ESTRO 2024 - Abstract Book

S2480

Clinical - Urology

ESTRO 2024

Results:

A total of 46 patients were included. Median PSA values at the first diagnosis and at the oligorecurrence were 7.62 ng/mL and 1.27 ng/mL, respectively. Median time between first diagnosis and oligorecurrence was 46 months. A total of 29 patients had only lymph nodal localization, while 17 had at least one bone localization. Considered variables across the different subgroups are shown in Table 1 . When stratified according to the median PSA at diagnosis, Median SUVmax resulted higher in patients with a PSA above the median value while median PSMA-TV and time to recurrence were comparable in both groups. When stratified according to the median PSA at recurrence, Median SUVmax resulted higher in patients with an higher PSA ( > 1.27) ng/ml, while patients in the lower PSA group had a smaller PSMA-TV (1.75 vs 2.28 cm3). Patients with a longer median time to recurrence had a higher median PSA at the recurrence. When grouping patients according to the metastatic site, those with at least one bone metastases had a shorter time interval between first diagnosis and recurrence and a lower median SUVmax.

Table 1. Median MaxSUV, PSMA-TV and time to recurrence for patients stratified accordi to PSA and lesion site.

PSA at diagnosis*

≤ 7.62

PSA at diagnosis* > 7.62 ng/ml (n = 22)

ng/ml (n = 22)

Median SUVmax (total, all lesions)

9.08

15.60

Median PSMA-TV (cm3)

2.17

2.03

Median time to recurrence (months)

49.6

45.3

PSA at recurrence

≤ 1.27

PSA at recurrence > 1.27 ng/ml (n = 23)

ng/ml (n = 23)

Median SUVmax (total, all lesions)

9.56

13.87

Median PSMA-TV (cm3)

1.75

2.28

Median time to recurrence (months)

45.3

69.9

Lymph node lesions

Bone lesions

(n = 29)

(n = 17)

Median SUVmax (total, all lesions)

14.30

10.97

Median PSMA-TV (cm3)

2.05

2.20

Median time to recurrence (months)

47.9

40.4

List of abbreviations: PSMA-TV (PSMA tumor volume ); PSA (prostate specific antigen); SUV (standardized uptake value).

*missing data for 2 patients

Conclusion:

Patients with higher PSA values both at first diagnosis and at the recurrence have an higher median SUVmax, and patients with a lower PSA at the oligorecurrence had a lower lesion volume (median PSMA-TV 1.75) and a shorter