Periodical assessment of genitourinary and gastrointestinal toxicity in patients who underwent prostate low-dose-rate brachytherapy.

1.5 MB·English

by  Tanaka, Nobumichi

Tanakaetal.RadiationOncology2013,8:25
http://www.ro-journal.com/content/8/1/25
RESEARCH Open Access
Periodical assessment of genitourinary and
gastrointestinal toxicity in patients who
underwent prostate low-dose-rate brachytherapy
Nobumichi Tanaka1,4*, Isao Asakawa2, Satoshi Anai1, Akihide Hirayama1, Masatoshi Hasegawa2,
Noboru Konishi3 and Kiyohide Fujimoto1
Abstract
Background: Tocompare theperiodical incidence rates of genitourinary (GU) and gastrointestinal (GI) toxicity in
patients who underwent prostate low-dose-rate brachytherapy between themonotherapy group (seed
implantation alone) and theboost group (incombinationwith external beam radiation therapy (EBRT)).
Methods: A total of218 patients with a median follow-up of 42.5 months were enrolled. The patients were divided
into2 groups bytreatmentmodality, namely, the monotherapy group (155 patients) and the boost group (63
patients). The periodical incidence rates of GU and GI toxicity were separately evaluated and compared between
themonotherapy group and the boost group using theNational Cancer Institute- Common Terminology Criteria
for Adverse Events, version 3.0. Toelucidatean independentfactor among clinical and postdosimetric parameters
to predict grade 2or higherGU and GI toxicity inthe acute and late phases, univariateand multivariate logistic
regression analyses were carried out.
Results: Ofall patients, 78.0% showed acute GU toxicity, and 7.8% showed acute GI toxicity, while63.8%showed
lateGU toxicity, and 21.1% showed lateGI toxicity. The incidence ratesof late GUand GI toxicity were significantly
higher inthe boost group. Multivariate analysis showed that theInternational Prostate Symptom Score (IPSS)before
seed implantation was a significant parameter to predict acute GUtoxicity, whiletherewere nosignificant
predictive parameters for acute GI toxicity. Onthe other hand, combination withEBRT was a significant predictive
parameter for lateGU toxicity, and rectal volume (mL) receiving 100% ofthe prescribed dose (R100) was a
significant predictiveparameter for late GI toxicity.
Conclusions: The boostgroup showed higher incidence rates ofboth GU and GI toxicity. Higher IPSS before seed
implantation, combination with EBRT and ahigher R100 were significant predictors for acute GU, late GU and late
GI toxicity.
Keywords: Prostate cancer, LDR-brachytherapy, GUtoxicity, GI toxicity
Background (EBRT),because of the achievement of a high biological
Low-dose-ratebrachytherapy(LDR-brachytherapy)isavery effective dose (BED) [1]. On the other hand, genitour-
effectivemodalitytoadministeracurativedosetothepros- inary (GU) toxicity and gastrointestinal (GI) toxicity
tate while avoiding unnecessary irradiation to the normal are important distress factors associated with LDR-
surrounding tissues such as the urethra and rectum, espe- brachytherapy. Many investigators have reported ad-
cially in combination with external beam radiation therapy verse events after LDR-brachytherapy. Usually, adverse
events are evaluated in the acute and late phases using
the Radiation Therapy Oncology Group (RTOG) scale
*Correspondence:[email protected] [2-8] or the National Cancer Institute (NCI) Common
1DepartmentsofUrology,NaraMedicalUniversity,Kashihara,Japan
4DepartmentofUrology,NaraMedicalUniversity,840Shijo-cho,Kashihara, TerminologyCriteriaforAdverseEvents(CTCAE)[9-13].
Nara634-8522,Japan However, there have been few reports that refer to
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Tanakaetal.RadiationOncology2013,8:25 Page2of8
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the periodical incidence of adverse events after LDR- Table1Patients’characteristics
brachytherapy [7]. Monotherapy Boost Total pvalue
In this study, we evaluated the GU and GI toxicity in
(n=155) (n=63) (n=218)
patients who underwent LDR-brachytherapy, not only in
Age(year)
the acute and late phases, but also in each period after
mean±SD 68.1±6.6 70.3±6.2 68.7±6.5 0.023§
seed implantation using the NCI-CTCAE. We also com-
PSAatdiagnosis
pared the incidence rates of GU and GI toxicity in the
(ng/mL)
monotherapygroup (seedimplantationalone)with those
mean±SD 7.2±2.4 12.5±6.1 8.7±4.5 <0.001§
in the boost group (combination of external beam radi-
ation therapy). To our best knowledge, this is the first 10orless 139 22 161
study designed to assess the periodical incidence rates of 10-20 16 34 50
both GU and GI toxicity in patients who underwent greaterthan20 0 7 7 <0.001※
prostate LDR-brachytherapy.
biopsyGleason
score
Methods
6orless 111 22 133
A total of 218 patients who were clinically diagnosed
7 44 32 76
with localized prostate cancer (cT1c-2cN0M0) and who
8-10 0 9 9 <0.001※
underwent LDR-brachytherapy between July 2004 and
clinicalTstage
November 2008 were enrolled in this prospective study.
The patients’ characteristics are shown in Table 1. The T1c 99 32 131
median age, PSA value at diagnosis, and follow-up T2a 51 19 70
period were 68.7 years (range: 51–80), 8.7 ng/mL T2b 5 6 11
(range: 3.1-32.1), and 42.5 months (range: 1–72), respect- T2c 0 6 6 <0.001※
ively.A singlepathologist(K.N)withexpertiseinprostate
neoadjuvant/adjuvant
cancer diagnosis reviewed the Gleason score of all biopsy
ADT
specimens centrally. GU and GI toxicity were evaluated
none 112 37 149
using the National Cancer Institute - Common Termin-
neoadjuvant(+) 42 18 60
ology Criteria for Adverse Events, version 3.0 (CTCAE
ver.3.0)at1,3,and6monthsafterseedimplantation,and adjuvant(+) 0 5 5
every 6 months thereafter. The incidence rates of each both 1 3 4 0.001※
adverse event at 1 to 5 months, 6 to 12 months, 13 to IPSSatbaseline
24 months, 25 to 36 months, and 37 to 48 months mean±SD 8.7±6.9 7.2±5.6 8.3±6.6 0.107§
were separately calculated according to CTCAE ver.
Follow-upperiod
3.0 grading, and were compared between the mono- (month)
therapy group and the boost group. This study was per- mean±SD 44.2±14.9 38.3±16.2 42.5±15.5 0.011§
formed in compliance with the Helsinki Declaration. The
※Chi-squaretestand§t-test.
institutional reviewer board approved this prospective
study,andinformedconsentwasobtainedfromallpatients
Table2Postdosimetricparameters(allpatients:n=218)
afterexplainingtheaimandmethodsofthisstudy.
Monotherapy Boost Pvalue
Treatment (n=155) (n=63) (t-test)
Ofallthepatients,149didnotreceiveneoadjuvantorad- PV(mL)atpostdosimetry 27.8±8.3 27.2±9.4 0.660
juvant androgen deprivation therapy (ADT), 4 received %D90(%) 109.4±9.7 113.7±9.1 0.002
both neoadjuvant and adjuvant ADT, 60 received only
D90(Gy) 164.7±16.6 125.1±10.0 <0.001
neoadjuvantADT,and5receivedonlyadjuvantADT.The
V100(%) 93.3±3.8 94.8±2.8 0.005
study treatment was seed implantation alone in 155
V150(%) 61.5±9.9 64.9±11.0 0.029
patients (monotherapy group), whereas 63 patients were
treatedwithseedimplantationincombinationwithEBRT UD30(Gy) 211.1±28.5 156.0±20.1 <0.001
(boostgroup)(Table1). %UD30(%) 140.9±19.0 141.7±18.6 0.784
From July 2004 to April 2007, there were 97 patients R100(mL) 0.08±0.16 0.11±0.19 0.349
who were treated with seed implantation at a prescribed
%RD30(%) 26.1±8.1 27.2±7.4 0.330
dose of 145 Gy, and 58 patients were treated at a pre-
RD30(Gy) 39.9±11.0 30.3±7.4 <0.001
scribed dose of 160 Gy after May 2007. The prescribed
BED(Gy2) 174.3±18.4 216.1±23.2 <0.001
dose was 110 Gy for the patients who received seed
Tanakaetal.RadiationOncology2013,8:25 Page3of8
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Table3GUandGItoxicityinallpatients ofthedosereceivedby90%oftheprostategland(%D90),
Grade0 Grade1 Grade2 Grade3 minimal dose (Gy) received by 90% of the prostate gland
(D90), percentage of the prostate volume receiving 100%
GU(acute) 48(22.0) 157(72.0) 10(4.6) 3(1.4)
and 150% of the prescribed minimal peripheral dose
GU(late) 79(36.2) 112(51.4) 25(11.5) 2(0.9)
(V100/150), minimal percentage of the dose and minimal
GI(acute) 201(92.2) 16(7.3) 1(0.5) 0
dose (Gy) received by 30% of the urethra (%UD30 and
GI(late) 172(78.9) 40(18.3) 6(2.8) 0 UD30), rectal volume (mL) receiving 100% of the pre-
NCI-CTCAE(ver.3.0) (%) scribed dose (R100), minimal percentage of the dose and
minimaldose(Gy)receivedby30%oftherectum(%RD30
implantation in combination with EBRT. The target por- andRD30),andbiologicallyeffectivedose(BED).BEDwas
tion of EBRT was determined one month after seed im- calculated to evaluate an independent factor to predict
plantation,andthepatientsreceived45Gy(in25fractions GUandGItoxicity,andanα/βratioof2wasused[1].
of 1.8 Gy per fraction) using a four-field box technique
with 6–10 MV photon energy. The clinical target volume Statisticanalysis
included both the whole prostate and a third of the prox- To elucidate independent factors to predict grade 2 or
imalseminalvesicle. higher GU and GI toxicity in the acute and late phases,
From July 2004 to April 2007, seed implantation was the prostate volume at postdosimetry, %D90, D90,V100,
performed after preplanning by modified peripheral V150, UD30, %UD30, R100, %RD30, RD30, BED, use of
loading techniques using a Mick’s applicator [14]. From neoadjuvant ADT, adjuvant ADT, International Prostate
May 2007 to October 2008, we introduced an intrao- Symptom Score (IPSS), treatment modality (monother-
perative planning method, and thereafter we used a real- apy vs. boost), and prescribed dose (145 Gy, 160 Gy, or
time planning technique and a peripheral loading 110Gy)were evaluated.
technique. In this study, acute toxicitywasdefined astoxicity that
occurred<6 months after seed implantation and late
Postdosimetricevaluation toxicity as toxicity that occurred after 6 months or later.
Therapeutic planning and post-implant dosimetric evalu- The t-test was used to compare continuous variables,
ation were performed using the planning system Inter- andthe chi-squaretestforcategorical variables.
plant Version 3.3 (CMS, Inc., St. Louis, USA) from July The chi-square testwas also used totest the difference
2004 to October 2008, and Variseed 8.0 (Varian Medical in the incidence of adverse events between the mono-
Systems,PaloAlto,CA,USA)thereafter. therapy group and the boost group at each visit. Both
Post-implant CTscanning and post-implant dosimetric univariate and multivariate logistic regression analyses
studywasperformedbyasingleradiationoncologist(A.I) (stepwiseselectionmethod)wereconductedtodiscrimin-
at 1 month after seed implantation. The dosimetric para- atethepredictiveparametersofgrade2orhigherGUand
metersanalyzedinthisstudyweretheminimalpercentage GI toxicity in the acute and late phases. The parameters
P=0.046 P<0.001
(%) 1.9 1.3 1.6 1.3
100 3.9 6.3 6.5 6.3
7.7 9.5 12.3
90 20.6
80
33.3
70
53.5
60 72.3 71.4 46.0
50
93.5
88.9 86.5
40
30 60.3
20 37.4 33.3 G3
21.9 22.2 G2
10
G1
0 G0
Mono Boost Mono Boost Mono Boost Mono Boost
GU (acute) GU (late) GI (acute) GI (late)
Figure1TheincidenceratesofbothacuteandlateGUandGItoxicitystratifiedbythemonotherapygroupandtheboostgroup.
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(%)
12
10
8
10.7
6
4 6.3
4.1
2 2.6 1.9 2.0 3.4 3.1 G1
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure2Theperiodicalincidenceratesofhematuria.
that showed univariate significance (p-value of less than Regardingthe postdosimetric parameters,%D90,V100,
0.10) were input into multivariate models. All statistical V150, and BED in the boost group were significantly
analyses were performed using PASW Statistics 17.0 higher than those in the monotherapy group, while
(SPSS Inc., Chicago, IL, USA). All p values below 0.05 UD30 and D90 (Gy) of the boost group was significantly
wereconsideredstatisticallysignificant. lowerthanthatinthemonotherapygroup (Table2).
Of all patients, 78.0% showed grade 1 or higher acute
Results GU toxicity, 7.8% showed grade 1 or higher acute GI
PSA at diagnosis, biopsy Gleason score, and clinical toxicity, 63.8% showed grade 1 or higher late GU tox-
stageinthemonotherapygroupweresignificantlyhigher icity, and 21.1% showed grade 1 or higher late GI tox-
than those in the boost group, while patients’ age in the icity(Table3).
monotherapy group was significantly younger than that Figure 1 shows a comparison of GU and GI toxicity
in the boost group. A higher proportion of patients in between the monotherapy group and the boost group in
the boost group received androgen deprivation therapy boththeacuteandlatephases.Therewerenosignificant
compared with the monotherapy group. There were no differences in acute GU and GI toxicity between the two
significant differences in the baseline IPSS between the groups, while late GU and GI toxicity were significantly
monotherapy group and the boost group. The mean higher intheboost group.
follow-up period in the monotherapy group was signifi- Figures 2, 3, 4, 5, 6, 7 and 8 shows the results of each
cantly longerthanthatintheboost group (Table1). comparison of GU and GI toxicity regarding hematuria,
(%)
12
10
1.7
8
1.3
4.5
6 2.3
0.7 8.5
4
6.5
6.3 2.0
4.6 4.5 G2
2 3.3 3.6 G1
1.6 2.0
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure3Theperiodicalincidenceratesofmictionpain.
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(%)
16 P=0.001
14
12 6.8
2.3
10
3.3
8
6 1.0
9.1
9.5
4 6.6 8.5
5.3 G2
2 5.2 3.9 2.7 4.1 3.6 G1
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure4Theperiodicalincidenceratesofurinaryincontinence.
miction pain, urinary incontinence, urinary frequency/ parameters for acute GU toxicity in the univariate ana-
urgency, urinary retention, proctitis, and rectal bleeding. lysis. In the multivariate analysis, IPSS before seed im-
Severe complications were infrequent, most complica- plantation was a significant predictive parameter for
tions were G2 or lower, except for urinary retention. acute GU toxicity, and there was no significant predict-
There were several patients who developed G3 urinary re- ive parameter for acute GI toxicity. On the other hand,
tention in the monotherapy group. Overall, 8 of all the BED, %D90,V100 and combination with EBRT remained
patients developed acute urinary retention during the predictiveparametersforlateGUtoxicityintheunivariate
follow-up period. Six of these 8 patients developed acute analysis. Finally, combination with EBRT remained in the
urinary retention within 1 month after seed implantation, multivariate analysis. Regarding late GI toxicity, BED,
andtheother2developeditat42and53monthsafterseed R100, %RD 30 and combination with EBRT remained in
implantation, respectively. The incidence rates of urinary theunivariateanalysis.Finally,R100remainedinthemulti-
incontinence, urinary frequency/urgency rectal bleeding variateanalysis.
and proctitis in the boost group were significantly higher
thanthoseinthemonotherapygroup. Discussion
To elucidate the predictive parameters for GU and GI Many investigators [2-14] have reported adverse events
toxicity, univariate and multivariate logistic regression after LDR-brachytherapy. In some studies the adverse
analyses were carried out (Table 4). IPSS before seed im- eventswereassessedbytheRTOGorRTOG/EORTCscale
plantation and neoadjuvant ADT remained as predictive [2-8], and in others, by the NCI-CTCAE scale [9-13].
(%)
80
1.9 3.3
70
60
4.9
50
0.7
40 69.0 67.2 P=0.041
30
44.3
20 37.9 0.8
G2
25.4
10 14.0 12.2 13.6 5.2 G1
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure5Theperiodicalincidenceratesofurinaryfrequency/urgency.
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(%)
16
14
1.9 3.2
12 0.6
10
1.3
8 G3
11.6 G2
6 11.1 G1
4
5.9
2 3.6
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure6Theperiodicalincidenceratesofurinaryretention.
Acute and late GU and GI toxicity were mostly evaluated parameter (uroflowmetry) and a subjective parameter
in tetrameric style. To our best knowledge, this is the first (IPSS) showed transient deterioration in the first
study designed to assess the periodical incidence rates of 6 months after seed implantation [15]. There were no
both GU and GI toxicity in patients who had undergone significant differences between the two groups. However,
prostateLDR-brachytherapy.Overall,severeadverseevents the grade of toxicity was low, and most patients had
were infrequent in the present study population. Only 6 grade 1. On the other hand, acute GI toxicity was not
patientsdevelopedgrade3toxicity(3patients:acuteGU,3 frequently observed in either group, as was previously
patients: late GU). No patients developed grade 3 GI tox- reported[5,9,11].
icity. Stratified by treatment modality, the boost group To see the details of the GU and GI toxicities in each
showed significantly higher incidence rates of late GUand follow-up period, there were no significant differences in
GItoxicitycomparedwiththemonotherapygroup.Onthe the incidence rates of hematuria, urinary retention be-
other hand, there were no significant differences in acute tween the monotherapy and the boost groups (Figures 2,
GUandGItoxicitybetweenthetwogroups. 3, 6), but the incidence rates of urinary incontinence,
In particular, acute GU toxicity was well observed in urinary frequency/urgency, proctitis and rectal bleeding
both the monotherapy group and the boost group. were significantly higher in the boost group than in the
Around 80% of patients showed acute GU toxicity. This monotherapygroup(Figures4,5,7,8).Inparticular,rec-
is comparable to the previous reports [5,7,10,11]. Our tal bleeding and proctitis were often observed in the
previous report has also demonstrated that an objective boost group. There were no significant differences in the
(%)
9 P=0.022
8
P=0.006
7
3.3
6
5
4
3 6.3 6.8
2 4.9 G2
3.6 G1
1
1.3 1.3
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure7Theperiodicalincidenceratesofproctitis.
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(%)
35
P<0.001
30 3.4
P<0.001
25
20
P=0.041
15 27.1
22.7
10 17.9
1.6
0.7 0.8 G2
5 13.1 0.7 G1
5.8 4.8 3.9 3.8 6.2
2.0
0
1-5 6-12 13-24 25-36 37-48 (months)
Mono Boost Mono Boost Mono Boost Mono Boost Mono Boost
Figure8Theperiodicalincidenceratesofrectalbleeding.
R100 value between the monotherapy and the boost implantation, because most previous reports had merely
groups (Table 2). It can however easily be conceived that evaluated acute and late GU and GI toxicity in acute
the total dose to the rectum must be higher in the boost andlatephases.
group. Indeed, Snyder et al. reported that the risk of
developing grade 2 proctitis was significantly associated Conclusions
with the rectal volume (cut-off value: 1.3 mL) receiving The incidence rates of GU and GI toxicity were signifi-
the prescribed dose (160 Gy) [2]. Zelefsky also reported cantly different between patients in the monotherapy
similar results [9]. Ohashi et al. also reported that the and the boost groups. The boost group showed a higher
predictive parameter of grade 2 or higher GI toxicity incidence rate, especially of GI toxicity. Patients with a
was the maximal rectal dose in multivariate analysis higher IPSS before seed implantation showed a higher
[4]. Aoki et al. concluded that R150 was a significant incidence rate of acute GU toxicity, while patients
prognostic factor for rectal bleeding in multivariate
analysis [6]. Table4Theunivariateandmultivariateanalysesin
In our present study, IPSS was the only prognostic fac- predictingacuteGU,lateGUandlateGItoxicityofgrade
tor predicting grade 2 or higher acute GU toxicity in 2orgreaterinallpatients
multivariate analysis. Zelefsky et al. had similarly con- Univariate Multivariate
cluded that treatment modality (implant alone vs. com- Pvalue Pvalue OR 95%C.I.
bined modality) and IPSS were significant predictors of AcuteGU
the incidence of acute grade 2 toxicities by CTCAE grad- IPSS 0.025 0.025 1.084 1.010–1.163
ing [11]. Keyes et al. also reported that the IPSS was the
ADT no reference
most significant factor by the RTOG score [7]. On the
yes 0.057 n.s.
other hand, there were no significant factors predicting
grade 2 or higher acute GI toxicity in our study, because LateGU
there were only a few patients who developed grade 2 or BED(Gy2) 0.020 n.s.
higher acute GI toxicity. Meanwhile, our present study %D90(%) 0.069 n.s.
demonstratedthatcombinationwithEBRTwasapredict-
V100(%) 0.088 n.s.
ive factor for late GU toxicity. The only predictive factor
EBRT no reference
forlateGItoxicityinourpresentstudywasR100.Thisre-
yes 0.022 0.022 2.619 1.152–5.951
sultwascomparabletopreviousreports[6,8,9,11].
There were several limitations in the present study LateGI
such as a small number of patients (n=218), a medium BED(Gy2) 0.049 n.s.
follow-up period (42.5 months), a heterogeneous patient R100(mL) 0.02 0.034 16.626 1.235–223.837
population, etc. However, we believe that it is meaning-
%RD30(%) 0.039 n.s.
ful to assess the periodical incidence rates of both GU
EBRT no reference
and GI toxicity in detail to elucidate the time course
yes 0.061 n.s.
changes of urinary and rectal morbidity after seed
Tanakaetal.RadiationOncology2013,8:25 Page8of8
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treated with EBRTshowedahigher incidence rate oflate 11. ZelefskyMJ,NedelkaMA,AricanZL,YamadaY,CohenGN,ShippyAM,Park
GU toxicity. Regarding late GI toxicity, R100 was a sig- JJ,ZaiderM:Combinedbrachytherapywithexternalbeamradiotherapy
forlocalizedprostatecancer:reducedmorbiditywithanintraoperative
nificant parameter
brachytherapyplanningtechniqueandsupplementalintensity-
modulatedradiationtherapy.Brachytherapy2008,7:1–6.
Abbreviations
12. ZilliT,TausskyD,DonathD,LeHP,LaroucheRX,Béliveau-NadeauD,
LDR-brachytherapy:Low-dose-ratebrachytherapy;PSA:Prostate-specific
HervieuxY,DelouyaG:Urethra-sparing,intraoperative,real-timeplanned,
antigen;EBRT:Externalbeamradiationtherapy;IPSS:InternationalProstate
permanent-seedprostatebrachytherapy:toxicityanalysis.IntJRadiat
SymptomScore;BED:Biologicallyeffectivedose;ADT:Androgendeprivation OncolBiolPhys2011,81:e377–e383.
therapy;%D90:Minimalpercentageofthedosereceivedby90%ofthe
13. MohammedN,KestinL,GhilezanM,KraussD,ViciniF,BrabbinsD,
prostategland;D90:Minimaldose(Gy)receivedby90%oftheprostate
GustafsonG,YeH,MartinezA:Comparisonofacuteandlatetoxicitiesfor
gland;V100/150:Percentageprostatevolumereceiving100%and150%of
threemodernhigh-doseradiationtreatmenttechniquesforlocalized
theprescribedminimalperipheraldose;%UD30:Minimalpercentageofthe prostatecancer.IntJRadiatOncolBiolPhys2012,82:204–212.
dosereceivedby30%oftheurethra;UD30:Minimaldose(Gy)by30%ofthe
14. TanakaN,AsakawaI,KondoH,TanakaM,FujimotoK,HasegawaM,Konishi
urethra;%RD30:Minimalpercentageofthedosereceivedby30%ofthe
N,HiraoY:Technicalacquisitionanddosimetricassessmentofiodine-
rectum;RD30:Minimaldose(Gy)by30%oftherectum;R100:Rectalvolume
125permanentbrachytherapyinlocalizedprostatecancer:ourfirst
(mL)receiving100%oftheprescribeddose;PV:Prostatevolume. seriesof100patients.IntJUrol2009,16:70–74.
15. TanakaN,FujimotoK,HiraoY,AsakawaI,HasegawaM,KonishiN:
Competinginterests
Variationsininternationalprostatesymptomscores,uroflowmetric
Theauthorsdeclarethattheyhavenocompetinginterests.
parameters,andprostatevolumeafter(125)Ipermanentbrachytherapy
forlocalizedprostatecancer.Urology2009,74:407–411.
Authors’contributions
TN,FK,andHMconceivedofthisstudy.AI,AS,KN,andTNparticipatedin
doi:10.1186/1748-717X-8-25
datacollection.FKandHAhelpedtodraftthemanuscript.TNcarriedout
Citethisarticleas:Tanakaetal.:Periodicalassessmentofgenitourinary
thestatisticalanalysis.Allauthorsreadandapprovedthefinalmanuscript.
andgastrointestinaltoxicityinpatientswhounderwentprostatelow-
dose-ratebrachytherapy.RadiationOncology20138:25.
Authordetails
1DepartmentsofUrology,NaraMedicalUniversity,Kashihara,Japan.
2DepartmentofRadiationOncology,NaraMedicalUniversity,Kashihara,
Japan.3DepartmentofPathology,NaraMedicalUniversity,Kashihara,Japan.
4DepartmentofUrology,NaraMedicalUniversity,840Shijo-cho,Kashihara,
Nara634-8522,Japan.
Received:30November2012Accepted:20December2012
Published:30January2013
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Five-yearoutcomeofintraoperativeconformalpermanentI-125
interstitialimplantationforpatientswithclinicallylocalizedprostate
cancer.IntJRadiatOncolBiolPhys2007,67:65–70. Submit your manuscript at
www.biomedcentral.com/submit