• MR-guided radiation therapy
• MRI
• MRgRT
• RT
• SABR
• SBRT
• SMART
• ablative radiation therapy
• adaptive radiation therapy
• image guided radiotherapy
• magnetic resonance imaging
• mpMRI
• multiparametric MRI
• plan optimization
• radiation therapy
• stereotactic ablative radiotherapy
• stereotactic body radiotherapy
• stereotactic magnetic resonance-guided adaptive radiotherapy
• tumor motion management
• ultra-hypofractionated radiation therapy

• Male
• Humans
• United States/epidemiology
• Aged
• Prostatic Neoplasms/epidemiology
• Prostatic Neoplasms/radiotherapy
• Breast Neoplasms/epidemiology
• Breast Neoplasms/radiotherapy
• Breast Neoplasms/surgery
• Radiosurgery
• Radiation Dose Hypofractionation

• K08 CA252640 NCI NIH HHS
• P30 CA008748 NCI NIH HHS

Magnetic resonance-guided radiotherapy (MRgRT) utilization is rapidly expanding, driven by advanced capabilities including better soft tissue imaging, continuous intrafraction target visualization, automatic triggered beam delivery, and the availability of on-table adaptive replanning. Our objective was to describe patterns of 0.35 Tesla (T)-MRgRT utilization in Europe and Asia among early adopters of this novel technology.

Anonymized administrative data from all 0.35T-MRgRT treatment systems in Europe and Asia were extracted for patients who completed treatment from 2015 to 2020. Detailed treatment information was analyzed for all MR-linear accelerators (linac) and -cobalt systems.

From 2015 through the end of 2020, there were 5796 completed treatment courses delivered in 46,389 individual fractions. 23.5% of fractions were adapted. Ultra-hypofractionated (UHfx) dose schedules (1–5 fractions) were delivered for 63.5% of courses, with 57.8% of UHfx fractions adapted on-table. The most commonly treated tumor types were prostate (23.5%), liver (14.5%), lung (12.3%), pancreas (11.2%), and breast (8.0%), with increasing compound annual growth rates (CAGRs) in numbers of courses from 2015 through 2020 (pancreas: 157.1%; prostate: 120.9%; lung: 136.0%; liver: 134.2%).

This is the first comprehensive study reporting patterns of utilization among early adopters of a 0.35T-MRgRT system in Europe and Asia. Intrafraction MR image-guidance, advanced motion management, and increasing adoption of on-table adaptive RT have accelerated a transition to UHfx regimens. MRgRT has been predominantly used to treat tumors in the upper abdomen, pelvis and lungs, and increasingly with adaptive replanning, which is a radical departure from legacy radiotherapy practices.

• ART
• Care patterns
• MR-IGRT
• MRI-guided radiotherapy
• On-table adaptive radiation therapy
• SABR
• SBRT
• Stereotactic ablative radiation therapy
• Stereotactic body radiotherapy
• oART

• CyberKnife
• Ejaculation
• Prostate Cancer
• SBRT

• Aged
• Ejaculation
• Humans
• Male
• Prospective Studies
• Prostatic Neoplasms/etiology
• Prostatic Neoplasms/radiotherapy
• Prostatic Neoplasms/surgery
• Quality of Life
• Radiosurgery/adverse effects
• Retrospective Studies

High-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.

A 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.

Seven 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.

Fractionated 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.

• biochemical recurrence-free survival
• high-dose-rate brachytherapy
• meta-analysis
• prostate cancer

• 0.35 T MRI-Linac
• SpaceOAR
• adaptive radiotherapy

• Humans
• Hydrogels
• Magnetic Resonance Imaging
• Male
• Organs at Risk
• Prostate
• Prostatic Neoplasms/radiotherapy
• Radiosurgery
• Radiotherapy Dosage
• Radiotherapy Planning, Computer-Assisted
• Rectum/diagnostic imaging
• Urinary Bladder/diagnostic imaging

• MR-guided
• SBRT
• non-adaptive
• prostate

• Hydrogel
• Patient-reported outcomes
• Prostate cancer
• Radiation therapy
• Stereotactic body radiotherapy
• Toxicity

• Adaptive
• Dose accumulation
• MRgRT
• Prostate cancer
• SBRT
• Urinary toxicity

• Stereotactic Body Radiation Therapy
• prostate
• prostate cancer
• radiotherapy
• stereotactic

• Health-related quality of life
• Magnetic resonance-guided
• Online plan adaptation
• Patient-reported outcomes
• Prostate cancer
• Stereotactic body radiotherapy

• SBRT
• image-guidance
• margins
• planning target volume
• prostate cancer
• prostate motion
• stereotactic body radiation therapy

• Clinical trial
• EPIC
• HDR brachytherapy
• Hypofractionation
• Prostate cancer
• SBRT

• Active surveillance
• External beam radiotherapy
• Intensity-modulated radiotherapy
• Localized prostate cancer
• Patient-reported quality of life
• Stereotactic body radiotherapy

• Aged
• Brachytherapy/methods
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Patient Reported Outcome Measures
• Prospective Studies
• Prostatic Neoplasms/radiotherapy
• Quality of Life
• Stereotaxic Techniques
• Watchful Waiting/methods

• CER-1310-06453 Patient-Centered Outcomes Research Institute

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.

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.

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.

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.

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

• Dosimetry
• Prostate cancer
• Rectal toxicity
• SpaceOAR hydrogel
• Stereotactic body radiotherapy

Utilization of patient-reported outcomes (PROs) to guide symptom management during radiation therapy is increasing. This study focuses on the use of the Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC-CP) as a tool to assess urinary and bowel bother during stereotactic body radiation therapy (SBRT) and its utility in guiding medical management.

Between September 2015 and January 2017, 107 patients with clinically localized prostate cancer were treated with 35–36.25 Gy via SBRT in five fractions. PROs were assessed using EPIC-CP 1 h prior to the first fraction and after each subsequent fraction. Symptom management medications were prescribed based on the physician clinical judgment or if patients reported a moderate to big problem. Clinical significance was assessed using a minimally important difference of 1/2 SD from baseline score.

A median baseline EPIC-CP urinary symptom score of 1.5 significantly increased to 3.7 on the day of the final treatment (p < 0.0001). Prior to treatment, 9.3% of men felt that their overall urinary function was a moderate to big problem that increased to 28% by the end of the fifth treatment. A median baseline EPIC-CP bowel symptom score of 0.3 significantly increased to 1.4 on the day of the final treatment (p < 0.0001). Prior to treatment, 1.9% of men felt that their overall bowel function was a moderate to big problem that increased to 3.7% by the end of the fifth treatment. The percentage of patients requiring an increased dose of alpha-antagonist increased to 47% by the end of treatment, and an additional 28% of patients required a short steroid taper to manage moderate to big urinary problems. Similarly, the percentage of patients requiring antidiarrheals reached 12% by the fifth treatment.

During the course of SBRT, an increasing percentage of patients experienced clinically significant symptoms many of which required medical management. Monitoring patient symptoms during treatment allowed for prompt detection and management of acute urinary and bowel symptoms. The usage of symptom management medications was high in this study compared to historical controls and may be due to increased physician awareness of moderate to big patient problems.

• CyberKnife
• Expanded Prostate Cancer Index Composite
• patient-reported outcome
• prostate cancer
• stereotactic body radiation therapy

• Hypofractionation
• Prostate cancer
• Radiation therapy
• Stereotactic ablative radiotherapy
• Stereotactic body radiotherapy
• Toxicity

Our previous work on early PSA kinetics following prostate stereotactic body radiation therapy (SBRT) demonstrated that an initial rapid and then slow PSA decline may result in very low PSA nadirs. This retrospective study sought to evaluate the PSA nadir 5 years following SBRT for low- and intermediate-risk prostate cancer (PCa).

65 low- and 80 intermediate-risk PCa patients were treated definitively with SBRT to 35–37.5 Gy in 5 fractions at Georgetown University Hospital between January 2008 and October 2011. Patients who received androgen deprivation therapy were excluded from this study. Biochemical relapse was defined as a PSA rise >2 ng/ml above the nadir and analyzed using the Kaplan–Meier method. The PSA nadir was defined as the lowest PSA value prior to biochemical relapse or as the lowest value recorded during follow-up. Prostate ablation was defined as a PSA nadir <0.2 ng/ml. Univariate logistic regression analysis was used to evaluate relevant variables on the likelihood of achieving a PSA nadir <0.2 ng/ml.

The median age at the start of SBRT was 72 years. These patients had a median prostate volume of 36 cc with a median 25% of total cores involved. At a median follow-up of 5.6 years, 86 and 37% of patients achieved a PSA nadir ≤0.5 and <0.2 ng/ml, respectively. The median time to PSA nadir was 36 months. Two low and seven intermediate risk patients experienced a biochemical relapse. Regardless of the PSA outcome, the median PSA nadir for all patients was 0.2 ng/ml. The 5-year biochemical relapse free survival (bRFS) rate for low- and intermediate-risk patients was 98.5 and 95%, respectively. Initial PSA (p = 0.024) and a lower testosterone at the time of the PSA nadir (p = 0.049) were found to be significant predictors of achieving a PSA nadir <0.2 ng/ml.

SBRT for low- and intermediate-risk PCa is a convenient treatment option with low PSA nadirs and a high rate of early bRFS. Fewer than 40% of patients, however, achieved an ablative PSA nadir. Thus, the role of further dose escalation is an area of active investigation.

• PSA
• PSA bounce
• PSA kinetics
• PSA recurrence
• ablation
• biochemical relapse
• prostate cancer
• stereotactic body radiation therapy

• adoption
• intensity-modulated radiotherapy
• prostate cancer
• stereotactic body radiation treatment
• technology

• Carcinoma, Non-Small-Cell Lung/radiotherapy
• Humans
• Lung Neoplasms/radiotherapy
• Radiosurgery/methods
• Treatment Outcome

• Lymph node recurrence
• Oligometastases
• Recurrent prostate cancer
• Robotic stereotactic radiotherapy
• Salvage radioablation

• Expanded Prostate Cancer Index (EPIC)
• Patient-reported outcomes (PRO)
• health-related quality of life (HRQOL)
• prostate cancer
• stereotactic body radiation (SBRT)