TY - JOUR
T1 - Pretreatment Endorectal Magnetic Resonance Imaging and Magnetic Resonance Spectroscopic Imaging Features of Prostate Cancer as Predictors of Response to External Beam Radiotherapy
AU - Joseph, Tim
AU - McKenna, David A.
AU - Westphalen, Antonio C.
AU - Coakley, Fergus V.
AU - Zhao, Shoujun
AU - Lu, Ying
AU - Hsu, I. Chow
AU - Roach, Mack
AU - Kurhanewicz, John
N1 - Funding Information:
Supported by National Institutes of Health grant R01 CA079980.
PY - 2009/3/1
Y1 - 2009/3/1
N2 - Purpose: To evaluate whether pretreatment combined endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) findings are predictive of outcome in patients who undergo external beam radiotherapy for prostate cancer. Methods and Materials: We retrospectively identified 67 men with biopsy-proven prostate cancer who underwent combined endorectal MRI and MRSI at our institution between January 1998 and October 2003 before whole-pelvis external beam radiotherapy. A single reader recorded tumor presence, stage, and metabolic abnormality at combined MRI and MRSI. Kaplan-Meier survival and Cox univariate and multivariate analyses explored the relationship between clinical and imaging variables and outcome, using biochemical or metastatic failure as endpoints. Results: After a mean follow-up of 44 months (range, 3-96), 6 patients developed both metastatic and biochemical failure, with an additional 13 patients developing biochemical failure alone. Multivariate Cox analysis demonstrated that the only independent predictor of biochemical failure was the volume of malignant metabolism on MRSI (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.29-2.06; p < 0.0001). The two independent predictors of metastatic failure were MRI tumor size (HR 1.34, 95% CI 1.03-1.73; p = 0.028) and the finding of seminal vesicle invasion on MRI (HR 28.05, 95% CI 3.96-198.67; p = 0.0008). Conclusions: In multivariate analysis, MRI and MRSI findings before EBRT in patients with prostate cancer are more accurate independent predictors of outcome than clinical variables, and in particular, the findings of seminal vesicle invasion and extensive tumor predict a worse prognosis.
AB - Purpose: To evaluate whether pretreatment combined endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) findings are predictive of outcome in patients who undergo external beam radiotherapy for prostate cancer. Methods and Materials: We retrospectively identified 67 men with biopsy-proven prostate cancer who underwent combined endorectal MRI and MRSI at our institution between January 1998 and October 2003 before whole-pelvis external beam radiotherapy. A single reader recorded tumor presence, stage, and metabolic abnormality at combined MRI and MRSI. Kaplan-Meier survival and Cox univariate and multivariate analyses explored the relationship between clinical and imaging variables and outcome, using biochemical or metastatic failure as endpoints. Results: After a mean follow-up of 44 months (range, 3-96), 6 patients developed both metastatic and biochemical failure, with an additional 13 patients developing biochemical failure alone. Multivariate Cox analysis demonstrated that the only independent predictor of biochemical failure was the volume of malignant metabolism on MRSI (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.29-2.06; p < 0.0001). The two independent predictors of metastatic failure were MRI tumor size (HR 1.34, 95% CI 1.03-1.73; p = 0.028) and the finding of seminal vesicle invasion on MRI (HR 28.05, 95% CI 3.96-198.67; p = 0.0008). Conclusions: In multivariate analysis, MRI and MRSI findings before EBRT in patients with prostate cancer are more accurate independent predictors of outcome than clinical variables, and in particular, the findings of seminal vesicle invasion and extensive tumor predict a worse prognosis.
KW - Cancer-prostate
KW - Magnetic resonance imaging
KW - Outcome analysis
KW - Radiotherapy
KW - Spectroscopy-prostate
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U2 - 10.1016/j.ijrobp.2008.04.056
DO - 10.1016/j.ijrobp.2008.04.056
M3 - Article
C2 - 18760545
AN - SCOPUS:59649108542
SN - 0360-3016
VL - 73
SP - 665
EP - 671
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 3
ER -