Indications et résultats de la radiothérapie de rattrapage dans les cancers de la prostate

[Single center experience of (18F)-fluorocholine positron emission tomography: analysis of its impact on salvage local therapy in patients with prostate adenocarcinoma]

PURPOSE

To assess usefulness of ((18)F)-fluorocholine positron emission tomography (PET) for localizing relapse in patients with biochemical relapse from prostate adenocarcinoma and its impact on indications of salvage local therapy.

PATIENTS AND METHODS

An ((18)F)-fluorocholine PET coupled with computed tomography was performed in 28 patients with biochemical progression from prostate adenocarcinoma. At the time of ((18)F)-fluorocholine PET, median prostate specific antigen (PSA) was 3.0 ng/mL (from 0.34 to 93 ng/mL) and 17 patients (60.7%) received hormone therapy. Eighteen patients from this cohort were potentially candidates to salvage radiotherapy.

RESULTS

A pathologic uptake was shown in 11 patients (39.3%) and 17 patients (60.7%) had no pathologic uptake. Median PSA was 2.4 ng/mL (0.33 to 36 ng/mL) in case of negative ((18)F)-fluorocholine PET, versus 6.75 ng/mL (1.21 to 93 ng/mL) in case of pathologic uptake (P=0.04). Among the 17 patients candidates to salvage radiotherapy, ((18)F)-fluorocholine PET helped deciding for salvage radiotherapy in five patients, since it showed only centropelvic pathologic uptake (27.7%). In one patient, it showed metastatic and radiotherapy was contraindicated. After prostatectomy, ((18)F)-fluorocholine PET was positive in only one patient candidate to salvage radiotherapy (9.1%), showing anastomotic relapse.

CONCLUSION

((18)F)-fluorocholine was positive in about a third of patients with biochemical progression. Its clinical impact is being prospectively investigated.

[Prostate specific antigen: utilization modalities and interpretation]

The prostate specific antigen test has become one of the most popular blood test. However, its result should be analyzed with caution due to physiologic variability. The PSA test is performed for prostate cancer (PC) screening or for post-treatment PC surveillance. According to the applied treatment (surgery or radiation therapy with or without hormonal therapy), PSA analysis can confirm biochemical control or relapse. New PSA data regarding the evolution of this biomarker during the surveillance (PSA doubling time and PSA velocity) are now important to consider in case of biochemical relapse.