The early adoption of intensity-modulated radiotherapy and stereotactic body radiation treatment among older Medicare beneficiaries with prostate cancer

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.

Outcomes in studies regarding older patients with prostate cancer: A systematic review

INTRODUCTION

Older patients are often deemed ineligible for clinical research, and many frequently-used endpoints and outcome measures are not as relevant for older patients for younger ones. This systematic review aimed to present an overview of outcomes used in clinical research regarding patients over the age of 65 years with prostate cancer.

MATERIALS AND METHODS

PubMed and Embase were systematically searched to identify studies on prostate cancer (treatment) in patients aged ≥65 between 2016 and 2023. Data on title, study design, number of participants and age, stage of disease, treatment, and investigated outcomes were synthesized and descriptively analyzed.

RESULTS

Sixty-eight studies were included. Of these most included patients over 65 years, while others used a higher age. Overall, 39 articles (57.3%) reported on survival-related outcomes, 22 (32.4%) reported on progression of disease and 38 (55.9%) used toxicity or adverse events as an outcome measure. Health-related quality of life and functional outcomes were investigated in 29.4%, and cognition in two studies. The most frequently investigated survival-related outcomes were overall and cancer-specific survival (51.3%); however, 38.5% only studied overall survival.

DISCUSSION

The main focus of studies included in this review remains survival and disease progression. There is limited attention for health-related quality of life and functional status, although older patients often prioritize the latter. Future research should incorporate outcome measures tailored to the aged population to improve care for older patients with prostate cancer.

Ten-Year Single Institutional Analysis of Geographic and Demographic Characteristics of Patients Treated With Stereotactic Body Radiation Therapy for Localized Prostate Cancer

Objectives

Stereotactic Body Radiation Therapy (SBRT) offers definitive treatment for localized prostate cancer with comparable efficacy and toxicity to conventionally fractionated radiotherapy. Decreasing the number of treatment visits from over 40 to five may ease treatment burden and increase accessibility for logistically challenged patients. Travel distance is one factor that affects a patient’s access to treatment and is often related to geographic location and socioeconomic status. In this study, we review the demographic and geographic factors of patients treated with SBRT for prostate cancer for a single institution with over a decade of experience.

Methods

Patient zip codes from one thousand and thirty-five patients were derived from a large, prospectively maintained quality of life database for patients treated for prostate cancer with SBRT from 2008 to 2017. The geospatial distance between the centroid of each zip code to our institution was calculated using the R package Geosphere. Characteristics for seven hundred and twenty-one patients were evaluated at the time of analysis including: race, age, and insurance status. To assess the geographic reach of our institution, we evaluated the demographic features of each zip code using US Census data. Statistical comparisons for these features and their relation to distance traveled for treatment was performed using the Mann-Whitney U test. Finally, an unsupervised learning algorithm was performed to identify distinct clusters of patients with respect to median income, racial makeup, educational level, and rural residency.

Results

Patients traveled from 246 distinct zip codes at a median distance of 11.35 miles. Forty percent of patients were African American, 6.9% resided in a rural region, and 22% were over the age of 75. Using K-means cluster analysis, four distinct patient zip-code groups were identified based on the aforementioned demographic features: Suburban/high-income (45%), Urban (30%), Suburban/low-income (17%), and Rural (8%). For each of the clusters, the average travel distance for SBRT was significantly different at 11.17, 9.26, 11.75, and 40.2 miles, respectively (p-value: <0.001).

Conclusions

Distinct demographic features are related to travel distance for prostate SBRT. In our large cohort, travel distance did not prevent uptake of prostate SBRT in African American, elderly or rural patient populations. Prostate SBRT offers a diverse population modern treatment for their localized prostate cancer and particularly for those who live significant distances from a treatment center.

Diffusion of innovation in radiation oncology in the United States

Objective:

To develop an instrument for quantifying innovation and assess the diffusion of innovation in radiation oncology (RO) in the United States.

Methods:

Primary data were collected for using total population convenience sampling. Innovation Score and Innovation Utilization Score were determined using 20 indicators. 240 medical physicists (MPs) practicing in RO in the United States completed a custom Internet-based survey.

Results:

Centers with no academic affiliation are trailing behind in innovation in total (MD = 1.65, 95% C I[0.38,2.917], p = 0.011, d = 0.351), in patient treatment (MD = 0.39, 95% CI [0.021,0.76], p = 0.038, d = 0.282), and workflow innovation (MD = 7.09, 95% CI [0.78,13.39], p = 0.028, d = 0.330). Centers with no academic affiliation are trailing behind in innovation utilization in total (MD = 0.46, 95% CI [0.05,0.86], p = 0.028, d = 0.188). Rural center are trailing behind in patient positioning in innovation (MD = 0.31, 95% CI [0.011,0.612], p = 0.042, d = 0.293) and innovation utilization (MD = 16.22, 95% CI [0.73,31.72], p = 0.04, d = 0.608). Rural centers are trailing behind in innovative treatments (MD = 0.62, 95% CI [0.23,1.00], p = 0.002, d = 0.457). Motivation (r_s = 0.224, p = 0.002) and appreciation (r_s = 0.215, p = 0.003) were statistically significant personal factors influencing innovation utilization.

Conclusions:

There is a wide range of innovation across RO centers in the United States. RO centers in the United States are not practicing as innovative as reasonably achievable.

Advances in knowledge:

This work quantified how innovative RO in the United States is and results provide guidance on how to improve it in the future.

Stereotactic Radiosurgery After Resection of Brain Metastases: Changing Patterns of Care in the United States

OBJECTIVE

Management of symptomatic brain metastases often includes surgical resection with postoperative radiotherapy. Postoperative whole-brain radiotherapy (WBRT) improves intracranial control but detrimentally impacts quality of life and neurocognition. We sought to characterize the use in the United States of postoperative stereotactic radiosurgery (SRS), an evolving standard-of-care associated with reduced cognitive effects.

METHODS

With the MarketScan Commercial Claims and Encounters Database from 2007 to 2015, we identified patients aged 18-65 years treated with resection of a brain metastasis followed by SRS or WBRT within 60 days of surgery. Logistic regression estimated associations between co-variables (treatment year, age, sex, geographic region, place of service, insurance type, disease histology, comorbidity score, and median area household income and educational attainment) and SRS receipt.

RESULTS

Of 4007 patients included, 1506 (37.6%) received SRS and 2501 (62.4%) received WBRT. Postoperative SRS increased from 16.5% (2007-2008) to 56.8% (2014-2015). Patients residing in areas with a median household income or an educational attainment below 50th percentile were significantly less likely to receive SRS after controlling for treatment year and other demographic characteristics (P < 0.01). Factors associated with greater odds of receiving SRS included younger age, female sex, melanoma histology, Western region location, hospital-based facility, and high-deductible health plan enrollment (P < 0.05 for each).

CONCLUSIONS

Postoperative SRS for brain metastases has increased from 2007 to 2015, with the majority of patients now receiving SRS over WBRT. Patients in areas of lower socioeconomic class were less likely to receive SRS, warranting further investigation of barriers to SRS adoption.

Radiation oncologists' attitudes and beliefs about intensity-modulated radiation therapy and stereotactic body radiation therapy for prostate cancer

BACKGROUND

To better understand how radiation oncologists perceive intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) for prostate cancer and how these perceptions may influence treatment decisions.

METHODS

We conducted semi-structured interviews of radiation oncologists between January-May, 2016. We used a purposeful sampling technique to select participants across a wide range of experience, regions, and practice types. Two trained qualitative researchers used an inductive, iterative approach to code transcripts and identify themes. We then used content analysis and thematic analysis of the coded transcripts to understand radiation oncologists' attitudes and beliefs about IMRT and SBRT.

RESULTS

Thematic saturation was achieved after 20 interviews. Participants were affiliated with academic (n = 13; 65%), private (n = 5; 25%), and mixed (n = 2; 10%) practices and had a wide range of clinical experience (median 19 years; range 4-49 years). Analysis of interview transcripts revealed four general themes: 1) most radiation oncologists offered surgery, brachytherapy, IMRT, and active surveillance for low-risk patients; 2) there was no consensus on the comparative effectiveness of IMRT and SBRT; 3) key barriers to adopting SBRT included issues related to insurance, reimbursement, and practice inertia; and 4) despite these barriers, most participants envisioned SBRT use increasing over the next 5-10 years.

CONCLUSIONS

In the absence of strong opinions about effectiveness, nonclinical factors influence the choice of radiation treatment. Despite a lack of consensus, most participants agreed SBRT may become a standard of care in the future.

Patterns of stereotactic body radiation therapy: The influence of lung cancer treatment on prostate cancer treatment

INTRODUCTION

Technology availability and prior experience with novel cancer treatments may partially drive their use. We sought to examine this issue in the context of stereotactic body radiation therapy (SBRT) by studying how its use for an established indication (lung cancer) impacts its use for an emerging indication (prostate cancer).

METHODS

Using SEER-Medicare from 2007 to 2011, we developed prostate cancer-specific physician-hospital networks. Our primary dependent variable was SBRT use for prostate cancer and our primary independent variable was SBRT use for lung cancer, both at the network level. To assess the influence of SBRT availability and experiential use, we generated predicted probabilities of SBRT use for prostate cancer stratified by a network's use of lung cancer SBRT, adjusting for network characteristics. To assess intensity of use, we examined the correlation between the proportion of prostate cancer patients and lung cancer patients receiving SBRT within a network.

RESULTS

We identified 316 networks that served 41,034 prostate cancer and 83,433 lung cancer patients. A network was significantly more likely to use SBRT for prostate cancer if that network used SBRT for lung cancer (e.g., in 2011, odds ratio [OR] 12.7; 95% confidence interval [CI] 3.9-41.8). The Pearson's correlation between the proportion of prostate cancer patients and lung cancer patients receiving SBRT in a network was 0.34, which was not statistically significant (P = 0.12).

CONCLUSIONS

SBRT availability and experiential use for lung cancer influences its use for prostate cancer, but intensity of use for one does not relate to intensity of use for the other.

The Influence of Stereotactic Body Radiation Therapy Adoption on Prostate Cancer Treatment Patterns

PURPOSE

To our knowledge it is unknown whether stereotactic body radiation therapy of prostate cancer is a substitute for other radiation treatments or surgery, or for expanding the pool of patients who undergo treatment instead of active surveillance.

MATERIALS AND METHODS

Using SEER (Surveillance, Epidemiology, and End Results)-Medicare we identified men diagnosed with prostate cancer between 2007 and 2011. We developed physician-hospital networks by identifying the treating physician of each patient based on the primary treatment received and subsequently assigning each physician to a hospital. We examined the relative distribution of prostate cancer treatments stratified by whether stereotactic body radiation therapy was performed in a network by fitting logistic regression models with robust SEs to account for patient clustering in networks.

RESULTS

We identified 344 physician-hospital networks, including 30 (8.7%) and 314 (91.3%) in which stereotactic body radiation therapy was and was not performed, respectively. Networks in which that therapy was and was not done did not differ with time in the performance of robotic and radical prostatectomy, and active surveillance (all p >0.05). The relationship with intensity modulated radiation therapy did not show any consistent temporal pattern. In networks in which it was performed less intensity modulated radiation therapy was initially done but there were similar rates in later years. Brachytherapy trends differed among networks in which stereotactic body radiation therapy was vs was not performed with a lower brachytherapy rate in networks in which stereotactic body radiation therapy was done (p=0.03).

CONCLUSIONS

Surgery and active surveillance rates did not differ in networks in which stereotactic body radiation therapy was vs was not performed but when that therapy was done there was a lower brachytherapy rate. Stereotactic body radiation therapy may represent more of an alternative to brachytherapy than to active surveillance.