Abstract
ObjectiveTo determine whether an interim 18F-fluoride positron-emission tomography/computed tomography (PET/CT) study performed after the third cycle of radium-223 dichloride (223RaCl2) therapy is able to identify patients that will not respond to treatment.Materials and MethodsWe retrospectively reviewed 34 histologically confirmed cases of hormone-refractory prostate cancer with bone metastasis in patients submitted to 223RaCl2 therapy. All of the patients underwent baseline and interim 18F-fluoride PET/CT studies. The interim study was performed immediately prior to the fourth cycle of 223RaCl2. The skeletal tumor burden-expressed as the total lesion fluoride uptake above a maximum standardized uptake value of 10 (TLF10)-was calculated for the baseline and the interim studies. The percent change in TLF10 between the baseline and interim studies (%TFL10) was calculated as follows: %TFL10 = interim TLF10 - baseline TLF10 / baseline TLF10. End points were overall survival, progression-free survival, and skeletal-related events.ResultsThe mean age of the patients was 72.4 ± 10.2 years (range, 43.3-88.8 years). The %TLF10 was not able to predict overall survival (p = 0.6320; hazard ratio [HR] = 0.753; 95% confidence interval [CI]: 0.236-2.401), progression-free survival (p = 0.5908; HR = 1.248; 95% CI: 0.557-2.797) nor time to a bone event (p = 0.5114; HR = 1.588; 95% CI: 0.399-6.312).ConclusionThe skeletal tumor burden on an interim 18F-fluoride PET/CT, performed after three cycles of 223RaCl2, is not able to predict overall survival, progression-free survival, or time to bone event, and should not be performed to monitor response at this time.
Highlights
Baseline whole-body 18F-fluoride positron-emission tomography/computed tomography (PET/CT) is ideal for staging and restaging prostate cancer and has been shown to be an independent prognostic imaging biomarker of patients undergoing radium-223 dichloride (223RaCl2)therapy[1]
Objective: To determine whether an interim 18F-fluoride positron-emission tomography/computed tomography (PET/CT) study performed after the third cycle of radium-223 dichloride (223RaCl2) therapy is able to identify patients that will not respond to treatment
This phenomenon has been well described in conventional bone scintigraphy, and that method is not recommended for use as the sole means of determining the response to treatment[5,6]
Summary
Baseline whole-body 18F-fluoride PET/CT is ideal for staging and restaging prostate cancer and has been shown to be an independent prognostic imaging biomarker of patients undergoing radium-223 dichloride (223RaCl2)therapy[1]. Baseline whole-body 18F-fluoride PET/CT is ideal for staging and restaging prostate cancer and has been shown to be an independent prognostic imaging biomarker of patients undergoing radium-223 dichloride (223RaCl2). Treatment with 223RaCl2 improves survival in prostate cancer patients[2,3,4], not all patients respond to this therapy. That can be confused with the osteoblastic reaction and inflammation that occur in response to tumor-associated growth factors during progression. This phenomenon has been well described in conventional bone scintigraphy, and that method is not recommended for use as the sole means of determining the response to treatment[5,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
