Radium-223 outcomes after multiple lines of metastatic castration-resistant prostate cancer therapy in clinical practice: implication of pre-treatment spinal epidural disease.

BACKGROUND: Magnetic resonance imaging (MRI) is not routinely performed before initiating radium-223 to document spinal epidural disease. However, radium-223 decays to form α-particles with very short path lengths that may not reach the epidural space. Herein, we investigate the impact of baseline spinal epidural disease on metastatic castration-resistant prostate cancer (mCRPC) patients treated with radium-223. METHODS: Between October 2013 to December 2014, 41 consecutive mCRPC patients at a large tertiary cancer center were prescribed radium-223 as part of standard of care. 29% of patients had pre-treatment epidural disease (posMRI), 27% had no epidural disease (negMRI), and 44% did not have a baseline MRI (noMRI). All patients had post-treatment spinal imaging. Actuarial survival times were calculated for overall survival (OS), spinal axis radiographic progression-free survival (spinePFS) and epidural progression-free survival (epiPFS) from time of first radium-223 treatment. RESULTS: For patients with posMRI (n=12), noMRI (n=18) and negMRI (n=11) cumulative rates of development or worsening of epidural disease and/or high-grade cord compression at time of last follow-up were 83%, 44% and 9%, respectively (P=0.001). For the posMRI, noMRI and negMRI groups the median OS was 6.3 months, 12.6 months and not reached (P=0.01), the median spinePFS was 3.2 months, 4.8 months and not reached (P=0.01), and the median epiPFS was 3.2 months, 10.4 months and not reached (P=0.001). Completing less than six cycles of radium-223 was significantly associated with worse OS (P<0.0001), spinePFS (P=0.007) and epiPFS (P=0.01). Greater than or equal to twenty osseous lesions pre-treatment was significantly associated with worse spinePFS (P=0.001) and epiPFS (P=0.03). CONCLUSIONS: In a heavily pre-treated small cohort, patients with baseline epidural disease frequently progressed to spinal cord compression and early cessation of radium-223 therapy. Studies are needed to determine the optimal timing of radium-223 with other mCRPC therapies given the predilection for epidural disease and treatment failure after multiple prior lines of mCRPC therapy.

Predictors of pneumothorax after CT-guided transthoracic needle lung biopsy: the role of quantitative CT.

AIM: To evaluate the association of quantitative computed tomography (CT) measures of emphysema with the occurrence of pneumothorax after CT-guided needle lung biopsy (NLB) accounting for other risk factors. MATERIALS AND METHODS: One hundred and sixty-three CT-guided NLBs performed between 2008 and 2013 with available complete chest CT within 30 days were reviewed for the occurrence of post-procedure pneumothorax. Percent emphysema was determined quantitatively as the percentage of lung voxels below -950 HU on chest CT images using automated software. Multivariable regression was used to assess the association of percent emphysema volume with the occurrence of post-procedure pneumothorax. The association of percent emphysema volume with the pneumothorax size and need for chest tube placement after NLB was also explored. RESULTS: Percent emphysema was significantly associated with the incidence of post-NLB pneumothorax (OR=1.10 95% confidence interval: 1.01-1.15; p=0.03) adjusting for lower-lobe lesion location, needle path length, lesion size, number of passes, and pleural needle trajectory angle. Percent emphysema was not associated with the size of the pneumothorax, nor the need for chest tube placement after NLB. CONCLUSION: Percent emphysema determined quantitatively from chest CT is a significant predictor of post-NLB pneumothorax.