4D perfusion CT of prostate cancer for image-guided radiotherapy planning: A proof of concept study

Abstract

PurposeAdvanced forms of prostate cancer (PCa) radiotherapy with either external beam therapy or brachytherapy delivery techniques aim for a focal boost and thus require accurate lesion localization and lesion segmentation for subsequent treatment planning. This study prospectively evaluated dynamic contrast-enhanced computed tomography (DCE-CT) for the detection of prostate cancer lesions in the peripheral zone (PZ) using qualitative and quantitative image analysis compared to multiparametric magnet resonance imaging (mpMRI) of the prostate.MethodsWith local ethics committee approval, 14 patients (mean age, 67 years; range, 57–78 years; PSA, mean 8.1 ng/ml; range, 3.5–26.0) underwent DCE-CT, as well as mpMRI of the prostate, including standard T2, diffusion-weighted imaging (DWI), and DCE-MRI sequences followed by transrectal in-bore MRI-guided prostate biopsy. Maximum intensity projections (MIP) and DCE-CT perfusion parameters (CTP) were compared between healthy and malignant tissue. Two radiologists independently rated image quality and the tumor lesion delineation quality of PCa using a five-point ordinal scale. MIP and CTP were compared using visual grading characteristics (VGC) and receiver operating characteristics (ROC)/area under the curve (AUC) analysis.ResultsThe PCa detection rate ranged between 57 to 79% for the two readers for DCE-CT and was 92% for DCE-MRI. DCE-CT perfusion parameters in PCa tissue in the PZ were significantly different compared to regular prostate tissue and benign lesions. Image quality and lesion visibility were comparable between DCE-CT and DCE-MRI (VGC: AUC 0.612 and 0.651, p>0.05).ConclusionOur preliminary results suggest that it is feasible to use DCE-CT for identification and visualization, and subsequent segmentation for focal radiotherapy approaches to PCa.

Rectal preparation significantly improves prostate imaging quality: Assessment of the PI-QUAL score with visual grading characteristics

“…However, visual grading data is commonly transformed to numerical values and calculations of mean values and/or standard deviations of ratings are examples of statistically wrong operations that are often used [14]. VGC has been used in various fields of imaging including the prostate [15,16].…”

“…However, the significant VGC results in favor of preparation for the DWI sequence allows an indirect conclusion that the amount of rectal gas was less in the preparation group. Although visual grading characteristics are an established and suitable method for image comparison studies [15,16,32], we did not investigate potential confounders such as general bowel filling and motile activity as well as age, body size and composition etc. This was mainly due to the low case numbers which also hampers an accurate, generalizable quantification of the clinical relevance of rectal preparation regarding false negative outcomes.…”

Contrast Agent Dynamics Determine Radiomics Profiles in Oncologic Imaging

“…These two cancer types were selected due to their contrary contrast agent uptake characteristics: PzC is characterized by rapid, intense contrast agent uptake compared to the surrounding non-tumoral peripheral zone tissue. This enables the visualization of pzPC using dynamic imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (dceMRI) [19] or dceCT [15]. In contrast, NSCLC does show a more heterogonous and weaker contrast agent uptake compared to pzPC, and is characterized by a longer contrast agent plateau phase with a slower in-and out-flow of the contrast agent [16].…”

“…For the purpose of this study, two tumor entities were examined: peripheral zone prostate cancer (pzPC) and non-small cell lung cancer (NSCLC); each of which are exemplified by distinct contrast agent uptake characteristics. pzPC is characterized by rapid intense contrast agent uptake compared to the surrounding non-tumoral peripheral zone tissue [15], while NSCLC shows a more heterogeneous and less intense uptake [16]. Dynamic contrast-enhanced computed tomography (dceCT) or MRI (dceMRI) images, which provided a high temporal resolution of radiomics profiles after contrast agent application (see graphical abstract), were included in this study.…”

Comparison of image quality assessments between interventional radiographers and interventional radiologists using digital subtraction angiography

“…5,15 There is a paucity of literature on the use of VGC analysis for evaluating the image quality of angiographic images. Studies have previously used VGC analysis for extremity computed tomography (CT), [16][17][18] chest, appendicular, and spine radiography, [19][20][21][22][23][24] abdominal CT, [25][26][27] head CT, 28,29 pelvic CT, 30 propagation-based phase-contrast CT, 31 pediatric radiograph, 32 and magnetic resonance imaging (MRI) olfactory bulb volumetry sequences. 33 Fridh et al 10 used angiographic images from lower limb DSA runs to detect infrapopliteal lesions, where the observers were interventional radiologists or vascular surgeons.…”