Use, complications, and costs of stereotactic body radiotherapy for localized prostate cancer

Secondary Cancer in Prostate Cancer Patients Treated With Advanced External Beam Radiation Therapy

Purpose

Previous studies have shown that external beam radiation therapy is associated with an increased risk of second primary cancer (SPC) among prostate cancer (PCa) patients, but the relative risks associated with newer and advanced radiation modalities such as proton beam therapy (PBT) and stereotactic body radiation therapy (SBRT) are unclear. This study aimed to assess the relative probability of SPC among patients treated with these newer modalities compared to intensity-modulated radiation therapy (IMRT).

Patients and Methods

Using the National Cancer Database (NCDB), N0M0 PCa cases diagnosed between 2004 and 2018 were identified. Second primary cancer probabilities were compared among those treated with curative-intent PBT, SBRT, and IMRT. Multivariable logistic regression and inverse probability of treatment weighting were used to generate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

Results

In total, 133 898 patients were included, with a median age of 69 years and median follow-up of 6.4 years. As their first course of treatment, 3420 (2.6%) received PBT, 121 211 (90.5%) received IMRT, and 9267 (6.9%) received SBRT. Compared with IMRT, PBT and SBRT were associated with lower SPC risk (aORs and 95% CIs, PBT: 0.49 [0.40-0.60], SBRT: 0.57 (0.51-0.63), P < .001). Inverse probability of treatment weighting analyses corroborated these results.

Conclusion

In this large national cohort, PBT and SBRT performed similarly and were associated with reduced SPC risk compared to IMRT when used as the first course of treatment.

Stereotactic Body Radiation Adoption Impacts Prostate Cancer Treatment Patterns

OBJECTIVE

To investigate stereotactic body radiation (SBRT) adoption for prostate cancer. As evidence supporting SBRT mounts, its utilization and impact relative to other prostate cancer treatments is unknown.

METHODS

We used SEER-Medicare to identify patients diagnosed with localized prostate cancer from 2008 to 2017. We then identified physician networks by identifying the primary treating physician of each patient based on primary treatment, then linking each physician to a practice. We examined trends in prostate cancer treatment between networks performing SBRT or not using chi-squared tests and logistic regression models.

RESULTS

There were 35,972 patients who received treatment for prostate cancer at 234 physician networks. Of these patients, 30,635 were treated in a non-SBRT network (n = 190), while 5337 received treatment in a SBRT network (n = 44). Patients who received care in an SBRT network were more likely to live in metropolitan areas ≥1 million (70% vs 46%, P <.001), have a higher median income >$60,000 (62% vs 42%, P <.001), and live in the northeast (35% vs 12%) or west (40% vs 38%, P <.001) compared to non-SBRT networks. In SBRT networks, more patients received IMRT (31% vs 23%), and fewer patients received prostatectomy (16% vs 23%) or active surveillance (15% vs 19%) compared to non-SBRT networks. Black men were 45% less likely to receive SBRT (OR=0.55, CI: 0.36-0.85) compared to White men.

CONCLUSION

SBRT utilization is increasing relative to other prostate cancer treatments. Prostate cancer treatment mix is different in networks that offer SBRT, and SBRT is less available to some patient groups, raising concern for novel treatment inequity.

Risk Factors for Artificial Urinary Sphincter Explantation and Erosion in Male Nonneurological Patients

PURPOSE

This study was performed to assess the risk factors for artificial urinary sphincter (AUS) explantation in a large multicenter cohort.

METHODS

We retrospectively reviewed the medical records for all 1,233 implantations of the AMS-800 AUS device in male nonneurological patients from 2005 to 2020 across 13 French centers. Patients with neurological conditions were excluded from the study. To identify factors associated with explantation-free survival, survival analysis was performed. Explantation was defined as the complete removal of the device, whereas revision referred to the replacement of the device or its components.

RESULTS

The study included 1,107 patients, of whom 281 underwent AUS explantation. The median survival without explantation was 83 months. The leading causes of explantation were infection and erosion. Univariate analysis revealed several significant risk factors for explantation: age above 75 years (34.6% in the explanted group vs. 25.8% in the nonexplanted group, P=0.007), history of radiotherapy (43.5% vs. 31.3%, P=0.001), and anticoagulant use (15% vs. 8.6%, P<0.001). In logistic regression analysis, the only significant risk factor was previous radiotherapy (odds ratio [OR], 2.05; P<0.05). Cox proportional hazards analysis revealed 2 factors associated with earlier explantation: transcorporal cuff implantation (hazard ratio [HR], 2.67; P=0.01) and the annual caseload of the center (HR, 1.08; P=0.02). When specifically examining explantation due to erosion, radiotherapy was the sole factor significantly associated with the risk of erosion (OR, 2.47; P<0.05) as well as earlier erosion (HR, 1.90; P=0.039).

CONCLUSION

In this series, conducted in a real-world setting across multiple centers with different volumes and levels of expertise, the median survival without AUS explantation was 83 months. This study confirms that radiotherapy represents the primary independent risk factor for AUS erosion in male nonneurological patients.

Extreme hypofractionated stereotactic radiotherapy for localized prostate Cancer: Efficacy and late urinary toxicity according to transurethral resection of the prostate history

Background and purpose

Extreme hypofractionated stereotactic body radiotherapy (SBRT) is a therapeutic alternative for localized low- or intermediate-risk prostate cancer. Despite the availability of several studies, the toxicity profile of SBRT has not been comprehensively described. This real-world evidence study assessed the efficacy and toxicities associated with this regimen, and potential prognosis factors for genitourinary toxicities.

Materials and methods

This retrospective study included 141 consecutive patients with localized prostatic adenocarcinoma treated with CyberKnife™ SBRT, as primary irradiation, at the Oscar Lambret Center between 2010 and 2020. The prescribed dose was 36.25 Gy in 5 fractions. Acute and late toxicities were graded according to the CTCAE (version 5.0). Biochemical recurrence-free survival (bRFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The cumulative incidence of biochemical recurrence (cBR) was estimated using the Kalbfleisch-Prentice method.

Results

Among the included patients, 13.5 % had a history of transurethral resection of the prostate (TURP). The median follow-up was 48 months. At 5 years, bRFS, cBR, and OS were 72 % (95 %CI: 61-81), 7 % (95 %CI: 3-14), and 82 % (95 %CI: 73-89), respectively. Twenty-nine patients experienced at least one late toxicity of grade ≥ 2; genitourinary (N = 29), including 3 cases of chronic hematuria, and/or gastrointestinal (N = 1). The cumulative incidence of late urinary toxicity of grade ≥ 2 was 20.6 % at 5 years (95 %CI: 13.9-28.1). Multivariate analysis revealed that a history of TURP was significantly associated with late urinary toxicity of grade ≥ 2, after adjusting for clinical target volume (Odds Ratio = 3.06; 95%CI: 1.05-8.86; P = 0.04).

Conclusion

Extreme hypofractionated SBRT is effective for localized prostate cancer with a low risk of late toxicity. A history of TURP is associated with a higher risk of late urinary toxicity. These findings may contribute to the optimal management of patients treated with this regimen, particularly those with a history of TURP.

The Status and Challenges for Prostate Stereotactic Body Radiation Therapy Treatments in United States Proton Therapy Centers: An NRG Oncology Practice Survey

Purpose

To report the current practice pattern of the proton stereotactic body radiation therapy (SBRT) for prostate treatments.

Materials and Methods

A survey was designed to inquire about the practice of proton SBRT treatment for prostate cancer. The survey was distributed to all 30 proton therapy centers in the United States that participate in the National Clinical Trial Network in February, 2023. The survey focused on usage, patient selection criteria, prescriptions, target contours, dose constraints, treatment plan optimization and evaluation methods, patient-specific QA, and image-guided radiation therapy (IGRT) methods.

Results

We received responses from 25 centers (83% participation). Only 8 respondent proton centers (32%) reported performing SBRT of the prostate. The remaining 17 centers cited 3 primary reasons for not offering this treatment: no clinical need, lack of volumetric imaging, and/or lack of clinical evidence. Only 1 center cited the reduction in overall reimbursement as a concern for not offering prostate SBRT. Several common practices among the 8 centers offering SBRT for the prostate were noted, such as using Hydrogel spacers, fiducial markers, and magnetic resonance imaging (MRI) for target delineation. Most proton centers (87.5%) utilized pencil beam scanning (PBS) delivery and completed Imaging and Radiation Oncology Core (IROC) phantom credentialing. Treatment planning typically used parallel opposed lateral beams, and consistent parameters for setup and range uncertainties were used for plan optimization and robustness evaluation. Measurements-based patient-specific QA, beam delivery every other day, fiducial contours for IGRT, and total doses of 35 to 40 GyRBE were consistent across all centers. However, there was no consensus on the risk levels for patient selection.

Conclusion

Prostate SBRT is used in about 1/3 of proton centers in the US. There was a significant consistency in practices among proton centers treating with proton SBRT. It is possible that the adoption of proton SBRT may become more common if proton SBRT is more commonly offered in clinical trials.

SBRT vs. Y90: HCC Treatment Outcomes and Costs

OBJECTIVES

Stereotactic Body Radiotherapy (SBRT) and Yttrium-90 (Y90) are among the ablative therapies used as treatment options for localized hepatocellular carcinoma (HCC). To date, direct comparisons of the 2 modalities' outcomes and costs are lacking. This study aimed to analyze demographic, treatment, and cost information for patients with HCC treated with SBRT and Y90.

METHODS

Patients with HCC treated with SBRT or Y90 radioembolization between January 2018 and January 2020 at one institution were retrospectively reviewed. Demographic and treatment data were compared utilizing χ 2 tests. Kaplan-Meier curves and log-rank tests were applied to compare overall survival and progression-free survival in different treatment groups. Cox proportional hazard models were applied to analyze the unadjusted and adjusted survival differences. Ten SBRT and 10 Y90 patients were randomly selected for Medicare cost analysis.

RESULTS

Sixty-three patients received Y90, and 21 received SBRT. On univariable and multivariable analysis, there was no significant difference in overall survival or progression-free survival between the Y90 and SBRT cohorts. SBRT patients had higher American Joint Committee on Cancer staging ( P =0.039), greater tumor size (4.07 vs. 2.96 cm, P =0.013), and greater rates of prior liver-directed therapy (71.4% SBRT vs. 12.7% Y90, P <0.001). The average cost for SBRT was $15,148, and Y90 was $41,360.

CONCLUSIONS

SBRT and Y90 are effective therapies in the treatment of HCC, specifically having similar overall survival and progression-free survival. Y90 was found to have a significantly higher cost than SBRT. This study demonstrates the need for prospective studies to assess these modalities in treating HCC.

Stereotactic body radiation therapy for prostate cancer: a study comparing 3-year genitourinary toxicity between CyberKnife and volumetric-modulated arc therapy by propensity score analysis

BACKGROUND

To investigate whether the rate of stereotactic body radiation therapy-related (SBRT-related) genitourinary (GU) toxicity is lower in patients with prostate cancer treated with CyberKnife.

METHODS

We retrospectively reviewed the medical records of patients with nonmetastatic prostate cancer at two institutions between 2017 and 2020. We analyzed 70 patients who were extracted by propensity score matching based on age, pre-treatment International Prostate Symptom Score (IPSS), and prostate volume. The patients were treated with SBRT, with a total dose of 36.25 Gy in five fractions over five consecutive weekdays, using CyberKnife or volumetric-modulated arc therapy (VMAT).

RESULTS

The low-, medium-, and high-risk patients were 2, 19, and 14, respectively, in the CyberKnife group and 4, 17, and 14, respectively, in the VMAT group. The median follow-up time in both groups was 3 years. One patient with CyberKnife died of unrelated causes. No biochemical or clinical recurrence, distant metastases, or death from prostate cancer was observed. The peak values of IPSS in the acute phase (< 3 months) were significantly lower in the CyberKnife than in the VMAT group (CyberKnife:16.2 vs VMAT:20.2, p = 0.025). In multiple regression analyses, the treatment modality (p = 0.03), age (p = 0.01), bladder medication pre-irradiation (p = 0.03), and neoadjuvant androgen deprivation therapy (p = 0.04) contributed to the peak value of the acute-phase IPSS. The incidence of treatment-related grade 2 acute GU toxicity tended to be lower in the CyberKnife than the VMAT group (CyberKnife: 22.9% vs. VMAT: 45.7%, p = 0.077). No difference was noted between the groups with regard to late IPSS or GU toxicity and gastrointestinal toxicity in all phases. Toxicities of grade ≥ 3 have not been observed to date.

CONCLUSIONS

Regardless of treatment modality, SBRT is effective in treating prostate cancer without serious toxicity. However, CyberKnife has an advantage over VMAT in terms of acute prostate symptoms.

Equity, Diversity, and Inclusion in Radiation Oncology: A Bibliometric Analysis and Critical Review

The promotion of equity, diversity, and inclusion (EDI) is being increasingly pursued in health care, both in general and within radiation oncology. Because bibliometrics is a powerful tool to reveal the scientific literature on a specific topic during a certain timespan, a systematic bibliometric analysis of the documents published on EDI in radiation oncology was performed, aiming at exploring common patterns in research and emerging trends, tracking collaborations and networks, and anticipating future directions in clinical research. Standard descriptive statistics and bibliometric techniques were used in the analysis. A collaboration network and thematic map were generated from the data. Four domains were represented: (1) motor themes, including themes well developed and important for the structuring of the research field; (2) niche themes, representing the isolated topics that do not share important external links with other themes; (3) emerging themes, referring to still weakly developed topics; and (4) basic themes, including the essential topics. EDI in the profession of radiation oncology is essential to ensure that the workforce delivering radiation oncology care both draws from the full talent pool of human capital and delivers the highest quality science and clinical care to all patients. The burgeoning literature on EDI in radiation oncology suggests that a large and growing cohort of scholars within radiation oncology are dedicated to addressing these important challenges.

Hypofractionation and SABR: 25 years of evolution in medical physics and a glimpse of the future

As we were invited to write an article for celebrating the 50^th Anniversary of Medical Physics journal, on something historically significant, commemorative, and exciting happening in the past decades, the first idea came to our mind is the fascinating radiotherapy paradigm shift from conventional fractionation to hypofractionation and stereotactic ablative radiotherapy (SABR). It is historically and clinically significant since as we all know this RT treatment revolution not only reduces treatment duration for patients, but also improves tumor control and cancer treatment outcomes. It is also commemorative and exciting for us medical physicists since the technology development in medical physics has been the main driver for the success of this treatment regimen which requires high precision and accuracy throughout the entire treatment planning and delivery. This article provides an overview of the technological development and clinical trials evolvement in the past 25 years for hypofractionation and SABR, with an outlook to the future improvement.

Reducing PTV margins for prostate SBRT with motion compensation and gating techniques

The purpose of this study is to investigate the dosimetric accuracy of prostate SBRT when motion is considered. To account for target movement, motion compensation and gating techniques were investigated with PTV margins reduced to 2 mm. To allow for dosimetric measurements a Delta4 phantom, Gafchromic film, and Hexamotion motion platform were utilized. Four motion files were utilized that represent a range of motions. Analysis of measured prostate motions for fifteen patients was performed to ensure detected motions were similar to those previously reported and motion files utilized were suitable. Five patient plans were utilized to allow for the effects of MLC and target motion interplay to be investigated. For both motion compensation and gating techniques, plans were delivered to the stationary phantom and for each of four motion types with/without compensation/gating enabled. Using a 3%, 2 mm and 80% threshold gamma criteria, film measurements had an average pass rate of 80.5% for uncorrected deliveries versus 96.0% for motion compensated deliveries. For gated techniques average pass rates increased from 89.9% for uncorrected to 94.8% with gating enabled. Measurements with the Delta4 arrays were analyzed with a 3%, 2 mm and 10% threshold dose. An average pass rate of 83.8% was measured for uncorrected motions versus 94.8% with motion compensation. For the gated technique an average pass rate of 87.2% was found for uncorrected motions versus 96.9% with gating enabled. These results show that very high gamma pass rates are achievable when motion compensation or gating techniques are applied. When target motion is not accounted for shifts up to 5 mm in planned versus delivered isodose distributions were found. However, when motion compensation, or gated techniques were applied, much smaller differences between planned and delivered isodose distributions were found. With these techniques dose delivery accuracy is greatly improved, allowing for PTV margins to be reduced.

Four-year quality-of-life outcomes in low- to intermediate-risk prostate cancer patients following definitive stereotactic body radiotherapy versus management with active surveillance

OBJECTIVE

To review quality-of-life (QoL) metrics between patients who underwent definitive stereotactic body radiotherapy (SBRT) versus active surveillance (AS) for management of low- to intermediate-risk prostate cancer (PCa).

METHODS

A prospectively maintained PCa database was reviewed containing results of patient-reported QoL surveys. Patients with localized disease who chose AS or SBRT and completed at least one survey within four years of treatment were included. Patients who received salvage therapy were excluded. Survey results were compared across time using mixed-effects repeated measures analysis of covariance models that adjusted for factors significant in univariate analysis. A group x time interaction effect was examined to compare rate of change over time between AS and SBRT. P < 0.05 was significant.

RESULTS

148 AS and 161 SBRT patients were included. Significantly more SBRT patients had intermediate-risk disease (p < 0.0001). AS had significantly worse sexual function compared to SBRT across time. While not significant, bowel function scores were lower for SBRT patients across time points. SBRT patients had significantly lower anxiety than AS patients at 24 months (p < 0.011) and 36 months (p < 0.010). Urinary function though worse in SBRT patients at 12 months in EPIC, was not significantly different in both groups across time points.

CONCLUSION

SBRT patients have excellent QoL compared to AS with regard to anxiety post treatment. Though SBRT patients initially have worse urinary and bowel function than AS, scores were eventually similar in both cohorts by 48 months. SBRT patients have significantly worse sexual function post treatment. This study may help facilitate counseling in patients choosing PCa treatment.

Sociodemographic index and global trends in prostate cancer: 1990-2017

BACKGROUND

Considered globally, prostate cancer is a disease of the aging male that increases in prevalence with exposure to screening and diagnostic testing, and which requires a population with the health and longevity to encounter it. The Global Burden of Disease (GBD) dataset is an aggregation of worldwide registries and health data systems that reports global and regional assessment of disease impact.

METHODS

Using the GBD database, 1171 worldwide registries and health registration systems from 1990 to 2016 were aggregated for prostate cancer disease codes and outcomes. Disease-Adjusted Life Years (DALYs) were calculated and segregated by sociodemographic index (SDI) quintile, and compared to other urologic diseases and tuberculosis (TB).

RESULTS

Prostate cancer exerts a burden of disease that is vastly higher in the top quintile of SDI. The three lowest SDI quintiles represent the majority of global population but are currently less impacted by prostate cancer. Conversely, TB has its highest impact on the lowest SDI levels, although these rates are declining.

CONCLUSIONS

As a global disease, prostate cancer predominantly affects high SDI men who enjoy a longer life expectancy in which to suffer from this disease and a greater exposure to screening and diagnosis. As lower SDI men are elevated in health and income, reallocation of DALYs will occur, and a greater burden of prostate cancer can be expected. These epidemiologic trends have great implications for the allocation of resources, as the population of men affected by prostate cancer outpaces urologic workforce growth.

Trends and variations in utilization and costs of radiotherapy for prostate cancer: A SEER medicare analysis from 2007 through 2016

OBJECTIVE

To assess recent changes and disparities in utilization and costs of radiotherapy in Medicare beneficiaries with prostate cancer.

METHODS

Surveillance, Epidemiology and End Results (SEER) -Medicare linked data from 2006-2016 were used to identify continuously enrolled Medicare beneficiaries with a first-time diagnosis of prostate cancer who, within 12 months of diagnosis, underwent at least one radiotherapy related service. Trends in the utilization of different radiotherapy techniques over time, yearly changes in per-patient costs of radiotherapy, and effect of socio-demographic and clinical characteristics on total cost were measured. Per patient annual costs, annual incidence of prostate cancer, and utilization of radiotherapy were used to estimate total costs of radiotherapy to the Medicare program.

RESULTS

For Medicare beneficiaries with a first-time diagnosis of prostate cancer, the utilization of intensity modulated radiation therapy (IMRT), proton therapy, and stereotactic body radiation therapy (SBRT) increased 23.62%, 0.74% and 1.61% respectively (p <0.0001) while brachytherapy decreased 17.04% (p <0.0001). Cost per beneficiary decreased $340.24 (95% CI: $136.05 - $544.43) annually (p = 0.0065). Age, registry region, and Gleason score were all associated with expenditures. The total cost to the Medicare program was estimated at US $1.16 billion in the year 2016.

DISCUSSION

In Medicare beneficiaries with prostate cancer treated with radiotherapy, IMRT is the primary mode of treatment. Utilization of brachytherapy decreased significantly despite the efficacy and cost-effectiveness. Although per patient costs have decreased, the share of patient responsibility remained unaltered across years. The current costs to Medicare of radiotherapy for newly diagnosed prostate cancer patients is substantial.

Management of the kidney transplant patient with Cancer: Report from a Multidisciplinary Consensus Conference

INTRODUCTION

Cancer is the second most common cause of mortality and morbidity in Kidney Transplant Recipients (KTRs). Immunosuppression can influence the efficacy of cancer treatment and modification of the immunosuppressive regimen may restore anti-neoplastic immune responses improving oncologic prognosis. However, patients and transplant physicians are usually reluctant to modify immunosuppression, fearing rejection and potential graft loss. Due to the lack of extensive and recognised data supporting how to manage the immunosuppressive therapy in KTRs, in the context of immunotherapy, chemotherapy, radiotherapy and loco-regional treatments, a Consensus Conference was organised under the auspices of the European Society of Organ Transplantation and the Italian Society of Organ Transplantation. The conference involved a multidisciplinary group of transplant experts in the field across Europe.

METHODS

The overall process included a) the formulation of 12 specific questions based on the PICO methodology, b) systematic literature review and summary for experts for each question, c) a two-day conference celebration and the collection of experts' agreements. The conference was articulated in three sessions: "Immunosuppressive therapy and immunotherapy", "Systemic therapy", "Integrated Therapy", while the final experts' agreement was collected with a televoting procedure and defined according to the majority criterion.

RESULTS

Twenty-six European experts attended the conference and expressed their vote. A total of 14 statements were finally elaborated and voted. Strong agreement was found for ten statements, moderate agreement for two, moderate disagreement for one and uncertainty for the last one.

CONCLUSIONS

The consensus statements provide guidance to transplant physicians caring for kidney transplant recipients with cancer and indicate key aspects that need to be addressed by future clinical research.

Stereotactic body radiation therapy for Japanese patients with localized prostate cancer: 2-year results and predictive factors for acute genitourinary toxicities

OBJECTIVE

We aimed to report the 2-year results of stereotactic body radiation therapy for prostate cancer and identify the clinical and dosimetric factors that predict acute genitourinary toxicities.

METHODS

We retrospectively reviewed the medical records of patients with non-metastatic prostate cancer treated at Toyota Memorial Hospital between 2017 and 2020. The patients were treated with stereotactic body radiation therapy with a total dose of 36.25 Gy in five fractions on consecutive weekdays. While low-risk patients received radiotherapy alone, intermediate- to high-risk patients also received androgen deprivation therapy.

RESULTS

We analysed a total of 104 patients, including 10, 60 and 34 low-, intermediate- and high-risk patients, respectively. The median follow-up duration was 2 years. We did not observe biochemical/clinical recurrence, distant metastasis or death from prostate cancer. One patient died of another cause. Grade 2 acute genitourinary toxicity was observed in 40 (38%) patients. Age (P = 0.021), genitourinary toxicity of grade ≥1 at baseline (P = 0.023) and bladder mean dose (P = 0.047) were significantly associated with the incidence of grade 2 acute genitourinary toxicity. The cut-off value of 65 years for age and 10.3 Gy for the bladder mean dose were considered the most appropriate. Grade 2 acute gastrointestinal toxicity was observed in five (5%) patients. None of the patients experienced grade ≥3 acute or late toxicity.

CONCLUSIONS

Stereotactic body radiation therapy is feasible for Japanese patients with prostate cancer, with acceptable acute toxicity. Age, genitourinary toxicity at baseline and bladder mean dose predict grade 2 acute genitourinary toxicity.

Small Molecule, Multimodal, [18F]-PET and Fluorescence Imaging Agent Targeting Prostate-Specific Membrane Antigen: First-in-Human Study

BACKGROUND

A first-in-human study of [¹⁸F]-BF3-Cy3-ACUPA, a small-molecule contrast agent that can be unimolecularly both positron emitting and fluorescent, is conducted to determine its: its safety, biodistribution, radiation dosimetry, feasibility in tumor detection by preoperative positron emission tomography (PET), as well as its intraoperative fluorescence imaging utility in patients with prostate-specific membrane antigen positive (PSMA⁺) tumors.

METHODS

Ten patients aged 66 ± 7 years received a 6.5 ± 3.2 mCi intravenous injection of [¹⁸F]-BF3-Cy3-ACUPA and underwent PET/computed tomography (CT) imaging. Radiation dosimetry of [¹⁸F]-BF3-Cy3-ACUPA, normal organ biodistribution, and tumor uptakes were examined. Two patients were prescheduled for radical prostatectomy (RP) with extended pelvic lymphadenectomy approximately 24 hours following [¹⁸F]-BF3-Cy3-ACUPA injection and imaging. Without reinjection, intraoperative fluorescence imaging was performed on freshly excised tissue during RP. Frozen sections of excised tissue during RP were submitted for confirmatory histopathology and multiphoton fluorescence and brightfield microscopy.

RESULTS

Absorbed doses by organs including the kidneys and salivary glands were similar to 68Ga-PSMA-11 imaging. [¹⁸F]-BF3-Cy3-ACUPA physiologic radiotracer accumulation and urinary/biliary excretion closely resembled the distribution of other published PSMA tracers including [¹⁸F]-JK-PSMA-7, [¹⁸F]-PSMA-1007, [¹⁸F]-DCFPyL, and [¹⁸F]-DCFBC. ¹⁹F-BF3-Cy3-ACUPA was retained in PSMA⁺ cancer in patients for at least 24 hours, allowing for intraoperative fluorescence assessment of the prostate and of the embedded prostate cancer without contrast reinjection. After 24 hours, the majority of contrast had decayed or cleared from the blood pool. Preoperative PET and fluorescence imaging findings were confirmed with final histopathology and multiphoton microscopy.

CONCLUSION

Our first-in-human results demonstrate that [¹⁸F]-BF3-Cy3-ACUPA is both safe and useful in humans. Larger trials with this PET tracer are expected to further define its capabilities and its clinical role in the management of PSMA⁺ tumors, especially in prostate cancer.

Urinary Outcomes for Men With High Baseline International Prostate Symptom Scores Treated With Prostate SBRT

Purpose

There are limited data regarding high-dose stereotactic body radiation therapy (SBRT) for prostate cancer in patients with poor baseline urinary function. The purpose of this study was to evaluate genitourinary (GU) toxicity and changes in patient-reported symptom severity scores after prostate SBRT in men with a high pretreatment International Prostate Symptom Score (IPSS).

Methods and Materials

Seven hundred fifty-three patients treated with prostate SBRT at our institution from 2012 to 2019 were identified, of whom 72 consecutive patients with baseline IPSS ≥15 were selected for this study. GU toxicity according to Common Terminology Criteria for Adverse Events (CTCAE) v3.0 and IPSS were prospectively documented at each follow-up visit. Univariable logistic regression was used to evaluate for potential predictors of GU toxicity.

Results

Median follow-up in survivors was 26.8 months. The rates of acute grade 2 and 3 GU toxicity were 20.8% and 1.4%, respectively. The rates of late grade 2 and 3 GU toxicity were 37.5% and 5.6%, respectively. The majority of grade 2+ toxicities resolved by last follow-up, and when toxicities were regraded per CTCAE v5.0, there were no longer any grade 3 adverse events. Total IPSS and individual symptom subscores improved over time. Compared with baseline, median total IPSS at 24 ± 6 months was significantly lower (18 vs 12; P < .001) and the proportion of patients with severe scores (IPSS ≥20) decreased from 29.2% to 13.9%. Pretreatment urinary urgency was associated with late grade 2+ GU toxicity (odds ratio, 2.10; 95% confidence interval, 1.33-3.31; P = .001).

Conclusions

In men with baseline IPSS ≥15 managed with prostate SBRT, the rate of severe GU toxicity was low and patient-reported symptoms generally improved over time. Thus, high pretreatment IPSS should not deter clinicians from offering prostate SBRT.

Making radiation therapy more effective in the era of precision medicine

Cancer has become a leading cause of death and constitutes an enormous burden worldwide. Radiation is a principle treatment modality used alone or in combination with other forms of therapy, with 50%–70% of cancer patients receiving radiotherapy at some point during their illness. It has been suggested that traditional radiotherapy (daily fractions of approximately 1.8–2 Gy over several weeks) might select for radioresistant tumor cell sub-populations, which, if not sterilized, give rise to local treatment failure and distant metastases. Thus, the challenge is to develop treatment strategies and schedules to eradicate the resistant subpopulation of tumorigenic cells rather than the predominant sensitive tumor cell population. With continued technological advances including enhanced conformal treatment technology, radiation oncologists can increasingly maximize the dose to tumors while sparing adjacent normal tissues, to limit toxicity and damage to the latter. Increased dose conformality also facilitates changes in treatment schedules, such as changes in dose per treatment fraction and number of treatment fractions, to enhance the therapeutic ratio. For example, the recently developed large dose per fraction treatment schedules (hypofractionation) have shown clinical advantage over conventional treatment schedules in some tumor types. Experimental studies suggest that following large acute doses of radiation, recurrent tumors, presumably sustained by the most resistant tumor cell populations, may in fact be equally or more radiation sensitive than the primary tumor. In this review, we summarize the related advances in radiotherapy, including the increasing understanding of the molecular mechanisms of radioresistance, and the targeting of these mechanisms with potent small molecule inhibitors, which may selectively sensitize tumor cells to radiation.

Practical brachytherapy solutions to an age-old quandary

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Age should not be a limiting factor for brachytherapy in patients with localised cancer or for palliation in metastatic disease.

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In tumour streams where brachytherapy forms part of the curative management, it should not be omitted in elderly patients who are medically fit for treatment.

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Treatment decisions should factor in patient preferences, the relative merits of different therapeutic approaches and maintaining minimal impact on quality of life.

Cancer is predominantly a disease of the elderly and as population life expectancy increases, so will the incidence of malignant disease. Elderly patients often have other comorbidities and social complexities, increasing the support required to safely deliver all treatment modalities. Brachytherapy is a relatively simple technique by which radiation therapy can be delivered. It offers dosimetric advantages through a highly conformal dose distribution thereby limiting radiation exposure to normal tissues reducing toxicity. Requiring fewer hospital visits, it also offers practical and logistical advantages to the elderly population and in many cases can be performed without the need for general anaesthesia. In tumour streams where brachytherapy forms part of the curative management, it should not be omitted in elderly patients who are medically fit for treatment. In the palliative setting, brachytherapy often offers an excellent means for achieving either local tumour and/or symptom control and should be actively considered in the therapeutic armamentarium of the oncologist in this context.

Overall Survival After Treatment of Localized Prostate Cancer With Proton Beam Therapy, External-Beam Photon Therapy, or Brachytherapy

With limited high-level evidence, we carried out a comparative effectiveness study for the effect of proton beam therapy (PBT) on overall survival compared to external-beam radiotherapy (EBRT) and brachytherapy (BT) among patients with localized prostate cancer using a national database. PBT was associated with a significant overall survival benefit compared to EBRT and had a similar performance as BT.

Stereotactic Body Radiotherapy for Prostate Cancer

Prostate cancer remains the most common and second most deadly cancer diagnosed amongst U.S. men. External beam radiotherapy is a standard-of-care definitive treatment option for localized prostate cancer and historically constituted an 8–9-week treatment course comprised of 39–45 doses of 1.8–2.0 Gy each (conventional fractionation, CF). Based on the notion that prostate cancer may respond favorably to a higher dose per day, considerable research efforts have been focused on characterizing the safety and efficacy profile of shorter and shorter radiation courses. Ultrahypofractionation (UHF) involves condensing the radiation course into just 5–7 treatments of 6–8 Gy each. When utilizing modern techniques that allow the precise sculpting of a dose distribution that delivers high doses to the prostate and lower doses to surrounding normal tissues over five or fewer treatments, this treatment is called stereotactic body radiotherapy (SBRT). Two randomized trials (HYPO-RT-PC and PACE-B) have compared UHF to longer radiation courses. The former demonstrated that UHF and CF have similar long-term toxicity and efficacy, while the latter demonstrated that modern SBRT has equivalent short-term toxicity as well. A separate report from a consortium of studies data provides prospective, albeit nonrandomized, data supporting the longer-term safety and efficacy of SBRT specifically. Thus, mounting high-level evidence suggests that SBRT is an acceptable standard care of option for men with localized prostate cancer.

Whole Pelvic Radiotherapy With Stereotactic Body Radiotherapy Boost vs. Conventionally Fractionated Radiotherapy for Patients With High or Very High-Risk Prostate Cancer

Background: Whole pelvic radiotherapy (WPRT) with stereotactic body radiotherapy (SBRT) boost has been shown to be effective in patients with high-risk prostate cancer (PC). However, no study has directly compared the efficacy of WPRT with SBRT boost with that of conventionally fractionated radiotherapy (CFRT). We compared the clinical outcomes between CFRT and WPRT with SBRT boost in patients with high or very high-risk PC (National Comprehensive Cancer Network definition).

Methods: In total, 132 patients treated with CFRT and 121 patients treated with WPRT followed by SBRT boost were retrospectively analyzed. For the CFRT group, the prescribed dose range was 74–79.2 Gray (Gy) administered at 1.8–2 Gy per fraction. For WPRT with SBRT boost, the prescribed doses were 45 Gy administered in 25 fractions to the whole pelvis followed by 21 Gy boost (3 fractions of 7 Gy each) to prostate and seminal vesicles. The overall survival (OS) and biochemical failure (Phoenix definition) free survival (bFFS) were assessed by using the Kaplan–Meier method or the Cox proportional hazards regression model. The gastrointestinal (GI) and genitourinary (GU) tract toxicity were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) v3.0.

Results: The estimated 4-years overall survival in the CFRT and WPRT with SBRT boost groups was 91.6 and 97.7%, respectively (P = 0.18). The estimated 4-years biochemical failure-free survival in the CFRT and WPRT with SBRT boost groups was 89.1 and 93.9%, respectively (P = 0.41). No acute grade 3 or higher GI and GU toxicity was observed in both groups. Late grade 3 GI and GU toxicity occurred in 2.3 and 2.3% in the CFRT group, and in 1.7 and 0.8% in the WPRT with SBRT boost group, respectively. There was no significant between-group difference with respect to acute or late toxicity.

Conclusions: In patients with high or very high-risk localized PC, compared with CFRT, WPRT with SBRT boost resulted in similar biochemical-free and overall survival rate with minimal toxicity. WPRT with SBRT boost is a feasible option for patients with high or very high-risk PC.

The Cost-Effectiveness and Value Proposition of Brachytherapy

Brachytherapy is an effective treatment modality for a wide range of malignancies. However, brachytherapy utilization for both prostate and gynecologic malignancies has significantly declined over the last 20 years in favor of external beam radiation techniques. The cause of this decline is multifactorial, with logistical challenges, lower reimbursement, and inadequate training contributing to the preference of many radiation oncologists to more frequently recommend external beam radiation therapy. While the authors recognize the application of brachytherapy to a wider range of disease presentations among which include breast, skin, head and neck, and connective tissue cancers, in this review, we will review the analyses supporting brachytherapy as a cost-effective component of the management in patients with prostate, cervix, and endometrial cancer.

Costs and Complications After a Diagnosis of Prostate Cancer Treated With Time-Efficient Modalities: An Analysis of National Medicare Data

PURPOSE

Recent trends in payer and patient preferences increasingly incentivize time-efficient (≤2-week treatment time) prostate cancer treatments.

METHODS AND MATERIALS

National Medicare claims from January 1, 2011, through December 31, 2014, were analyzed to identify newly diagnosed prostate cancers. Three "radical treatment" cohorts were identified (prostatectomy, brachytherapy, and stereotactic body radiation therapy [SBRT]) and matched to an active surveillance (AS) cohort by using inverse probability treatment weighting via propensity score. Total costs at 1 year after biopsy were calculated for each cohort, and treatment-specific costs were estimated by subtracting total 1-year costs in each radical treatment group from those in the AS group.

RESULTS

Mean 1-year adjusted costs were highest among patients receiving SBRT ($26,895), lower for prostatectomy ($23,632), and lowest for brachytherapy ($19,980), whereas those for AS were $9687. Costs of radical modalities varied significantly by region, with the Mid-Atlantic and New England regions having the highest cost ranges (>$10,000) and the West South Central and Mountain regions the lowest range in costs (<$2000). Quantification of toxic effects showed that prostatectomy was associated with higher genitourinary incontinence (hazard ratio [HR] = 10.8 compared with AS) and sexual dysfunction (HR = 3.5), whereas the radiation modalities were associated with higher genitourinary irritation/bleeding (brachytherapy HR = 1.7; SBRT HR = 1.5) and gastrointestinal ulcer/stricture/fistula (brachytherapy HR = 2.7; SBRT HR = 3.0). Overall mean toxicity costs were highest among patients treated with prostatectomy ($3500) followed by brachytherapy ($1847), SBRT ($1327), and AS ($1303).

CONCLUSIONS

Time-efficient treatment techniques exhibit substantial variability in toxicity and costs. Furthermore, geographic location substantially influenced treatment costs.

A phase IB clinical trial of 15 Gy HDR brachytherapy followed by hypofractionated/SBRT in the management of intermediate-risk prostate cancer

PURPOSE

High dose-rate (HDR) brachytherapy is commonly administered as a boost to external beam radiation therapy (EBRT). Our purpose was to compare toxicity with increasingly hypofractionated EBRT in combination with a single 15 Gy HDR boost for men with intermediate-risk prostate cancer.

METHODS AND MATERIALS

Forty-two men were enrolled on this phase IB clinical trial to one of three EBRT dose cohorts: 10 fractions, seven fractions, or five fractions. Patients were followed prospectively for safety, efficacy, and health-related quality of life (Expanded Prostate Index Composite). Efficacy was assessed biochemically using the Phoenix definition.

RESULTS

With a median follow up of 36 months, the biochemical disease-free survival was 95.5%. One man developed metastatic disease at 5 years. There was no significant minimally important difference in EPIC PRO for either urinary, bowel, or sexual domains. There was one acute Grade 3 GI and GU toxicity, but no late Grade 3 GU or GI toxicities.

CONCLUSION

Fifteen gray HDR brachytherapy followed by a five fraction SBRT approach results in high disease control rates and low toxicity similar to previously reported HDR protocols with significant improvement in patient convenience and resource savings. While mature results with longer follow up are awaited, this treatment approach may be considered a safe and effective option for men with intermediate-risk disease.

Estimated Costs Associated With Radiation Therapy for Positive Surgical Margins During Radical Prostatectomy

IMPORTANCE

Prostate cancer is the most common malignant neoplasm among men and is the one with the highest positive surgical margin (PSM) rate. This high rate is due to the difficulty in balancing the risk of extraprostatic disease and excising periprostatic structures, which ultimately affects patients' quality of life. In the case of a PSM, the appropriateness of adjuvant radiation therapy (aRT) should be discussed. The financial burden of PSMs on health systems has not been investigated.

OBJECTIVE

To estimate the financial costs associated with a PSM during radical prostatectomy on the basis of the odds of undergoing aRT.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data on men with prostate cancer from the US National Cancer Database (January 1, 2010, through December 31, 2015). Data were requested in March 2019, accessed in April 2019, and analyzed in August 2019.

EXPOSURE

Treatment with radical prostatectomy followed by aRT, if indicated.

MAIN OUTCOMES AND MEASURES

The attributable risk fraction of PSMs on undergoing aRT was estimated from a logistic regression with aRT administration as the outcome. The analysis was adjusted for patients' socioeconomic and demographic characteristics and tumor characteristics. The aRT cost for the year 2019 was calculated using the Medicare Physician Fee Schedule and the Hospital Outpatient Prospective Payment System. The fraction of this cost attributable to a PSM was estimated according to its attributable risk fraction.

RESULTS

In total, 230 175 men were identified (median [interquartile range] age at diagnosis, 62.0 [56.0-67.0] years). Overall, 22.8% of the patients had a PSM. Patients with PSMs were more likely than those without PSMs to be older (median [interquartile range] age, 62.0 [56.0-66.0] years vs 62.0 [57.0-67.0] years) and nonwhite (9320 patients [17.8%] vs 29 872 patients [16.8%]), to have higher comorbidity scores (1604 patients [3.1%] vs 4884 patients [2.7%] with a Charlson-Deyo Comorbidity Index score ≥2) and worse tumor characteristics (category T3 and T4 disease, 26 394 patients [50.3%] vs 36 040 patients [20.3%]), and to have lower socioeconomic indicators (median annual income <$30 000, 5708 patients [10.9%] vs 17 874 patients [10.1%]; proportion of individuals without a high school degree in the area ≥29%, 6925 patients [13.2%] vs 22 648 patients [12.7%]). In addition, PSMs were documented more frequently at nonacademic institutions than academic ones (31 702 patients [60.5%] vs 20 714 patients [39.5%]). A total of 11 585 patients (5.0%) underwent aRT, and 7698 of them (3.3%) had a PSM at the final pathology examination. When controlling for patients' socioeconomic and demographic characteristics and tumor characteristics, men with PSMs were more likely than those with negative margins to undergo aRT, with an odds ratio of 3.79 (95% CI, 3.63-3.96; P < .001). The attributable risk fraction of the presence of a PSM on aRT was 44% (95% CI, 42%-45%). The attributable cost of a PSM was calculated as $17 356 (95% CI, $16 567-$17 751). Assuming 60 000 prostatectomies in 2019 and similar trends of PSM and aRT, the overall health burden attributable to PSMs was calculated to be $52 068 000 (95% CI, $49 701 000-$53 253 000).

CONCLUSIONS AND RELEVANCE

The estimated aRT cost attributable to the presence of a PSM was $17 356, resulting in $52 068 000 in spending on aRT in 2019. Strategies to reduce PSMs could be associated with a reduction in the overall health costs of surgically treated PCa.

Critical review of multidisciplinary non-surgical local interventional ablation techniques in primary or secondary liver malignancies

Local non-surgical interventional percutaneous ablation represents nowadays an important part of the potential treatment strategies. Although surgical ablation represents the gold standard, in the past decade there was an expansion in the use of non-surgical ablative techniques: radiofrequency, microwave, laser, cryoablation, irreversible electroporation, and interventional radiotherapy (brachytherapy) in primary as well as secondary liver cancers. With the growing experience in the field, there was implemented a new pillar for cancer treatment, together with surgery, chemotherapy as well as radiotherapy, so-called interventional oncology (IO). To date, there are no published papers regarding a comparative interdisciplinary evaluation of all these non-surgical interventional local ablation therapies. Our paper offers a critical interdisciplinary overview of the treatments in both primary and secondary liver tumors, including from a cost-effective point of view. Furthermore, the present status of education in IO and a comparison of actual economic aspects of the treatments are also provided.

Treatment Options in Oncology

Multiple treatment strategies exist for many oncologic problems. In this review, we provide a summary of various reasons for the existence of multiple treatment options in oncology, including factors that concern the treating physician (eg, treatment preferences), environmental factors (eg, financial, regulatory, and scientific aspects), and individual patient-specific factors (eg, medical condition, preferences). We demonstrate the vital role of available treatment options and their origins for clinical decision making and patient communication. These aspects are particularly helpful in the process of shared decision making, which is increasingly favored in situations where there are multiple medically reasonable options.

Stereotactic body radiotherapy with periprostatic hydrogel spacer for localized prostate cancer: toxicity profile and early oncologic outcomes

Background

Multiple phase I-II clinical trials have reported on the efficacy and safety of prostate stereotactic body radiotherapy (SBRT) for the treatment of prostate cancer. However, few have reported outcomes for prostate SBRT using periprostatic hydrogel spacer (SpaceOAR; Augmenix). Herein, we report safety and efficacy outcomes from our institutional prostate SBRT experience with SpaceOAR placement.

Methods

Fifty men with low- or intermediate-risk prostate cancer treated at a single institution with linear accelerator-based SBRT to 3625 cGy in 5 fractions, with or without androgen deprivation therapy (ADT) were included. All patients underwent SpaceOAR and fiducial marker placement followed by pre-treatment MRI. Toxicity assessments were conducted at least weekly while on treatment, 1 month after treatment, and every follow-up visit thereafter. Post-treatment PSA measurements were obtained 4 months after SBRT, followed by every 3–6 months thereafter. Acute toxicity was documented per RTOG criteria.

Results

Median follow up time was 20 (range 4–44) months. Median PSA at time of diagnosis was 7.4 (2.7–19.5) ng/ml. Eighteen men received 6 months of ADT for unfavorable intermediate risk disease. No PSA failures were recorded. Median PSA was 0.9 ng/mL at 20 months; 0.08 and 1.32 ng/mL in men who did and did not receive ADT, respectively. Mean prostate-rectum separation achieved with SpaceOAR was 9.6 ± 4 mm at the prostate midgland.

No grade ≥ 3 GU or GI toxicity was recorded. During treatment, 30% of men developed new grade 2 GU toxicity (urgency or dysuria). These symptoms were present in 30% of men at 1 month and in 12% of men at 1 year post-treatment. During treatment, GI toxicity was limited to grade 1 symptoms (16%), although 4% of men developed grade 2 symptoms during the first 4 weeks after SBRT. All GI symptoms were resolving by the 1 month post-treatment assessment and no acute or late rectal toxicity was reported > 1 month after treatment.

Conclusions

Periprostatic hydrogel placement followed by prostate SBRT resulted in minimal GI toxicity, and favorable early oncologic outcomes. These results indicate that SBRT with periprostatic spacer is a well-tolerated, safe, and convenient treatment option for localized prostate cancer.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1346-5) contains supplementary material, which is available to authorized users.

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.

Increasing Utilization of Multiparametric Magnetic Resonance Imaging in Prostate Cancer Active Surveillance

OBJECTIVE

To characterize the use of multiparametric magnetic resonance imaging (mpMRI) in male Medicare beneficiaries electing active surveillance for prostate cancer. mpMRI has emerged as a tool that may improve risk-stratification and decrease repeated biopsies in men electing active surveillance. However, the extent to which mpMRI has been implemented in active surveillance has not been established.

METHODS

Using Surveillance, Epidemiology, and End Results registry data linked to Medicare claims data, we identified men with localized prostate cancer diagnosed between 2008 and 2013 and managed with active surveillance. We classified men into 2 treatment groups: active surveillance without mpMRI and active surveillance with mpMRI. We then fit a multivariable logistic regression models to examine changing mpMRI utilization over time, and factors associated with the receipt of mpMRI.

RESULTS

We identified 9467 men on active surveillance. Of these, 8178 (86%) did not receive mpMRI and 1289 (14%) received mpMRI. The likelihood of receiving mpMRI over the entire study period increased by 3.7% (P = .004). On multivariable logistic regression, patients who were younger, white, had lower comorbidity burden, lived in the northeast and west, had higher incomes and lived in more urban areas had greater odds of receiving mpMRI (all P < .05).

CONCLUSION

From 2008 to 2013, use of mpMRI in active surveillance increased gradually but significantly. Receipt of mpMRI among men on surveillance for prostate cancer varied significantly across demographic, geographic, and socioeconomic strata. Going forward, studies should investigate causes for this variation and define ideal strategies for equitable, cost-effective dissemination of mpMRI technology.

Long-term Outcomes of Stereotactic Body Radiotherapy for Low-Risk and Intermediate-Risk Prostate Cancer

Importance

Stereotactic body radiotherapy harnesses improvements in technology to allow the completion of a course of external beam radiotherapy treatment for prostate cancer in the span of 4 to 5 treatment sessions. Although mounting short-term data support this approach, long-term outcomes have been sparsely reported.

Objective

To assess long-term outcomes after stereotactic body radiotherapy for low-risk and intermediate-risk prostate cancer.

Design, Setting, and Participants

This cohort study analyzed individual patient data from 2142 men enrolled in 10 single-institution phase 2 trials and 2 multi-institutional phase 2 trials of stereotactic body radiotherapy for low-risk and intermediate-risk prostate cancer between January 1, 2000, and December 31, 2012. Statistical analysis was performed based on follow-up from January 1, 2013, to May 1, 2018.

Main Outcomes and Measures

The cumulative incidence of biochemical recurrence was estimated using a competing risk framework. Physician-scored genitourinary and gastrointestinal toxic event outcomes were defined per each individual study, generally by Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events scoring systems. After central review, cumulative incidences of late grade 3 or higher toxic events were estimated using a Kaplan-Meier method.

Results

A total of 2142 men (mean [SD] age, 67.9 [9.5] years) were eligible for analysis, of whom 1185 (55.3%) had low-risk disease, 692 (32.3%) had favorable intermediate-risk disease, and 265 (12.4%) had unfavorable intermediate-risk disease. The median follow-up period was 6.9 years (interquartile range, 4.9-8.1 years). Seven-year cumulative rates of biochemical recurrence were 4.5% (95% CI, 3.2%-5.8%) for low-risk disease, 8.6% (95% CI, 6.2%-11.0%) for favorable intermediate-risk disease, 14.9% (95% CI, 9.5%-20.2%) for unfavorable intermediate-risk disease, and 10.2% (95% CI, 8.0%-12.5%) for all intermediate-risk disease. The crude incidence of acute grade 3 or higher genitourinary toxic events was 0.60% (n = 13) and of gastrointestinal toxic events was 0.09% (n = 2), and the 7-year cumulative incidence of late grade 3 or higher genitourinary toxic events was 2.4% (95% CI, 1.8%-3.2%) and of late grade 3 or higher gastrointestinal toxic events was 0.4% (95% CI, 0.2%-0.8%).

Conclusions and Relevance

In this study, stereotactic body radiotherapy for low-risk and intermediate-risk disease was associated with low rates of severe toxic events and high rates of biochemical control. These data suggest that stereotactic body radiotherapy is an appropriate definitive treatment modality for low-risk and intermediate-risk prostate cancer.

Pelvic Complications After Prostate Cancer Radiation Therapy and Their Management: An International Collaborative Narrative Review

CONTEXT

Radiotherapy used for treating localized prostate cancer is effective at prolonging cancer-specific and overall survival. Still, acute and late pelvic toxicities are a concern, with gastrointestinal (GI) and genitourinary (GU) sequelae being most common as well as other pelvic complications.

OBJECTIVE

To present a critical review of the literature regarding the incidence and risk factors of pelvic toxicity following primary radiotherapy for prostate cancer and to provide a narrative review regarding its management.

EVIDENCE ACQUISITION

A collaborative narrative review of the literature from 2010 to present was conducted.

EVIDENCE SYNTHESIS

Regardless of the modality used, the incidence of acute high-grade pelvic toxicity is low following conventionally fractionated external beam radiotherapy (EBRT). After moderate hypofractionation, the crude cumulative incidences for late grade 3 or higher (G3+) GI and GU complications are as high as 6% and 7%, respectively. After extreme hypofractionation, the 5-yr incidences of G2+ GU and GI toxicities are 3-9% and 0-4%, respectively. Following brachytherapy monotherapy, crude rates of late G3+ GU toxicity range from 6% to 8%, while late GI toxicity is rare. With combination therapy (EBRT and brachytherapy), the cumulative incidence of late GU toxicity is high, between 18% and 31%; however, the prevalence is lower at 4-14%. Whole pelvic radiotherapy remains a controversial treatment option as there is increased G3+ GI toxicity compared with prostate-only treatment, with no overall survival benefit. Proton beam therapy appears to have similar toxicity to photon therapies currently in use. With respect to specific complications, urinary obstruction and urethral stricture are the most common severe urinary toxicities. Rectal and urinary bleeding can be recurrent long-term toxicities. The risk of hip fracture is also increased following prostate radiotherapy. The literature is mixed on the risk of in-field secondary pelvic malignancies following prostate radiotherapy. Urinary and GI fistulas are rare complications. Management of these toxicities may require invasive treatment and reconstructive surgery for refractory and severe symptoms.

CONCLUSIONS

There has been progress in the delivery of radiotherapy, enabling the administration of higher doses with minimal tradeoff in terms of slightly increased or equal toxicity. There is a need to focus future improvements in radiotherapy on sparing critical structures to reduce GU and GI morbidities. While complications such as fistulae, bone toxicity, and secondary malignancy are rare, there is a need for higher-quality studies assessing these outcomes and their management.

PATIENT SUMMARY

In this report, we review the literature regarding pelvic complications following modern primary prostate cancer radiotherapy and their management. Modern radiotherapy technologies have enabled the administration of higher doses with minimal increases in toxicity. Overall, high-grade long-term toxicity following prostate radiotherapy is uncommon. Management of late high-grade pelvic toxicities can be challenging, with patients often requiring invasive therapies for refractory cases.

Contemporary prostate cancer radiation therapy in the United States: Patterns of care and compliance with quality measures

PURPOSE

Quality measures represent the standards of appropriate treatment agreed upon by experts in the field and often supported by data. The extent to which providers in the community adhere to quality measures in radiation therapy (RT) is unknown.

METHODS AND MATERIALS

The Comparative Effectiveness Analysis of Surgery and Radiation study enrolled men with clinically localized prostate cancer in 2011 and 2012. Patients completed surveys and medical records were reviewed. Patients were risk-stratified according to D'Amico classification criteria. Patterns of care and compliance with 8 quality measures as endorsed by national consortia as of 2011 were assessed.

RESULTS

Overall, 926 men underwent definitive RT (69% external beam radiation therapy [EBRT]), 17% brachytherapy (BT), and 14% combined EBRT and BT with considerable variation in radiation techniques across risk groups. Most men who received EBRT had dose-escalated EBRT (>75 Gy; 93%) delivered with conventional fractionation (<2 Gy; 95%), intensity modulated RT (76%), and image guided RT (85%). Most men treated with BT received I125 (77%). Overall, 73% of the men received EBRT that was compliant with the quality measures (dose-escalation, image-guidance, appropriate use of androgen deprivation therapy, and appropriate treatment target) but only 60% of men received BT that was compliant with quality measures (postimplant dosimetry and appropriate dose). African-American men (64%) and other minorities (62%) were less likely than white men (77%) to receive EBRT that was compliant with quality measures.

CONCLUSIONS

Most men who received RT for localized prostate cancer were treated with an appropriately high dose and received image guidance and intensity modulated RT. However, compliance with some nationally recognized quality measures was relatively low and varied by race. There are significant opportunities to improve the delivery of RT and especially for men of a minority race.

A Younger Man With Localized Prostate Cancer Asks, "Which Type of Radiation Is Right for Me?"

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 61-year-old man presents with stage II prostate cancer after a period of active surveillance. Work-up reveals T1cN0M0 carcinoma, a prostate-specific antigen (PSA) level of 4.8 ng/mL, and Grade Group II (highest Gleason 3+4) in three cores of 12 taken, at the right mid-gland and right apex. The patient has been on active surveillance for the past 16 months. He was originally diagnosed after biopsy for an elevated PSA with stage I prostate cancer, T1cN0M0; PSA, 4.5 ng/mL; Grade Group 1 (Gleason 3+3) in one core of 12 taken, also at the right mid-gland. A multiparametric magnetic resonance imaging scan showed a heterogeneous peripheral zone without a dominant lesion and a calculated prostate volume of 28 mL. His medical history includes hypercholesterolemia, for which he takes atorvastatin. He is otherwise healthy and has no other significant medical or surgical history. His father had prostate cancer in his 70s and died of other causes at 89 years of age. The patient reports 2- to 3-hour urinary frequency and 0 to 1 nocturia, and has no difficulty obtaining or maintaining an erection. After meeting with his urologist, he sees a radiation oncologist.

Cost effectiveness of prostate cancer radiotherapy

The use of radiotherapy in the treatment of prostate cancer has evolved from treatments utilizing large fields with hand placed blocks to radiotherapy treatments given with a linear accelerator moving around the patient on a robotic arm. These technologic developments have allowed radiation dose escalations resulting in improvements in disease and patient reported outcomes with longer biochemical disease-free survival (DFS) as well as improved quality of life. Increased costs have accompanied these technologic improvements with some private payers questioning the increased cost of the newer treatments and in some instances refusing to pay for some treatment modalities such as intensity-modulated radiotherapy (IMRT) or proton beam therapy (PBT). Cost-effectiveness analysis have been used in an attempt to illustrate these new treatments were cost-effective when compared to the older treatments. Cost-effectiveness analyses will need to be adapted in the current health care environment to provide an assessment of value as many payers, including medicare, move to a value-based reimbursement system.

National trends in management of localized prostate cancer: A population based analysis 2004-2013

PURPOSE

Recent years have brought many changes in the management of localized prostate cancer as national screening guidelines have been updated and diagnostic practice patterns evolved. We sought to better understand how the changing landscape influenced treatment utilization in the United States.

METHODS

We used the SEER database in this retrospective analysis of patients with clinically localized prostate cancer between 2004 and 2013. We evaluated utilization of primary treatment modalities over time with descriptive and trend analyses, and examined treatment utilization by cancer risk group and age at diagnosis.

RESULTS

Of 398 074 patients in the analytic data set, 38% elected radiation therapy, 38% underwent radical prostatectomy, and 24% opted for expectant management. While in 2004 radiation treatment was almost twice as common as expectant management (42% vs 23%), by 2013 approximately equal percentages of patients were treated with each of the three modalities. Expectant management use increased over time, while the proportion of patients opting for surgery decreased remarkably with increasing age at diagnosis in intermediate- and higher-risk disease. Among radiotherapy options, brachytherapy was most common among lower-risk patients in 2004 but substantially decreased over time (P < 0.001).

CONCLUSIONS

Management of localized prostate cancer changed substantially over time in the United States. Utilization of expectant management has increased for men with low- and intermediate risk cancer. Among those who pursue curative therapy, younger men remain more likely to elect surgery whereas older men tend to choose radiotherapy. Further studies are needed to better characterize factors contributing to treatment selection.

Changes in prostate orientation due to removal of a Foley catheter

PURPOSE

Investigate the impact on prostate orientation caused by use and removal of a Foley catheter, and the dosimetric impact on men prospectively treated with prostate stereotactic body radiotherapy (SBRT).

METHODS

Twenty-two men underwent a CT simulation with a Foley in place (FCT), followed immediately by a second treatment planning simulation without the Foley (TPCT). The change in prostate orientation was determined by rigid registration of three implanted transponders between FCT and TPCT and compared to measured orientation changes during treatment. The impact on treatment planning and delivery was investigated by analyzing the measured rotations during treatment relative to both CT scans, and introducing rotations of ±15° in the treatment plan to determine the maximum impact of allowed rotations.

RESULTS

Removing the Foley caused a statistically significant prostate rotation (P < 0.0028) compared to normal biological motion in 60% of patients. The largest change in rotation due to removing a Foley occurs about the left-right axis (tilt) which has a standard deviation two to five times larger than changes in rotation about the Sup-Inf (roll) and Ant-Post (yaw) axes. The change in tilt due to removing a Foley for prone and supine patients was -1.1° ± 6.0° and 0.3° ± 7.4°, showing no strong directional bias. The average tilt during treatment was -1.6° ± 7.1° compared to the TPCT and would have been -2.0° ± 7.1° had the FCT been used as the reference. The TPCT was a better or equivalent representation of prostate tilt in 82% of patients, vs 50% had the FCT been used for treatment planning. However, 92.7% of fractions would still have been within the ±15° rotation limit if only the FCT were used for treatment planning. When rotated ±15°, urethra V_{105% = 38.85Gy}  < 20% was exceeded in 27% of the instances, and prostate (CTV) coverage was maintained above D_95%  > 37 Gy in all but one instance.

CONCLUSIONS

Removing a Foley catheter can cause large prostate rotations. There does not appear to be a clear dosimetric benefit to obtaining the CT scan with a Foley catheter to define the urethra given the changes in urethral position from removing the Foley catheter. If urethral sparing is desired without the use of a Foley, utilization of an MRI to define the urethra may be necessary, or a pseudo-urethral planning organ at risk volume (PRV) may be used to limit dosimetric hot spots.

Comparative Toxicities and Cost of Intensity-Modulated Radiotherapy, Proton Radiation, and Stereotactic Body Radiotherapy Among Younger Men With Prostate Cancer

Purpose To compare the toxicities and cost of proton radiation and stereotactic body radiotherapy (SBRT) with intensity-modulated radiotherapy (IMRT) for prostate cancer among men younger than 65 years of age with private insurance. Methods Using the MarketScan Commercial Claims and Encounters database, we identified men who received radiation for prostate cancer between 2008 and 2015. Patients undergoing proton therapy and SBRT were propensity score-matched to IMRT patients on the basis of clinical and sociodemographic factors. Proportional hazards models compared the cumulative incidence of urinary, bowel, and erectile dysfunction toxicities by treatment. Cost from a payer's perspective was calculated from claims and adjusted to 2015 dollars. Results A total of 693 proton therapy patients were matched to 3,465 IMRT patients. Proton therapy patients had a lower risk of composite urinary toxicity (33% v 42% at 2 years; P < .001) and erectile dysfunction (21% v 28% at 2 years; P < .001), but a higher risk of bowel toxicity (20% v 15% at 2 years; P = .02). Mean radiation cost was $115,501 for proton therapy patients and $59,012 for IMRT patients ( P < .001). A total of 310 SBRT patients were matched to 3,100 IMRT patients. There were no significant differences in composite urinary, bowel, or erectile dysfunction toxicities between SBRT and IMRT patients ( P > .05), although a higher risk of urinary fistula was noted with SBRT (1% v 0.1% at 2 years; P = .009). Mean radiation cost for SBRT was $49,504 and $57,244 for IMRT ( P < .001). Conclusion Among younger men with prostate cancer, proton radiation was associated with significant reductions in urinary toxicity but increased bowel toxicity at nearly twice the cost of IMRT. SBRT and IMRT were associated with similar toxicity profiles; SBRT was modestly less expensive than IMRT.

Comparing photon and proton-based hypofractioned SBRT for prostate cancer accounting for robustness and realistic treatment deliverability

OBJECTIVE

To investigate whether photon or proton-based stereotactic body radiation therapy (SBRT is the preferred modality for high dose hypofractionation prostate cancer treatment. Achievable dose distributions were compared when uncertainties in target positioning and range uncertainties were appropriately accounted for.

METHODS

10 patients with prostate cancer previously treated at our institution (Montefiore Medical Center) with photon SBRT using volumetric modulated arc therapy (VMAT) were identified. MRI images fused to the treatment planning CT allowed for accurate target and organ at risk (OAR) delineation. The clinical target volume was defined as the prostate gland plus the proximal seminal vesicles. Critical OARs include the bladder wall, bowel, femoral heads, neurovascular bundle, penile bulb, rectal wall, urethra and urogenital diaphragm. Photon plan robustness was evaluated by simulating 2 mm isotropic setup variations. Comparative proton SBRT plans employing intensity modulated proton therapy (IMPT) were generated using robust optimization. Plan robustness was evaluated by simulating 2 mm setup variations and 3% or 1% Hounsfield unit (HU) calibration uncertainties.

RESULTS

Comparable maximum OAR doses are achievable between photon and proton SBRT, however, robust optimization results in higher maximum doses for proton SBRT. Rectal maximum doses are significantly higher for Robust proton SBRT with 1% HU uncertainty compared to photon SBRT (p = 0.03), whereas maximum doses were comparable for bladder wall (p = 0.43), urethra (p = 0.82) and urogenital diaphragm (p = 0.50). Mean doses to bladder and rectal wall are lower for proton SBRT, but higher for neurovascular bundle, urethra and urogenital diaphragm due to increased lateral scatter. Similar target conformality is achieved, albeit with slightly larger treated volume ratios for proton SBRT, >1.4 compared to 1.2 for photon SBRT.

CONCLUSION

Similar treatment plans can be generated with IMPT compared to VMAT in terms of target coverage, target conformality, and OAR sparing when range and HU uncertainties are neglected. However, when accounting for these uncertainties during robust optimization, VMAT outperforms IMPT in terms of achievable target conformity and OAR sparing. Advances in knowledge: Comparison between achievable dose distributions using modern, robust optimization of IMPT for high dose per fraction SBRT regimens for the prostate has not been previously investigated.

Image-guided surgery in cancer: A strategy to reduce incidence of positive surgical margins

Primary treatment for many solid cancers includes surgical excision or radiation therapy, with or without the use of adjuvant therapy. This can include the addition of radiation and chemotherapy after primary surgical therapy, or the addition of chemotherapy and salvage surgery to primary radiation therapy. Both primary therapies, surgery and radiation, require precise anatomic localization of tumor. If tumor is not targeted adequately with initial treatment, disease recurrence may ensue, and if targeting is too broad, unnecessary morbidity may occur to nearby structures or remaining normal tissue. Fluorescence imaging using intraoperative contrast agents is a rapidly growing field for improving visualization in cancer surgery to facilitate resection in order to obtain negative margins. There are multiple strategies for tumor visualization based on antibodies against surface markers or ligands for receptors preferentially expressed in cancer. In this article, we review the incidence and clinical implications of positive surgical margins for some of the most common solid tumors. Within this context, we present the ongoing clinical and preclinical studies focused on the use of intraoperative contrast agents to improve surgical margins. This article is categorized under: Laboratory Methods and Technologies > Imaging.

Prostate cancer high dose-rate brachytherapy: review of evidence and current perspectives

INTRODUCTION

Patients with intermediate to high risk disease (prostate specific antigen (PSA) ≥ 10, Gleason score ≥ 7, or clinical stage ≥ T2b) suffer from poorer long-term biochemical control (freedom from an increasing prostate specific antigen level) when treated with external beam radiation (EBRT) alone. In order to improve biochemical control while limiting long-term complications, brachytherapy has been incorporated into radiotherapy treatment, either alone or in combination with EBRT.

AREAS COVERED

Current literature regarding the use of high dose-rate (HDR) brachytherapy for localized prostate cancer, including as a boost and monotherapy. The efficacy and toxicities of various approaches are evaluated including comparisons to low dose-rate (LDR) brachytherapy.

EXPERT COMMENTARY

Prostate HDR brachytherapy has higher conformality than EBRT, potentially improving the therapeutic ratio by allowing higher doses per fraction to tumor cells. The improved biochemical control shown in trials have resulted in EBRT plus brachytherapy to be included as a standard treatment option supported by the NCCN and ASCO guidance documents for intermediate to high risk prostate cancer.

[Toxicity and quality of life comparison of iodine 125 brachytherapy and stereotactic radiotherapy for prostate cancers]

Quality of life is a major issue for good prognostic prostate cancer, for which brachytherapy is one of the reference treatments. Stereotactic Body Radiotherapy (SBRT) is a recent alternative however not yet validated as a standard treatment. This review of the literature reports and compares the toxicities and the quality of life, either after exclusive brachytherapy with iodine 125 or after SBRT. The comparison is made with the limitations of the absence of randomized trial comparing the two treatment techniques. Acute toxicity appears to be lower after SBRT compared to brachytherapy (from 10 to 40 % versus 30 to 40 %, respectively). Conversely, acute and late gastrointestinal toxicity (from 0 to 21 % and from 0 to 10 % of grade 2, respectively) appears more frequent with SBRT. Late urinary toxicity seems identical between both techniques (from 20 to 30 % of grade 2), with a possible urinary flare syndrome. Both treatments have an impact on erectile dysfunction, although it is not possible to conclude that a technique is superior because of the limited data on SBRT. SBRT has better bowel and urinary (irritation or obstruction) quality of life scores than brachytherapy; while sexual and urinary incontinence remain the same. The absence of randomized trial comparing SBRT with brachytherapy for prostate cancers does not allow to conclude on the superiority of one technique over another, thus justifying a phase III medicoeconomic evaluation.

Hospital Quality Factors Influencing the Mobility of Patients for Radical Prostate Cancer Radiation Therapy: A National Population-Based Study

Purpose

To investigate whether patients requiring radiation treatment are prepared to travel to alternative more distant centers in response to hospital choice policies, and the factors that influence this mobility.

Methods and Materials

We present the results of a national cohort study using administrative hospital data for all 44,363 men who were diagnosed with prostate cancer and underwent radical radiation therapy in the English National Health Service between 2010 and 2014. Using geographic information systems, we investigated the extent to which men choose to travel beyond (“bypass”) their nearest radiation therapy center, and we used conditional logistic regression to estimate the effect of hospital and patient characteristics on this mobility.

Results

In all, 20.7% of men (n=9161) bypassed their nearest radiation therapy center. Travel time had a very strong impact on where patients moved to for their treatment, but its effect was smaller for men who were younger, more affluent, and from rural areas (P for interaction always <.001). Men were prepared to travel further to hospitals that offered hypofractionated prostate radiation therapy as their standard schedule (odds ratio 3.19, P<.001), to large-scale radiation therapy units (odds ratio 1.56, P<.001), and to hospitals that were early adopters of intensity modulated radiation therapy (odds ratio 1.37, P<.001).

Conclusions

Men with prostate cancer are prepared to bypass their nearest radiation therapy centers. They are more likely to travel to larger established centers and those that offer innovative technology and more convenient radiation therapy schedules. Indicators that accurately reflect the quality of radiation therapy delivered are needed to guide patients' choices for radiation therapy treatment. In their absence, patient mobility may negatively affect the efficiency and capacity of a regional or national radiation therapy service and offer perverse incentives for technology adoption.