Page 34 - Towards personalized therapy for metastatic prostate cancer: technical validation of [18F]fluoromethylcholine

Chapter 2
Carlo process is performed where ROC curves are produced for 500 datasets randomly generated so that each patient has only one lesion. The range of the sensitivities and specificities of the optimal thresholds from these ROC curves were visually compared with the sensitivities and specificities calculated using all observations.
RESULTS
We identified 25 eligible patients who had 54 lymph nodes with enhanced [18F]FCH uptake that met our inclusion criteria. In 13/25 (52%) patients the PET/CT had been performed because of PSA relapse (I1), and in 9/25 (36%) for staging at presentation (I2); the remaining three patients had been referred for restaging in the context of presumed oligometastases (I3). The mean interval between the primary therapy and the time of referral to [18F]FCH PET/CT was 23 months (range: 3-48 months). In 17 patients (pelvic group; median age: 63 years; range: 50-80 years) we found 34 enlarged pelvic nodes (classified as malignant, see methods), and there were 7 patients (inguinal group; median age: 63 years; range: 57-68 years) with 15 [18F]FCH positive inguinal LN, classified as benign. One patient had enhanced [18F]FCH uptake in both two inguinal and three enlarged pelvic nodes. In either group the median number of eligible lymph nodes per patient was 2 (range: 1-6). Patient characteristics are presented in Table 1.
Table 1. Patient characteristics. Mean age (years)
Mean serum PSA (ng/ml) at diagnosis Mean serum PSA (ng/ml) at PET time Gleason score (number of patients)
<7 7
63 (range: 50-80) 63 51 27 38 37
63 (range: 57-68) 18
17
Total patients (N=25)
Pelvic group (N=17)
Combined pelvic & inguinal (N=1)
Inguinal group (N=7)
>7
Previous therapy: number of patients (indication)
EBRT (±ADT ±PLND) EBRT + RP
RP
ADT
BT NA
5 (3×I1 + 2×I3) -
2 (2×I1) -
1 (I1) -
1 (I1) -
1 (I1) - -
4 - 2 7-4 6 1 1
7 (7×I2) 1 (I3)
2 (2×I1)
1 (I1)
2 (2×I1)
1 (I3)
1 (I2)
N number, EBRT external -beam radiation therapy, ADT anti-androgen therapy, PLND pelvic lymph node dissection, RP radical prostatectomy, BT brachytherapy , NA not applicable, I1: PSA relapse after therapy, I2: newly diagnosed prostate cancer, I3: staging patients with suspected oligometastases from prostate cancer
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