Monotherapy For Localized Prostate Cancer Research Articles

Unpacking overuse of androgen deprivation therapy for prostate cancer to inform de-implementation strategies

BackgroundMany men with prostate cancer will be exposed to androgen deprivation therapy (ADT). While evidence-based ADT use is common, ADT is also used in cases with no or limited evidence resulting in more harm than benefit, i.e., overuse. Since there are risks of ADT (e.g., diabetes, osteoporosis), it is important to understand the behaviors facilitating overuse to inform de-implementation strategies. For these reasons, we conducted a theory-informed survey study, including a discrete choice experiment (DCE), to better understand ADT overuse and provider preferences for mitigating overuse.MethodsOur survey used the Action, Actor, Context, Target, Time (AACTT) framework, the Theoretical Domains Framework (TDF), the Capability, Opportunity, Motivation–Behavior (COM-B) Model, and a DCE to elicit provider de-implementation strategy preferences. We surveyed the Society of Government Service Urologists listserv in December 2020. We stratified respondents based on the likelihood of stopping overuse as ADT monotherapy for localized prostate cancer (“yes”/“probably yes,” “probably no”/“no”), and characterized corresponding Likert scale responses to seven COM-B statements. We used multivariable regression to identify associations between stopping ADT overuse and COM-B responses.ResultsOur survey was completed by 84 respondents (13% response rate), with 27% indicating “probably no”/“no” to stopping ADT overuse. We found differences across respondents who said they would and would not stop ADT overuse in demographics and COM-B statements. Our model identified 2 COM-B domains (Opportunity–Social, Motivation–Reflective) significantly associated with a lower likelihood of stopping ADT overuse. Our DCE demonstrated in-person communication, multidisciplinary review, and medical record documentation may be effective in reducing ADT overuse.ConclusionsOur study used a behavioral theory-informed survey, including a DCE, to identify behaviors and context underpinning ADT overuse. Specifying behaviors supporting and gathering provider preferences in addressing ADT overuse requires a stepwise, stakeholder-engaged approach to support evidence-based cancer care. From this work, we are pursuing targeted improvement strategies.Trial registrationClinicalTrials.gov, NCT03579680

5-Year result of single-institute cohort study in single-fraction HDR monotherapy for localised prostate cancer.

362 Background: The aim if this single institute UK-based study was to look at 3-year and 5-year bRFS and toxicity profiles. Methods: It is a prospective data study with a total number of 174 patients who were treated with single-fraction HDR monotherapy between July 2014 and February 2017. Biochemical recurrence is defined using Phoenix criteria. Results: The median age was 67.5 years with the median presenting PSA of 8. Majority of patients were lower risk group with 55% for combined low and favourable intermediate risks. 81 patients had Gleason score 6(3+3) and 77 patients had GS 7(3+4). Total hormone duration was 8 months and median duration of hormone prior to HDR monotherapy was 4 months. Overall bRFS at 3 years was 96% and 5 years was 88%. 5-year bRFS as per risk stratification was 100% in low risk, 92% in favourable intermediate risk, 83% in unfavourable intermediate risk and 79% in high-risk groups. This study had better 5-year overall bRFS compared to published data in single fraction HDR monotherapy (88% vs 73.5%, p value 0.001) (Morton et al., 2020). Despite inferior 5-year overall bRFS in compared to 2-fractionated HDR monotherapy (88% vs 95%) (p value 0.001), no difference in 5-year bRFS noted in low and favourable intermediate risk groups (100% vs 100% and 92% vs 93% respectively) (Morton et al., 2020). Two-thirds (71%) of biochemically recurred patients found to have local recurrence disease. The median time of biochemical recurrence was 47 months. Higher risk groups had higher 5-year biochemical recurrence risk. Acute and late toxicity profiles were minimum with acute G2 GU toxicity (2%) and GI toxicity (1%); late G2 GU toxicity (2%) and GI toxicity (0%) with no G3, G4 GU or GI toxicities. Conclusions: This prospective study had shown better overall 5-year bRFS especially in low and favourable intermediate risk groups with minimal toxicities. Therefore, single-fraction HDR monotherapy could be considered for elderly or patients with significant co-morbidities who are more suitable for single treatment rather than 2 fractions in these risk groups. Further randomised multicentre studies in these risk groups are suggested.

Unpacking low-value castration practices using behavior specification to guide de-implementation in prostate cancer care.

e17055 Background: Many men with prostate cancer will be exposed to ADT at some point during cancer survivorship. Unfortunately, ADT overuse in low-value scenarios is not uncommon (e.g., monotherapy in localized prostate cancer, biochemically-recurrent non-metastatic disease) resulting in more harms than benefits. We conducted an innovative survey study to unpack ADT overuse to inform behavior change and de-implementation strategies. Methods: Our survey used the Theoretical Domains Framework (TDF), and the Capability, Opportunity, Motivation – Behavior (COM-B) Model. The survey was fielded to the Society of Government Service Urologists listserv in December 2020. We stratified respondents based on their likelihood of stopping ADT monotherapy in the case of a localized prostate cancer patient presenting to their office (yes/probably yes, probably no/no), and characterized Likert scale responses to 7 COM-B statements. We used multivariable logistic regression to identify associations between stopping ADT and COM-B responses across a dichotomized Likert scale of “strongly disagree/disagree/neutral” and “agree/strongly agree.”. Results: Our survey was completed by 84 respondents (13% response rate), with 27% indicating ‘probably no’/‘no’ to stopping low-value ADT monotherapy in the case of a localized prostate cancer patient presenting to their office. Our multivariable model identified 2 COM-B statements significantly associated with lower likelihood of stopping low-value ADT. Conclusions: Using an innovative, behavioral theory-informed survey, we identified that providers less likely to stop low-value ADT had greater concern about patient worry and were more interested in providing ADT recommendations consistent with peers, informing de-implementation strategy selection. Clinical trial information: MCT03579680. [Table: see text]

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

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. 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. 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. 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.

PP-0156 HDR and LDR comparison as monotherapy in localized prostate cancer: PSA kinetic and late toxicity

PP-0156 HDR and LDR comparison as monotherapy in localized prostate cancer: PSA kinetic and late toxicity

PO-0239 20 Gy HDR brachytherapy as monotherapy for localized prostate cancer: Early outcomes

PO-0239 20 Gy HDR brachytherapy as monotherapy for localized prostate cancer: Early outcomes

PO41: 21 Gy Single Fraction High Dose Rate Brachytherapy for Early Stage Prostate Cancer: Early Outcomes from a Single Institution Prospective Clinical Trial

Purpose: Previous reports investigating single fraction high dose rate (HDR) brachytherapy as monotherapy for localized prostate cancer have reported favorable toxicity profiles but higher than expected local failure rates. This analysis reports outcomes of a series of patients treated with single fraction HDR brachytherapy to an escalated whole gland dose of 21 Gy.

High-dose-rate fractionated brachytherapy monotherapy for localized prostate cancer: a systematic review and meta-analysis.

PurposeHigh-dose-rate (HDR) brachytherapy as primary therapy (monotherapy) is a standard National Comprehensive Cancer Network (NCCN) endorsed treatment option for patients with localized prostate cancer. Thus far, most data are limited to single-institution experiences. Accordingly, we sought to systematically review rates of biochemical recurrence-free survival (bRFS) and toxicity associated with fractionated HDR monotherapy.Material and methodsA systematic review was performed using PubMed and Embase databases for relevant articles published between January 1999 and December 2019, according to preferred reporting items for systematic review and meta-analyses (PRISMA) guidelines. Included studies were limited to fractionated HDR monotherapy publications in full manuscript form with at least 5-year median follow-up, at least 80 patients included, and adequate reporting of bRFS and toxicity data. Meta-analyses were performed with random-effect modeling. Extent of heterogeneity between studies was determined using I2 and Cochran’s Q tests.ResultsSeven unique studies were identified, including 2,123 patients. NCCN low-, intermediate-, and high-risk patients comprised 40%, 40%, and 20% of patients, respectively. Median follow-up at the study group level was 74 months (range, 60-131 months). The 5-year bRFS rate was 95% (95% confidence interval [CI]: 93-96%), and after adjusting to control for publication bias, it was 96% (95% CI: 94-99%). Estimated adjusted late grade ≥ 3 genitourinary and gastrointestinal toxicity rates were 2% (95% CI: 1-4%) and 0.3% (95% CI: 0-1.1%), respectively.ConclusionsFractionated HDR monotherapy is associated with high rates of disease control and low rates of toxicity. Future studies are needed to better define the value of this treatment modality relative to other options.

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

BackgroundHDR 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 methodsSeven 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. ResultsA 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. ConclusionThis 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.

Ten-year longitudinal health-related quality of life following iodine-125 brachytherapy monotherapy for localized prostate cancer.

PurposeThis prospective longitudinal study quantifies health-related quality of life (HRQoL) up to 10 years following permanent iodine-125 (125I) prostate brachytherapy alone for localized prostate cancer.Material and methodsIn total, 120 patients completed a validated expanded prostate cancer index composite (EPIC) questionnaire pre-treatment and at 8 time points after treatment (6 weeks, 6, 10, 18 months, and 2, 3, 5, 10 years). At each time point, clinically relevant small, moderate, and severe declines in HRQoL were defined as 0.2-0.5 SD, 0.5-0.8 SD, and > 0.8 SD of baseline function for each of urinary, bowel, and sexual domains, respectively.ResultsResponse rates in the first two years were > 90%, but thereafter dropped to 75% and 48% at 5 and 10 years, respectively. 50 patients (41.6%) responded at all stages. Maximal deterioration in mean urinary and sexual summary scores was noted 6 weeks after implant, with severe urinary symptoms and moderate bowel/sexual symptoms. At 6 months, urinary and bowel quality of life (QoL) had improved to mild impairment, which then fully resolved at 10 months. Sexual QoL remained mildly impaired throughout the 10 years of follow-up. At 10 years, new mild impairment of urinary and bowel QoL was found.ConclusionsClinically mild changes in urinary, bowel, and sexual QoL are found 10 years after 125I monotherapy. The impairment in sexual function persists from treatment, but urinary and bowel symptoms are new at 10 years.

High-dose-rate brachytherapy as monotherapy for localized prostate cancer using three different doses - 14 years of single-centre experience.

PurposeTo evaluate clinical outcomes in patients with localized prostate cancer (LPC) treated with 3D conformal high-dose-rate (HDR) brachytherapy (BT) as monotherapy.Material and methodsFrom March 2004 to November 2017, 277 men with LPC underwent 3D conformal HDR-BT as monotherapy, with a temporary implant. The dose prescription was: 38 Gy in 4 fractions (149 patients), 27 Gy in 2 fractions (41 patients), and 19-20 Gy in a single fraction (87 patients). Biochemical progression-free survival (bPFS), progression-free survival (PFS), and cancer-specific survival (CSS) were calculated. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicity assessment were performed using Common Terminology Criteria for Adverse Events v5.0.ResultsThe mean age was 67 (range, 47-81) years. Overall, 145 patients were low-risk, 116 intermediate-risk, and 16 high-risk prostate cancer. After a median follow-up of six years (range, 6-160 months), bPFS, PFS, and CSS were 81%, 96%, and 97%, respectively. Dose prescription, initial prostate specific antigen (iPSA) ≥ 9,5 ng/ml, and high-risk disease resulted in prognostic factors regarding bPFS. Only G2-G3 acute or late GI and GU toxicities were observed.ConclusionsHDR-BT as monotherapy is a valid and safe treatment modality for localized prostate cancer. After a long follow-up, patients receiving 19-20 Gy in a single fraction had a lower biochemical control rate compared to patients receiving 38 Gy in 4 fractions or 27 Gy in 2 fractions. Randomized prospective trials with a longer follow-up are necessary to confirm our results, and define total doses and dose per fraction for HDR-BT in patients with LPC.

A pilot study on dosimetric and radiomics analysis of urethral strictures following HDR brachytherapy as monotherapy for localized prostate cancer.

A cohort of high dose-rate (HDR) monotherapy patients was analyzed to (i) establish the frequency of non-malignant urethral stricture; (ii) explore the relation between stricture formation with the dose distribution along the length of the urethra, and MRI radiomics features of the prostate gland. A retrospective review of treatment records of patients who received 19 Gy single fraction of HDR brachytherapy (BT) was carried out. A matched pair analysis used one control for each stricture case matched with pre-treatment International Prostate Symptom Score (IPSS) score, number of needles used and clinical target volume volume for each stricture case identified.For all data sets, pre-treatment T2 weighted MRI images were used to define regions of interests along the urethra and within the whole prostate gland. MRI textural radiomics features-energy, contrast and homogeneity were selected. Wilcoxon signed-rank test was performed to investigate significant differences in dosimetric parameters and MRI radiomics feature values between cases and controls. From Nov 2010 to July 2017, there were 178 patients treated with HDR BT delivering 19 Gy in a single dose. With a median follow-up of 28.2 months, a total of 5/178 (3%) strictures were identified.10 patients were included in the matched pair analysis. The urethral dosimetric parameters investigated were not statistically different between cases and controls (p > 0.05). With regards to MRI radiomics feature analysis, significant differences were found in contrast and homogeneity between cases and controls (p < 0.05). However, this did not apply to the energy feature (p = 0.28). In this matched pair analysis, no association between post-treatment stricture and urethral dosimetry was identified. Our study generated a preliminary clinical hypothesis suggesting that the MRI radiomics features of homogeneity and contrast of the prostate gland can potentially identify patients who develop strictures after HDR BT. Although the sample size is small, this warrants further validation in a larger patient cohort. Urethral stricture has been reported as a specific late effect with prostate HDR brachytherapy. Our study reported a relatively low stricture rate of 3% and no association between post-treatment stricture and urethral dosimetry was identified. MRI radiomics features can potentially identify patients who are more prone to develop strictures.

Influence of transitioning of planning techniques in high-dose-rate brachytherapy monotherapy for clinically localized prostate cancer from two- to three-dimensional planning

PurposeThe purpose of this study was to examine the influence of transitioning treatment planning techniques in high-dose-rate interstitial brachytherapy monotherapy for localized prostate cancer. Methods and MaterialsWe compared 113 patients treated with initial two-dimensional treatment planning (2D: 74% received 54 Gy/nine fractions) to 240 patients treated with three-dimensional planning (3D: 70 CT image-guided 3D [CT-3D]: 84% 45.5 Gy/seven fractions and 170 MRI image-guided [MRI-3D]: 87% received 49 Gy/nine fractions). ResultsThe actuarial 5-year biochemical failure-free survival rates for 2D and 3D planning were 88.4% and 95.1% (p = 0.0285 between 2D and 3D) (89.4% in CT-3D and 97.5% in MRI-3D), respectively; the rates for 2D and 3D planning were not available and 100% in the low-risk group (100% and 100%), 97.7% and 94.5% (p = 0.7626) (85.1% and 100%) in the intermediate-risk group, and 82.5% and 94.4% (p = 0.0507) (93.8% and 94.7%) for the high-risk group. Late gastrointestinal (GI) toxicity Grade 1, Grade 2, and Grade 3 was found in 13%, 4%, and 1% in 2D, whereas 8%, 2%, and 0% in 3D group (p = 0.0699), respectively. 3D decreased GI toxicity Grade 2 ≤ than 2D (19% and 10%, p = 0.0169). Late genitourinary toxicity Grade 1, Grade 2, and Grade 3 was 21%, 12%, and 3% for 2D and 32%, 18%, and 3% for 3D, respectively (p = 0.0217). ConclusionsThe 3D technique has the potential to reduce GI toxicity and improve biochemical control rate compared to 2D planning, whereas 3D resulted in increased mild genitourinary toxicity.

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

PurposeThe 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 MaterialsDuring 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. ResultsAll 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. ConclusionsThe 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.

PO-1053 Efficacy/toxicity after high dose rate brachytherapy as monotherapy for localized prostate cancer

PO-1053 Efficacy/toxicity after high dose rate brachytherapy as monotherapy for localized prostate cancer

OC-0633 Single dose high dose-rate (HDR) brachytherapy as monotherapy for localised prostate cancer

OC-0633 Single dose high dose-rate (HDR) brachytherapy as monotherapy for localised prostate cancer

HIGH-DOSE-RATE AND LOW-DOSE-RATE BRACHYTHERAPY AS MONOTHERAPY FOR CLINICALLY LOCALIZED PROSTATE CANCER

PURPOSE:To compare the outcome of high-dose-rate interstitial brachytherapy (HDR-BT) and low-dose-ratebrachytherapy (LDR-BT) as monotherapy for localized prostate cancer of low and intermediate risks progression. METHODS AND MATERIALS: The study included 165 patients with localized prostate cancer in low and intermediate progression risk groups. We compared 65 patients treated with HDR-BT and 100 patients with LDR-BT as monotherapy. LDR-BT treated advanced disease with more hormonal therapy than HDR-BT. All patients were in low and intermediate risk groups for prostate cancer progression. HDR-BT as monotherapy was delivered in 2 fractions of 15 Gy, two weeks apart. LDR-BT was performed in a standard mode of 145 Gy. The median observation was 32 months. All patients gave written informed consent. RESULTS: Overall biochemical free survival rate (BFSR) is 95,8%. There are 7 people having a growing prostatic specific antigen (PSA) while the case follow-up (in the group HDR-BT - 2 patients, LDR - 5 patients). Two recurrence cases with metastases in lymph nodes and bones were brought out as a result of 68Ga-PSMA PET examination in the group of HDR-BT. In 4 cases out of 5 LDR-BT, a local recurrence was detected (p=0,085). All cases of relapse were found in patients at intermediate risk (p = 0,041). LDR-BT showed a higher incidence of genitourinary (GU) toxicity grade &gt;2 than that of HDR-BT in the acute phase and grade 1 toxicity in late phase. Accumulated incidence of late grade &gt;2 GU and GU toxicity was equivalent between HDR-BT and LDR-BT. CONCLUSION: HDR-BT monotherapy showed an equivalent outcome to that of LDR-BT for low and intermediate risk patients. LDR-BT showed equivalent incidence of grade &gt;2 late GU toxicities and higher grade &gt;2 acute GU toxicity as that of HDR-BT as a monotherapy.

Comparison of three moderate fractionated schedules employed in high-dose-rate brachytherapy monotherapy for clinically localized prostate cancer

BackgroundHerein, we report the outcomes of 3 schedules of high-dose-rate interstitial brachytherapy (HDR-BT) monotherapy for localized prostate cancer. Patients and methodsA total of 347 patients were treated with 45.5 Gy/7 fractions (n = 86; 45.5 Gy arm, median follow-up time 131 months), 49 Gy/7 fractions (n = 149; 49 Gy arm, 75.9 months), and 54 Gy/9 fractions (n = 112; 54 Gy arm, 68 months). ResultsThe actuarial 5-year biochemical failure-free survival rates were 86.8%, 94.1%, and 88.5% (p = 0.2023) for the 45.5 Gy, 49 Gy, and 54 Gy arms in the high-risk group; 90.4%, 100%, and 97.4% (p = 0.0818) in the intermediate-risk group; and not available, 100%, and 100% in the low-risk group, respectively. The 5-year distant metastasis-free (and overall) survival rates were 94.4%, 98.2%, and 96.3% (100%, 92.8%, and 99.1%) for the 45.5 Gy, 49 Gy, and 54 Gy arms (p = 0.5454 and p = 0.0028), respectively. At 5 years, accumulated incidence of grade ≥2 gastrointestinal toxicity was 1.2%, 2.7%, and 3.4% for the 45.5 Gy, 49 Gy, and 54 Gy arms (p = 0.5605), respectively. For genitourinary toxicity, the 49 Gy arm showed a higher grade ≥2 toxicity of 20.5% than those observed in the 45.5 Gy (2.4%) and 54 Gy arms (10.1%). No grade 4 or 5 of either type of toxicity was detected. ConclusionsThe 3 schedules showed equivocal outcomes in each risk group, with different toxicity profiles. HDR-BT monotherapy with these schedules is an acceptable treatment option for localized prostate cancer.

Proton Beam Therapy Alone for Intermediate- or High-Risk Prostate Cancer: An Institutional Prospective Cohort Study.

The role of proton beam therapy (PBT) as monotherapy for localized prostate cancer (PCa) remains unclear. The purpose of this study was to evaluate the efficacy and adverse events of PBT alone for these patients. Between January 2011 and July 2014, 218 patients with intermediate- and high-risk PCa who declined androgen deprivation therapy (ADT) were enrolled to the study and were treated with PBT following one of the following protocols: 74 Gray (GyE) with 37 fractions (fr) (74 GyE/37 fr), 78 GyE/39 fr, and 70 GyE/28 fr. The 5-year progression-free survival rate in the intermediate- and high-risk groups was 97% and 83%, respectively (p = 0.002). The rate of grade 2 or higher late gastrointestinal toxicity was 3.9%, and a significant increased incidence was noted in those who received the 78 GyE/39 fr protocol (p < 0.05). Grade 2 or higher acute and late genitourinary toxicities were observed in 23.5% and 3.4% of patients, respectively. Our results indicated that PBT monotherapy can be a beneficial treatment for localized PCa. Furthermore, it can preserve the quality of life of these patients. We believe that this study provides crucial hypotheses for further study and for establishing new treatment strategies.

EP-2267: Adverse events after HDR brachytherapy as monotherapy in localized prostate cancer

EP-2267: Adverse events after HDR brachytherapy as monotherapy in localized prostate cancer