Detection rate of PET/CT in patients with biochemical relapse of prostate cancer using [(68)Ga]PSMA I&T and comparison with published data of [(68)Ga]PSMA HBED-CC.

To determine the detection rate of PET/CT in biochemical relapse of prostate cancer using [(68)Ga]PSMA I&T and to compare it with published detection rates of [(68)Ga]PSMA HBED-CC.

We performed a retrospective analysis in 83 consecutive patients with documented biochemical relapse after prostatectomy. All patients underwent whole body [(68)Ga]PSMA I&T PET/CT. PET/CT images were evaluated for presence of local recurrence, lymph node metastases, and distant metastases. Proportions of positive PET/CT results were calculated for six subgroups with increasing prostate specific antigen (PSA) levels (<0.5 ng/mL, 0.5 to <1.0 ng/mL, 1.0 to <2.0 ng/mL, 2.0 to <5.0 ng/mL, 5.0 to <10.0, ≥10.0 ng/mL). Detection rates of [(68)Ga]PSMA I&T were statistically compared with published detection rates of [(68)Ga]PSMA HBED-CC using exact Fisher's test.

Median PSA was 0.81 (range: 0.01 - 128) ng/mL. In 58/83 patients (70 %) at least one [(68)Ga]PSMA I&T positive lesion was detected. Local recurrent cancer was present in 18 patients (22 %), lymph node metastases in 29 patients (35 %), and distant metastases in 15 patients (18 %). The tumor detection rate was positively correlated with PSA levels, resulting in detection rates of 52 % (<0.5 ng/mL), 55 % (0.5 to <1.0 ng/mL), 70 % (1.0 to <2.0 ng/mL), 93 % (2.0 to <5.0 ng/mL), 100 % (5.0 to <10.0 ng/mL), and 100 % (≥10.0 ng/mL). There was no significant difference between the detection rate of [(68)Ga]PSMA I&T and published detection rates of [(68)Ga]PSMA HBED-CC (all p>0.05).

[(68)Ga]PSMA I&T PET/CT has high detection rates of recurrent prostate cancer that are comparable to [(68)Ga]PSMA HBED-CC.

European journal of nuclear medicine and molecular imaging. 2016 Jan 28 [Epub ahead of print]

Christoph Berliner, Milena Tienken, Thorsten Frenzel, Yuske Kobayashi, Annabelle Helberg, Uve Kirchner, Susanne Klutmann, Dirk Beyersdorff, Lars Budäus, Hans-Jürgen Wester, Janos Mester, Peter Bannas

Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. ., Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany., Ambulatory Center, Department for Radiation Oncology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany., Martini-Klinik, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany., Pharmaceutical Radiochemistry, Technical University Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany.