Determining the minimal ultra-low dose CT for reliable attenuation correction of 18F-FDG PET-CT: a phantom study

An observational study was set up to assess the feasibility of [F18]FPRGD2 PET/CT for imaging patients with multiple myeloma (MM) and to compare its detection rate with low dose CT alone and combined [F18]NaF/[F18]FDG PET/CT images. Four patients (2 newly diagnosed patients and 2 with relapsed MM) were included and underwent whole-body PET/CT after injection of [F18]FPRGD2. The obtained images were compared with results of low dose CT and already available results of a combined [F18]NaF/[F18]FDG PET/CT. In total, 81 focal lesions (FLs) were detected with PET/CT and an underlying bone destruction or fracture was seen in 72 (89%) or 8 (10%) FLs, respectively. Fewer FLs (54%) were detected by [F18]FPRGD2 PET/CT compared to low dose CT (98%) or [F18]NaF/[F18]FDG PET/CT (70%) and all FLs detected with [F18]FPRGD2 PET were associated with an underlying bone lesion. In one newly diagnosed patient, more [F18]FPRGD2 positive lesions were seen than [F18]NaF/[F18]FDG positive lesions. This study suggests that [F18]FPRGD2 PET/CT might be less useful for the detection of myeloma lesions in patients with advanced disease as all FLs with [F18]FPRGD2 uptake were already detected with CT alone.

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Der Beitrag der 18FDG-PET in der Entzündungsdiagnostik

Der Nuklearmediziner ◽

10.1055/s-0043-105004 ◽

2017 ◽

Vol 40 (02) ◽

pp. 119-133

Author(s):

Martin Gotthardt ◽

Anja Schlieck ◽

James Nagarajah ◽

Erik Aarntzen

Keyword(s):

Fdg Pet ◽

Low Dose ◽

Wird Eine ◽

Fieber Unklarer Genese ◽

Low Dose Ct ◽

18Fdg Pet ◽

Pet Ct ◽

Fdg Pet Ct

ZusammenfassungDie 18FDG-PET/CT kann bei der Diagnostik entzündlicher Erkrankungen eine entscheidende Rolle spielen. Die PET/CT kombiniert die Möglichkeit der Ganzkörperaufnahme mit einer guten anatomischen Zuordnung von Befunden durch die simultan durchgeführte low dose CT. Sie ist daher eine exzellente Technik nicht nur für die Suche nach Entzündungsherden, sondern auch für die differenzialdiagnostische Unterscheidung von entzündlichen /Autoimmun-Erkrankungen und Tumorerkrankungen. Die hohe Sensitivität geht jedoch mit einer eher geringen Spezifität der FDG-Aufnahme einher. Daher ist die Erkennung bestimmter Muster und die korrekte Interpretation der Verteilung von Läsionen zusammen mit dem klinischen Kontext entscheidend für den Beitrag der FDG-PET/CT im Hinblick auf das klinische Management von Patienten. In dieser Arbeit wird eine Übersicht über die möglichen Ursachen und pathophysiologischen Mechanismen entzündlicher Erkrankungen (wie z. B. Sarkoidose, entzündliche Lungenerkrankungen, Osteomyelitis, Fieber unklarer Genese, Infektionen von Gefäßprothesen, Streuherde bei Infektionserkrankungen, etc.), sowie die damit verbundenen typischen Muster der FDG-Anreicherung gegeben. Weiterhin werden Differenzialdiagnosen diskutiert und Hinweise zur optimalen Bildinterpretation gegeben.

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1059P 18F-FDG-PET/CT response assessment in patients with advanced melanoma treated with combination of low-dose ipilimumab and anti-PD1: A real-world experience

Annals of Oncology ◽

10.1016/j.annonc.2021.08.1444 ◽

2021 ◽

Vol 32 ◽

pp. S883

Author(s):

C.D. De Liz ◽

M. Teixeira ◽

L.B. Mendes Gomes ◽

J.A. Rinck ◽

J.P.S. Lima ◽

...

Keyword(s):

Real World ◽

Fdg Pet ◽

Low Dose ◽

Response Assessment ◽

Advanced Melanoma ◽

Pet Ct ◽

18F Fdg ◽

Fdg Pet Ct

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Diagnosis of bone metastases in breast cancer: Lesion-based sensitivity of dual-time-point FDG-PET/CT compared to low-dose CT and bone scintigraphy

PLoS ONE ◽

10.1371/journal.pone.0260066 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0260066

Author(s):

Jeanette Ansholm Hansen ◽

Mohammad Naghavi-Behzad ◽

Oke Gerke ◽

Christina Baun ◽

Kirsten Falch ◽

...

Keyword(s):

Breast Cancer ◽

Bone Metastases ◽

Bone Scintigraphy ◽

Fdg Pet ◽

Low Dose ◽

Low Dose Ct ◽

Pet Ct ◽

Dual Time Point ◽

Fdg Pet Ct ◽

Time Point

We compared lesion-based sensitivity of dual-time-point FDG-PET/CT, bone scintigraphy (BS), and low-dose CT (LDCT) for detection of various types of bone metastases in patients with metastatic breast cancer. Prospectively, we included 18 patients with recurrent breast cancer who underwent dual-time-point FDG-PET/CT with LDCT and BS within a median time interval of three days. A total of 488 bone lesions were detected on any of the modalities and were categorized by the LDCT into osteolytic, osteosclerotic, mixed morphologic, and CT-negative lesions. Lesion-based sensitivity was 98.2% (95.4–99.3) and 98.8% (96.8–99.5) for early and delayed FDG-PET/CT, respectively, compared with 79.9% (51.1–93.8) for LDCT, 76.0% (36.3–94.6) for BS, and 98.6% (95.4–99.6) for the combined BS+LDCT. BS detected only 51.2% of osteolytic lesions which was significantly lower than other metastatic types. SUVs were significantly higher for all lesion types on delayed scans than on early scans (P<0.0001). Osteolytic and mixed-type lesions had higher SUVs than osteosclerotic and CT-negative metastases at both time-points. FDG-PET/CT had significantly higher lesion-based sensitivity than LDCT and BS, while a combination of the two yielded sensitivity comparable to that of FDG-PET/CT. Therefore, FDG-PET/CT could be considered as a sensitive one-stop-shop in case of clinical suspicion of bone metastases in breast cancer patients.

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18F-FDG-PET/CT response assessment in patients with advanced melanoma treated with combination of low-dose ipilimumab and anti-PD1: A real-world experience.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.e21533 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. e21533-e21533

Author(s):

Caio Dabbous Liz ◽

Marcos Rezende Teixeira ◽

Luciana Beatriz Mendes Gomes Siqueira ◽

Jose A. Rinck ◽

Joao Paulo S. N. Lima ◽

...

Keyword(s):

Fdg Pet ◽

Low Dose ◽

Stage Iv ◽

Complete Response ◽

Advanced Melanoma ◽

Response Evaluation ◽

Pet Ct ◽

18F Fdg ◽

Fdg Pet Ct

e21533 Background: Combination therapy with anti-PD1 and low-dose ipilimumab has shown reduced rate of immune-related adverse effects compared with standard dose used in the Checkmates studies 067 and 204. However, the discussion whether low-dose ipilimumab may hamper the response rate in advanced melanoma is still open. Methods: We conducted a retrospective analysis of response evaluation based on 18F-FDG PET/CT for patients with advanced melanoma treated with combination of nivolumab 3mg/kg plus ipilimumab 1mg/kg for 4 cycles (N3+I1) followed by anti-PD1 maintenance therapy and compared the results to RECIST 1.1 response criteria in the same population. Results: Between December 2017 and August 2020, 45 patients with advanced melanoma treated with N3+I1 in first-line setting were identified. Unresectable stage III/stage IV were 2/43 patients, respectively. Among stage IV patients, 60.5% were M1c, 23.3% had elevated LDH and 28% had brain metastasis (3 or more brain lesions: 58%). At a median follow-up of 16.7 months, 11 patients (24.4%) had G3/G4 toxicity. During induction phase, three patients (6.6%) discontinued all drugs and 2 other patients (4.4%) interrupted only ipilimumab. Review of response evaluation by RECIST was possible in 36 patients and showed an objective response of 50%. Complete response (CR): 11% and partial response (PR): 39%. Eight percent presented progressive disease (PD). In 37 patients, review of response evaluation using 18F-FDG PET/CT was possible. Twenty-four patients (65%) achieved metabolic CR, 5 (13.5%) PD and 8 (21.5%) were classified as non-CR non-PD. Median progression-free survival (PFS) and overall survival(OS) were not reached. 12-month PFS and OS were: 72.5 and 89%, respectively. During the study follow-up, only 1 patient with metabolic complete response relapsed and 3 out of 8 with non-CR non-PD progressed. Conclusions: Using low-dose ipilimumab combination does not hamper the response rates and, possibly due to fewer protocol interruptions, these patients may achieve more complete responses as showed by 18F-FDG PET/CT evaluation.

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