Underestimation of Positron Emission Tomography/Computerized Tomography in Assessing Tumor Burden in Prostate Cancer Nodal Recurrence: Head-to-Head Comparison of 68Ga-PSMA and 11C-Choline in a Large, Multi-Institutional Series of Extended Salvage Lymph Node Dissections

TY - JOUR

T1 - Underestimation of Positron Emission Tomography/Computerized Tomography in Assessing Tumor Burden in Prostate Cancer Nodal Recurrence: Head-to-Head Comparison of 68Ga-PSMA and 11C-Choline in a Large, Multi-Institutional Series of Extended Salvage Lymph Node Dissections

AU - Fossati, Nicola

AU - Scarcella, Simone

AU - Gandaglia, Giorgio

AU - Suardi, Nazareno

AU - Robesti, Daniele

AU - Boeri, Luca

AU - Karnes, R Jeffrey

AU - Heidenreich, Axel

AU - Pfister, David

AU - Kretschmer, Alexander

AU - Buchner, Alexander

AU - Stief, Christian

AU - Battaglia, Antonino

AU - Joniau, Steven

AU - Van Poppel, Hendrik

AU - Osmonov, Daniar

AU - Juenemann, Klaus-Peter

AU - Shariat, Shahrokh

AU - Hiester, Andreas

AU - Nini, Alessandro

AU - Albers, Peter

AU - Tilki, Derya

AU - Graefen, Markus

AU - Gill, Inderbir S

AU - Mottrie, Alexander

AU - Galosi, Andrea Benedetto

AU - Montorsi, Francesco

AU - Briganti, Alberto

PY - 2020/8

Y1 - 2020/8

N2 - PURPOSE: We compared the use of 11C-choline and 68Ga-prostate specific membrane antigen in men undergoing salvage lymph node dissection for nodal recurrent prostate cancer.MATERIALS AND METHODS: The study included 641 patients who experienced prostate specific antigen rise and nodal recurrence after radical prostatectomy and underwent salvage lymph node dissection. Lymph node recurrence was documented by positron emission tomography/computerized tomography using 11C-choline (407, 63%) or 68Ga-PSMA ligand (234, 37%). The outcome was underestimation of tumor burden (difference between number of positive nodes on final pathology and number of positive spots at positron emission tomography/computerized tomography). Multivariable analysis tested the association between positron emission tomography/computerized tomography tracer (11C-choline vs 68Ga-PSMA) and tumor burden underestimation.RESULTS: Overall the extent of tumor burden underestimation was significantly higher in the 11C-choline group compared to the 68Ga-PSMA group (p <0.0001), which was confirmed on multivariable analysis (p=0.028). Repeating these analyses according to prostate specific antigen, tumor burden underestimation was lower with 68Ga-PSMA only when prostate specific antigen was 1.5 ng/ml or less. Conversely, the underestimation of the 2 tracers became similar when prostate specific antigen was greater than 1.5 ng/ml. Furthermore, we evaluated the risk of underestimation by number of positive spots on positron emission tomography/computerized tomography. The higher the number of positive spots the higher the underestimation of tumor burden regardless of the tracer used (p=0.2).CONCLUSIONS: Positron emission tomography/computerized tomography significantly underestimates the burden of prostate cancer recurrence, regardless of the tracer used. 68Ga-PSMA was associated with a lower rate of underestimation in patients with a prostate specific antigen below 1.5 ng/ml and a limited nodal tumor load. In all other men there was no benefit from 68Ga-PSMA over 11C-choline in assessing the extent of nodal recurrence.

AB - PURPOSE: We compared the use of 11C-choline and 68Ga-prostate specific membrane antigen in men undergoing salvage lymph node dissection for nodal recurrent prostate cancer.MATERIALS AND METHODS: The study included 641 patients who experienced prostate specific antigen rise and nodal recurrence after radical prostatectomy and underwent salvage lymph node dissection. Lymph node recurrence was documented by positron emission tomography/computerized tomography using 11C-choline (407, 63%) or 68Ga-PSMA ligand (234, 37%). The outcome was underestimation of tumor burden (difference between number of positive nodes on final pathology and number of positive spots at positron emission tomography/computerized tomography). Multivariable analysis tested the association between positron emission tomography/computerized tomography tracer (11C-choline vs 68Ga-PSMA) and tumor burden underestimation.RESULTS: Overall the extent of tumor burden underestimation was significantly higher in the 11C-choline group compared to the 68Ga-PSMA group (p <0.0001), which was confirmed on multivariable analysis (p=0.028). Repeating these analyses according to prostate specific antigen, tumor burden underestimation was lower with 68Ga-PSMA only when prostate specific antigen was 1.5 ng/ml or less. Conversely, the underestimation of the 2 tracers became similar when prostate specific antigen was greater than 1.5 ng/ml. Furthermore, we evaluated the risk of underestimation by number of positive spots on positron emission tomography/computerized tomography. The higher the number of positive spots the higher the underestimation of tumor burden regardless of the tracer used (p=0.2).CONCLUSIONS: Positron emission tomography/computerized tomography significantly underestimates the burden of prostate cancer recurrence, regardless of the tracer used. 68Ga-PSMA was associated with a lower rate of underestimation in patients with a prostate specific antigen below 1.5 ng/ml and a limited nodal tumor load. In all other men there was no benefit from 68Ga-PSMA over 11C-choline in assessing the extent of nodal recurrence.

U2 - 10.1097/JU.0000000000000800

DO - 10.1097/JU.0000000000000800

M3 - SCORING: Journal article

C2 - 32068488

VL - 204

SP - 296

EP - 302

JO - J UROLOGY

JF - J UROLOGY

SN - 0022-5347

IS - 2

ER -