***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background To assess the feasibility and early toxicity of selective , IMRT-based dose escalation ( simultaneous integrated boost ) to biopsy proven dominant intra-prostatic lesions visible on MRI . Methods Patients with localized prostate cancer and an abnormality within the prostate on endorectal coil MRI were eligible . All patients underwent a MRI-guided transrectal biopsy at the location of the MRI abnormality . Gold fiducial markers were also placed . Several days later patients underwent another MRI scan for fusion with the treatment planning CT scan . This fused MRI scan was used to delineate the region of the biopsy proven intra-prostatic lesion . A 3 mm expansion was performed on the intra-prostatic lesions , defined as a separate volume within the prostate . The lesion + 3 mm and the remainder of the prostate + 7 mm received 94.5/75.6 Gray ( Gy ) respectively in 42 fractions . Daily seed position was verified to be within 3 mm . Results Three patients were treated . Follow-up was 18 , 6 , and 3 months respectively . Two patients had a single intra-prostatic lesion . One patient had 2 intra-prostatic lesions . All four intra-prostatic lesions , with margin , were successfully targeted and treated to 94.5 Gy . Two patients experienced acute RTOG grade 2 genitourinary ( GU ) toxicity . One had grade 1 gastrointestinal ( GI ) toxicity . All symptoms completely resolved by 3 months . One patient had no acute toxicity . Conclusion These early results demonstrate the feasibility of using IMRT for simultaneous integrated boost to biopsy proven dominant intra-prostatic lesions visible on MRI . The treatment was well tolerated PURPOSE To prospect ively determine the accuracies of T2-weighted magnetic resonance ( MR ) imaging , dynamic contrast material -enhanced MR imaging , and quantitative three-dimensional ( 3D ) proton MR spectroscopic imaging of the entire prostate for prostate cancer localization , with whole-mount histopathologic section findings as the reference st and ard . MATERIAL S AND METHODS This study was approved by the institutional review board , and informed consent was obtained from all patients . Thirty-four consecutive men with a mean age of 60 years and a mean prostate-specific antigen level of 8 ng/mL were examined . The median biopsy Gleason score was 6 . T2-weighted MR imaging , dynamic contrast-enhanced MR imaging , and 3D MR spectroscopic imaging were performed , and on the basis of the image data , two readers with different levels of experience recorded the location of the suspicious peripheral zone and central gl and tumor nodules on each of 14 st and ardized regions of interest ( ROIs ) in the prostate . The degree of diagnostic confidence for each ROI was recorded on a five-point scale . Localization accuracy and ROI-based receiver operating characteristic ( ROC ) curves were calculated . RESULTS For both readers , areas under the ROC curve for T2-weighted MR , dynamic contrast-enhanced MR , and 3D MR spectroscopic imaging were 0.68 , 0.91 , and 0.80 , respectively . Reader accuracy in tumor localization with dynamic contrast-enhanced imaging was significantly better than that with quantitative spectroscopic imaging ( P < .01 ) . Reader accuracy in tumor localization with both dynamic contrast-enhanced imaging and spectroscopic imaging was significantly better than that with T2-weighted imaging ( P < .01 ) . CONCLUSION Compared with use of T2-weighted MR imaging , use of dynamic contrast-enhanced MR imaging and 3D MR spectroscopic imaging facilitated significantly improved accuracy in prostate cancer localization The study was approved by the animal care and use committee . The purpose of the study was to prospect ively establish proof of principle in vivo in canines for a magnetic resonance ( MR ) imaging-compatible robotic system design ed for image-guided prostatic needle intervention . The entire robot is built with nonmagnetic and dielectric material s and in its current configuration is design ed to perform fully automated brachytherapy seed placement within a closed MR imager . With a 3.0-T imager , in four dogs the median error for MR imaging-guided needle positioning and seed positioning was 2.02 mm ( range , 0.86 - 3.18 mm ) and 2.50 mm ( range , 1.45 - 10.54 mm ) , respectively . The robotic system is capable of accurate MR imaging-guided prostatic needle intervention within a st and ard MR imager in vivo in a canine model OBJECTIVE The aim of this study was to assess the roles of transrectal color Doppler and gray-scale sonography in revealing prostatic cancer , using biopsy as the reference st and ard . SUBJECTS AND METHODS Two hundred fifty-six patients referred for urologic studies underwent transrectal sonography using gray-scale and color Doppler scanning . All abnormal areas shown on gray-scale or color Doppler sonography or both were targeted and biopsies were performed . The patients also underwent r and om sextant biopsies . All biopsies were individually correlated with histopathologic findings and all results were analyzed . RESULTS Cancer was found on biopsy in 100 patients ( 39 % ) , and equivocal sonographic results or prostatic intraepithelial neoplasia was found in 22 other patients ( 9 % ) . In 16 of the patients in whom cancer was detected , the tumors were correctly revealed only with color Doppler sonography . These 16 patients had a mean Gleason score of 6.4 ( range , 5 - 8 ) . Biopsy findings in these 16 patients showed eight patients with extensive lesions , three with moderate lesions , and five with minimal lesions . However , in nine other patients with cancer ( 9 % of cancers detected ) , both gray-scale and color Doppler sonography failed to reveal lesions that were found on sextant biopsy . An analysis showed that , although highly sensitive , color Doppler sonography was somewhat less specific than gray-scale sonography . CONCLUSION Color Doppler sonography should become a routine part of transrectal sonography of the prostate gl and to improve detection and targeting of lesions . The practice of performing r and om sextant biopsies should also continue OBJECTIVES The aim of this prospect i ve study was to evaluate the sensitivity of the sextant biopsy protocol compared with a more extensive procedure for the detection of prostate cancer and to define a biopsy model with the minimal number of biopsies necessary to maintain diagnostic accuracy . METHODS A total of 512 consecutive patients with suspected prostate cancer were examined with transrectal ultrasound ( TRUS ) and underwent TRUS-guided core biopsy .  All patients had 8 or 10 st and ardized biopsy sample s taken , with the number depending on the size of the gl and . Additional biopsy sample s were taken from hypoechoic or hyperechoic lesions located outside the predetermined location for the st and ardized biopsies ( ie , target biopsies ) . The sensitivity of the detection of cancer for different combinations of biopsy sample s was analyzed and compared with that of our model with 8 to 10 biopsies . RESULTS In all , 276 cancers were detected , of which 88 ( 32 % ) had an isoechoic appearance . Sensitivity was 59 % for focal lesions detected by TRUS , 85 % to 97 % for different combinations of systematic biopsy sample s , and 93 % to 98 % for a combination of systematic and target biopsy sample s. The sensitivity for the st and ard sextant protocol was 85 % . By adding target biopsies , the sensitivity increased to 93 % . CONCLUSIONS The st and ard sextant protocol leaves 15 % of cancers undetected compared with results obtained from a more extensive biopsy procedure . By combining systematic and target sampling , the sensitivity increases ; however , a major concern is that the clinical importance of cancers detected by multiple biopsies needs to be evaluated The diagnosis of prostatic carcinoma is most commonly made today by transrectal ultrasound guided needle biopsy . Often hypoechoic and peripheral zone lesions are the only areas sample d. Recently , we showed that this approach missed a quarter of the cancers that would be detected by a systematic biopsy technique . We term these missed cancers isoechoic carcinomas . We review ed 1,549 systematic sextant prostate needle biopsies  , of which 417 cancers were detected and subdivided into  hypoechoic cancers ( cancers detected on biopsy of a hypoechoic sector and isoechoic cancers ( cancers found only in normal [ isoechoic ] peripheral zone ) . We noted in men with only isoechoic cancers that fewer biopsy cores per prostate revealed cancer ( mean 1.6 versus 3.0 , p < 0.0001 ) and that these men had lower serum prostate specific antigen levels ( mean 14.4 versus 43.7 , p < 0.001 ) . The Gleason scores for the isoechoic and hypoechoic cancers were indistinguishable . The pathological staging of hypoechoic and isoechoic cancers was also similar . This study suggests that while isoechoic cancers are generally smaller than hypoechoic cancers , they do not represent low grade clinical ly insignificant carcinomas . A systematic approach to performing prostate biopsy is recommended 
    Output:
    
Systematic TRUSBx is the gold st and ard , but it fails to detect numerous tumors .
Diagnostic MR imaging provides more accurate selection of regions in which tumors are suspected .
Using these diagnostic images during an MR-directed biopsy procedure improves quality of the biopsy .