Immune checkpoint inhibition and single fraction stereotactic radiosurgery in brain metastases from non-small cell lung cancer: an international multicenter study of 395 patients

PURPOSE

Approximately 80% of brain metastases originate from non-small cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICI) and stereotactic radiosurgery (SRS) are frequently utilized in this setting. However, concerns remain regarding the risk of radiation necrosis (RN) when SRS and ICI are administered concurrently.

METHODS

A retrospective study was conducted through the International Radiosurgery Research Foundation. Logistic regression models and competing risks analyses were utilized to identify predictors of any grade RN and symptomatic RN (SRN).

RESULTS

The study included 395 patients with 2,540 brain metastases treated with single fraction SRS and ICI across 11 institutions in four countries with a median follow-up of 14.2 months. The median age was 67 years. The median margin SRS dose was 19 Gy; 36.5% of patients had a V12 Gy ≥ 10 cm3. On multivariable analysis, V12 Gy ≥ 10 cm3 was a significant predictor of developing any grade RN (OR: 2.18) and SRN (OR: 3.95). At 1-year, the cumulative incidence of any grade and SRN for all patients was 4.8% and 3.8%, respectively. For concurrent and non-concurrent groups, the cumulative incidence of any grade RN was 3.8% versus 5.3%, respectively (p = 0.35); and for SRN was 3.8% vs. 3.6%, respectively (p = 0.95).

CONCLUSION

The risk of any grade RN and symptomatic RN following single fraction SRS and ICI for NSCLC brain metastases increases as V12 Gy exceeds 10 cm3. Concurrent ICI and SRS do not appear to increase this risk. Radiosurgical planning techniques should aim to minimize V12 Gy.

Concurrent Administration of Immune Checkpoint Inhibitors and Single Fraction Stereotactic Radiosurgery in Patients With Non-Small Cell Lung Cancer, Melanoma, and Renal Cell Carcinoma Brain Metastases is Not Associated With an Increased Risk of Radiation Necrosis Over Nonconcurrent Treatment: An International Multicenter Study of 657 Patients

PURPOSE

Stereotactic radiosurgery (SRS) and immune checkpoint inhibitors (ICI) are highly effective treatments for brain metastases, particularly when these therapies are administered concurrently. However, there are limited data reporting the risk of radiation necrosis (RN) in this setting.

METHODS AND MATERIALS

Patients with brain metastases from primary non-small cell lung cancer, renal cell carcinoma, or melanoma treated with SRS and ICI were considered. Time-to-event analyses were conducted for any grade RN and symptomatic RN (SRN) with death incorporated as a competing risk. As a secondary analysis, recursive partitioning analysis (RPA) was used for model development, and a loop of potential models was analyzed, with the highest-fidelity model selected. Brain V12 Gy thresholds identified on RPA were then incorporated into the competing risks analysis. Concurrent SRS and ICI administration.

RESULTS

Six hundred fifty-seven patients with 4182 brain metastases across 11 international institutions were analyzed. The median follow-up for all patients was 13.4 months. The median follow-up was 12.8 months and 14.1 months for the concurrent and nonconcurrent groups, respectively (P = .03). The median patient age was 66 years, and the median Karnofsky Performance Status was 90. In patients with any grade RN, 1- and 2-year rates were 6.4% and 9.9%, respectively. In patients with SRN, 1- and 2-year rates were 4.8% and 7.2%, respectively. On RPA, the highest-fidelity models consistently identified V12 Gy as the dominant variable predictive of RN. Three risk groups were identified by V12 Gy: (1) < 12 cm³; (2) 20 cm³ ≥ V12 Gy ≥ 12 cm³; (3) V12 Gy > 20 cm³. In patients with any grade RN, 1-year rates were 3.7% (V12 Gy < 12 cm³), 10.3% (20 cm³ ≥ V12 Gy ≥ 12 cm³), and 12.6% (V12 Gy > 20 cm³); the 2-year rates were 7.5% (V12 Gy < 12 cm³), 13.8% (20 cm³ ≥ V12 Gy ≥ 12 cm³), and 15.4% (V12 Gy > 20 cm³) (P < 0.001). In patients with any SRN, 1-year rates were 2.4% (V12 Gy < 12 cm³), 8.9% (20 cm³ ≥ V12 Gy ≥ 12 cm³), and 10.3% (V12 Gy > 20 cm³); the 2-year rates were 4.4% (V12 Gy < 12 cm³), 12.4% (20 cm³ ≥ V12 Gy ≥ 12 cm³), and 13.1% (V12 Gy > 20 cm³; P < 0.001). There were no statistically significant differences in rates of any grade RN or SRN when accounting for therapy timing for all patients and by V12 risk group identified on RPA.

CONCLUSIONS

The use of SRS and ICI results in a low risk of any grade RN and SRN. This risk is not increased with concurrent administration. Therefore, ICI can safely be administered within 4-weeks of SRS. Three risk groups based on V12 Gy were identified, which clinicians may consider to further reduce rates of RN.

Concurrent Administration of Immune Checkpoint Inhibitors and Stereotactic Radiosurgery Is Well-Tolerated in Patients With Melanoma Brain Metastases: An International Multicenter Study of 203 Patients

BACKGROUND

Melanoma brain metastases are commonly treated with stereotactic radiosurgery (SRS) and immune checkpoint inhibitors (ICIs). However, the toxicity of these 2 treatments is largely unknown when administered concurrently.

OBJECTIVE

To evaluate the risk of radiation necrosis (RN) with concurrent and nonconcurrent SRS and ICIs.

METHODS

The guidelines from the Strengthening the Reporting of Observational Studies in Epidemiology checklist were used. Inverse probability of treatment weighting, univariable and multivariable logistic regression, and the Kaplan-Meier method was utilized.

RESULTS

There were 203 patients with 1388 brain metastases across 11 international institutions in 4 countries with a median follow-up of 15.6 months. The rates of symptomatic RN were 9.4% and 8.2% in the concurrent and nonconcurrent groups, respectively ( P =.766). On multivariable logistic regression, V12 ≥ 10 cm 3 (odds ratio [OR]: 2.76; P =.006) and presence of BRAF mutation (OR: 2.20; P =.040) were associated with an increased risk of developing symptomatic RN; the use of concurrent over nonconcurrent therapy was not associated with an increased risk (OR: 1.06; P =.877). There were 20 grade 3 toxic events reported, and no grade 4 events reported. One patient experienced a grade 5 intracranial hemorrhage. The median overall survival was 36.1 and 19.8 months for the concurrent and nonconcurrent groups (log-rank P =.051), respectively.

CONCLUSION

Concurrent administration of ICIs and SRS are not associated with an increased risk of RN. Tumors harboring BRAF mutation, or perhaps prior exposure to targeted agents, may increase this risk. Radiosurgical optimization to maintain V12 < 10 cm 3 is a potential strategy to reduce the risk of RN.

Imaging-defined necrosis after treatment with single-fraction stereotactic radiosurgery and immune checkpoint inhibitors and its potential association with improved outcomes in patients with brain metastases: an international multicenter study of 697 patients

OBJECTIVE

Immune checkpoint inhibitors (ICIs) and stereotactic radiosurgery (SRS) are commonly utilized in the management of brain metastases. Treatment-related imaging changes (TRICs) are a frequently observed clinical manifestation and are commonly classified as imaging-defined radiation necrosis. However, these findings are not well characterized and may predict a response to SRS and ICIs. The objective of this study was to investigate predictors of TRICs and their impact on patient survival.

METHODS

This retrospective multicenter cohort study was conducted through the International Radiosurgery Research Foundation. Member institutions submitted de-identified clinical and dosimetric data for patients with non-small cell lung cancer (NSCLC), melanoma, and renal cell carcinoma (RCC) brain metastases that had been treated with SRS and ICIs. Data were collected from March 2020 to February 2021. Univariable and multivariable Cox and logistic regression analyses were performed. The Kaplan-Meier method was used to evaluate overall survival (OS). The diagnosis-specific graded prognostic assessment was used to guide variable selection. TRICs were determined on the basis of MRI, PET/CT, or MR spectroscopy, and consensus by local clinical providers was required.

RESULTS

The analysis included 697 patients with 4536 brain metastases across 11 international institutions in 4 countries. The median follow-up after SRS was 13.6 months. The median age was 66 years (IQR 58-73 years), 54.1% of patients were male, and 57.3%, 36.3%, and 6.4% of tumors were NSCLC, melanoma, and RCC, respectively. All patients had undergone single-fraction radiosurgery to a median margin dose of 20 Gy (IQR 18-20 Gy). TRICs were observed in 9.8% of patients. The median OS for all patients was 24.5 months. On univariable analysis, Karnofsky Performance Status (KPS; HR 0.98, p < 0.001), TRICs (HR 0.67, p = 0.03), female sex (HR 0.67, p < 0.001), and prior resection (HR 0.60, p = 0.03) were associated with improved OS. On multivariable analysis, KPS (HR 0.98, p < 0.001) and TRICs (HR 0.66, p = 0.03) were associated with improved OS. A brain volume receiving ≥ 12 Gy of radiation (V12Gy) ≥ 10 cm3 (OR 2.78, p < 0.001), prior whole-brain radiation therapy (OR 3.46, p = 0.006), and RCC histology (OR 3.10, p = 0.01) were associated with an increased probability of developing TRICs. The median OS rates in patients with and without TRICs were 29.0 and 23.1 months, respectively (p = 0.03, log-rank test).

CONCLUSIONS

TRICs following ICI and SRS were associated with a median OS benefit of approximately 6 months in this retrospective multicenter study. Further prospective study and additional stratification are needed to validate these findings and further elucidate the role and etiology of this common clinical scenario.

Physician Satisfaction With Telemedicine During the COVID-19 Pandemic: The Mayo Clinic Florida Experience

OBJECTIVE

To evaluate physician perceptions and attitudes toward telemedicine use at a tertiary care academic institution in northeast Florida during the coronavirus disease 2019 pandemic.

PATIENTS AND METHODS

An anonymous 38-question cross-sectional survey was developed using Qualtrics survey software (Qualtrics) and e-mailed to all staff physicians from all specialty disciplines at Mayo Clinic in Florida. The survey was open from August 17, 2020, through September 1, 2020. Collected data included general demographic characteristics and employment information, attitude and experience with telemedicine use before and during the coronavirus disease 2019 pandemic, perception of patients' experience, and the effect of telemedicine on burnout.

RESULTS

The survey was distributed to 529 eligible physicians at our institution, with 103 physicians responding (20%). The distribution of specialties was 22% primary care specialties, 41% other internal medicine subspecialties, and 18% surgical specialties. Collectively, 63% found comparable quality of care when provided virtually (vs in-person) whereas 80% perceived telemedicine as cost-effective. A total of 76% of physicians felt that telemedicine increased flexibility and control over patient care activities, with 36% reporting improved work-life balance and 30% reporting improved burnout symptoms. Overall, 42% preferred using telemedicine over in-person visits when possible.

CONCLUSION

Physicians generally had positive attitudes regarding the adoption of telemedicine and perceived that the quality of health care delivery as generally comparable to in-person care. Future studies are needed to explore attitudes regarding telemedicine after the pandemic and how this virtual technology may be further used to improve physicians' professional and personal well-being.

The Role of Particle Therapy in Adenoid Cystic Carcinoma and Mucosal Melanoma of the Head and Neck

Particle irradiation is suitable for resistant histologies owing to a combination of improved dose delivery with potential radiobiologic advantages in high linear energy transfer radiation. Within the head and neck, adenoid cystic carcinoma and mucosal melanoma are two such histologies, being radioresistant and lying closely proximal to critical structures. Here, we review the use of particle irradiation for adenoid cystic carcinoma and mucosal melanoma of the head and neck.

Boron Neutron Capture Therapy: A Review of Clinical Applications

Boron neutron capture therapy (BNCT) is an emerging treatment modality aimed at improving the therapeutic ratio for traditionally difficult to treat tumors. BNCT utilizes boronated agents to preferentially deliver boron-10 to tumors, which, after undergoing irradiation with neutrons, yields litihium-7 and an alpha particle. The alpha particle has a short range, therefore preferentially affecting tumor tissues while sparing more distal normal tissues. To date, BNCT has been studied clinically in a variety of disease sites, including glioblastoma multiforme, meningioma, head and neck cancers, lung cancers, breast cancers, hepatocellular carcinoma, sarcomas, cutaneous malignancies, extramammary Paget's disease, recurrent cancers, pediatric cancers, and metastatic disease. We aim to provide an up-to-date and comprehensive review of the studies of each of these disease sites, as well as a review on the challenges facing adoption of BNCT.

Estimating the Number of Patients Eligible for Carbon Ion Radiotherapy in the United States

Purpose

Carbon ion radiotherapy (CIRT) is an emerging radiotherapy modality with potential advantages over conventional photon-based therapy, including exhibiting a Bragg peak and greater relative biological effectiveness, leading to a higher degree of cell kill. Currently, 13 centers are treating with CIRT, although there are no centers in the United States. We aimed to estimate the number of patients eligible for a CIRT center in the United States.

Materials and Methods

Using the National Cancer Database, we analyzed the incidence of cancers frequently treated with CIRT internationally (glioblastoma, hepatocellular carcinoma, cholangiocarcinoma, locally advanced pancreatic cancer, non-small cell lung cancer, localized prostate cancer, soft tissue sarcomas, and specific head and neck cancers) diagnosed in the United States in 2015. The percentage and number of patients likely benefiting from CIRT was estimated with inclusion criteria from clinical trials and retrospective studies, and that ratio was applied to 2019 cancer statistics. An adaption correction rate was applied to estimate the potential number of patients treated with CIRT. Given the high dependency on prostate and lung cancers and the uncertain adoption of CIRT in those diseases, the data were then reanalyzed excluding those diagnoses.

Results

Of the 1 127 455 new cases of cancer diagnosed in the United States in 2015, there were 213 073 patients (18.9%) eligible for treatment with CIRT based on inclusion criteria. When applying this rate and the adaption correction rate to the 2019 incidence data, an estimated 89 946 patients (42.2% of those fitting inclusion criteria) are eligible for CIRT. Excluding prostate and lung cancers, there were an estimated 8922 patients (10% of those eligible for CIRT) eligible for CIRT. The number of patients eligible for CIRT is estimated to increase by 25% to 27.7% by 2025.

Conclusion

Our analysis suggests a need for CIRT in the United States in 2019, with the number of patients possibly eligible to receive CIRT expected to increase during the coming 5 to 10 years.

Repeat Radiation in the Brain: Managing Patients With Locally Recurrent Glioma

Treatment of recurrent gliomas is especially challenging, as many of these patients have previously been treated with extensive surgery, radiation, or systemic therapy. Due to this, the optimum therapy for patients with recurrent glioma is controversial, with widely variable practice patterns. In this opinion piece, a multidisciplinary panel of experts provides rationale for their treatment approach in a patient with recurrent glioma following subtotal resection with adjuvant chemoradiation for an anaplastic astrocytoma. In summary, the consensus of the panel was to recommend re-resection if possible with hypofractionated radiotherapy schedules, with re-irradiation and systemic therapy as directed by a multidisciplinary team through repeat analysis of the tumor specimen for an updated mutational burden.

Assessment of unintended shifts during frame-based stereotactic radiosurgery using cone beam computed tomography image guidance

PURPOSE

To investigate the frequency, magnitude and possible causes of frame-shifts that may occur between treatment planning and treatment delivery when performing Gamma Knife radiosurgery with rigid frame-based immobilization.

METHODS

Differences between computed tomography (CT) framed fiducial stereotactic coordinate reference and cone beam computed tomography stereotactic coordinates after image registration were recorded for 49 frame-based GK radiosurgery cases performed using the Gamma Knife Icon. Parameters recorded include rotational shifts, translational shifts, and the GK-computed Maximum Shot Displacement (MSD) between the two stereotactic coordinate spaces. Other patient-specific parameters were collected and linear regression analysis was performed to evaluate predictors of increased displacement.

RESULTS

The median values of rotational shifts were: pitch 0.14°, yaw 0.17°, and roll 0.13°. The median absolute values of translational shifts were: left-right 0.39 mm, anteroposterior 0.14 mm, and superior-inferior 0. 22 mm. The median value of MSD was 0.71 mm. Twelve cases (24.5%) had a MSD of greater than 1.0 mm. Male gender was associated with increased MSD (p = 0.013) and translational shifts (root-mean-squared value, p = 0.017). Cases with large differences between right and left sided pin lengths were also associated with increased MSD (p = 0.011).

CONCLUSIONS

The use of CBCT image guidance in frame-based GK radiosurgery allows unintended frame shifts to be identified and corrected. A significant fraction (24.5%) of patients had large enough shifts to result in a MSD of greater than 1.0 mm. Male gender and eccentrically placed frames were associated with increased MSD, and particular care should be taken in these cases.

Proton beam therapy utilization in adults with primary brain tumors in the United States

The utilization of proton beam therapy (PBT) as the primary treatment of adults with primary brain tumors (APBT) was evaluated through query of the National Cancer Database (NCDB) between the years 2004 and 2015. International Classification of Diseases for Oncology code for each patient was stratified into six histology categories; high-grade gliomas, medulloblastomas, ependymomas, other gliomas, other malignant tumors, or other benign intracranial tumors. Demographics of the treatment population were also analyzed. A total of 1,296 patients received PBT during the 11-year interval for treatment of their primary brain tumor. High-grade glioma, medulloblastoma, ependymoma, other glioma, other malignant, and other benign intracranial histologies made up 39%, 20%, 13%, 12%, 13%, and 2% of the cohort, respectively. The number of patients treated per year increased from 34 to 300 in years 2004 to 2015. Histologies treated with PBT varied over the 11-year interval with high-grade gliomas comprising 75% and 45% at years 2004 and 2015, respectively. The majority of the patient population was 18-29 years of age (59%), Caucasian race (73%), had median reported income of over $63,000 (46%), were privately insured (68%), and were treated at an academic institution (70%). This study characterizes trends of malignant and benign APBT histologies treated with PBT. Our data from 2004 through 2015 illustrates a marked increase in the utilization of PBT in the treatment of APBT and shows variability in the tumor histology treated over this time.

Carbon Ion Therapy: A Modern Review of an Emerging Technology

Radiation therapy is one of the most widely used therapies for malignancies. The therapeutic use of heavy ions, such as carbon, has gained significant interest due to advantageous physical and radiobiologic properties compared to photon based therapy. By taking advantage of these unique properties, carbon ion radiotherapy may allow dose escalation to tumors while reducing radiation dose to adjacent normal tissues. There are currently 13 centers treating with carbon ion radiotherapy, with many of these centers publishing promising safety and efficacy data from the first cohorts of patients treated. To date, carbon ion radiotherapy has been studied for almost every type of malignancy, including intracranial malignancies, head and neck malignancies, primary and metastatic lung cancers, tumors of the gastrointestinal tract, prostate and genitourinary cancers, sarcomas, cutaneous malignancies, breast cancer, gynecologic malignancies, and pediatric cancers. Additionally, carbon ion radiotherapy has been studied extensively in the setting of recurrent disease. We aim to provide a comprehensive review of the studies of each of these disease sites, with a focus on the current trials using carbon ion radiotherapy.

Intracranial motion during frameless Gamma-Knife stereotactic radiosurgery

PURPOSE/OBJECTIVES

The Gamma-Knife radiosurgery (GKRS) (Elekta AB, Stockholm) platform delivers highly conformal and precise radiation; however, intracranial displacement during treatment allows for the potential of a marginal target-miss. Frameless (mask-based) GKRS using the Gamma Knife Icon system monitors nasal tip motion as a surrogate for intracranial motion by tracking an infrared marker using a high-definition motion management (HDMM) system. To date, there is limited data available regarding the incidence and severity of motion and factors that impact intrafraction motion when treating with frameless GKRS.

MATERIALS/METHODS

A retrospective study was performed to evaluate patients with brain tumors who were treated with frameless GKRS using the Gamma Knife Icon between May and December 2018. All patients underwent mask-based immobilization using a thermoplastic mask. Data on patient demographics, mask type, use of bite block, and number of treatments received, use of anxiolytics, treatment time, and whether a physics clearance check was performed prior to treatment were collected. For each treatment session, average displacement (mm), maximum displacement (mm) and total treatment time (min) were recorded and logistic regression analyses were performed.

RESULTS

Data was collected for 89 consecutive treatments (38 patients). Of these, an anxiolytic was used in 61 treatments and a physics clearance check was performed for 45 treatments. The median average and maximum displacement was 0.60 mm and 1.22 mm, respectively. An average displacement greater than 0.60 mm was seen with Eastern Cooperative Oncology Group performance status (ECOG) > 1, male gender, and malignant tumors (p < 0.05). Anxiolytic use prior to treatment was associated with a significant reduction in average displacement (p < 0.05). Significantly greater odds of observing a maximum displacement over 1.22 mm was seen with patients with ECOG > 1, male gender, and increased treatment time (p < 0.05). Age > 65 and anxiolytic use were associated with a significant reduction in maximum displacement (p < 0.05). Performance of clearance checks and use of bite block use did not impact average or maximum patient displacement.

CONCLUSIONS

This is the first study to evaluate patient and treatment-related factors that influence intrafraction motion during GKRS with mask-based immobilization through HDMM tracking. Increased intracranial displacement during frameless GKRS was associated with higher ECOG, male gender, increased treatment time and malignant tumors, while anxiolytics were shown to mitigate excessive motion. Radiosurgery teams should consider these patient factors when treating patients with mask immobilization.

The management of elderly patients with brain metastases from breast cancer

Breast cancer is the most common type of malignancy diagnosed in women worldwide, as well as the second most common cause of metastatic brain lesions in the general population. Most breast cancer patients enrolled in clinical trials are relatively young. Elderly patients, as compared to their younger counterparts, pose unique clinical scenarios because there is limited data in this subpopulation of patients with brain metastases from breast cancer. Elderly patients are commonly treated with less aggressive therapies, perhaps due to comorbid conditions, patient preference, or other age-related concerns. Current treatment modalities offering more favorable toxicity profiles, along with more accurate prognosis, can represent an opportunity to offer improved care for this patient population. From the few efforts studying brain metastatic disease in the elderly, it is be possible to infer that age alone may not play an independent role in treatment selection and that a patient-specific evaluation and ultimate clinical judgment should guide clinical decision-making.

Public interest in stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) in the United States

Stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery have become widely used in both palliative and curative treatments for variety of primary and secondary malignancies. Although the indications and use of stereotactic techniques have increased substantially in the past decades, there been no studies to date analyzing public interest in these techniques. Using Google Trends (Google LLC, Mountain View, CA), four search terms ("SBRT," "stereotactic radiosurgery," "Gamma Knife" and "Cyberknife") were analyzed in the U.S. from January 2004 to June 2019. Each term was assigned a relative interest score based on frequency of searches. "SBRT" is becoming an increasingly popular search term, reaching peak interest in October 2018. Conversely, "stereotactic radiosurgery" and "Gamma Knife" radiosurgery initially had high interest, before declining over the past decade. "Cyberknife" was most popular in the mid-2000s but decreased steadily since that time. These trends were subsequently compared against PubMed publication data over the same time.

Idiopathic mast cell activation syndrome and radiation therapy: a case study, literature review, and discussion of mast cell disorders and radiotherapy

BACKGROUND

Mast Cell Activation Syndrome (MCAS) is classified as an idiopathic mast cell disorder where inconsistent or unknown triggers release inflammatory mediators and cause a constellation of symptoms. Studies demonstrate mast cells increase histamine, tryptase, and inflammatory cytokine expression following ionizing radiation. Additionally, there are cases of cutaneous mastocytosis developing within the initial radiation field suggesting mast cells play a role in local tissue reactions. Literature is sparse on radiation induced toxicity in patients with mast cell disorders.

CASE PRESENTATION

A 62 year old female patient with a history of MCAS received breast conservation therapy for invasive lobular carcinoma of the left breast initially AJCC 7th Stage IIB, pT3 pN0 M0. The patient underwent external beam radiotherapy (EBRT) and received 4500 cGy to the left whole breast, followed by a 1000 cGy boost to the lumpectomy cavity. She developed grade 1 radiation dermatitis. Two years later she progressed distantly and received stereotactic body radiation therapy to a lumbar vertebrae lesion to a dose of 2400 cGy in a single fraction. She developed no in-field dermatologic or systemic flare in her MCAS symptoms during radiation therapy.

CONCLUSIONS

To our knowledge there are no reported cases in the literature of patients diagnosed with MCAS or other idiopathic mast cell disorders undergoing radiation therapy. Idiopathic mast cell disorders such as MCAS and primary mast cell disorders alike should not be considered a contraindication to treatment with EBRT. This patient population appears to tolerate treatment without systemic flares in symptoms.

Google Search Trends in Oncology and the Impact of Celebrity Cancer Awareness

Introduction

There is widespread public interest when celebrities are diagnosed with cancer. We sought to assess how this interest impacts awareness of prevalent cancers.

Methods

We reviewed common cancer-related search terms using Google Trends (Google LLC, Mountain View, CA) between the years 2004 and 2017 and retrospectively correlated these findings with media or celebrity-related events. The Google Trends application was used to obtain the “search volume index” (SVI), defined as the number of searches for a specific term standardized to the total number of searches over that time period. Data were presented in a graphical format. Isolated peaks of greater than 25% from the baseline SVI were identified. Using the date of the peaks, a further search was performed to determine if any event in the media triggered the peak.

Results

“Lung Cancer,” “Pancreas Cancer,” “Endometrial Cancer,” “Cervical Cancer,” “Brain Cancer,” and “Glioblastoma” each had the highest peak correspond with a celebrity-related event covered in the media. These search terms displayed several additional isolated peaks, the majority of which could all be correlated with a significant media event (%). The search term “Breast Cancer” consistently had a peaked interest during October (breast cancer awareness month). Breast cancer events relating to public figures had little to no relative impact on search volume during this period. None of the other cancer search terms displayed the same cyclical pattern during their respective awareness months. Colon, rectal, and prostate cancer demonstrated stable search volumes over time, without an isolated peak.

Conclusion

Internet search activity among English speakers of most general cancer terms exhibit peaks coinciding with events that occur to celebrity figures or advances in medicines that are substantially covered in the media. In all cases but “breast cancer,” these events lend to higher search activity as compared to campaigns and awareness months. Our study suggests that media coverage of public figures with cancer may trigger substantial Internet interest in non-breast cancers, more so than traditional efforts to raise awareness.

Identifying the Most Costly Patients in Radiation Oncology and Predicting the Top Spenders

PURPOSE:

Quality payment programs aim to adjust payments on the basis of quality and cost; however, few quality metrics exist in radiation oncology. This study evaluates and predicts the top spenders (TS) after radiation therapy (RT).

MATERIALS AND METHODS:

Patient characteristics, cancer details, treatments, toxicity, and survival data were collected for patients treated with RT at Mayo Clinic from 2007 to 2016. Standardized costs were obtained and adjusted for inflation. TSs were identified as those with greater than 93rd percentile costs (≥ $120,812). Prediction models were developed to predict TSs using training and validation sets using information available at consultation, after RT, and at last follow-up.

RESULTS:

A total of 15,131 patients were included and 1,065 TSs identified. Mean cost overall was $55,290 (median, $39,996) for all patients. Prediction models 1, 2, and 3 had concordance statistics of 0.83 to 0.83, 0.85 to 0.85, and 0.87 to 0.88, respectively in training and validation, indicating excellent prediction of TSs. Factors that were most predictive of TSs included stage N/A and stage 4 ( v stage 0; odds ratio [OR], 18.23 and 8.44, respectively; P < .001); hematologic, upper GI, skin and lung cancers ( v breast; OR, 11.45, 7.69, 3.81, and 2.43, respectively; P < .01); immunotherapy, surgery, and chemotherapy use (OR, 4.36, 2.51, and 1.61, respectively; P < .01); hospitalizations within 90 days of RT (OR, 2.26; P < .01); or death during the episode (OR, 1.56; P < .01).

CONCLUSION:

This is the first study of its kind to predict with high accuracy the highest spenders in radiation oncology. These patients may benefit from pre-emptive management to mitigate costs, or may require exclusion or adjustment from quality payment programs.

Identifying and predicting the most costly patients in oncology

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Background: Quality based payment programs in medicine are currently being introduced nationally, aimed to improve care and reduce cost. This study aimed to evaluate the top spenders (TS) after cancer diagnosis and predict TS at two separate time points using predictive analytics. Methods: Patient characteristics, cancer details, treatments, adverse events, and outcomes were collected for patients treated for cancer at Mayo Clinic from 2007 - 2017. Standardized costs over a 2 year period after first treatment were obtained from the Mayo Clinic Cost Data Warehouse with Medicare reimbursements assigned to all services and adjusted to the 2017 GDP Implicit Price Deflator for inflation. TS were identified as those with greater than 93rd percentile costs (≥$113,158) due to a sharp rise in cost at that level. Descriptive statistics and univariate analysis were used for comparison. A prediction model with a training (80%) and validation set (20%) using multivariate selection was used to predict TS and was repeated using information available at 1) the time of consultation and 2) at last follow-up. Results: A total of 80,385 patients were included and 5,626 TS were identified. Mean cost (25th, 75th percentile) overall was $44,953 ($16,776, $51,889). Prediction models at time 1 and 2 had ROC AUC statistics of 0.82 and 0.89 in training and 0.82 and 0.88 in the validation indicating good prediction of high costs. Factors most predictive of TS included need for blood transfusions within 90 days of treatment (OR 5.3), bone marrow transplant (OR 4.0), mild liver disease (OR 3.5), hemiplegia (OR 3.4), weight loss > 10% within 90 days of treatment (OR 3.3), upper GI cancer (OR 3.0), ‘other’ cancer type (OR 2.8), immunotherapy use (OR 2.7), and hospitalizations within 90 days (OR 2.4), all p < 0.001, among others. The largest costs were due to hospital services in the TS and non-TS groups, mean costs $114,258 and $13,185 respectively. Conclusions: This is the first study to predict with high accuracy the top spenders in Oncology. Patient comorbidities and toxicities were among the strongest predictors of high costs, along with certain treatments (bone marrow transplant and immunotherapy). Our findings suggest that quality payment programs should adjust for comorbidities, and that reducing toxicity may be an effective method at reducing costs.

The cost implications of palliative radiation therapy dose and fractionation for painful metastatic bone lesions

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Background: Palliative radiation treatment (pRT) is used for symptomatic bone metastases (mets). Several fractionation schedules show equal efficacy for pain relief, and ASTRO’s Choosing Wisely recommends 8Gy x1, 4Gy x5, or 3Gy x10. This study aims to investigate the cost implications of pRT for bone mets. Methods: Patients (Pts) treated with pRT for bone mets at Mayo Clinic from 2007 - 2016 were included in this study. Costs for all services were subdivided into RT and total costs at 30 & 90 days (30D & 90D). Standardized costs were obtained from the Mayo Clinic Cost Data Warehouse and Medicare reimbursements were assigned to all services with cost to charge adjustments and 2017 GDP Implicit Price Deflator for inflation. Cost means were compared via the Kruskal-Wallis test. Results: 538 pts were treated with pRT, 124 receiving 8Gy x1, 204 receiving 4Gy x5, and 210 receiving 3Gy x10. Pts with breast and prostate cancer were most likely to be treated with 3Gy x10 and pts with GI and lung cancer were most likely to be treated with 8Gy x1. RT costs at 30D were $1,497, $1,891, and $1,982 (p=0.03) and RT costs at 90D were $2,602, $2,753, and $3,032 (p=0.08) for initial RT regimens of 8Gy x1, 4Gy x5, and 3Gy x10. Total costs of care at 30D were similar from $15,969 - 17,687 (p=0.6) and total costs at 90D were similar from $22,361 - 23,219 (p=0.7) between arms. A total of 23%, 28%, and 39% of pts were alive 2 years following pRT from each arm (p=0.07). Conclusions: This is the first study of its kind to analyze actual treatment costs for the three most common pRT regimens in bone mets. Single fraction RT was most used for pts with poor prognoses and was associated with lower RT costs at 30D, but similar RT costs at 90D, possibly due to retreatment. RT choice had no impact on overall costs of care at 30D or 90D. pRT remains of high value, representing only 11-13% of total costs.[Table: see text]

Toxicity following palliative radiation therapy for painful metastatic bone lesions

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Background: Palliative radiation treatment (pRT) is a common and effective treatment for patients with symptomatic bone metastases. However, patients receiving RT for bone metastases often may have a poor performance status and are more likely to experience toxicity during or after treatment. This study aims to investigate the number and type of toxicity event occurring during or after pRT for bone metastases. Methods: Patients treated with RT for bone metastases at Mayo Clinic from 2007 to 2016 were included in this study. Demographic, disease, treatment, and toxicity information were collected. Specifically, toxicity events were identified as emergency department (ED) visits and inpatient hospitalization (IH) within 90 days, breaks in treatment >4 days, and excessive 30 day financial toxicity defined as standardized Medicare costs >1 standard deviation above the mean. RT treatment was compared by dose and fractionation via descriptive statistics. Results: A total of 538 patients treated with pRT were identified, 124 receiving 8Gy x1, 204 receiving 4Gy x5, and 210 receiving 3Gy x10. Patients with breast and prostate cancer were most likely to be treated with 3Gy x10 and patients with GI and Lung cancer were most likely to be treated with 8Gy x1. A description of the patient characteristics and toxicities are shown in Table 1. For 8Gy x1, 4Gy x5, and 3Gy x10 breaks in treatment were rare (0%, 2%, and 3.3%), ED visits (15%, 24%, & 28%), IH (12%, 23%, & 19%), and financial toxicity (13%, 18%, & 21%) were common. A total of 22.6%, 27.5%, and 38.6% of patients were alive two years following pRT from each group. Conclusions: Toxicity during or shortly after pRT of bone metastases is common. This study confirms that additional steps should be taken to monitor and mitigate toxicity in this vulnerable patient group. [Table: see text]