I-125 Permanent Prostate Brachytherapy Research Articles

Correlations between intraplan and postplan parameters in I-125 permanent prostate brachytherapy using loose seeds or linked seeds.

ABSTRACTThe purpose of this study was to determine the most appropriate seed arrangement by comparing two different methods (linked seeds and loose seeds). A total of sixty-one patients (28 linked seed brachytherapy cases and 33 loose seed brachytherapy cases) with clinically localized prostate cancer were treated with I-125 permanent prostate brachytherapy. Modified peripheral loading was the method used for seed placement. The parameters evaluated were as follows: prostate D90, V100, and V150; urethral D90, D10, and D5; and rectal V100 (RV100) and D2 (RD2). Coefficient parameters (r and r2) were assessed by regression analysis. Prostate V150, urethral D90, urethral D10, urethral D5, and RD2 showed significant correlations between both methods in all patients. Urethral D90, urethral D10, urethral D5, and RD2 showed significant correlations in patients who received linked seed brachytherapy. Prostate V150, urethral D90, urethral D10, urethral D5, RV100, and RD2 showed significant correlations in patients who received loose seed brachytherapy. Urethral D90, urethral D10, urethral D5, and RD2 showed significant correlations in the linked seed and loose seed brachytherapy analyses. In contrast, prostate D90 and prostate V100 showed no correlation. Parameters of normal organ damage showed good correlations between intraplan and postplan parameters. These parameters may be useful to determine normal organ damage during guided brachytherapy with two different methods (linked seeds and loose seeds).

Local seed displacement from Day 0 to Day 30 in I-125 permanent prostate brachytherapy: A detailed, computed tomography-based analysis

PURPOSETo accurately quantify local seed displacement from Day 0 to Day 30 for our brachytherapy procedure. To quantify seed loss/migration and to identify the locations from where seeds are missing. METHODS AND MATERIALSSeed displacements were analyzed in 62 consecutive patients, who received brachytherapy with stranded I-125 seeds. At the start of the procedure, four fiducial gold markers were implanted. At the end of the implantation procedure an in-room 3D CBCT scan (Day 0) was acquired for accurate seed localization. At Day 30 a regular CT scan was acquired. This CT scan was rigidly registered to the CBCT scan using the fiducials. Subsequently, the Hungarian method was used to find pairs of corresponding seeds. Displacements were calculated and missing seeds were identified. RESULTSLocal seed displacements are smaller than 5 mm for 76.3% of the seeds; 2.3% show displacements larger than 10 mm. The largest seed displacements are seen along the inferior-superior axis: on average 1.0 ± 3.2 mm in superior direction with respect to the intraprostatic fiducials. Largest displacements are seen at the inferior-lateral sides of the prostate. On average, the inferior seeds move 1.0 ± 2.8 mm in anterior and 1.8 ± 3.3 mm in superior direction. The percentage of missing seeds is 0.2% (8 out of 3893 seeds for 5 patients). Most of the missing seeds were also originally implanted at the inferior-lateral sides of the prostate. CONCLUSIONSLocal seed displacements and number of missing seeds are small, and predominantly occur around the apex.

Long Term Results from a Prospective Randomized Trial of 131Cs vs 125I Permanent Prostate Brachytherapy

Prostate cancer represents the leading cause of cancer in men, with an estimated incidence of 180,890 cases in 2016. Long-term outcomes reveal equivalent biochemical outcomes with brachytherapy (BT) compared to radical prostatectomy and external beam radiotherapy (EBRT). Iodine-125 (125I) represents the most commonly used isotope for prostate BT. Cesium-131 (131Cs) was introduced as an alternative isotope in 2004. Its higher dose rate and shorter dose delivery time has demonstrated a shorter duration of acute urinary morbidity. Long term data suggest excellent oncologic outcomes with use of 131Cs, yet there is a gap in knowledge about how outcomes between 131Cs and 125I compare. Our institution initiated a prospective randomized trial comparing the two isotopes and report out biochemical outcomes and comparisons.

The Effect of Dose and Quality Assurance in Early Prostate Cancer Treated with Low Dose Rate Brachytherapy as Monotherapy

AimsTo examine the relationship between post-implant computed tomography dosimetry and long-term prostate-specific antigen relapse-free survival in patients treated with iodine 125 (I-125) low dose rate prostate brachytherapy as monotherapy and, second, to audit recent practice against Royal College of Radiologists' (RCR) guidelines after the re-introduction of post-implant dosimetry for all patients in our centre. Materials and methodsBetween March 1995 and September 2007, 2157 consecutive patients with localised prostate cancer underwent I-125 permanent prostate brachytherapy as monotherapy in a single UK centre. All patients were transrectal ultrasound planned delivering a 145 Gy (TG 43) minimum peripheral dose. None received supplemental external beam radiotherapy. Post-implant computed tomography-based dosimetry was undertaken between 4 and 6 weeks after treatment and was available for 711 (33%). Outcomes were analysed in terms of the relationship of D90 to prostate-specific antigen relapse-free survival (nadir 2+ definition) and all patients had a minimum follow-up of 5 years. For contemporary patients from 2011, quality metrics from post-implant computed tomography as defined by RCR guidelines are presented. ResultsA mean D90 of 138.7 Gy (standard deviation 24.7) was achieved for the historic cohort. Biochemical control at 10 years was 76% in patients with D90 > 140 Gy and 68% in those with D90 < 140 Gy (P < 0.01). In current practice, over the last 3 years the mean (standard deviation) D90 has increased from 154 (15.3) Gy in 2011 to 164 (13.5) Gy in 2013. Similarly, an increase in the mean (standard deviation) V100 from 92 (4.4) to 95 (3.2) % is noted over time. No difference between clinicians was noted. ConclusionD90 values of less than 140 Gy continue to be predictive of increased risk of recurrence of prostate cancer across risk groups with longer follow-up. Quality assurance can be used to ensure improved and consistent implant quality in a team with multiple clinicians.

Sector analysis to provide additional spatial information on the permanent prostate brachytherapy learning curve.

93 Background: To evaluate the spatial pattern of permanent prostate brachytherapy (PBT) learning curve using post-implant multi-sector dosimetric analysis. Methods: Two hundred patients treated with I-125 PBT at a single institution were assessed. A 12 sector analysis of post-implant CT was created for each case by dividing the prostate base, mid gland and apex into 4 sectors each. Dosimetric analysis was evaluated for whole prostate and individual sectors assessing: minimum dose to 90% of prostate (D90) and dose to 0.1 cm3 of the rectum (D0.1cc). Linear regression analysis and Pearson’s correlation co-efficient were used to investigate changes in D90with case number. Results: Global prostate analysis demonstrated a post-implant learning curve with significant improvement in D90 (p&lt;0.01) in the last 50 cases (157.0 Gy ± 9.7) when compared to the initial 50 (141.6 Gy ± 14.5). Linear regression confirmed a significant improvement in global D90 with case number (r2=0.19, p=0.0001) at a rate of 0.11 Gy/case. Sector analysis demonstrated greatest improvement in base sectors with increasing case number with an improvement of 0.16 Gy/case (Table; p=0.049 when compared to global D90). Further, D90 in posterior mid-gland reduced with case number and correlated with reduced rectal D0.1cc. Conclusions: Sector analysis demonstrated increased spatial information on the PBT learning curve which may enable on-going improvements in implant quality. [Table: see text]

Aging Effect and Long-Term Erectile Function following I-125 Permanent Prostate Brachytherapy

To evaluate long-term post-treatment erectile function in men treated with iodine-125 permanent prostate brachytherapy and to determine factors predictive for erectile dysfunction (ED) including natural aging effect.

A sector-based postimplant dosimetric comparison of sagittal and axial ultrasound-guided source placement during I-125 permanent prostate brachytherapy.

262 Background: To use sector based pre- and postimplant dosimetric analysis to evaluate the effect of changes in implant technique in a developing I-125 permanent prostate brachytherapy program (PPB). Methods: 109 men treated with PPB were divided into two groups by implant technique. The first 50 patients (group 1) had needle-by-needle seed deposition under axial ultrasound (USS) guidance and subsequent 59 patients (group 2) having needle placement row-by-row then seed deposition under sagittal USS guidance. Twelve sector dose volume analysis of pre-implant ultrasound (USpre) and postimplant CT (CTpost) study was performed in all cases. Individual sectors were created by dividing the cranio-caudal prostate into three equal lengths creating prostate base, midgland and apex. Each of these volumes was then divided into four axial sectors (right and left anterior, right and left posterior). The difference in the minimum dose delivered to 90% of prostate volume (D90) and the prostate volume receiving 100%, 150%, and 200% of the prescribed dose (V100, V150, and V200) was compared between both groups. Results: In both groups, the volume of prostate in sectors one through six (entire base and anterior midgland) were significantly larger on CTpost when compared to equivalent sectors in USpre (p &lt; 0.001), conversely the volumes in sectors 11 and 12 (posterior apex) were significantly smaller (p =0.001). When comparing dosimetric parameters of all equivalent sectors in CTpost of both groups, it was found that D90 of sector seven and eight (posterior midgland) in Group 1 received increased dose leading to elevated dose to the rectum but was significantly reduced in Group 2 (p &lt; 0.01), which resulted in achieving the dose as planned in USpre. Prostate implant dosimetry was significantly improved in group 2 with a trend to increased equivalent dose between CTpost and USpre to each sectors and significant decrease in V150 and V200 in majority of the sectors. Conclusions: The row-by-row technique under sagittal USS guidance significantly improved our post implant dosimetric parameters when compared to single needle source placement under axial USS guidance as assessed by 12 sector analysis.

Comparison between preoperative and real-time intraoperative planning 125I permanent prostate brachytherapy: long-term clinical biochemical outcome

BackgroundThe purpose of the study is to evaluate the long-term clinical outcome through biochemical no evidence of disease (bNED) rates among men with low to intermediate risk prostate cancer treated with two different brachytherapy implant techniques: preoperative planning (PP) and real-time planning (IoP).MethodsFrom June 1998 to July 2011, 1176 men with median age of 67 years and median follow-up of 47 months underwent transperineal ultrasound-guided prostate 125I-brachytherapy using either PP (132) or IoP (1044) for clinical T1c-T2b prostate adenocarcinoma Gleason <8 and prostate-specific antigen (PSA) <20 ng/ml. Men with Gleason 7 received combination of brachytherapy, external beam radiation and 6-month androgen deprivation therapy (ADT). Biological effective dose (BED) was calculated using computerized tomography (CT)-based dosimetry 1-month postimplant. Failure was determined according to the Phoenix definition.ResultsThe 5- and 7-year actuarial bNED rate was 95% and 90% respectively. The 7-year actuarial bNED was 67% for the PP group and 95% for the IoP group (P < 0.001). Multivariate Cox regression analyses identified implant technique or BED, ADT and PSA as independent prognostic factors for biochemical failure.ConclusionsFollowing our previous published results addressing the limited and disappointing outcomes of PP method when compared to IoP based on CT dosimetry and PSA kinetics, we now confirm the long-term clinical, bNED rates clear cut superiority of IoP implant methodology.

Conventional Versus Automated Implantation of Loose Seeds in Prostate Brachytherapy: Analysis of Dosimetric and Clinical Results

To review the clinical outcome of I-125 permanent prostate brachytherapy (PPB) for low-risk and intermediate-risk prostate cancer and to compare 2 techniques of loose-seed implantation. 574 consecutive patients underwent I-125 PPB for low-risk and intermediate-risk prostate cancer between 2000 and 2008. Two successive techniques were used: conventional implantation from 2000 to 2004 and automated implantation (Nucletron, FIRST system) from 2004 to 2008. Dosimetric and biochemical recurrence-free (bNED) survival results were reported and compared for the 2 techniques. Univariate and multivariate analysis researched independent predictors for bNED survival. 419 (73%) and 155 (27%) patients with low-risk and intermediate-risk disease, respectively, were treated (median follow-up time, 69.3 months). The 60-month bNED survival rates were 95.2% and 85.7%, respectively, for patients with low-risk and intermediate-risk disease (P=.04). In univariate analysis, patients treated with automated implantation had worse bNED survival rates than did those treated with conventional implantation (P<.0001). By day 30, patients treated with automated implantation showed lower values of dose delivered to 90% of prostate volume (D90) and volume of prostate receiving 100% of prescribed dose (V100). In multivariate analysis, implantation technique, Gleason score, and V100 on day 30 were independent predictors of recurrence-free status. Grade 3 urethritis and urinary incontinence were observed in 2.6% and 1.6% of the cohort, respectively, with no significant differences between the 2 techniques. No grade 3 proctitis was observed. Satisfactory 60-month bNED survival rates (93.1%) and acceptable toxicity (grade 3 urethritis<3%) were achieved by loose-seed implantation. Automated implantation was associated with worse dosimetric and bNED survival outcomes.

Re-implantation after insufficient primary 125-i permanent prostate brachytherapy

IntroductionWe describe five patients receiving a re-implantation (RI) after post-operative dosimetry of the primary 125-I permanent prostate brachytherapy (BT) for prostate cancer revealed an insufficient dose coverage.Materials and methodsFive out of 222 consecutive patients treated (from March, 2001 to August, 2012) with 125-I BT, received a RI after dosimetric verification by CT and MRI fusion four to eight weeks after implantation displayed an insufficient dose coverage. RIs were performed with 10 to 19 seeds, three to four months after primary intervention. Dosimetry after RI showed an improved and sufficient total dose coverage in all patients.ResultsAt last follow-up (18 to 99 months, median 57 months), none of the patients had relevant implant associated side-effects. Functional outcome was comparable to patients after one-time implantation. PSA levels post intervention showed a decreasing tendency in 4 patients. One patient had a local recurrence after 12 months.ConclusionIn our series, approximately 2% of the patients treated with permanent prostate BT required a RI due to insufficient dose coverage. None of the patients who underwent RI experienced complications. Our series, although only with 5 cases and limited follow-up, along with other published reports, demonstrates good tolerability.

PO-0971: The impact of TRUS probe type on treatment planning of I-125 permanent prostate brachytherapy

PO-0971: The impact of TRUS probe type on treatment planning of I-125 permanent prostate brachytherapy

EP-1340: Re-implantation after insufficient primary 125-I permanent prostate brachytherapy

EP-1340: Re-implantation after insufficient primary 125-I permanent prostate brachytherapy

Sector analysis of 125I permanent prostate brachytherapy provides a rapid and effective method of evaluating and comparing pre- and post-implant dosimetry

To evaluate a sector analysis program in the assessment and comparison of pre- and post-implant dosimetric parameters during the development of an (125)I permanent prostate brachytherapy service. A total of 50 consecutive men being treated with permanent prostate brachytherapy had dose-volume analysis in 12 sectors of their pre-implant ultrasound (USpre) and post-implant CT (CTpost) studies. Individual sectors were created by dividing prostate into three equal lengths, namely base, midgland, and apex. Each of these volumes was then divided into four axial sectors. Dosimetric parameters were compared in adjoining sectors within each study and between studies. There were statistically significant differences between individual sectors on USpre and CTpost volumes with CTpost higher than USpre (p=0.001). Statistically significant differences were found in corresponding sectors on USpre and CTpost for all dosimetric parameters. The dosimetric parameters were significantly lower on CTpost in the anterior base and midgland (p=0.001) and significantly higher at the posterior apex and midgland (p=0.05). Dose homogeneity was demonstrated in adjoining sectors in all USpre and most adjoining sectors on CTpost. Sector analysis allows rapid assessment of USpre and CTpost dosimetry. It offers a scientific method of identifying areas of increased and reduced dosing on CTpost when compared with USpre, providing a learning tool to refine dosimetric analysis and highlight sectors where implant quality could be improved.

Impact of pre‐implant lower urinary tract symptoms on postoperative urinary morbidity after permanent prostate brachytherapy

To assess the impact of baseline lower urinary tract symptoms on postoperative urinary morbidity in patients being treated for prostate cancer with 125-I permanent prostate brachytherapy. A total of 104 prostate cancer patients were enrolled in this study. Their urinary morbidity was followed up using the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for 12 months or more after permanent prostate brachytherapy. Patients were classified into two groups based on their baseline International Prostate Symptom Score: the low International Prostate Symptom Score group (score ≤ 7) and the high International Prostate Symptom Score group (score ≥ 8). Urinary morbidity was estimated in each group based on the results of the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite measured before permanent prostate brachytherapy, and at 1, 3, 6, 9 and 12 months after the end of all radiation therapy. The overall mean total International Prostate Symptom Score, International Prostate Symptom Score quality of life score, and urinary-related scores for Expanded Prostate Cancer Index Composite were significantly worse at 1 month after the end of treatment, but they improved gradually after the treatment and recovered to the baseline level within 12 months. Even in the high-International Prostate Symptom Score group, the International Prostate Symptom Score and International Prostate Symptom Score Quality of Life score were significantly worse at 1-3 months after permanent prostate brachytherapy, and then recovered to the baseline level without prolongation. Although the urination-related Expanded Prostate Cancer Index Composite score in the high-International Prostate Symptom Score group was significantly worse at 1 month after permanent prostate brachytherapy in comparison with that in the low-International Prostate Symptom Score group, it recovered to the baseline level without prolongation. The present findings suggest that the presence of lower urinary tract symptoms before implantation does not prolong urinary morbidity after permanent prostate brachytherapy.

Use of sector analysis of I-125 permanent prostate brachytherapy to evaluate and compare pre- and postimplant dosimetry.

242 Background: To evaluate 12 sector analysis in the assessment and comparison of pre- and post- implant dosimetric parameters during the development of an I-125 prostate brachytherapy (PPB) service. Methods: 50 consecutive men being treated with PPB had dose volume analysis in 12 sectors of their pre implant ultrasound (PIUS) and post implant CT (PICT) data using a Variseed 8.0 treatment planning system. PIUS dosimetry was performed 2 weeks prior to implantation and PICT dosimetry 4 weeks post implant. Individual sectors were created by dividing the cranio-caudal prostate length into 3 equal lengths creating prostate base (PB), midgland (PM) and apex (PA). Each of these volumes was then divided into four axial sectors (right and left anterior, right and left posterior). The planning target volume (PTV), dose to 90% of prostate (D90), prostate volume enclosed by 100% (V100), 150% (V150) and 200% (V200) dose were recorded in each sector on PIUS and PICT. Adjacent sectors on PIUS were assessed for dose-volume homogeneity as were adjacent sectors on PICT. Differences in individual sectors on PIUS and PICT were evaluated. Results: Adjacent sector analysis demonstrated dose homogeneity in all sectors of PIUS and the majority of sectors on PICT. Statistically significant differences between PIUS and PICT were noted in target volume, particularly in PB with PICT &gt;PIUS. When individual sectors on PIUS and PICT were compared, statistically significant differences were noted in the majority of dosimetric parameters. The anterior PB and PM were significantly lower on PICT (p value &lt; 0.001) and significantly higher at the posterior PM and PA (p value &lt; 0.05). These changes were consistent across all analysed parameters. In particular, significant absolute differences in D90 in equivalent sectors on PIUS and PICT were seen. Conclusions: 12 sector analysis allows rapid assessment of PIUS and PICT dose and volume homogeneity. It offers a scientific method of identifying areas of relative over and under dosing on PICT when compared with PIUS providing both clinicians and physicists with a learning tool to refine dosimetric analysis and highlight sectors where implant quality could be improved.

Erectile Function Following 125I Permanent Prostate Brachytherapy: 5- and 8-Year Results in 1411 Men

Erectile Function Following 125I Permanent Prostate Brachytherapy: 5- and 8-Year Results in 1411 Men

Practical Nomograms Based on Dose-volume Histogram Parameters to Predict Total Seed Activity for I-125 Permanent Prostate Brachytherapy

Although there are several nomograms to predict the total seed activity for I-125 permanent prostate brachytherapy (IPPB), they are based on theoretical models or clinical experiences of their advocators. However, some practitioners may be puzzled which nomogram to be used. Therefore we tried to generate nomograms based on dose-volume histogram (DVH) parameters and compared our nomograms with the reported ones.

Long-Term Biochemical and Survival Outcome of 921 Patients Treated With I-125 Permanent Prostate Brachytherapy

To assess long-term biochemical and survival outcome after permanent prostate brachytherapy (BT). Data on 921 patients, treated with permanent interstitial BT monotherapy between 1989 and 2004 for <or=T2c Nx/0 Mx/0 prostate cancer were evaluated. All patients were treated with I-125 seeds (prescription dose 144 Gy). Eighty-five patients with a gland volume >or=50cc received 6 months of antiandrogen therapy before treatment. Patients were classified into risk groups with 232 defined as low-, 369 intermediate-, and 320 high-risk disease. The median follow-up was 69 months (range, 4-186 months); mean age was 67 years. Average 5- and 10-year biochemical no evidence of disease (bNED) rates were 79% and 57%. Average 10-year bNED rates by risk group were 88% for low-risk, 61% for intermediate-risk, and 30% for high-risk disease. The average 10-year overall and disease-specific survival rates were 59% and 82%. Ten-year overall and disease-specific survival rates by risk group were, respectively, 68% and 96% for low-risk, and 64% 87% for intermediate-risk, and 49% and 69% for high-risk disease. In multivariate Cox regression analysis, both risk group and treatment era were independent predictors of bNED and survival. These data on long-term survival continue to support the use of I-125 monotherapy for prostate cancer in low-risk patients and, in particular, demonstrate its efficacy in intermediate-risk patients.

33 oral: Long Term Biochemical and Survival Outcome of 921 Patients Treated by I-125 Permanent Prostate Brachytherapy

33 oral: Long Term Biochemical and Survival Outcome of 921 Patients Treated by I-125 Permanent Prostate Brachytherapy

Dosimetric analysis of biochemical outcome following 125I permanent prostate brachytherapy

Dosimetric analysis of biochemical outcome following 125I permanent prostate brachytherapy