25% highest perfusion. Results: The mean and maximum K{sup trans} values were positively correlated with the corresponding SUVs ({rho} = 0.596, p = 0.001 and {rho} = 0.779, p < 0.001). Also, positive correlations were found for K{sup trans} values andmore » SUVs within the subregions (mean, {rho} = 0.413, p < 0.001; and max, {rho} = 0.540, p < 0.001). The mean FDG uptake in the 25% highest-perfused tumor regions was significantly higher compared with the 25% lowest-perfused regions (10.6% {+-} 5.1%, p = 0.017). During hypofractionated radiotherapy, stable mean (p = 0.379) and maximum (p = 0.280) FDG uptake levels were found, whereas the mean (p = 0.040) and maximum (p = 0.003) K{sup trans} values were found to significantly increase. Conclusion: Highly perfused rectal tumors presented with higher FDG-uptake levels compared with relatively low perfused tumors. Also, intratumor regions with a high FDG uptake demonstrated with higher levels of perfusion than regions with a relatively low FDG-uptake. Early after hypofractionated RT, stable FDG uptake levels were found, whereas tumor perfusion was found to significantly increase.« less

Authors:
 [1]; ; ; ; ;  [1]
  1. Department of Radiation Oncology, Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht (Netherlands)
Publication Date:
OSTI Identifier:
22056043
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 82; Journal Issue: 2; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; CORRELATIONS; FLUORODEOXYGLUCOSE; IMAGES; NEOPLASMS; PATIENTS; POSITRON COMPUTED TOMOGRAPHY; RADIOTHERAPY; RECTUM; UPTAKE

Citation Formats

Janssen, Marco H.M., E-mail: marco.janssen@maastro.nl, Aerts, Hugo J.W.L., Buijsen, Jeroen, Lambin, Philippe, Lammering, Guido, and Oellers, Michel C. Repeated Positron Emission Tomography-Computed Tomography and Perfusion-Computed Tomography Imaging in Rectal Cancer: Fluorodeoxyglucose Uptake Corresponds With Tumor Perfusion. United States: N. p., 2012. Web. doi:10.1016/J.IJROBP.2010.10.029.
Janssen, Marco H.M., E-mail: marco.janssen@maastro.nl, Aerts, Hugo J.W.L., Buijsen, Jeroen, Lambin, Philippe, Lammering, Guido, & Oellers, Michel C. Repeated Positron Emission Tomography-Computed Tomography and Perfusion-Computed Tomography Imaging in Rectal Cancer: Fluorodeoxyglucose Uptake Corresponds With Tumor Perfusion. United States. doi:10.1016/J.IJROBP.2010.10.029.
Janssen, Marco H.M., E-mail: marco.janssen@maastro.nl, Aerts, Hugo J.W.L., Buijsen, Jeroen, Lambin, Philippe, Lammering, Guido, and Oellers, Michel C. Wed . "Repeated Positron Emission Tomography-Computed Tomography and Perfusion-Computed Tomography Imaging in Rectal Cancer: Fluorodeoxyglucose Uptake Corresponds With Tumor Perfusion". United States. doi:10.1016/J.IJROBP.2010.10.029.
@article{osti_22056043,
title = {Repeated Positron Emission Tomography-Computed Tomography and Perfusion-Computed Tomography Imaging in Rectal Cancer: Fluorodeoxyglucose Uptake Corresponds With Tumor Perfusion},
author = {Janssen, Marco H.M., E-mail: marco.janssen@maastro.nl and Aerts, Hugo J.W.L. and Buijsen, Jeroen and Lambin, Philippe and Lammering, Guido and Oellers, Michel C.},
abstractNote = {Purpose: The purpose of this study was to analyze both the intratumoral fluorodeoxyglucose (FDG) uptake and perfusion within rectal tumors before and after hypofractionated radiotherapy. Methods and Materials: Rectal cancer patients, referred for preoperative hypofractionated radiotherapy (RT), underwent FDG-positron emission tomography (PET)-computed tomography (CT) and perfusion-CT (pCT) imaging before the start of hypofractionated RT and at the day of the last RT fraction. The pCT-images were analyzed using the extended Kety model, quantifying tumor perfusion with the pharmacokinetic parameters K{sup trans}, v{sub e}, and v{sub p}. The mean and maximum FDG uptake based on the standardized uptake value (SUV) and transfer constant (K{sup trans}) within the tumor were correlated. Also, the tumor was subdivided into eight subregions and for each subregion the mean and maximum SUVs and K{sup trans} values were assessed and correlated. Furthermore, the mean FDG uptake in voxels presenting with the lowest 25% of perfusion was compared with the FDG uptake in the voxels with the 25% highest perfusion. Results: The mean and maximum K{sup trans} values were positively correlated with the corresponding SUVs ({rho} = 0.596, p = 0.001 and {rho} = 0.779, p < 0.001). Also, positive correlations were found for K{sup trans} values and SUVs within the subregions (mean, {rho} = 0.413, p < 0.001; and max, {rho} = 0.540, p < 0.001). The mean FDG uptake in the 25% highest-perfused tumor regions was significantly higher compared with the 25% lowest-perfused regions (10.6% {+-} 5.1%, p = 0.017). During hypofractionated radiotherapy, stable mean (p = 0.379) and maximum (p = 0.280) FDG uptake levels were found, whereas the mean (p = 0.040) and maximum (p = 0.003) K{sup trans} values were found to significantly increase. Conclusion: Highly perfused rectal tumors presented with higher FDG-uptake levels compared with relatively low perfused tumors. Also, intratumor regions with a high FDG uptake demonstrated with higher levels of perfusion than regions with a relatively low FDG-uptake. Early after hypofractionated RT, stable FDG uptake levels were found, whereas tumor perfusion was found to significantly increase.},
doi = {10.1016/J.IJROBP.2010.10.029},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 2,
volume = 82,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2012},
month = {Wed Feb 01 00:00:00 EST 2012}
}
  • Purpose: To develop an unsupervised tumor delineation method based on time-activity curve (TAC) shape differences between tumor tissue and healthy tissue and to compare the resulting contour with the two tumor contouring methods mostly used nowadays. Methods and Materials: Dynamic positron emission tomography-computed tomography (PET-CT) acquisition was performed for 60 min starting directly after fluorodeoxyglucose (FDG) injection. After acquisition and reconstruction, the data were filtered to attenuate noise. Correction for tissue motion during acquisition was applied. For tumor delineation, the TAC slope values were k-means clustered into two clusters. The resulting tumor contour (Contour I) was compared with a contourmore » manually drawn by the radiation oncologist (Contour II) and a contour generated using a threshold of the maximum standardized uptake value (SUV; Contour III). Results: The tumor volumes of Contours II and III were significantly larger than the tumor volumes of Contour I, with both Contours II and III containing many voxels showing flat TACs at low activities. However, in some cases, Contour II did not cover all voxels showing upward TACs. Conclusion: Both automated SUV contouring and manual tumor delineation possibly incorrectly assign healthy tissue, showing flat TACs, as being malignant. On the other hand, in some cases the manually drawn tumor contours do not cover all voxels showing steep upward TACs, suspected to be malignant. Further research should be conducted to validate the possible superiority of tumor delineation based on dynamic PET analysis.« less
  • Purpose: To determine the optimal time point for repeated {sup 18}F-fluorodeoxyglucose-positron emission tomography (PET)-CT imaging during preoperative radiochemotherapy (RCT) and the best predictive factor for the prediction of pathological treatment response in patients with locally advanced rectal cancer. Methods and Materials: A total of 30 patients referred for preoperative RCT treatment were included in this prospective study. All patients underwent sequential PET-CT imaging at four time points: prior to therapy, at day 8 and 15 during RCT, and shortly before surgery. Tumor metabolic treatment responses were correlated with the pathological responses by evaluation of the tumor regression grade (TRG) andmore » the pathological TN (ypT) stage of the resected specimen. Results: Based on their TRG evaluations, 13 patients were classified as pathological responders, whereas 17 patients were classified as pathological nonresponders. The response index (RI) for the maximum standardized uptake value (SUV{sub max}) on day 15 of RCT was found to be the best predictive factor for the pathological response (area under the curve [AUC] = 0.87) compared to the RI on day 8 (AUC = 0.78) or the RI of presurgical PET imaging (AUC = 0.66). A cutoff value of 43% for the reduction of SUV{sub max} resulted in a sensitivity of 77% and a specificity of 93%. Conclusions: The SUV{sub max}-based RI calculated after the first 2 weeks of RCT provided the best predictor of pathological treatment response, reaching AUCs of 0.87 and 0.84 for the TRG and the ypT stage, respectively. However, a few patients presented with peritumoral inflammatory reactions, which led to mispredictions. Exclusion of these patients further enhanced the predictive accuracy of PET imaging to AUCs of 0.97 and 0.89 for TRG and ypT, respectively.« less
  • Purpose: Evaluation of the dose distribution for lung cancer patients using a patient setup procedure based on the bony anatomy or the primary tumor. Methods and materials: For 39 patients with non-small-cell lung cancer, the planning fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scan was registered to a repeated FDG-PET/CT scan made in the second week of treatment. Two patient setup methods were analyzed based on the bony anatomy or the primary tumor. The original treatment plan was copied to the repeated scan, and target and normal tissue structures were delineated. Dose distributions were analyzed using dose-volume histograms for the primarymore » tumor, lymph nodes, lungs, and spinal cord. Results: One patient showed decreased dose coverage of the primary tumor caused by progressive disease and required replanning to achieve adequate coverage. For the other patients, the minimum dose to the primary tumor did not significantly deviate from the planned dose: -0.2 {+-} 1.7% (p = 0.71) and -0.1 {+-} 1.7% (p = 0.85) for the bony anatomy setup and the primary tumor setup, respectively. For patients (n = 31) with nodal involvement, 10% showed a decrease in minimum dose larger than 5% for the bony anatomy setup and 13% for the primary tumor setup. The mean lung dose exceeded the maximum allowed 20 Gy in 21% of the patients for the bony anatomy setup and in 13% for the primary tumor setup, whereas for the spinal cord this occurred in 10% and 13% of the patients, respectively. Conclusions: In 10% and 13% of patients with nodal involvement, setup based on bony anatomy or primary tumor, respectively, led to important dose deviations in nodal target volumes. Overdosage of critical structures occurred in 10-20% of the patients. In cases of progressive disease, repeated imaging revealed underdosage of the primary tumor. Development of practical ways for setup procedures based on repeated high-quality imaging of all tumor sites during radiotherapy should therefore be an important research focus.« less
  • Purpose: To investigate the prognostic role of metabolic response by the use of serial sets of positron emission tomography/computed tomography (PET/CT) in patients with cervical cancer who were treated with concurrent chemoradiation therapy (CCRT). Methods and Materials: A total of 60 patients who were treated with CCRT between February 2009 and December 2010 were analyzed. Three sequential PET/CT images were acquired for each patient: pre-CCRT, during-CCRT at 4 weeks of CCRT, and 1 month post-CCRT PET/CT. Metabolic responses were assessed qualitatively. The percentage changes in the maximum values of standardized uptake value (ΔSUV{sub max}%) from the PET/CT images acquired pre-CCRTmore » and during-CCRT were calculated. Receiver operating characteristic (ROC) curve analysis was performed to evaluate whether ΔSUV{sub max}% could predict complete response (CR) on the post-CCRT PET/CT and to identify the best cutoff value. Prognostic factors of progression-free survival (PFS) were analyzed. Results: During-CCRT PET/CT showed that 8 patients (13%) had CR, and the other 52 patients (87%) had partial response (PR). On the post-CCRT PET/CT, 43 patients (73%) had CR, 12 patients (20%) had PR, and 4 patients (7%) had progressive disease. The average SUV{sub max} in primary tumors was 16.3 (range, 6.4-53.0) on the pre-CCRT PET/CT images and 5.3 (range, 0-19.4) on the during-CCRT PET/CT images. According to ROC curve analysis, ΔSUV{sub max}% could predict CR response on post-CCRT PET/CT (P<.001, cutoff value of 59.7%). In all patients, the PFS rate was 71.9% at 2 years. Multivariate analysis showed that ΔSUV{sub max}% ≥60% (P=.045) and CR response on the post-CCRT PET/CT (P=.012) were statistically significant predictors of PFS. Conclusion: Metabolic responses on the during-CCRT images at 4 weeks of treatment and 1-month post-CCRT PET/CT images may predict treatment outcomes in patients with cervical cancer. ΔSUV{sub max}% ≥60% at 4 weeks of CCRT may predict CR response on 1-month post-CCRT PET/CT and also PFS.« less
  • Purpose: To evaluate dynamic [{sup 18}F]-fluorodeoxyglucose (FDG) uptake methodology as a post–radiation therapy (RT) response assessment tool, potentially enabling accurate tumor and therapy-related inflammation differentiation, improving the posttherapy value of FDG–positron emission tomography/computed tomography (FDG-PET/CT). Methods and Materials: We prospectively enrolled head-and-neck squamous cell carcinoma patients who completed RT, with scheduled 3-month post-RT FDG-PET/CT. Patients underwent our standard whole-body PET/CT scan at 90 minutes, with the addition of head-and-neck PET/CT scans at 60 and 120 minutes. Maximum standardized uptake values (SUV{sub max}) of regions of interest were measured at 60, 90, and 120 minutes. The SUV{sub max} slope between 60 and 120 minutes and changemore » of SUV{sub max} slope before and after 90 minutes were calculated. Data were analyzed by primary site and nodal site disease status using the Cox regression model and Wilcoxon rank sum test. Outcomes were based on pathologic and clinical follow-up. Results: A total of 84 patients were enrolled, with 79 primary and 43 nodal evaluable sites. Twenty-eight sites were interpreted as positive or equivocal (18 primary, 8 nodal, 2 distant) on 3-month 90-minute FDG-PET/CT. Median follow-up was 13.3 months. All measured SUV endpoints predicted recurrence. Change of SUV{sub max} slope after 90 minutes more accurately identified nonrecurrence in positive or equivocal sites than our current standard of SUV{sub max} ≥2.5 (P=.02). Conclusions: The positive predictive value of post-RT FDG-PET/CT may significantly improve using novel second derivative analysis of dynamic triphasic FDG-PET/CT SUV{sub max} slope, accurately distinguishing tumor from inflammation on positive and equivocal scans.« less