ABSTRACT
Objective:
To evaluate the value of 18F-
prostate specific
membrane antigen (PSMA)-3Q
PET/CT imaging in
prostate cancer patients with
serum prostate specific antigen (PSA) less than 1.00 μg/L after radical
prostatectomy.
Methods:
From May 2021 to August 2022, 18F-PSMA-3Q
PET/CT images and clinical data of 58
patients with
prostate cancer (age 52-82 years) after radical
prostatectomy with PSA less than 1.00 μg/L in
Chinese PLA
General Hospital were analyzed retrospectively. According to the level of PSA,
patients were divided into three groups (0-0.19 μg/L group, 0.20-0.49 μg/L group, and 0.50-0.99 μg/L group). 18F-PSMA-3Q
PET/CT images were analyzed according to the standardized evaluation criteria of
molecular imaging, and lesions with the scores of
molecular imaging PSMA (miPSMA)≥1 were defined as recurrent or metastatic lesions. The
detection rates of 18F-PSMA-3Q
PET/CT for
patients in different PSA level groups were compared ( χ2 test). The PSA levels of
patients with positive and negative scans were compared by using independent-sample t test.
Results:
Of the 58
patients, 36(62.1%, 36/58)
patients and 85 lesions were found by 18F-PSMA-3Q
PET/CT. There was 91.7%(33/36) with oligofocal lesions (1≤number of foci≤3) and 8.3%(3/36) with multiple lesions (number of foci>3). According to the
location, 5.2%(3/58) of the recurrent lesions were found in the prostatic
bed, 39.7%(23/58) in the
bone lesions, 37.9%(22/58) in the pelvic
lymph nodes, 12.0%(7/58) in the retroperitoneal
lymph nodes and 5.2%(3/58) in the left clavicular
lymph node metastases. There were 15 cases in 0-0.19 μg/L group, 22 cases in 0.20-0.49 μg/L group, and 21 cases in 0.50-0.99 μg/L group. The
detection rates of 18F-PSMA-3Q
PET/CT in the above groups were 5/15, 59.1%(13/22) and 85.7%(18/21), respectively ( χ2=10.33, P=0.006). There was significant difference in PSA level between
patients with positive ( n=36) and negative ( n=22) 18F-PSMA-3Q
PET/CT scans ((0.48±0.28) vs (0.28±0.25) μg/L; t=2.67, P=0.010).
Conclusions:
18F-PSMA-3Q
PET/CT can be used to detect the
recurrence or
metastasis in
prostate cancer patients with PSA level lower than 1.00 μg/L after radical
prostatectomy. In this kind of
patients, the common sites of lesions are
bone, pelvic lymph nodes, retroperitoneal
lymph nodes, left clavicular
lymph nodes and prostatic
bed, and oligofocal
patients are more common.