Diagnostic value of very early diffusion weighted changes at MRI after single-dose ablative radiation therapy (SDART) for organ-confined prostate cancer
Cammillo Roberto Giovanni Leopoldo Oreste Massimiliano Talei Franzesi, Milan / Italy
Author Block: C. R. G. L. O. M. Talei Franzesi, D. G. Gandola, P. N. Franco, C. Maino, D. Panizza, R. Lucchini, S. Arcangeli, R. Corso, D. Ippolito; Milan/ITPurpose: The objective of this study was to investigate diagnostic value of diffusion-weighted MRI early changes, an hour after treatment, in patients with organ confined unfavorable prostate cancer(PCa) treated with single-dose ablative radiation therapy(SDART), in comparison with biochemical markers(PSA and testosterone).Methods or Background: Twenty-four patients treated with a single fraction of 24Gy to the whole prostate with urethra sparing in association with androgen deprivation therapy(ADT) were enrolled. MRI was performed before SDART(time0), one-hour post-SDART(time1), and 3-month after treatment(time2). All the patients were examined on a - 0-T-MRI(Ingenia;Philips Healthcare) with a phased-array external coil, with bowel preparations and 20 mg of butyl-scopolamine(Buscopan); the bladder was filled with 120 cc of saline solution, to simulate the same conditions during irradiation. MRI was performed with axial T1-weighted TSE and high resolution multi-planar T2-weighted TSE sequences. DWI was acquired with six b-values (0,50,100,150,800,1600mm2/s) and Apparent Diffusion Coefficient(ADC) (0,800) maps were calculated. Finally, axial contrast-enhanced dynamic imaging was obtained during intravenous injection of gadobutrol. ADC values were calculated at time 0,1,and 2 by placing region-of-interests(ROI) on ADC maps and the results were compared with PSA and testosterone blood levels at time 0 and 2.
Results or Findings: Median patient’s age was 78 years. Median prostate volume was - 2 cc. An increase of ADC value of tumour lesion of 27%(range 7%-69%) and 54%(range 20%-83%) was registered at time 1 and time 2 respectively, compared to the baseline. Median prostate volume was found unchanged at time 1, while decreased by about 25%(range 9%-59%) at time 2. At 3-months follow-up,all patients were found bNED with PSA and testosterone levels of<0.01 ng/ml and<0.20 ng/ml, respectively, and nine of them obtained a complete response.
Conclusion: Our findings demonstrated high diagnostic value of DWI imaging with good correlation between very early changes (one-hour after treatment) in ADC values after SDART and later tumour response (biochemical and imaging) in patients with unfavorable PCa.Limitations: One limitation was that this was a single-centre study.Funding for this study: No funding was received for this study.Has your study been approved by an ethics committee? Not applicableEthics committee - additional information: This study utilised retrospective anonymous data analysis.