Comparison of lesion detection and quantitation of tracer uptake between PET from a simultaneously acquiring whole-body PET/MR hybrid scanner and PET from PET/CT

15 Background: Whole body PET/CT is commonly utilized in breast cancer (BC) patients (pts). Limitations include assessment of treatment response in bone metastases (mets), high physiologic uptake in brain and liver, and cumulative radiation exposure. The site of mets can have prognostic and therapeutic implications. PET/MR, an exciting new hybrid technology, delivers less radiation than PET/CT. Our aim was to compare the differences in metastatic lesion detection using PET/CT & PET/MR in all BC subtypes. Methods: After a single 18-FDG injection, pts had whole body PET/CT for staging and assessment of treatment response. They were transported to another NYU facility & then underwent whole body PET/MR. PET/MR & PET/CT images were each read by a radiologist blinded to prior exams or reports. Number of mets (up to 6) per organ was recorded. 2 experienced radiologists unblinded to imaging and pathology reports served as the “reference standard”. Results: Forty-eight BC pts underwent PET/CT & PET/MR (28 in metastatic setting, 5 for staging & 15 to rule out recurrence). Median age: 55; range 32-79 with 31 ER+/HER2-, 8 ER+/HER2+, 2 ER-/HER2+, 6 ER-/HER2+, 1 unknown. 20 pts had no distant mets on scan. In the remaining 28 pts, the reference standard detected 9 liver, 18 bone, 7 lung/pleura, 5 brain & 10 lymph node (LN) metastases; some patients had ≥1 metastatic site. PET/CT had more false positives (FP) and false negatives (FN) in the detection of mets (Table). PET/MR had 1 FP in the liver. PET/MR accurately detected 2 bone (ER+/HER2-), 3 liver (ER+/HER2-), 2 LN (1 ER+/HER2+; 1 ER+/HER2-) and 5 brain lesions (1 ER+/HER2-; 3 ER-/HER2+; 1 ER+/HER2+) in 10 unique pts that were not identified on PET/CT. 1 liver (ER+/HER2-) and 2 brain mets (ER-/HER2+) identified on PET/MR were previously unknown. Conclusions: Our preliminary data suggest that PET/MR outperformed PET/CT in detecting mets in the liver, brain, LN & possibly bone. Prospective studies of PET/MR are warranted to determine whether early detection of mets, including occult brain mets in HER2+ pts, impacts survival.[Table: see text]

Download Full-text

Performance of the Relative Difference Prior for Hot Lesion Detection in Whole-Body PET/CT: an Evaluation with Numerical and Real Observers

IEEE Nuclear Science Symposium Conference Record, 2005 ◽

10.1109/nssmic.2005.1596761 ◽

2006 ◽

Cited By ~ 1

Author(s):

J. Nuyts ◽

C. Michel

Keyword(s):

Relative Difference ◽

Lesion Detection ◽

Whole Body ◽

Pet Ct

Download Full-text

Comparison of whole-body PET/CT and PET/MRI in breast cancer patients: Lesion detection and quantitation of 18F-deoxyglucose uptake in lesions and in normal organ tissues

European Journal of Radiology ◽

10.1016/j.ejrad.2013.11.002 ◽

2014 ◽

Vol 83 (2) ◽

pp. 289-296 ◽

Cited By ~ 90

Author(s):

Leonardo Pace ◽

Emanuele Nicolai ◽

Angelo Luongo ◽

Marco Aiello ◽

Onofrio A. Catalano ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Lesion Detection ◽

Whole Body ◽

Breast Cancer Patients ◽

Normal Organ ◽

Pet Ct

Download Full-text

Comparing lesion detection efficacy and image quality across different PET system generations to optimize the iodine-124 PET protocol for recurrent thyroid cancer

EJNMMI Physics ◽

10.1186/s40658-021-00361-y ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

David Kersting ◽

Walter Jentzen ◽

Miriam Sraieb ◽

Pedro Fragoso Costa ◽

Maurizio Conti ◽

...

Keyword(s):

Thyroid Cancer ◽

Image Quality ◽

Neck Region ◽

Lesion Detection ◽

Whole Body ◽

Acquisition Time ◽

Region Detection ◽

Pet Ct ◽

Bed Position ◽

New Generation

Abstract Background In recurrent differentiated thyroid cancer patients, detectability in 124I PET is limited for lesions with low radioiodine uptake. We assess the improvements in lesion detectability and image quality between three generations of PET scanners with different detector technologies. The results are used to suggest an optimized protocol. Methods Datasets of 10 patients with low increasing thyroglobulin or thyroglobulin antibody levels after total thyroidectomy and radioiodine therapies were included. PET data were acquired and reconstructed on a Biograph mCT PET/CT (whole-body, 4-min acquisition time per bed position; OSEM, OSEM-TOF, OSEM-TOF+PSF), a non-TOF Biograph mMR PET/MR (neck region, 4 min and 20 min; OSEM), and a new generation Biograph Vision PET/CT (whole-body, 4 min; OSEM, OSEM-TOF, OSEM-TOF+PSF). The 20-min image on the mMR was used as reference to calculate the detection efficacy in the neck region. Image quality was rated on a 5-point scale. Results All detected lesions were in the neck region. Detection efficacy was 8/9 (Vision OSEM-TOF and OSEM-TOF+PSF), 4/9 (Vision OSEM), 3/9 (mMR OSEM and mCT OSEM-TOF+PSF), and 2/9 (mCT OSEM and OSEM-TOF). Median image quality was 4 (Vision OSEM-TOF and OSEM-TOF+PSF), 3 (Vision OSEM, mCT OSEM-TOF+PSF, and mMR OSEM 20-min), 2 (mCT OSEM-TOF), 1.5 (mCT OSEM), and 1 (mMR OSEM 4 min). Conclusion At a clinical standard acquisition time of 4 min per bed position, the new generation Biograph Vision using a TOF-based image reconstruction demonstrated the highest detectability and image quality and should, if available, be preferably used for imaging of low-uptake lesions. A prolonged acquisition time for the mostly affected neck region can be useful.

Download Full-text

Head-to-Head Comparison of 68Ga-PSMA-11 and 131I in the Follow-Up of Well-Differentiated Metastatic Thyroid Cancer: A New Potential Theragnostic Agent

Frontiers in Endocrinology ◽

10.3389/fendo.2021.794759 ◽

2021 ◽

Vol 12 ◽

Author(s):

Quetzali Pitalua-Cortes ◽

Francisco Osvaldo García-Perez ◽

Joel Vargas-Ahumada ◽

Sofia Gonzalez-Rueda ◽

Edgar Gomez-Argumosa ◽

...

Keyword(s):

Thyroid Cancer ◽

Lymph Nodes ◽

Lesion Detection ◽

Whole Body ◽

Image Method ◽

Psma Pet ◽

Pet Ct ◽

Well Differentiated ◽

Metastatic Thyroid Cancer

IntroductionThyroid cancer is the main endocrine neoplasia worldwide, for which 131I therapy is the cornerstone treatment. One of the main problems of follow up in patients with this type of cancer, is the need for thyroglobulin stimulation, not to mention the poor availability of 123I or 124I, to perform studies with a higher degree of sensitivity. Prostatic Specific Membrane Antigen (PSMA) PET/CT has demonstrated to be quite useful in a diversified number of neoplasms, on behalf of its capacity of evaluating the extent of type II carboxypeptidase expression in vascular endothelium. The end point of this article is to assess whether this novel image method possesses applicability in thyroid neoplasms follow up, for diagnostic and potentially therapeutic purposes.MethodsWe retrospectively evaluated well differentiated metastatic thyroid cancer patients, who underwent a post therapeutic 131I dose whole body scan (WBS) and complementary SPECT/CT, as well as 68Ga-PSMA–11 PET/CT.ResultsTen patients with differentiated thyroid cancer were included, of whom 80% were women and 20% men, mean age was 58 years old (± 11.6). Sixty-four metastatic lesions were analyzed, 67.19% had papillary histology and 32.81% were follicular type, the most affected site of metastases was bone in 57.81%, followed by lung 17.19%, lymph nodes 7.81%, postoperative thyroid bed 4.69%, brain 4.69% and others 7.81%. 68Ga PSMA-11 PET/CT detected 64/64 lesions, all of them also identified by computed tomography (CT), whereas 131I SPECT/CT detected 55/64 lesions. Discrepant lesions were localized in lung 44.4%, brain 22.2%, postoperative thyroid bed 11.1%, lymph nodes 11.1% and bone 11.1%. The degree of correspondence among observers was outstanding for both radiotracers, but close upon perfect for PSMA-11 (κ = 0.98; 95% CI, 0.80 – 0.91), as opposed to 131 I (κ = 0.86; 95% CI, 0.71 – 0.76).Conclusions68Ga-PSMA PET/CT showed an utterly superior capability for metastatic lesion detection when compared to 131I SPECT/CT. These findings suggest that PSMA PET/CT could possibly and precociously identify radioiodine refractoriness. PSMA uptake values not only expedite diagnosis, but also award it the ability to be used for therapeutic intents.

Download Full-text

Evaluating a Machine Learning Tool for the Classification of Pathological Uptake in Whole-Body PSMA-PET-CT Scans

Tomography ◽

10.3390/tomography7030027 ◽

2021 ◽

Vol 7 (3) ◽

pp. 301-312

Author(s):

Annette Erle ◽

Sobhan Moazemi ◽

Susanne Lütje ◽

Markus Essler ◽

Thomas Schultz ◽

...

Keyword(s):

Machine Learning ◽

Area Under The Curve ◽

Ground Truth ◽

Tracer Uptake ◽

Whole Body ◽

Clinical Environment ◽

Physiological Uptake ◽

Psma Pet ◽

Pet Ct ◽

Unseen Data

The importance of machine learning (ML) in the clinical environment increases constantly. Differentiation of pathological from physiological tracer-uptake in positron emission tomography/computed tomography (PET/CT) images is considered time-consuming and attention intensive, hence crucial for diagnosis and treatment planning. This study aimed at comparing and validating supervised ML algorithms to classify pathological uptake in prostate cancer (PC) patients based on prostate-specific membrane antigen (PSMA)-PET/CT. Retrospective analysis of 68Ga-PSMA-PET/CTs of 72 PC patients resulted in a total of 77 radiomics features from 2452 manually delineated hotspots for training and labeled pathological (1629) or physiological (823) as ground truth (GT). As the held-out test dataset, 331 hotspots (path.:128, phys.: 203) were delineated in 15 other patients. Three ML classifiers were trained and ranked to assess classification performance. As a result, a high overall average performance (area under the curve (AUC) of 0.98) was achieved, especially to detect pathological uptake (0.97 mean sensitivity). However, there is still room for improvement to detect physiological uptake (0.82 mean specificity), especially for glands. The ML algorithm applied to manually delineated lesions predicts hotspot labels with high accuracy on unseen data and may be an important tool to assist in clinical diagnosis.

Download Full-text

Feasibility of equivalent performance of 3D TOF [18F]-FDG PET/CT with reduced acquisition time using clinical and semiquantitative parameters

EJNMMI Research ◽

10.1186/s13550-021-00784-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Julia Pilz ◽

Lukas Hehenwarter ◽

Georg Zimmermann ◽

Gundula Rendl ◽

Gregor Schweighofer-Zwink ◽

...

Keyword(s):

Image Quality ◽

Fdg Pet ◽

Lesion Detection ◽

Whole Body ◽

Body Region ◽

Acquisition Time ◽

Routine Practice ◽

Short Acquisition Time ◽

Pet Ct ◽

Fdg Pet Ct

Abstract Background High-performance time-of-flight (TOF) positron emission tomography (PET) systems have the capability for rapid data acquisition while preserving diagnostic image quality. However, determining a reliable and clinically applicable cut-off of the acquisition time plays an important role in routine practice. This study aimed to assess the diagnostic equivalence of short acquisition time of 57 with routine 75 seconds per bed position (s/BP) of [18F]-fluoro-deoxy-glucose (FDG) PET. Phantom studies applying EARL criteria suggested the feasibility of shortened acquisition time in routine clinical imaging by 3D TOF PET/CT scanners. Ninety-six patients with melanoma, lung or head and neck cancer underwent a standard whole-body, skull base-to-thigh or vertex-to-thigh [18F]-FDG PET/CT examination using the 3D TOF Ingenuity TF PET/CT system (Philips, Cleveland, OH). The [18F]-FDG activity applied was equal to 4MBq per kg body weight. Retrospectively, PET list-mode data were used to calculate a second PET study per patient with a reduced acquisition time of 57 s instead of routine 75 s/BP. PET/CT data were reconstructed using a 3D OSEM TOF algorithm. Blinded patient data were analysed by two nuclear medicine physicians. The number of [18F]-FDG-avid lesions per body region (head&neck, thorax, abdomen, bone, extremity) and image quality (grade 1–5) were evaluated. Semiquantitative analyses were performed by standardized uptake value (SUV) measurements using 3D volume of interests (VOI). The visual and semiquantitative diagnostic equivalence of 214 [18F]-FDG-avid lesions were analysed in the routine standard (75 s/BP) as well as the calculated PET/CT studies with short acquisition time. Statistical analyses were performed by equivalence testing and Bland–Altman plots. Results Lesion detection rate per patient’s body region agreed in > 98% comparing 57 s/BP and 75 s/BP datasets. Overall image quality was determined as equal or superior to 75 s in 80% and 69%, respectively. In the semiquantitative lesion-based analyses, a significant equivalence was found between the 75 s/BP and 57 s/BP PET/CT images both for SUVmax (p = 0.004) and SUVmean (p = 0.003). Conclusion The results of this study demonstrate significant clinical and semiquantitative equivalence between short acquisition time of 57 s/BP and standard 75 s/BP 3D TOF [18F]-FDG PET/CT scanning, which may improve the patient’s workflow in routine practice.

Download Full-text