initially introduced in the mid-1960 's , with the adoption of radioactive i into clinical practice , prostate brachytherapy remains a highly effective treatment modality for organ confined prostate cancer . with further development of the transperineal approach in the 1980 's
tumor registry studies initially revealed an increase utilization of prostate brachytherapy as a primary treatment modality in the late 1990 's and early 2000 's , as targeted radiotherapy approaches were limited during that time period .
however , this trend has reported to have recently reversed as newer technologies have gained acceptance , such as intensity modulated radiotherapy ( imrt ) , proton therapy , as well as improvement of surgical options , such as robotic assisted prostatectomy [ 4 , 5 ] .
others have suggested that outside issues , such as financial reimbursement , lack of physician skill proficiency in brachytherapy , as well as stage migration towards more intermediate and high grade disease , which may be less likely to include prostate brachytherapy , have played a role in this trend .
these issues have led to several provocative studies suggesting that prostate brachytherapy is on a steep decline .
most of these studies reporting on the decline of prostate brachytherapy have analyzed its usage in comparison to all available treatment options . in this study we sought to utilize the national cancer database ( ncdb ) in order to evaluate the temporal trends of prostate brachytherapy in the setting of men with low risk disease who have elected to undergo treatment with radiotherapy . by limiting our cohort to those who are most likely to select brachytherapy ( patients with low risk disease ) and
have selected radiation therapy over observation or surgery , we sought to obtain a more nuanced view into whether prostate brachytherapy is really on the decline compared to external beam radiation .
the ncdb is a hospital - based registry that is the joint project of the american cancer society and the commission on cancer of the american college of surgeons .
it is estimated that 70% of all diagnosed malignancies in the united states are captured by facilities participating in this registry and reported to the ncdb .
the commission on cancer 's ncdb and the hospitals participating in the ncdb are the source of the de - identified data used in this study .
however , they have not verified and are not responsible for the statistical validity or conclusions derived by the authors of this study .
exemption was obtained from the new york harbor veterans affairs committee for research and development prior to the initiation of this study . men with prostate cancer diagnosed between 2004 - 2012 and treated with either external beam radiation and/or prostate brachytherapy
were abstracted from the ncdb . in order to be included , men had to be clinically staged as t1c - t2anx-0mx-0 adenocarcinoma of the prostate , gleason score  6 , and prostate specific antigen  10.0 ng / ml , who were treated with radiation therapy were included in this analysis .
this limited inclusion to men with low risk prostate cancer as classified by the national comprehensive cancer network . in order to accurately assess treatment selection by facility type , we further limited analysis to those who received all of their therapy in one center , which is suggested by the ncdb for analyses that include facility type as one of the covariables .
descriptive statistics were used to analyze brachytherapy utilization over time , as well as by other factors such as facility type , insurance status , and race .
comparisons were made via  , fisher 's exact test , and mann whitney test where appropriate .
the variables analyzed in the multivariate model included age grouping ( < 60 years , 60 - 70 years , > 70 years ) , year of diagnosis ( 2004 through 2012 in single year increments ) , race
( white , black , other ) , distance from treatment center ( divided into 4 quartiles ) , facility type ( academic , non - academic ) , and insurance type ( none , private insurance , medicaid , medicare , other government , unknown ) .
significant values were defined as those with a p - value < 0.05 . statistical analysis was performed using spss , version 23 ( ibm inc , armonk , ny , usa ) .
there were 89,143 men included in this study . of these , 37,054 ( 41.6% ) received external beam radiation alone , and 52,089 received brachytherapy ( 58.4% ) , which consisted of 50,248 men who received brachytherapy alone , and 1,841 men who received brachytherapy in addition to external beam radiation .
the median age was 66 years ( interquartile range 61 - 72 years ) . for those who received external beam radiation , the median dose was 75.6 gy ( interquartile range 74 - 78 gy ) .
men who received brachytherapy tended to be younger , live further away from the treatment center , have private insurance , and were white .
further details regarding external beam radiation and brachytherapy usage , as well as a comparison between the groups are available in table 1 . 
 
patient characteristics of those with low risk prostate cancer receiving external beam radiation therapy or brachytherapy ebrt 
external beam radiation therapy brachytherapy usage declined every year from 2004 - 2012 , with the exception of 2010 , when there was a small relative increase compared to 2009 . nevertheless , brachytherapy remained the more commonly utilized modality overall . in 2004
, brachytherapy was utilized 62.9% of the time whereas by 2012 this was reduced to 51.3% of the time .
brachytherapy utilization 2004 - 2012 the overall utilization of brachytherapy differed significantly by the distance from the treatment site .
as noted in table 1 , those in the closest quartile were treated with brachytherapy 50.2% of the time , whereas those who were furthest away received brachytherapy 69.2% of the time . for those men who were furthest away from the treatment center , the relative decline of brachytherapy was less steep , from 71.1% to 65.3% .
in contrast , for those who were closest to the treatment center , brachytherapy declined from 55.5% to 40.3% . the decline in brachytherapy was also a bit steeper for men treated at an academic center compared to a non - academic center . in 2004 , brachytherapy was utilized 60.8% of the time at academic centers and this declined to 47.0% by 2012 .
in non - academic centers , brachytherapy was utilized 63.7% of the time in 2004 and this declined to 53.0% by 2012 .
this was despite the fact that the relative percentage of men treated at an academic center increased from 26% to 31% with increasing distance from the treatment center .
additionally , for men treated in the furthest quartile , brachytherapy declined from 70.8% in 2004 to 62.4% in 2012 at academic centers , whereas during this same time period the decline change in utilization was 71.3% in 2004 to 66.5% in 2012 at non - academic centers .
on multivariate analysis , increasing distance from the treatment center was associated with an increased likelihood of brachytherapy utilization , as well as the presence of private insurance , medicare , or government insurance .
in contrast , older age , race other than white , year of diagnosis between 2006 - 2012 , and treatment at an academic program was associated with a lower likelihood of receiving brachytherapy .
initial population - based studies demonstrated an increase in utilization of prostate brachytherapy . a study published from the surveillance , epidemiology and end results ( seer ) database , demonstrated an increase in utilization of brachytherapy between 1986 and 2004 from 0% to 29% .
this increase was more pronounced in the well and moderately differentiated cancers than in the lower grade cancers .
when they included all treatment options , there was an increase in the use of brachytherapy from 15% to 17.7% .
this change was more pronounced in the 60 - 64 age group ( 19.6% to 25.2% ) .
our study used the ncdb database to identify almost 90,000 men diagnosed with low risk prostate cancer between 2004 - 2012 who were treated with radiation treatment . in total , brachytherapy utilization outnumbered external beam ( 58.4% vs. 41.6% ) .
however , when trended by year of diagnosis , brachytherapy utilization fell 12% between 2004 and 2012 .
on multivariate analysis , increased brachytherapy utilization was associated with increased distance from the treatment center , private insurance , medicare or government insurance ; while older ages , race other than white , years of diagnosis between 2006 - 2012 and treatment at an academic program was associated with increased use of external beam radiation therapy ( ebrt ) .
a recently reported seer analysis observed treatment practices of patients with any low , intermediate , or high risk disease diagnosed between 2004 and 2009 , and were treated with radiation therapy . in that study ,
ebrt monotherapy increased from 55.8% to 62% , while all brachytherapy usage decreased from 44.2% to 38.0% .
this decrease was significantly more pronounced in low risk patients when compared to other risk groups ( p < 0.0001 ) .
interestingly , they found a decrease of brachytherapy utilization in white patients , whereas our study demonstrated that the odds ratio for brachytherapy was 0.80 ( p < 0.001 ) for black patients and 0.86 ( p < 0.001 ) for other ethnicities .
an additional recently published study used the ncdb and observed overall treatment trends in patients diagnosed between 1998 and 2010 . during that time period they identified an increase in the use of surgery from 46.1% in 1998 to 59.1% in 2010 , while they noted a decline in all other treatment modalities .
they found that brachytherapy use peaked in 2002 at 16.7% and then declined to a low of 8% in 2010 .
low risk patients exhibited the sharpest decline in brachytherapy use by 9.4% . in our study , we noted that prostate brachytherapy still remains an important treatment of choice for many patients with > 50% of men undergoing radiation therapy choosing brachytherapy in 2012 .
however , given the current trend , one would expect this to continue to decline into the next decade .
the utilization rates in our study are higher than in other reports , which is likely due to different methodologies .
the seer database study looked at global declining rates of brachytherapy amongst all risk groups , but did not detail the relative usage of brachytherapy compared to ebrt by risk group . the aforementioned ncdb study compared brachytherapy usage to all other modalities , including surgery , hormones , and no treatment .
in addition , they excluded several brachytherapy variables due to questions regarding the fidelity of those variables at the time of their analysis , which may have led to some degree of underestimation of brachytherapy usage .
in fact , a prior seer based study using more similar methodology to ours reported that prostate brachytherapy utilization was 56.1% for low risk patients , which is consistent with our findings . regardless of the precise comparative methodologies used ,
the consistent findings from all of these studies are that prostate brachytherapy appears to be declining .
this is somewhat surprising , as many studies to date demonstrate an increase in prostate - specific antigen ( psa ) progression free survival with brachytherapy versus other modalities .
the prostate cancer results study group recently published a study , which included almost 850 different publications and found that compared to ebrt or radical prostatectomy , brachytherapy was associated with the most sustained psa progression free survival over 12 years .
another retrospective analysis looked at almost 8,000 low and intermediate risk patients treated in canada with radiotherapy , and found that the use of brachytherapy led to statistically significant improvement in psa progression free survival , with a hazard ratio of 4.58 for intermediate risk patients and 2.90 for low risk patients .
the recently reported ascende - rt trial showed an increased survival with the addition of brachytherapy to ebrt in intermediate and high risk patients .
several possibilities have been suggested to explain this trend , including increased utilization of robotic assisted surgery , fewer practitioners being trained , and possibly financial incentives . with imrt paying almost $ 15,000 per patient ,
prostate cancer is among the top five most expensive cancers in the united states , with approximately $ 12 billion spent annually .
it is estimated that approximately 70,110 low risk prostate cancers will be diagnosed in the united states within the next ten years , and the cost to treat them with low - dose - rate ( ldr ) brachytherapy would be $ 18.3 billion , $ 32.2 billion for high - dose - rate ( hdr ) brachytherapy and $ 54 billion for imrt . in the current era of increased emphasis on cost containment , these financial issues will likely become an urgent healthcare issue in the united states .
although financial incentive seems like a strong driver for the decrease in brachytherapy utilization , our study demonstrated a much larger decline of brachytherapy utilization in academic centers , where one would expect financial incentive to play less of a role .
this finding suggests that there may be other factors driving these changes and is of particular concern as academic centers provide most of resident training throughout the county .
recent association of residents in radiation oncology ( arro ) survey reported an enormous decrease in resident reported clinical experience in brachytherapy from 88% in the 2005 - 2008 survey to 15 - 30% in the 2013 - 2015 survey .
another recently published study determined that the number of academic centers performing  1 brachytherapy procedure a month has increased from 56.4% to 73.7% .
this translates into practicing physicians who are uncomfortable with performing the procedure , limiting treatment options offered to patients , and will likely lead to further decline through the years .
it is incumbent on academic centers to take an increased responsibility for this issue , in order to prevent a nationwide drought of brachytherapy efficient physicians .
we also noted that distance clearly plays a role in brachytherapy utilization , as there was an increase in utilization in patients who lived further from treatment facilities .
this was most pronounced in those that lived furthest from treatment facilities , where the brachytherapy peaked to 70% in those patients .
as typical ebrt treatment require 8 - 9 weeks of therapy , it would be taxing for one that lives far away from the treatment facilities to undergo daily treatment for that time period , further favoring brachytherapy in that group . as with all tumor registry studies , limitations to this study include selection bias , incomplete data , and coding errors .
the ncdb in particular is a hospital based database , and therefore if patients either received external beam at an outpatient facility and received brachytherapy at an ncdb hospital or vice versa , it may lead to an over or underestimation of the findings .
for example , if a patient received external beam at a hospital but brachytherapy at a private institution , this may have underestimated true brachytherapy utilization . in attempt to account for that potential bias ,
only patients who received all of their treatment at the same facility were included in this analysis . in conclusion ,
prostate brachytherapy remains for now the most commonly selected radiation treatment for low risk disease .
however , there has been a consistent trend of reduced brachytherapy usage over the last decade , which if it continues may eventually lead to marginalization of prostate brachytherapy over time .
given its favorable clinical and cost effectiveness , further studies should be directed to determine barriers to brachytherapy , particularly at academic centers , in order to reduce this trend .
 purposeseveral prior studies have suggested that brachytherapy utilization has markedly decreased , coinciding with the recent increased utilization of intensity modulated radiation therapy , as well as an increase in urologist - owned centers . 
 we sought to investigate the brachytherapy utilization in a large , hospital - based registry.material and methodsmen with prostate cancer diagnosed between 2004 - 2012 and treated with either external beam radiation and/or prostate brachytherapy were abstracted from the national cancer database . in order to be included , men had to be clinically staged as t1c - t2anx-0mx-0 , gleason 6 , psa  10.0 ng / ml . 
 descriptive statistics were used to analyze brachytherapy utilization over time and were compared via 2 . 
 multivariate logistic regression was used to assess for covariables associated with increased brachytherapy usage.resultsthere were 89,413 men included in this study , of which 37,054 ( 41.6% ) received only external beam radiation , and 52,089 ( 58.4% ) received prostate brachytherapy . 
 the use of brachytherapy declined over time from 62.9% in 2004 to 51.3% in 2012 ( p < 0.001 ) . 
 this decline was noted in both academic facilities ( 60.8% in 2004 to 47.0% in 2012 , p < 0.001 ) as well as in non - academic facilities ( 63.7% in 2004 to 53.0% in 2012 , p < 0.001 ) . 
 the decline was more pronounced in patients who lived closer to treatment facilities than those who lived further . 
 the use of intensity modulated radiation therapy increased during this same time period from 18.4% in 2004 to 38.2% in 2012 ( p < 0.001 ) . 
 on multivariate analysis , treatment at an academic center , increasing age , decreasing distance from the treatment center , and years of diagnosis from 2006 - 2012 were significantly associated with reduced brachytherapy usage.conclusionsin this hospital - based registry , prostate brachytherapy usage has declined for low risk prostate cancer as intensity modulated radiation therapy usage has increased . 
 however , it still remains the treatment of choice for 51.3% of patients as of 2012 . 
Purpose
Material and methods
Results
Discussion with Conclusions
Disclosure