Permanent prostate brachytherapy monotherapy with I-125 for low- and intermediate-risk prostate cancer: Outcomes in 974 patients

A new technique for trans-perirectal iodine-125 seed implantation in prostatic cancer guided by CT and 3D printed template: Two case reports

Low-dose-rate prostate brachytherapy with permanent iodine-125 is an important curative treatment for low-risk prostate cancer, and it has been demonstrated that brachytherapy with permanent seeds is an effective treatment. However, differences in prostate volume, spatial location, and gland deformation between images obtained in the pre-planning phase and those obtained during the implantation procedure affect accurate delivery of the pre-planned dose. Furthermore, the complicated procedure could be a burden to elderly patients, for example, the risks associated with general anesthesia. In addition, ultrasound images are not as clear as computed tomography (CT) images with regard to identifying the location of seeds. Therefore, a new method for guidance during the procedure is urgently needed. Here, we have described a new method for precise trans-perirectal insertion of radioactive iodine-125 seeds in patients with prostate cancer under the guidance of CT and a 3D-printed template. These are some of the advantages of this technique over the standard procedure for seed implantation in the prostate: It requires only local anesthesia, the pre-planning phase can be completed before the procedure, and the operation time is considerably shorter. This report describes trans-pararectal iodine-125 seed brachytherapy for prostate cancer under local anesthesia and the guidance of a 3D printed template in two elderly patients. The dose parameters determined in the preoperative planning phase were verified postoperatively and found to be consistent. Further, the procedure was completely successfully with no major complications in both cases, and the patients’ prostate-specific antigen levels were normal at the most recent follow-up conducted 50 months after the procedure. Therefore, this technique seems promising for prostate cancer brachytherapy, and its application needs to be researched and extended further in the future.

Prostate-Specific Antigen Bounce after 125I Brachytherapy Using Stranded Seeds with Intraoperative Optimization for Prostate Cancer

Prostate-specific antigen (PSA) bounce is common in patients undergoing 125I brachytherapy (BT), and our study investigated its clinical features. A total of 100 patients who underwent BT were analyzed. PSA bounce and large bounce were defined as an increase of ≥0.2 and ≥2.0 ng/mL above the initial PSA nadir, respectively, with a subsequent decline without treatment. Biochemical failure was defined using the Phoenix definition (nadir +2 ng/mL), except for a large bounce. With a median follow-up of 49 months, 45% and 7% of the patients experienced bounce and large bounce, respectively. The median time to bounce was 24 months, and the median PSA value at the bounce spike was 1.62 ng/mL, a median raise of 0.44 ng/mL compared to the pre-bounce nadir. The median time to bounce recovery was 4 months. The post-bounce nadir was obtained at a median of 36 months after low-dose-rate BT. On univariate analysis, age, the PSA nadir value at 2 years, and prostate volume were significant factors for PSA bounce. The PSA nadir value at 2 years remained significant in multivariate analysis. We should carefully monitor young patients with high prostate volume having a >0.5 PSA nadir value at 2 years for PSA bounce.

Detection of failure patterns using advanced imaging in patients with biochemical recurrence following low-dose-rate brachytherapy for prostate cancer

PURPOSE/OBJECTIVE(S)

This study describes the pattern of failure in patients with biochemical (BCR) recurrence after low-dose-rate (LDR) brachytherapy as a component of definitive treatment for prostate cancer.

METHODS

Patients with BCR after LDR brachytherapy ± external beam radiation therapy (EBRT) were enrolled on prospective IRB approved advanced imaging protocols. Patients underwent 3T multiparametric MRI (mpMRI); a subset underwent prostate specific membrane antigen (PSMA)-based PET/CT. Pathologic confirmation was obtained unless contraindicated.

RESULTS

Between January 2011 and April 2021, 51 patients with BCR after brachytherapy (n = 36) or brachytherapy + EBRT (n = 15) underwent mpMRI and were included in this analysis. Of 38 patients with available dosimetry, only two had D90<90%. The prostate and seminal vesicles were a site of failure in 66.7% (n = 34) and 39.2% (n = 20), respectively. PET/CT (n = 32 patients) more often identified lesions pelvic lymph nodes (50%; n = 16) and distant metastases (18.8%; n = 6), than mpMRI. Isolated nodal disease (9.8%; n = 5) and distant metastases (n = 1) without local recurrence were uncommon. Recurrence within the prostate was located in the transition zone in 48.5%, central or midline in 45.5%, and anterior in 36.4% of patients.

CONCLUSION

In this cohort of patients with BCR after LDR brachytherapy ± EBRT, the predominant recurrence pattern was local (prostate ± seminal vesicles) with frequent occurrence in the anterior prostate and transition zone. mpMRI and PSMA PET/CT provided complementary information to localize sites of recurrence, with PSMA PET/CT often confirming mpMRI findings and identifying occult nodal or distant metastases.

Preoperative radio-guided localization of lung nodules with I-125 seeds: experience with 32 patients at a single institution

OBJECTIVES

Videothoracoscopic visualization and/or palpation of pulmonary nodules may be difficult due to their location, small size or limited solid component. The purpose of this study is to present our experience with computed tomography (CT)-guided preoperative localization of pulmonary nodules by percutaneous marking with radio-labelled iodine-125 seeds.

METHODS

A total of 34 pulmonary nodules were marked under CT with the placement of 33 radio-labelled iodine-125 seeds in 32 consecutive patients.

RESULTS

All patients underwent biportal video-assisted thoracic surgery (VATS) and in no case was conversion to thoracotomy necessary. A total of 88.2% of the lung nodules were successfully resected. In the remaining 11.8%, migration of the seed to the pleural cavity occurred, although these nodules were still resected during VATS. Of all the patients with pneumothorax after the marking procedure, only one required chest tube placement (3.1%). No major postoperative complications were observed.

CONCLUSIONS

Preoperative marking of pulmonary nodules with I-125 seeds under CT guidance is a feasible and safe technique that allows their intraoperative identification and resection.

Eligibility criteria according to EAU/ESTRO/SIOG guidelines for exclusive iodine-125 brachytherapy for intermediate-risk prostate adenocarcinoma patients: impact on relapse-free survival

Purpose

Iodine-125 (¹²⁵I) brachytherapy (BT) alone for intermediate-risk (IR) prostate adenocarcinoma (PCA) is controversial. The purpose of the study was to investigate potential predictive factors in selected IR-PCA patients treated with BT.

Material and methods

Among 547 patients treated with ¹²⁵I BT between 2003 and 2013, 149 IR-PCA cases were selected according to NCCN classification after an additional exclusion of patients with prostate specific antigen (PSA) > 15 ng/ml and ISUP group 3. A relapse was defined as a biochemical failure, using ASTRO Phoenix definition, or a relapse identified on imaging. Survival curves were estimated with Kaplan-Meier method. Potential prognostic variables including EAU/ESTRO/SIOG guidelines eligibility criteria were analyzed using univariate and Cox’s proportional hazards regression analysis.

Results

Of the 149 IR patients, 112 were classified as favorable, with 69 cases eligible to BT according to EAU/ESTRO/SIOG guidelines, and 37 patients were identified as unfavorable as per NCCN. Androgen deprivation therapy (ADT) was applied in 6 patients only. Percentage of positive biopsy cores were ≤ 33% and ≥ 50% for 119 and 11 patients, respectively. With a median follow-up of 8.5 years, 30 patients experienced a relapse. 10-year overall survival, progression-free survival (PFS), and relapse-free survival (RFS) were 84% (95% CI: 75-90%), 66% (95% CI: 56-75%), and 77% (95% CI: 67-84%), respectively. Failure to meet EAU/ESTRO/SIOG criteria was significantly associated with a lower RFS (p = 0.0267, HR = 2.37 [95% CI: 1.10-5.08%]).

Conclusions

Brachytherapy is an effective treatment for selected IR-PCA cases. Patients who were not eligible according to EAU/ESTRO/SIOG guidelines demonstrated a lower RFS.

PSA outcomes and late toxicity of single-fraction HDR brachytherapy and LDR brachytherapy as monotherapy in localized prostate cancer: A phase 2 randomized pilot study

PURPOSE

To evaluate the PSA outcomes and the late patient's reported health related quality of life (HRQOL) and toxicity after single-fraction High-Dose-Rate brachytherapy (HDRB) and Low-Dose-Rate brachytherapy (LDRB) for prostate cancer.

METHODS

Men with low and favorable intermediate-risk prostate cancer across 3 centres were randomized between monotherapy brachytherapy with either Iodine-125 LDRB or 19 Gy single-fraction HDRB. Biochemical outcomes were evaluated using the Phoenix definition, PSA nadir and absolute PSA value <0.4 ng/mL. Toxicities and HRQOL were recorded at 24 and 36 months.

RESULTS

A total of 31 patients were randomized, 15 in the LDRB arm and 16 patients in the HDRB arm. After a median follow-up of 45(36-53) months, 3 patients in the HDRB arm experienced biochemical failure (p = 0.092). Nineteen Gy single-fraction HDRB was associated with significantly higher PSA nadir compared to LDRB (1.02 ± 0.66vs 0.25 ± 0.39, p < 0.0001). Moreover, a significantly larger proportion of patients in the LDRB group had a PSA <0.4 ng/mL (13/15 vs 2/16, p < 0.0001). For late Genito-Urinary, Gastro-Intestinal, and sexual toxicities at 24 and 36 months, no significant differences were found between the 2 arms. As for HRQOL, the IPSS and EPIC-26 urinary irritative score were significantly better for patients treated with HDRB over the first 36 months post-treatment (p = 0.001 and p = 0.01, respectively), reflecting superior HRQOL.

CONCLUSION

HDRB resulted in superior HRQOL in the irritative urinary domain compared to LDRB. PSA nadir was significantly lower in the LDRB group and a higher proportion of patients in the LDRB group reached PSA <0.4 ng/mL.

Early health economic analysis of 1.5 T MRI-guided radiotherapy for localized prostate cancer: Decision analytic modelling

BACKGROUND AND PURPOSE

1.5 Tesla magnetic resonance imaging radiotherapy linear accelerator (MR-Linac) is gaining interest for treatment of localized prostate cancer. Clinical evidence is lacking and it therefore remains uncertain whether MR-Linac is cost-effective. An early health economic analysis was performed to calculate the necessary relative reduction in complications and the maximum price of MR-Linac (5 fractions) to be cost-effective compared to 5, 20 and 39 fractionation schedules of external beam radiotherapy (EBRT) and low-dose-rate (LDR) brachytherapy.

MATERIALS AND METHODS

A state transition model was developed for men with localized prostate cancer. Complication rates such as grade ≥2 urinary, grade ≥2 bowel and sexual complications, and utilities were based on systematic literature searches. Costs were estimated from a Dutch healthcare perspective. Threshold analyses were performed to identify the thresholds of complications and costs for MR-Linac to be cost-effective, while holding other outcomes such as biochemical progression and mortality constant. One-way sensitivity analyses were performed to outline uncertainty outcomes.

RESULTS

At €6460 per patient, no reductions in complications were needed to consider MR-Linac cost-effective compared to EBRT 20 and 39 fractions. Compared to EBRT 5 fractions and LDR brachytherapy, MR-Linac was found to be cost-effective when complications are relatively reduced by 54% and 66% respectively. Results are highly sensitive to the utilities of urinary, bowel and sexual complications and the probability of biochemical progression.

CONCLUSIONS

MR-Linac is found to be cost-effective compared to 20 and 39 fractions EBRT at baseline. For MR-Linac to become cost-effective over 5 fractions EBRT and LDR brachytherapy, it has to reduce complications substantially or be offered at lower costs.

Medium-term oncological and functional outcomes of hemi-gland brachytherapy using iodine-125 seeds for intermediate-risk unilateral prostate cancer

PURPOSE

To examine medium-term outcomes of hemi-gland low-dose-rate brachytherapy as a primary treatment for intermediate-risk prostate cancer.

METHODS

We recruited intermediate-risk unilateral prostate cancer patients for a prospective trial of hemi-gland brachytherapy. Twenty-four patients underwent hemi-gland iodine-125 seed implantation with a prescribed dose of 160 Gy. Serum prostate-specific antigen (PSA) was measured regularly and follow-up biopsy was scheduled after 2-3 years of treatment. When clinically needed afterward, for-cause biopsy was performed to confirm pathology. Treatment failure (TF)-free survival, which was defined as freedom from radical or systemic therapy, metastases, and cancer-specific mortality, was assessed, as was biochemical failure (BF)-free survival. Urinary and sexual functions were also evaluated.

RESULTS

Median follow-up duration was 61 months. Twenty-two patients (92%) exhibited a declining trend or decreased value of PSA for 12 months or longer after the treatment. Follow-up biopsy in the initial triennium and for-cause biopsy in the subsequent triennium were performed in 16 and four patients, respectively, and cancer was found from the treated lobe in one patient (4% of the cohort) and significant cancer was found from untreated lobes in four patients (17%) in total. Secondary treatments were performed in six patients successfully. Five-year freedom from BF, TF, and metastasis was 71%, 90%, and 100%, respectively. The International Prostate Symptom Score significantly deteriorated at 3 months and reversed itself afterward. The International Index of Erectile Function 5 had no significant decrease.

CONCLUSIONS

Hemi-gland low-dose-rate brachytherapy provides favorable medium-term oncological outcomes with genito-urinary functional preservation for men with intermediate-risk unilateral prostate cancer.

Long-term outcomes of a prospective randomized trial of 131Cs/125I permanent prostate brachytherapy

PURPOSE

Iodine-125 (¹²⁵I) is the most commonly used isotope for prostate brachytherapy (BT). Cesium-131 (¹³¹Cs) has a higher dose rate and shorter dose delivery time resulting in decreased duration of acute urinary morbidity. Long-term data suggest excellent oncologic outcomes; it is not known how outcomes compare. A prospective randomized trial comparing the two isotopes was initiated.

MATERIALS AND METHODS

Patients with low- or intermediate-risk disease were treated with a BT in a single outpatient facility. Prescription dose was 144 Gy for ¹²⁵I and 115 Gy for ¹³¹Cs. Androgen deprivation or supplemental EBRT was not allowed. The primary study objective was comparison of the mean EPIC Urinary Domain Score. Secondary objective was biochemical relapse-free survival (BRFS) comparison. Time-to-event for all outcomes of interest was measured from implant date.

RESULTS

One hundred forty men were enrolled; 81.4% were low-risk and 18.6% were intermediate-risk. The median followup was 97 months. Urinary and sexual health-related quality of life did not differ between isotopes at any recorded time point. At 2 months after implantation, bowel health-related quality of life was worse with ¹²⁵I; however, this difference was lost at subsequent time points. The 9-year BRFS was 87.2% and 84.0% for the ¹²⁵I and ¹³¹Cs group, respectively (p = 0.897). There was no statistically significant difference in BRFS based on initial T stage, PSA, or Gleason score.

CONCLUSIONS

Short- and long-term urinary, sexual, and bowel quality of life, as well as long-term biochemical control were comparable between ¹²⁵I and ¹³¹Cs. This report therefore supports the continued use of ¹³¹Cs as an effective and comparable alternative isotope.

Incidence of subsequent primary cancers and radiation-induced subsequent primary cancers after low dose-rate brachytherapy monotherapy for prostate cancer in long-term follow-up

BACKGROUND

As aging is the most significant risk factor for cancer development, long-term prostate cancer (PCa) survivors have an evident risk of developing subsequent primary cancers (SPCs). Radiotherapy itself is an additional risk factor for cancer development and the SPCs appearing beyond 5 years after radiotherapy in the original treatment field can be considered as radiation-induced subsequent primary cancers (RISPCs).

METHODS

During the years 1999-2008, 241 patients with localized PCa who underwent low dose-rate brachytherapy (LDR-BT) with I125 and were followed-up in Kuopio University Hospital, were included in this study. In this study the incidences and types of SPCs and RISPCs with a very long follow-up time after LDR-BT were evaluated.

RESULTS

During the median follow-up time of 11.4 years, a total of 34 (14.1%) patients developed a metachronous SPC. The most abundant SPCs were lung and colorectal cancers, each diagnosed in six patients (16.7% out of all SPCs). The crude incidence rate of RISPC was 1.7% (n = 4). Half of the SPC cases (50%) were diagnosed during the latter half of the follow-up time as the risk to develop an SPC continued throughout the whole follow-up time with the actuarial 10-year SPC rate of 7.0%. The crude death rates due to metachronous out-of-field SPCs and RISPCs were 50 and 50%, respectively.

CONCLUSION

The crude rate of SPC was in line with previously published data and the incidence of RISPC was very low. These results support the role of LDR-BT as a safe treatment option for patients with localized PCa.

Prostate high dose-rate brachytherapy as monotherapy for low and intermediate risk prostate cancer: Efficacy results from a randomized phase II clinical trial of one fraction of 19 Gy or two fractions of 13.5 Gy

BACKGROUND AND PURPOSE

High dose-rate (HDR) brachytherapy as monotherapy is a treatment option for localized prostate cancer, but optimal dose and fractionation is unknown. We report efficacy results of a randomized phase II trial of HDR monotherapy delivered as either one or two fractions.

MATERIALS AND METHODS

Eligible patients had low or intermediate risk prostate cancer, prostate volume <60 cc, and no androgen deprivation use. 170 patients were randomized to receive HDR as either a single fraction of 19 Gy or as two fractions of 13.5 Gy one week apart. Median age was 65 years, median PSA was 6.33 ng/ml, and Grade Group 1, 2 and 3 was present in 28%, 60%, and 12%, respectively. There was no difference in baseline factors between arms and 19%, 51% and 30% had low risk, favourable intermediate and unfavourable intermediate risk disease, respectively. The Phoenix definition was used to define biochemical failure, all local failures were confirmed by biopsy and toxicity was assessed using CTCAE v.4.

RESULTS

Median follow-up was 60 months. PSA decreased more quickly in the 2-fraction arm (p = 0.009). Median PSA at 5-years was 0.65 ng/ml in the single fraction and 0.16 ng/ml in the 2-fraction arm. The 5-year biochemical disease-free survival and cumulative incidence of local failure was 73.5% and 29% in the single fraction arm and 95% (p = 0.001) and 3% (p < 0.001) in the 2-fraction arm, respectively. Recurrence was not associated with initial stage, grade group, or risk group. Grade 2 late rectal toxicity occurred in 1% while the incidence of grade 2 and 3 urinary toxicity was 45% and 1%, respectively, with no difference between arms.

CONCLUSIONS

HDR monotherapy delivered as two fraction of 13.5 Gy is well tolerated with a high cancer control rate at 5 years. Single fraction monotherapy is inferior and should not be used.

Single dose high-dose rate (HDR) brachytherapy (BT) as monotherapy for localised prostate cancer: Early results of a UK national cohort study

BACKGROUND

HDR brachytherapy alone is effective for the treatment of localised prostate cancer when given in 2-4 or more fractions. Single dose treatment has been explored in small cohort studies to date. This paper reports a large patient population with localised prostate cancer treated with single dose HDR brachytherapy delivering 19 Gy providing early outcome data from this approach.

PATIENTS AND METHODS

Seven centres across the UK collaborated in this national protocol to deliver 19 Gy to the PTV defined by the prostate capsule and a 3 mm expansion with clearly defined planning constraints for the urethra and rectum. Entry criteria allowed all risk groups provided PSA ≤40 µg/L and staging investigations were negative for metastases. The primary end point was biochemical relapse free survival (bRFS) defined using the Phoenix definition. Toxicity was measured using CTCAE v4.0.

RESULTS

A total of 441 patients were entered with median follow up 26 months (range 2-56). Median age was 73 (range 54-84) and 10% were low risk, 65% intermediate risk and 25% high risk. ADT was received by 37.6% overall and 90% of high risk patients for a median period of 6 months. Three year bRFS was overall 88%: this was 100% in low risk, 86% in intermediate risk and 75% in high risk. Only Gleason score was an independent predictor of bRFS. Relapse in 25 patients was assessed radiologically and occurred in the prostate in 15 of these, 11 of whom had localised prostate relapse only. Acute toxicity was low with no grade 3 or 4 events; there were two cases of late urinary stricture and two grade 3 late rectal events.

CONCLUSION

This is the largest cohort of single dose HDR brachytherapy patients treated with a single dose published to date. It shows that with 19 Gy there is 100% bRFS at 3 years in low risk patients but results in intermediate and high risk groups are less encouraging falling to 86% and 75% at 3 years with relapse predominantly in the prostate. Limited by the short follow up period of this study, the long-term outcomes of this single dose HDR approach remains uncertain. It is important to have close ongoing surveillance of this cohort as the data matures.

MRI-Guided Ultrafocal Salvage High-Dose-Rate Brachytherapy for Localized Radiorecurrent Prostate Cancer: Updated Results of 50 Patients

PURPOSE

Most patients with local prostate cancer recurrence after radiation therapy undergo palliative androgen deprivation therapy because whole-gland salvage treatments have a high risk of severe toxicity. Focal treatment reduces this risk while offering a second opportunity for cure. We report updated outcomes of ultrafocal salvage high-dose-rate brachytherapy (HDR-BT).

METHODS AND MATERIALS

Prospectively collected data from the first 50 treated patients were analyzed. Disease status was assessed by 3T multiparametric magnetic resonance imaging (MRI), 18F-Choline or 68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography, and systematic or tumor-targeted biopsies. Ultrafocal salvage HDR-BT (1 × 19 Gy) was performed by implanting the clinical target volume (CTV: gross tumor volume + 5 mm margin) under fused transrectal ultrasound/MRI guidance. Follow-up included toxicity grading (using Common Terminology Criteria for Adverse Events 4.0), quality of life assessment, and prostate-specific antigen (PSA) testing.

RESULTS

Median follow-up was 31 months. Median CTV D95% was 18.8 Gy. We observed 2% grade 3 genitourinary toxicity, no grade 3 gastrointestinal toxicity, and 22% newly developed grade 3 erectile dysfunction. Five of 13 patients (38%) with self-reported pretreatment potency (International Index of Erectile Function >17) remained potent. Clinically relevant quality of life deterioration was reported for only 6 of 31 items and was not statistically significant. Biochemical failure (nadir + 2) occurred in 26 patients. Among intraprostatic recurrences, 73% were in field. After 2.5 years, biochemical disease-free survival was 51% (95% confidence interval, 37%-69%), metastases-free survival was 75% (64%-89%), androgen deprivation therapy-free survival was 90% (82%-99%), and overall survival was 98% (94%-100%). Presalvage PSA, CTV size, and stage ≥T3 were significantly associated with biochemical failure. Higher-risk patients (stage ≥T3, PSA ≥10, or PSA double time ≤9 months) had 25% biochemical disease-free survival at 2.5 years versus 71% for lower-risk patients.

CONCLUSIONS

At this early stage, MRI-guided ultrafocal HDR-BT seems to be a safe salvage treatment option, with acceptable biochemical control in a well-selected group of patients and potential for effectively postponing androgen deprivation therapy.

Treatment patterns of high-dose-rate and low-dose-rate brachytherapy as monotherapy for prostate cancer

PURPOSE

Monotherapy with high-dose-rate (HDR) or low-dose-rate (LDR) brachytherapy are both recommended modalities for prostate cancer. The choice between HDR and LDR is dependent on patient, physician, and hospital preferences. We sought to identify treatment patterns and factors associated with receipt of HDR or LDR monotherapy.

MATERIAL AND METHODS

We queried the National Cancer Database (NCDB) for patients with localized low- or intermediate-risk prostate cancer treated with HDR or LDR monotherapy. Descriptive statistics were used to analyze patterns of HDR vs. LDR. Patient characteristics were correlated with HDR vs. LDR using multivariable logistic regression.

RESULTS

We identified 50,326 patients from 2004-2014: LDR 37,863 (75.2%) vs. HDR 12,463 (24.8%). Median follow-up was 70.3 months. The overall use of monotherapy declined over time. HDR application declined relative to LDR. In 2004, 27.0% of cases were HDR compared to 19.2% in 2014. Factors associated with increased likelihood of HDR on multivariable analysis included: increasing age (OR: 1.01, 95% CI: 1.01-1.01), cT2c disease (OR: 1.25, 95% CI: 1.11-1.41), treatment at an academic center (OR: 2.45, 95% CI: 2.24-2.65), non-white race (OR: 1.34, 95% CI: 1.27-1.42), and income > $63,000 (OR: 1.73, 95% CI: 1.59-1.88). LDR was more common in 2010-2014 (OR: 0.59, 95% CI: 0.54-0.65), Charlson-Deyo comorbidity index > 0 (OR: 0.89, 95% CI: 0.84-0.95), and for patients receiving hormone therapy (OR: 0.88, 95% CI: 0.83-0.93). No difference in prostate-specific antigen (PSA) or Gleason score and receipt of HDR vs. LDR was observed. Mean overall survival was 127.0 months for HDR and 125.4 for LDR, and was not statistically different.

CONCLUSIONS

We observed an overall decrease in brachytherapy (BT) monotherapy use since 2004 for localized prostate cancer. Despite similar survival outcomes, the use of HDR monotherapy declined relative to LDR.

Long-term efficacy and urological toxicity of low-dose-rate brachytherapy (LDR-BT) as monotherapy in localized prostate cancer

PURPOSE

The purpose of this study was to evaluate the incidence of late severe (≥Grade 3) urinary toxicity and the long-term efficacy after low-dose-rate brachytherapy (LDR-BT) in patients with localized prostate cancer (PCa).

METHODS AND MATERIALS

During the years 1999-2008, 241 patients with PCa who underwent LDR-BT with I¹²⁵ and were followed up in Kuopio University Hospital were included to this analysis. The incidence of late severe (Grade 3) urinary toxicity and the long-term efficacy results were analyzed.

RESULTS

All D'Amico risk groups were represented, as 58.9%, 35.3%, and 5.8% of the patients were classified as low-, intermediate-, and high-risk patients, respectively. With a median followup of 11.4 years after implantation, the incidence of severe urinary toxicity increased throughout the followup period. The risk of Grade 3 urinary toxicity was highest among patients with higher Gleason scores (p = 0.016) and higher initial urine residual volumes (p = 0.017) and the cumulative incidence of severe urinary toxicity was 10.0%. The crude rate for transurethral prostatic resection was 5.8%. The relapse-free survival, the cause-specific survival, and the overall survival were 79.3%, 95.0%, and 66.4%, respectively.

CONCLUSIONS

The treatment was well tolerated as 90% of patients avoided any Grade 3 urinary toxicity. LDR-BT for localized PCa achieved high and durable efficacy. These results support the role of LDR-BT monotherapy as one of the valid primary treatment options for low-risk and favorable intermediate-risk patients.