Sensitivity and specificity of PET/CT regarding the detection of lymph node metastases in prostate cancer recurrence

Abstract

BackgroundThe aim of the study is to assess the efficacy of choline PET/CT regarding the detection of lymph node (LN) metastases in recurrent prostate cancer (PCa).Methods49 patients with a biochemical recurrence of PCa (PSA >0.2 ng/ml) were included in the study. All patients were selected for further diagnostics with a choline-PET/CT. All patients underwent salvage extended lymphadenectomy. The PET/CT result and the histological findings were analyzed regarding the specificity and sensitivity and with respect to the localization of the metastases. The detection rate of LN metastases was analyzed with respect to interdependencies between the pre-PET/CT PSA-value as well as the role of prior ADT.Results41 out of 49 (83.6%) patients showed positive PET/CT results. Positive LNs were found in 27 out of 49 patients (55.1%). 48.9% of the PET-CT-findings proved true positive, 36.7% were found to be false positive. 8.1% proved true negative and 8.1% false negative. This results in a specificity of 22.7% and a sensitivity of 85.1%. Out of the true positive PET/CT scans, 61.9% were not congruent regarding the localization of positive LNs. In patients with PSA [greater than or equal to] 5 ng/ml, the sensitivity of the PET/CT result was 93.7%, while specificity was 0%. In 24 patients who underwent ADT prior to the PET/CT diagnostics, the sensitivity was 84.6% and specificity 9.0%.ConclusionsThe reliability of PET/CT imaging for detection of LN metastases is limited by a high false-positive rate. The influence of ADT further diminishes the PET/CT reliability. Sensitivity of the PET/CT is highest in patients with a PSA of [greater than or equal to] 5 ng/ml. Based on our results, we propose the following conclusions: 1. There is no well-established diagnostic alternative to Choline-PET/CT Scan. Therefore this method may continue to be performed in patients with BCR. 2. It is not sufficient to remove only those LNs that show up in the PET/CT. 3. Salvage extended lymphadenectomy should follow a predefined template (e.g. the “Kiel template”) and not just the PET/CT scan results.

PET/CT with 11C-choline for evaluation of prostate cancer patients with biochemical recurrence: meta-analysis and critical review of available data

“…Of the 43 studies, 13 were excluded: patients without biochemical relapse but with advanced disease or assessed for primary staging, i.e. inclusion criteria not fulfilled (3 studies [17][18][19]); intervention not in the inclusion criteria (1 study [20]); outcome of interest not reported (4 studies [21][22][23][24]); and no reference standard reported (5 studies [25][26][27][28][29]). Finally, 29 studies with 2,686 participants were included (Fig.…”

Targeted salvage lymphadenectomy in patients treated with radical prostatectomy with biochemical recurrence: complete biochemical response without adjuvant therapy in patients with low volume lymph node recurrence over a long-term follow-up

“…Based on this data situation, salvage lymphadenectomy is seen as a possible option for patients with disease relapse limited to the LNs after radical prostatectomy [ 4 ]. Integrated [11C]choline or [18F]fluoroethylcholine PET/CT scans, despite their limitations [ 5 ], have exhibited good sensitivity and specificity for detecting small (>5 mm) LN metastases after radical prostatectomy. In patients with biochemical failure after local treatment with curative intent, actual meta-analysis results showed pooled sensitivity, specificity, and a diagnostic odds ratio of 85%, 88%, and 41.4 respectively, on a per-patient basis [ 6 ].…”

Cancer-specific and overall survival in patients with recurrent prostate cancer who underwent salvage extended pelvic lymph node dissection

“…Data from our own department show a low specificity of 18.2 % with a relatively satisfactory sensitivity of 85.2 %. Most importantly, the positive predictive value and negative predictive value were 56.1 % and 50.0 %, respectively [ 25 ]. Therefore, we conclude that the reliability of PET/CT imaging for detection of LN metastases is limited by a high false-positive rate, and the findings in patients with low PSA values were associated with a high ratio of errors.…”