Malignant melanoma with cavitary pulmonary metastasis: Diagnostic dilemma resolved by FDG PET/CT guided biopsy

Abstract Background 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a promising tool for diagnosing relapsing polychondritis (RP). However, its usefulness in assessing RP with airway involvement is unknown. Objective This study aimed to further evaluate and confirm the potency of 18F-FDG PET/CT in diagnosing RP with airway involvement and monitoring response to steroid-based therapy. Methods A total of 30 patients from a dedicated respiratory centre, diagnosed with RP in accordance with McAdam, Damiani or Levine criteria, were included in this study. All patients underwent baseline 18F-FDG PET/CT, and 10 patients underwent second scans after 2.5–15 months of steroid-based therapy. Visual scores (VS) and maximal standard uptake values (SUVmax) were analysed. Results In the initial scan, 83.3% (25/30) of patients were found to have FDG uptake in more than one cartilage. The median VS and SUVmax in the cartilages were 3 (range, 1–3) and 3.8 (range, 1.9–17.9), respectively. Positive rates for PET/CT-guided biopsy in nasal, auricular, and tracheal/bronchial cartilages were 100% (5/5), 88.9% (8/9), and 10.5% (2/19), respectively, but the positive biopsy rate in the auricular cartilage was 92.3% (12/13) even without PET/CT assessment. Based on biopsy-proven sites, the sensitivity of PET/CT was 55.6%, and the specificity was 5.3%. Compared with the baseline scan, the second scan showed much lower median VS (2 vs 3, respectively; p < 0.0001) and SUVmax (2.9 vs 3.8, respectively; p < 0.001). Of 10 patients who underwent second PET/CT, 8 had complete therapeutic response, while 2 had partial response. Conclusion 18F-FDG PET/CT assists in identifying multiple cartilage involvement in RP, but it seems neither a sensitive nor specific modality in diagnosing RP with airway involvement. Moreover, PET/CT has limited utility in locating biopsy sites and monitoring therapeutic response to corticosteroids.

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Real time intra-procedural 18F-FDG PET/CT-guided biopsy using automated robotic biopsy arm in the diagnostic evaluation of thoracic lesions with prior inconclusive biopsy results: Initial experience from a tertiary health care center

Journal of Vascular and Interventional Radiology ◽

10.1016/j.jvir.2016.12.765 ◽

2017 ◽

Vol 28 (2) ◽

pp. S73

Author(s):

R Radhakrishnan ◽

B Mittal ◽

A Reddy Gorla ◽

R Basher ◽

A Sood ◽

...

Keyword(s):

Health Care ◽

Fdg Pet ◽

Care Center ◽

Initial Experience ◽

Ct Guided ◽

Health Care Center ◽

Pet Ct ◽

Ct Guided Biopsy ◽

18F Fdg ◽

Fdg Pet Ct

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Real-time intraprocedural 18F-FDG PET/CT-guided biopsy using automated robopsy arm (ARA) in the diagnostic evaluation of thoracic lesions with prior inconclusive biopsy results: initial experience from a tertiary health care centre

British Journal of Radiology ◽

10.1259/bjr.20170258 ◽

2017 ◽

Vol 90 (1080) ◽

pp. 20170258 ◽

Cited By ~ 11

Author(s):

Renjith Kalathoorakathu Radhakrishnan ◽

Bhagwant Rai Mittal ◽

Arun Kumar Reddy Gorla ◽

Rajender Kumar Basher ◽

Ashwani Sood ◽

...

Keyword(s):

Health Care ◽

Fdg Pet ◽

Initial Experience ◽

Care Centre ◽

Health Care Centre ◽

Ct Guided ◽

Pet Ct ◽

Ct Guided Biopsy ◽

18F Fdg ◽

Fdg Pet Ct

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KRAS mutation effects on the 2-[18F]FDG PET uptake of colorectal adenocarcinoma metastases in the liver

10.21203/rs.3.rs-75633/v1 ◽

2020 ◽

Author(s):

Marko Popovic ◽

Olga Talarico ◽

Jörg van den Hoff ◽

Henry Kunin ◽

Zhigang Zhang ◽

...

Keyword(s):

Gene Amplification ◽

Fdg Pet ◽

Colorectal Adenocarcinoma ◽

Ct Guided ◽

Guided Biopsy ◽

Mutational Status ◽

Pet Ct ◽

Ct Guided Biopsy ◽

The Mean ◽

18F Fdg

Abstract Background: Deriving individual tumor genomic characteristics from patient imaging analysis is desirable. We explore the predictive value of 2-[18F]FDG uptake with regards to the KRAS mutational status of colorectal adenocarcinoma liver metastases (CLM). Methods : 2-[18F]FDG PET/CT images, surgical pathology and molecular diagnostic reports of 37 patients who underwent PET/CT-guided biopsy of CLM were reviewed under an IRB-approved retrospective research protocol. Sixty CLM in 39 interventional PET scans of the 37 patients were segmented using two different auto-segmentation tools implemented in different commercially available software packages. PET standard uptake values (SUV) were corrected for: 1) partial volume effect (PVE) using cold wall-corrected contrast recovery coefficients derived from phantom spheres with variable diameter; and 2) variability of arterial tracer supply and variability of uptake time after injection until start of PET scan derived from the tumor-to-blood standard uptake ratio (SUR) approach. The correlations between the KRAS mutational status and the mean, peak, and maximum SUV were investigated using Student ’ s t-test, Wilcoxon rank sum test with continuity correction, logistic regression and receiver operation characteristic (ROC) analysis. These correlation analyses were also performed for the ratios of the mean, peak and maximum tumor uptake to the mean blood activity concentration at the time of scan: SUR_mean, SUR_peak, and SUR_max , respectively. Results: Fifteen patients harbored KRAS missense mutations ( KRAS+ ) while another 3 harbored KRAS gene amplification. For 31 lesions the mutational status was derived from the PET/CT-guided biopsy. The Student ’ s-t p-values for separating KRAS mutant cases decreased after applying PVE correction to all uptake metrics of each lesion and when applying correction for uptake time variability to the SUR metrics. The observed correlations were strongest when both corrections were applied to SUR MAX and when the patients harboring gene amplification were grouped with the wild type: p ≤ 0.001; ROC area under the curve (AUC) = 0.77 and 0.75 for the two different segmentations respectively with a mean specificity of 0.69 and sensitivity of 0.85. Conclusions: The correlations observed after applying the described corrections show potential for assigning probabilities for the KRAS missense mutation status in CLM using 2-[18F]FDG PET images.

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KRAS mutation effects on the 2-[18F]FDG PET uptake of colorectal adenocarcinoma metastases in the liver

EJNMMI Research ◽

10.1186/s13550-020-00707-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

M. Popovic ◽

O. Talarico ◽

J. van den Hoff ◽

H. Kunin ◽

Z. Zhang ◽

...

Keyword(s):

Gene Amplification ◽

Fdg Pet ◽

Colorectal Adenocarcinoma ◽

Ct Guided ◽

Guided Biopsy ◽

Mutational Status ◽

Pet Ct ◽

Ct Guided Biopsy ◽

The Mean ◽

18F Fdg

Abstract Background Deriving individual tumor genomic characteristics from patient imaging analysis is desirable. We explore the predictive value of 2-[18F]FDG uptake with regard to the KRAS mutational status of colorectal adenocarcinoma liver metastases (CLM). Methods 2-[18F]FDG PET/CT images, surgical pathology and molecular diagnostic reports of 37 patients who underwent PET/CT-guided biopsy of CLM were reviewed under an IRB-approved retrospective research protocol. Sixty CLM in 39 interventional PET scans of the 37 patients were segmented using two different auto-segmentation tools implemented in different commercially available software packages. PET standard uptake values (SUV) were corrected for: (1) partial volume effect (PVE) using cold wall-corrected contrast recovery coefficients derived from phantom spheres with variable diameter and (2) variability of arterial tracer supply and variability of uptake time after injection until start of PET scan derived from the tumor-to-blood standard uptake ratio (SUR) approach. The correlations between the KRAS mutational status and the mean, peak and maximum SUV were investigated using Student’s t test, Wilcoxon rank sum test with continuity correction, logistic regression and receiver operation characteristic (ROC) analysis. These correlation analyses were also performed for the ratios of the mean, peak and maximum tumor uptake to the mean blood activity concentration at the time of scan: SURMEAN, SURPEAK and SURMAX, respectively. Results Fifteen patients harbored KRAS missense mutations (KRAS+), while another 3 harbored KRAS gene amplification. For 31 lesions, the mutational status was derived from the PET/CT-guided biopsy. The Student’s t test p values for separating KRAS mutant cases decreased after applying PVE correction to all uptake metrics of each lesion and when applying correction for uptake time variability to the SUR metrics. The observed correlations were strongest when both corrections were applied to SURMAX and when the patients harboring gene amplification were grouped with the wild type: p ≤ 0.001; ROC area under the curve = 0.77 and 0.75 for the two different segmentations, respectively, with a mean specificity of 0.69 and sensitivity of 0.85. Conclusion The correlations observed after applying the described corrections show potential for assigning probabilities for the KRAS missense mutation status in CLM using 2-[18F]FDG PET images.

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