Ga-PSMA-11 PET/CT Interobserver Agreement for Prostate Cancer Assessments

TY - JOUR

T1 - Ga-PSMA-11 PET/CT Interobserver Agreement for Prostate Cancer Assessments

T2 - An International Multicenter Prospective Study

AU - Fendler, Wolfgang Peter

AU - Calais, Jeremie

AU - Allen-Auerbach, Martin

AU - Bluemel, Christina

AU - Eberhardt, Nina

AU - Emmett, Louise

AU - Gupta, Pawan

AU - Hartenbach, Markus

AU - Hope, Thomas A

AU - Okamoto, Shozo

AU - Pfob, Christian Helmut

AU - Pöppel, Thorsten D

AU - Rischpler, Christoph

AU - Schwarzenböck, Sarah

AU - Stebner, Vanessa

AU - Unterrainer, Marcus

AU - Zacho, Helle D

AU - Maurer, Tobias

AU - Gratzke, Christian

AU - Crispin, Alexander

AU - Czernin, Johannes

AU - Herrmann, Ken

AU - Eiber, Matthias

N1 - © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

PY - 2017/10

Y1 - 2017/10

N2 - The interobserver agreement for 68Ga-PSMA-11 PET/CT study interpretations in patients with prostate cancer is unknown. Methods:68Ga-PSMA-11 PET/CT was performed in 50 patients with prostate cancer for biochemical recurrence (n = 25), primary diagnosis (n = 10), biochemical persistence after primary therapy (n = 5), or staging of known metastatic disease (n = 10). Images were reviewed by 16 observers who used a standardized approach for interpretation of local (T), nodal (N), bone (Mb), or visceral (Mc) involvement. Observers were classified as having a low (<30 prior 68Ga-PSMA-11 PET/CT studies; n = 5), intermediate (30-300 studies; n = 5), or high level of experience (>300 studies; n = 6). Histopathology (n = 25, 50%), post-external-beam radiation therapy prostate-specific antigen response (n = 15, 30%), or follow-up PET/CT (n = 10, 20%) served as a standard of reference. Observer groups were compared by overall agreement (% patients matching the standard of reference) and Fleiss' κ with mean and corresponding 95% confidence interval (CI). Results: Agreement among all observers was substantial for T (κ = 0.62; 95% CI, 0.59-0.64) and N (κ = 0.74; 95% CI, 0.71-0.76) staging and almost perfect for Mb (κ = 0.88; 95% CI, 0.86-0.91) staging. Level of experience positively correlated with agreement for T (κ = 0.73/0.66/0.50 for high/intermediate/low experience, respectively), N (κ = 0.80/0.76/0.64, respectively), and Mc staging (κ = 0.61/0.46/0.36, respectively). Interobserver agreement for Mb was almost perfect irrespective of prior experience (κ = 0.87/0.91/0.88, respectively). Observers with low experience, when compared with intermediate and high experience, demonstrated significantly lower median overall agreement (54% vs. 66% and 76%, P = 0.041) and specificity for T staging (73% vs. 88% and 93%, P = 0.032). Conclusion: The interpretation of 68Ga-PSMA-11 PET/CT for prostate cancer staging is highly consistent among observers with high levels of experience, especially for nodal and bone assessments. Initial training on at least 30 patient cases is recommended to ensure acceptable performance.

AB - The interobserver agreement for 68Ga-PSMA-11 PET/CT study interpretations in patients with prostate cancer is unknown. Methods:68Ga-PSMA-11 PET/CT was performed in 50 patients with prostate cancer for biochemical recurrence (n = 25), primary diagnosis (n = 10), biochemical persistence after primary therapy (n = 5), or staging of known metastatic disease (n = 10). Images were reviewed by 16 observers who used a standardized approach for interpretation of local (T), nodal (N), bone (Mb), or visceral (Mc) involvement. Observers were classified as having a low (<30 prior 68Ga-PSMA-11 PET/CT studies; n = 5), intermediate (30-300 studies; n = 5), or high level of experience (>300 studies; n = 6). Histopathology (n = 25, 50%), post-external-beam radiation therapy prostate-specific antigen response (n = 15, 30%), or follow-up PET/CT (n = 10, 20%) served as a standard of reference. Observer groups were compared by overall agreement (% patients matching the standard of reference) and Fleiss' κ with mean and corresponding 95% confidence interval (CI). Results: Agreement among all observers was substantial for T (κ = 0.62; 95% CI, 0.59-0.64) and N (κ = 0.74; 95% CI, 0.71-0.76) staging and almost perfect for Mb (κ = 0.88; 95% CI, 0.86-0.91) staging. Level of experience positively correlated with agreement for T (κ = 0.73/0.66/0.50 for high/intermediate/low experience, respectively), N (κ = 0.80/0.76/0.64, respectively), and Mc staging (κ = 0.61/0.46/0.36, respectively). Interobserver agreement for Mb was almost perfect irrespective of prior experience (κ = 0.87/0.91/0.88, respectively). Observers with low experience, when compared with intermediate and high experience, demonstrated significantly lower median overall agreement (54% vs. 66% and 76%, P = 0.041) and specificity for T staging (73% vs. 88% and 93%, P = 0.032). Conclusion: The interpretation of 68Ga-PSMA-11 PET/CT for prostate cancer staging is highly consistent among observers with high levels of experience, especially for nodal and bone assessments. Initial training on at least 30 patient cases is recommended to ensure acceptable performance.

KW - Aged

KW - Aged, 80 and over

KW - Edetic Acid

KW - Humans

KW - Image Interpretation, Computer-Assisted

KW - Male

KW - Middle Aged

KW - Observer Variation

KW - Oligopeptides

KW - Organometallic Compounds

KW - Positron Emission Tomography Computed Tomography

KW - Prospective Studies

KW - Prostatic Neoplasms

KW - Clinical Trial

KW - Journal Article

KW - Multicenter Study

KW - Research Support, U.S. Gov't, Non-P.H.S.

KW - Research Support, Non-U.S. Gov't

U2 - 10.2967/jnumed.117.190827

DO - 10.2967/jnumed.117.190827

M3 - SCORING: Journal article

C2 - 28408531

VL - 58

SP - 1617

EP - 1623

JO - J NUCL MED

JF - J NUCL MED

SN - 0161-5505

IS - 10

ER -