Impact of fluorocholine(18F) PET/CT in case of occult recurrence of prostate cancer

Objectives The ICHOROPRO prospective study aimed to determine the impact of fluorocholine(18F) (FCH) PET/CT on the management of patients with a past history of radical treatment for prostate cancer (PC) and whose serum levels of PSA were rising, without any conclusive result of imaging modalities, including at least abdominopelvic MRI and bone scintigraphy.

Methods Impact was determined prospectively by means of two questionnaires. At patient’s inclusion, the referring physician indicated the scheduled management before FCH PET/CT: surgery, radiotherapy (RT), high intensity focalised ultrasounds (HIFU), medical treatment (MT), or watchful waiting (WW). FCH PET/CT was started just after 4 MBq/kg body mass: 8 min dynamic acquisition on the pelvis, then whole-body low dose CT & PET acquisition. When the management decision was taken, the clinician mentioned in the 2nd questionnaire whether FCH PET/CT results prompted other examinations and whether they induced a change in patient management.

Results The two questionnaires are available for 177 of 181 patients (98% response rate) recruited in 15 centres: an impact on diagnostic thinking was reported in 106 (60%). In 29 cases, FCH PET/CT prompted another examination (invasive or not), without impact on PC treatment in 9 cases (but useful for the final decision in 5 of them: discovery of a 2nd primary lung or liver cancer). A change in PC management was then reported in the 20 other patients and in 77 patients without further examination. The rate of change in management was 97/177=55%: MT replaced WW in 20 cases, RT in 6, surgery in 5, HIFU in 3 & was modified in 6 cases; RT replaced MT in 20 cases, was associated to MT in 5 cases & was modified in 1 case; WW replaced MT in 12 cases & RT in 2; Surgery replaced MT in 9 cases & was associated to MT in 2 cases; HIFU replaced MT in 6 cases.

Conclusions FCH PET/CT changed management in more than 50% of the PC patients referred for occult recurrence, without conclusive results of MRI and bone scintigraphy.

Research Support PHRC 2007 AP-H