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whereas modern prostate brachytherapy using transrectal ultrasound and sophisticated treatment planning was met with much skepticism when introduced in the 1980s , favorable longer - term outcomes are fueling its widespread adoption [ 1 , 2 ] .  
brachytherapy has since enjoyed growing acceptance for treatment of low risk patients , that is , those with a psa less than 10  ng / ml , gleason score 6 , and low volume cancer in the biopsy core specimens [ 3 , 4 ] .  
however , there is a continued controversy regarding its use for patients at higher risk of extracapsular cancer extension ( ece ) [ 57 ] .  
it has been well established that patients with higher psa and gleason scores are at higher risk of ece , with the likelihood of ece being approximately 50% in patients with a psa over 10  ng / ml or a gleason score of 7 or higher .
it has been assumed that external beam radiation alone should be the basis of treatment for such patients , the logic being that ebrt would provide better coverage of ece .
some early reports appeared to support the concept of brachytherapy being ill - advised for these patients [ 10 , 11 ] .
while it may seem superficially logical to avoid brachytherapy for patients at higher risk of ece , studies regarding the radial extent of ece have cast doubt on such a policy .   
most importantly , ece is typically limited to 35  mm , and can be treated with peripherally loaded implants that provide high doses to the periprostatic tissues .  
although some early reports showed poor results using brachytherapy in patients having higher risk features , there is a growing number of reports showing favorable results with brachytherapy - based treatment for patients with a high likelihood of ece , especially when combined with supplemental ebrt [ 6 , 7 , 1316 ] .
one criticism of most brachytherapy outcomes reports has been the lack of long - term followup , with the possibility of prematurely concluding that cancer has been eradicated in high - risk patients .  
reports to date have generally been limited to a median followup of 5 years .  
accordingly , we have updated our ongoing analysis of external beam radiation ( ebrt ) plus brachytherapy using pd-103 .
three hundred twenty - one consecutive patients were treated between january 1992 and february 1997 by the primary author , and m. dattoli .    
patients were classified into prognostic risk groups as defined by the national comprehensive cancer network guidelines ( intermediate risk : t2b  t2c or gleason 7 , or psa 1020 ; high risk : t3a or gleason 810 , or psa above 20 ) .   
the original biopsy slides of the 321 patients were retrieved and rereviewed by outside pathologists ( l. true or d. bostwick ) to independently verify the patients ' tumor grade with 30% identified to be undergraded and 6% being overgraded .  
all biochemical data were also independently re - reviewed at the university of washington ( k.w . ) .   
enzymatic prostatic acid phosphatase ( pap ) was analyzed independent of risk stratification grouping as the primary author ( m. dattoli ) has previously identified the importance of this marker as an adverse prognosticator [ 6 , 17 , 18 ] .  
pap was determined by the method of roy and colleagues , with values up to 2.5  u considered normal [ 17 , 18 ] .   all patients who met intermediate or high - risk criteria underwent combination external beam irradiation plus pd-103 brachytherapy , with the only exception being that of patients having enlarged gland sizes in excess of 70  cm   and/or excessive turp defects .  
patients received a median 4140  cgy 3-dimensional conformal radiotherapy ( 3d - crt ) over 4.5 weeks to the pelvic field   covering the prostate , seminal vesicles , and lymph nodes up to the common iliacs ( dose range : 3960  gy , 180  cgy / fx ) , followed 2 to 4 weeks later by a pd-103 boost , using transrectal ultrasound and fluoroscopic guidance .  
only free seeds were utilized and all patients underwent pretreatment and intraoperative trus planning , while all patients underwent postimplant ct imaging for dosimetric analysis and source counting on postoperative day 1 .  
the prescribed minimum pd-103 dose to the prostate was 8090  gy ( pre - nist-99 ) .  
a median of 104.3  mci pd-103 was implanted with a range of 48144  mci .  
the median source strength was 1.4  mci ( range:1.01.6  mci / source ) .  
generous brachytherapy margins were utilized ; the clinical target volume extended 0.51.0  cm anterolaterally to the trus prostate margin ( no posterior margin was added beyond the trus delineated posterior border ) .  
patients having 3 or more risk features ( psa , gleason score , clinical stage , elevated pap ) were encouraged to receive hormonal agents and 143 patients received hormones in neoadjuvant or adjuvant fashion , median duration 4 months ( maximum 6 months ) .  
patients were planned to be followed at 6 and 12 months for the first 5 years , and then every 12 months thereafter .   at the time of their follow - up visit , data recorded included their ipss and rectal functioning assessment score ( r - fas ) .  
those patients who did not appear for their scheduled follow - ups ( beyond 12 months , 20 patients ) were mailed the ipss and r - fas .  
ultimately , all living patients in this study were evaluated by personal visits with the longest time lapse being 18 months .
eighteen patients experiencing grade ii proctitis beyond 6 months were recommended to undergo colonoscopy to rule out fistulas or ulceration , revealing only erythematous changes and/or prominent internal hemorrhoids .
freedom from biochemical failure was defined using a serum psa <  0.2  ng / ml ( at or after nadir ) at last follow - up . the phoenix definition of psa nadir + 2 was also used .  
using psa < 0.2  ng / ml for disease failure allows for reasonable comparison to radical prostatectomy series , as well as recent brachytherapy studies while psa nadir + 2 allows for comparison to contemporary imrt series [ 2022 ] .   
patients were censored at last follow - up if their serum psa was still decreasing ( 3 patients ) .  
psa nadired > 0.2  ng / ml or who exceeded the psa nadir + 2 definition were scored as failures at the time at which their psa progressed .   both definitions ( psa < 0.2 
ng / ml and psa nadir + 2 ) needed to be satisfied to be considered free from biochemical failure .  
the follow - up period for nonfailing patients was 16 years ( median 10.5 years ) .  
biochemical failure curves were calculated by the method of kaplan - meier and freedom from biochemical failure was defined as both a psa < 0.2 , or a rise in psa that does not exceed the psa nadir + 2 definition .  
individual nccn risk factors ( clinical stage , gleason score , psa ) were also subject to multivariate cox proportional hazards analysis considering each factor as a continuous variable .  
treatment with or without hormones was subject to the methods of kaplan - meier .  
since this primary author ( m. dattoli ) has previously identified pap as a significant adverse prognosticator , this risk feature was also subjected to the same multivariate analysis .
this included 218 patients having gleason score 7 or greater with 52 patients having gleason 810 ; 203 patients having psa > 20 ; 130 patients had clinical stage t3 ; 158 patients had clinical stage t2c ; 20 patients had clinical staget2b ; and 10 patients had clinical stage t2a and 3 patients had clinical stage t1c   ( table 1 ) .
the overall actuarial freedom from biochemical progression at 16 years is 82% , with 222 patients followed beyond five years and 149 patients followed beyond 10 years ( figure 1 ) .
the overall freedom - from - failure for the 157 patients with intermediate risk disease was 89% while the overall freedom - from - failure for the 164 patients having high risk features was 74% at 16 years .
it was most encouraging to find that the absolute risk of failure decreased progressively with time , with only 1% of patients failing beyond 6 years of completing treatment .  
of these 52 patients , 27 ( 51% ) failed within the first three years after treatment .  
follow - up transperineal saturation prostate biopsies ( minimum 25 cores ) were performed on all failing patients , within 2 months of biochemical failure ( md ) .  
none were characterized as  indeterminate  ( db ) nor was there clinical ( dre , new onset of obstructive uropathy , pelvic pain ) evidence of local failure .
of the 3 nccn risk features ( psa , gleason score , and clinical stage ) only pretreatment psa and gleason score were each associated with a higher failure rate ( table 2 ) .  
the strongest predictor of failure was gleason score ( p = .03 ) ( figure 2 ) and psa ( p = .041 ) ( figure 3 ) .   
neoadjuvant and adjunctive hormonal therapy did not affect the failure rates ( p = .14 , figure 4 ) .  
previous experience , pap was identified to be the strongest predictor of biochemical failure ( p = .001 ) .
postimplant prostatic dosimetric evaluation was performed on all patients demonstrating mean and median v100 's to be 99.5 and 98.3 , respectively , while mean and median d90 's were 105 and 102 , respectively .
treatment morbidity was primarily limited to 36 months rtog grade 1 - 2 urinary and rectal symptoms ( 80% rtog grade 1 , 20% grade 2 ) .  
these symptoms occurred 36 months following completion of treatment and all spontaneously resolved with the exception of one patient who developed rtog grade 3 toxicity .  
this patient experienced chronic intermittent urinary obstruction symptoms and had both a posttreatment tuip and turp resulting in low volume stress incontinence .  
fifteen patients required immediate postimplant catheterization limited to 2448 hours .   none required indwelling catheterization beyond 48 hours and none required repeated self - catheterization .  
the reintroduction of brachytherapy in the late 1980s was met with tremendous skepticism and misconceptions regarding which patients , if any , are best served with this modality .  
skepticism has since given way to widespread acceptance of brachytherapy alone for patients with low psa and gleason score .  
however , there still remains widespread perception that brachytherapy is not appropriate for patients at higher risk of ece .  
a recent european consensus statement , for instance , recommended that brachytherapy be limited to patients with low psa and gleason scores . on the contrary , this and other series suggest that brachytherapy - based treatment may , in fact , be a very desirable treatment modality for such patients when performed in combination with ebrt .  
brachytherapy , if designed to deliver generous cancercidal margins around the prostate given in addition to those with supplemental ebrt , appears capable of eradicating both larger intraprostatic tumor masses along with ece [ 22 , 23 ] .  
hormones offered no survival advantage ( p = .14 ) in keeping with multiple other brachytherapy studies using high dose radiation [ 6 , 2427 ] .
this is in contrast to recent studies demonstrating survival advantage using lower doses as is the case with full course external beam irradiation and androgen blockade without brachytherapy , including the trans - tasman randomized control trial ( median 6 months hormonal manipulation [ 28 , 29 ] ) and other studies using a median of 2 years and 3 years [ 3032 ] . 
because there is a large degree of overlap in psa , gleason score and clinical stage between patients with or without biochemical failure , even patients with markedly elevated parameters appear to have a chance for cure .  
accordingly , our policy is to treat patients with curative intent , even with markedly elevated parameters , provided a bone scan and pelvic ct are negative for metastatic disease .   
recent data suggest that in those patients having high risk malignancy , the disease is predominantly confined within the pelvis including the prostate and periprostatic tissues , seminal vesicles , and pelvic lymph nodes [ 6 , 33 , 34 ] .  
based on results obtained from our study published in 1996 which utilized preimplant external radiation followed by brachytherapy , beginning in february 1997 , we began boosting periprostatic tissues and lymph nodes up to the common iliacs to a much higher cancercidal dose level ( 6075  gy ) while blocking the prostate plus a calculated margin .  
this dose escalation boost has become more easily accomplished with the advent of the more sophisticated versions of imrt .  
initial studies demonstrate favorable tumor control rates with brachytherapy - based regimens were met with skepticism due to short follow - up times .  
however , the increasing number of studies with long - term follow - up uniformly achieves results that compare favorably to those with surgery or beam radiation alone .  
it is encouraging that the failure rate decreased to < 1% per year ( 90% of surviving patients having psa 's <  .05 and the remainder having psa 's of < .2 ) with follow - up beyond 6 years with no pathological local failures documented .  
while longer follow - up will always be beneficial , evidence from this patient group at higher risk of extracapsular cancer extension and others suggest that relatively high tumor control rates with brachytherapy - based therapy are quite durable [ 6 , 13 , 14 , 16 ] .  
this increasing body of evidence strengthens the rationale that brachytherapy - based treatment is a very desirable treatment modality for patients having intermediate and high risk disease , although prospective studies will ultimately be necessary to corroborate these positive results .
background . perception remains that brachytherapy - based regimens are inappropriate for patients having increased risk of extracapsular extension ( ece ) . methods . 
 321 consecutive intermediate and high - risk disease patients were treated between 1/92 and 2/97 by one author ( m. dattoli ) and stratified by nccn guidelines . 
 157 had intermediate - risk ; 164 had high - risk disease .   
 all were treated using the combination ebrt / brachytherapy  hormones .   
 biochemical failure was defined using psa > 0.2 and nadir + 2 at last followup . 
 nonfailing patients followup was median 10.5 years .   
 both biochemical data and original biopsy slides were independently rereviewed at an outside institution . 
 results .   
 overall actuarial freedom from biochemical progression at 16 years was 82% ( 89% intermediate , 74% high - risk ) with failure predictors : gleason score ( p = .01 ) and psa ( p = .03 ) .   
 hormonal therapy did not affect failure rates ( p = .14 ) . 
 conclusion .   
 this study helps to strengthen the rationale for brachytherapy - based regimens as being both durable and desirable treatment options for such patients .   
 prospective studies are justified to confirm these positive results .