A retrospective study assessing the accuracy of [18F]–fluorocholine PET/CT for primary staging of lymph node metastases in intermediate and high-risk prostate cancer patients undergoing robotic-assisted laparoscopic prostatectomy with extended lymph node dissection

Figures & data

Figure 1. Patients included in the study.

Table 1. Characteristics of patients.

Total number of patients	252
Age, years:
Mean (SD)	66.1 (7.2)
Median (range)	68 (41−79)
PSA in blood at diagnosis, ng/mL, n(%)
< 10	125 (49.6)
10 − 19.9	75 (29.8)
≥ 20	52 (20.6)
Median	9
Clinical tumor stage, n (%)
T1	94 (37.3)
T2	130 (51.6)
T3, T4	28 (11.1)
Tumor grade at diagnosis, n (%)
ISUP grade (Gleason score)
1 (≤3 + 3)	34 (13.5)
2 (3 + 4)	52 (20.6)
3 (4 + 3)	40 (15.9)
4 (8)	60 (23.8)
5 (9–10)	66 (26.2)
Pathological tumor stage, n (%)
T1	1 (0.4)
T2	78 (30.9)
T3, T4	169 (67.1)
Missing information	4 (1.6)
D’Amico risk classification, n (%)
Low	20 (7.9)
Intermediate	70 (27.8)
High	162 (64.3)

Table 2. Characteristics of lymph nodes removed at surgery (ePLND).

Total number of lymph nodes removed	6049
Lymph nodes without metastases (%)	5879 (97.2)
Lymph nodes with metastases (%)	170 (2.8)
Numbers of lymph nodes removed per patient
Median (range)	20 (1−83)
Mean (SD)	9.2 (11.8)

Table 3. Lymph node status by histopathology and by PET/CT.

	Lymph node status by histopathology
	Positive	Negative	Total
Lymph node status by PET CT
Positive	31	54	85
Negative	41	126	167
Total	72	180	252
	Lymph node status by histopathology
	Positive	Negative	Total
Lymph node status by PET CT High-risk
Positive	21	39	60
Negative	27	75	102
Total	48	114	162
Lymph node status by PET CT Intermediate risk
Positive	7	13	20
Negative	10	40	50
Total	17	53	70
Lymph node status by PET CT Low risk
Positive	3	2	5
Negative	4	11	15
Total	7	13	20

Table 4. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for prediction of lymph node metastases by PET/CT (95% confidence interval) with histopathology report as reference method.

A. All patients
Sensitivity	0.43 (0.32–0.55)
Specificity	0.70 (0.63–0.76)
PPV	0.36 (0.27–0.47)
NPV	0.75 (0.68–0.82)
B. Analyses based on risk groups.
	High-risk	Intermediate risk	Low-risk
Sensitivity	0.44 (0.31–0.58)	0.41 (0.22–0.64)	0.43 (0.16–0.75)
Specificity	0.66 (0.57–0.74)	0.75 (0.62–0.85)	0.85 (0.58–0.96)
PPV	0.35 (0.24–0.48)	0.35 (0.18–0.57)	0.6 (0.23–0.88)
NPV	0.74 (0.64–0.81)	0.8 (0.67–0.89)	0.73 (0.48–0.89)