The patient's perspective on breast radiotherapy: Initial fears and expectations versus reality.

BACKGROUND: Although the efficacy and toxicity of breast radiotherapy (RT) has been studied extensively, to the authors' knowledge little is known regarding the patient's perspective on the modern breast RT experience. To better inform future patients and providers, the authors explored patient perceptions of their RT experience. METHODS: Consecutive patients who were free of disease recurrence and who had been treated between 2012 and 2016 were surveyed regarding their original fears, how short-term and long-term toxicities compared with initial expectations, and how pretreatment beliefs concerning RT compared with the actual experience. RESULTS: A total of 502 patients were surveyed, with a response rate of 65% (327 patients). The median patient age and posttreatment follow-up was 59 years and 31 months, respectively. Approximately 83% of patients (269 patients) underwent breast conservation therapy. Although approximately 68% of patients (221 patients) endorsed that they initially had little to no knowledge regarding RT, approximately 47% (152 patients) reported that they had heard frightening stories. Approximately 2% of patients (6 patients) agreed that the negative stories they previously heard about RT were actually true. Approximately 92% of patients treated with breast conservation (247 patients) and 81% of patients who underwent mastectomy (47 patients) agreed with the statement "If future patients knew the real truth about RT, they would be less scared about treatment." Approximately 83% (272 patients) and 84% (274 patients), respectively, of all patients reported the overall severity of short-term and long-term side effects to be better than or as expected. CONCLUSIONS: Breast RT is associated with misconceptions and fears. Patients' experiences with modern breast RT appear to be superior to expectations, and the majority of patients in the current study agreed that their initial negative impressions were unfounded. Cancer 2018;124:1673-81. © 2018 American Cancer Society.

Patient-reported quality-of-life outcomes after de-escalated chemoradiation for human papillomavirus-positive oropharyngeal carcinoma: Findings from a phase 2 trial.

BACKGROUND: The current study represents a subset analysis of quality-of-life (QOL) outcomes among patients treated on a phase 2 trial of de-escalated chemoradiation for human papillomavirus (HPV)-associated oropharyngeal cancer. METHODS: Eligibility included newly diagnosed, (American Joint Committee on Cancer, 7th edition) stage III or IV oropharyngeal squamous cell carcinoma, p16 positivity, age ≥ 18 years, and a Zubrod performance status of 0 to 1. Treatment was induction paclitaxel at a dose of 175 mg/m2 and carboplatin at an area under the curve of 6 for 2 cycles followed by response-adapted, dose-reduced radiation of 54 Gy or 60 Gy with weekly concurrent paclitaxel at a dose of 30 mg/m2 . The University of Washington Quality of Life (UW-QOL) and the Functional Assessment of Cancer Therapy-Head and Neck questionnaires were used to assess patient-reported QOL as a secondary endpoint. RESULTS: A total of 45 patients were registered, 40 of whom completed QOL surveys and were evaluable. Nadirs for overall UW-QOL and Functional Assessment of Cancer Therapy-Head and Neck scores were reached at 4 weeks after treatment but returned to baseline at 3 months. Nearly all functional indices returned to baseline levels by 6 to 9 months. The mean overall UW-QOL score was 71.6 at baseline compared with 70.8, 73.0, 83.3, and 81.1, respectively, at 3 months, 6 months, 1 year, and 2 years after therapy. The percentage of patients rating their overall QOL as "very good" or "outstanding" at 6 months, 1 year, and 2 years using the UW-QOL was 50%, 77%, and 84%, respectively. CONCLUSIONS: This de-escalation regimen achieved QOL outcomes that were favorable compared with historical controls. These results serve as powerful evidence that ongoing de-escalation efforts lead to tangible gains in function and QOL. Cancer 2018;124:521-9. © 2017 American Cancer Society.

Radical Prostatectomy, External Beam Radiotherapy, or External Beam Radiotherapy With Brachytherapy Boost and Disease Progression and Mortality in Patients With Gleason Score 9-10 Prostate Cancer.

Importance: The optimal treatment for Gleason score 9-10 prostate cancer is unknown. Objective: To compare clinical outcomes of patients with Gleason score 9-10 prostate cancer after definitive treatment. Design, Setting, and Participants: Retrospective cohort study in 12 tertiary centers (11 in the United States, 1 in Norway), with 1809 patients treated between 2000 and 2013. Exposures: Radical prostatectomy (RP), external beam radiotherapy (EBRT) with androgen deprivation therapy, or EBRT plus brachytherapy boost (EBRT+BT) with androgen deprivation therapy. Main Outcomes and Measures: The primary outcome was prostate cancer-specific mortality; distant metastasis-free survival and overall survival were secondary outcomes. Results: Of 1809 men, 639 underwent RP, 734 EBRT, and 436 EBRT+BT. Median ages were 61, 67.7, and 67.5 years; median follow-up was 4.2, 5.1, and 6.3 years, respectively. By 10 years, 91 RP, 186 EBRT, and 90 EBRT+BT patients had died. Adjusted 5-year prostate cancer-specific mortality rates were RP, 12% (95% CI, 8%-17%); EBRT, 13% (95% CI, 8%-19%); and EBRT+BT, 3% (95% CI, 1%-5%). EBRT+BT was associated with significantly lower prostate cancer-specific mortality than either RP or EBRT (cause-specific HRs of 0.38 [95% CI, 0.21-0.68] and 0.41 [95% CI, 0.24-0.71]). Adjusted 5-year incidence rates of distant metastasis were RP, 24% (95% CI, 19%-30%); EBRT, 24% (95% CI, 20%-28%); and EBRT+BT, 8% (95% CI, 5%-11%). EBRT+BT was associated with a significantly lower rate of distant metastasis (propensity-score-adjusted cause-specific HRs of 0.27 [95% CI, 0.17-0.43] for RP and 0.30 [95% CI, 0.19-0.47] for EBRT). Adjusted 7.5-year all-cause mortality rates were RP, 17% (95% CI, 11%-23%); EBRT, 18% (95% CI, 14%-24%); and EBRT+BT, 10% (95% CI, 7%-13%). Within the first 7.5 years of follow-up, EBRT+BT was associated with significantly lower all-cause mortality (cause-specific HRs of 0.66 [95% CI, 0.46-0.96] for RP and 0.61 [95% CI, 0.45-0.84] for EBRT). After the first 7.5 years, the corresponding HRs were 1.16 (95% CI, 0.70-1.92) and 0.87 (95% CI, 0.57-1.32). No significant differences in prostate cancer-specific mortality, distant metastasis, or all-cause mortality (≤7.5 and >7.5 years) were found between men treated with EBRT or RP (cause-specific HRs of 0.92 [95% CI, 0.67-1.26], 0.90 [95% CI, 0.70-1.14], 1.07 [95% CI, 0.80-1.44], and 1.34 [95% CI, 0.85-2.11]). Conclusions and Relevance: Among patients with Gleason score 9-10 prostate cancer, treatment with EBRT+BT with androgen deprivation therapy was associated with significantly better prostate cancer-specific mortality and longer time to distant metastasis compared with EBRT with androgen deprivation therapy or with RP.

Predictors associated with MRI surveillance screening in women with a personal history of unilateral breast cancer but without a genetic predisposition for future contralateral breast cancer.

PURPOSE: For women with a personal history of breast cancer (PHBC), no validated mechanisms exist to calculate future contralateral breast cancer (CBC) risk. The Manchester risk stratification guidelines were developed to evaluate CBC risk in women with a PHBC, primarily for surgical decision making. This tool may be informative for the use of MRI screening, as CBC risk is an assumed consideration for high-risk surveillance. METHODS: Three hundred twenty-two women with a PHBC were treated with unilateral surgery within our multidisciplinary breast clinic. We calculated lifetime CBC risk using the Manchester tool, which incorporates age at diagnosis, family history, genetic mutation status, estrogen receptor positivity, and endocrine therapy use. Univariate and multivariate logistic regression analyses (UVA/MVA) were performed, evaluating whether CBC risk predicted MRI surveillance. RESULTS: For women with invasive disease undergoing MRI surveillance, 66% had low, 23% above-average, and 11% moderate/high risk for CBC. On MVA, previous mammography-occult breast cancer [odds ratio (OR) 18.95, p < 0.0001], endocrine therapy use (OR 3.89, p = 0.009), dense breast tissue (OR 3.69, p = 0.0007), mastectomy versus lumpectomy (OR 3.12, p = 0.0041), and CBC risk (OR 3.17 for every 10% increase, p = 0.0002) were associated with MRI surveillance. No pathologic factors increasing ipsilateral breast cancer recurrence were significant on MVA. CONCLUSIONS: Although CBC risk predicted MRI surveillance, 89% with invasive disease undergoing MRI had <20% calculated CBC risk. Concerns related to future breast cancer detectability (dense breasts and/or previous mammography-occult disease) predominate decision making. Pathologic factors important for determining ipsilateral recurrence risk, aside from age, were not associated with MRI surveillance.

Juxtapapillary and circumpapillary choroidal melanoma: globe-sparing treatment outcomes with iodine-125 notched plaque brachytherapy.

PURPOSE: Managing juxtapapillary and circumpapillary choroidal melanoma with brachytherapy is challenging because of technical complications with accurate plaque placement and high radiation toxicity given tumor proximity to the optic nerve. We evaluated our center's experience using ultrasound-guided, Iodine (I)-125 notched plaque brachytherapy for treating choroidal melanoma contiguous with (juxtapapillary) and at least partially surrounding the optic disc (circumpapillary). METHODS: All cases of choroidal melanoma treated with I-125 notched plaque brachytherapy at our center from September 2003-December 2013 were retrospectively reviewed. Only patients with ≥18 months of follow-up who had lesions contiguous with the optic disc (0 mm of separation) were included. The tumor apex prescription dose was 85 Gy. Outcomes evaluated included local control, distant metastasis-free survival (DMFS), cancer-specific survival (CSS), overall survival (OS), visual acuity, and radiation toxicity. RESULTS: Thirty-four patients were included with a median follow-up of 44.1 months (range 18.2-129.0). AJCC T-category was T1 in 58.8%, T2 in 26.5%, and T3 in 14.7%. Median circumferential optic disc involvement was 50% (range 10%-100%). Eye retention was achieved in 94.1%. Actuarial 2- and 4-year rates of local recurrence were 3.1% and 7.6%, DMFS were 97.0% and 88.5%, CSS were 97.0% and 92.8%, and OS were 97.0% and 88.9%, respectively. In addition, 23.5% had visual acuity ≥20/200 at last follow-up. CONCLUSIONS: I-125 notched plaque brachytherapy provides high eye preservation rates with acceptable longer-term post-treatment visual outcomes. Based on our experience, choroidal melanoma directly contiguous with and partially encasing the optic disc may be effectively treated with this technique.

Does the addition of targeted prostate biopsies to standard systemic biopsies influence treatment management for radiation oncologists?

OBJECTIVES: To study the management impact that magnetic resonance imaging (MRI)-guided targeted prostate biopsies could provide relative to using only non-targeted systematic biopsies in men with clinically localized prostate cancer (PCa). PATIENTS AND METHODS: A consecutive series of untreated men undergoing Artemis (MRI-ultrasonography fusion) biopsies between March 2010 and June 2013 was evaluated in this retrospective, institutional review board-approved study. Fusion biopsy included MRI-targeted and systematic sampling at the same session. 3-Tesla multiparametric MRI was performed at a median of 2 weeks before biopsy. Patients were included if ≥1 systematic core was found to harbour PCa. The impact of the information obtained from targeted vs systematic biopsies was studied with regard to the following: Gleason score (GS), National Comprehensive Cancer Network (NCCN) risk reclassification, cancer core length, percentage of core positive for tumour involvement, and percentage of positive biopsy cores. RESULTS: The study sample included 215 men (mean ± sd age 66 ± 8 years). The median (range) prostate-specific antigen (PSA) was 6.0 (0.7-181) ng/mL. The mean number of total biopsy samples was 18 (12 systematic and six targeted samples). Of 215 men, 34 (16%) had a higher GS on targeted vs systematic biopsy. A total of 21/183 men (12%) were stratified into a higher NCCN risk group when incorporating targeted biopsy GS results and 18/101 men (18%) were upgraded to intermediate- or high-risk from the low-risk group. Among the 34 men whose cancer severity was upgraded, increases in cancer core length, percentage of tumour involvement and percentage of cores involved were all statistically significant (P < 0.01). CONCLUSION: Targeted prostate biopsy provided information about GS, NCCN risk and tumour volume beyond that obtained in systematic biopsies, specifically increasing the proportions of men in the intermediate- and high-risk groups. Such men may be recommended for additional treatments (pelvic nodal irradiation or hormonal therapy). The appropriateness of changing treatment because of targeted biopsy results is still unclear.

How we used a patient visit tracker tool to advance experiential learning in systems-based practice and quality improvement in a medical student clinic.

Poorly designed healthcare systems increase costs and preventable medical errors. To address these issues, systems-based practice (SBP) education provides future physicians with the tools to identify systemic errors and implement quality improvement (QI) initiatives to enhance the delivery of cost-effective, safe and multi-disciplinary care. Although SBP education is being implemented in residency programs and is mandated by the Accreditation Council for Graduate Medical Education (ACGME) as one of its core competencies, it has largely not been integrated into undergraduate medical education. We propose that Medical Student-Faculty Collaborative Clinics (MSFCCs) may be the ideal environment in which to train medical students in SBPs and QI initiatives, as they allow students to play pivotal roles in project development, administration, and management. Here we describe a process of experiential learning that was developed within a newly established MSFCC, which challenged students to identify inefficiencies, implement interventions, and track the results. After identifying bottlenecks in clinic operations, our students designed a patient visit tracker tool to monitor clinic flow and implemented solutions to decrease patient visit times. Our model allowed students to drive their own active learning in a practical clinical setting, providing early and unique training in crucial QI skills.

Results of an Artificial Intelligence-Based Image Review System to Detect Patient Misalignment Errors in a Multi-institutional Database of Cone Beam Computed Tomography-Guided Radiation Therapy.

PURPOSE: Present knowledge of patient setup and alignment errors in image guided radiation therapy (IGRT) relies on voluntary reporting, which is thought to underestimate error frequencies. A manual retrospective patient-setup misalignment error search is infeasible owing to the bulk of cases to be reviewed. We applied a deep learning-based misalignment error detection algorithm (EDA) to perform a fully automated retrospective error search of clinical IGRT databases and determine an absolute gross patient misalignment error rate. METHODS AND MATERIALS: The EDA was developed to analyze the registration between planning scans and pretreatment cone beam computed tomography scans, outputting a misalignment score ranging from 0 (most unlikely) to 1 (most likely). The algorithm was trained using simulated translational errors on a data set obtained from 680 patients treated at 2 radiation therapy clinics between 2017 and 2022. A receiver operating characteristic analysis was performed to obtain target thresholds. DICOM Query and Retrieval software was integrated with the EDA to interact with the clinical database and fully automate data retrieval and analysis during a retrospective error search from 2016 to 2017 and from 2021 to 2022 for the 2 institutions, respectively. Registrations were flagged for human review using both a hard-thresholding method and a prediction trending analysis over each individual patient's treatment course. Flagged registrations were manually reviewed and categorized as errors (>1 cm misalignment at the target) or nonerrors. RESULTS: A total of 17,612 registrations were analyzed by the EDA, resulting in 7.7% flagged events. Three previously reported errors were successfully flagged by the EDA, and 4 previously unreported vertebral body misalignment errors were discovered during case reviews. False positive cases often displayed substantial image artifacts, patient rotation, and soft tissue anatomy changes. CONCLUSIONS: Our results validated the clinical utility of the EDA for bulk image reviews and highlighted the reliability and safety of IGRT, with an absolute gross patient misalignment error rate of 0.04% ± 0.02% per delivered fraction.

Multiparametric MRI of prostate cancer: an update on state-of-the-art techniques and their performance in detecting and localizing prostate cancer.

Magnetic resonance (MR) examinations of men with prostate cancer are most commonly performed for detecting, characterizing, and staging the extent of disease to best determine diagnostic or treatment strategies, which range from biopsy guidance to active surveillance to radical prostatectomy. Given both the exam's importance to individual treatment plans and the time constraints present for its operation at most institutions, it is essential to perform the study effectively and efficiently. This article reviews the most commonly employed modern techniques for prostate cancer MR examinations, exploring the relevant signal characteristics from the different methods discussed and relating them to intrinsic prostate tissue properties. Also, a review of recent articles using these methods to enhance clinical interpretation and assess clinical performance is provided. J. Magn. Reson. Imaging 2013;37:1035-1054. © 2013 Wiley Periodicals, Inc.

Seizure outcomes following single-fraction versus hypofractionated radiosurgery for brain metastases: a single-center experience.

OBJECTIVE: Although seizures are a relatively common phenomenon in the setting of brain metastases (BMs), there are no discrete recommendations regarding the use of antiepileptic drugs (AEDs) in this population, either in general or in the context of treatment. The authors' aim was to better understand the underlying pathological factors as well as the therapeutic techniques that may lead to seizures following the radiosurgical treatment of BMs with the goal of guiding appropriate AED prophylaxis. METHODS: Adult patients with BMs diagnosed from 2013 to 2020 at a single academic institution and treated with radiation therapy were included in this study. The authors evaluated factors associated with the incidence of seizures throughout the disease course, with a focus on seizures in the 90-day period following stereotactic radiosurgery (SRS). RESULTS: Four hundred forty-four patients with newly diagnosed BMs were identified, 10% of whom had seizures at the time of presentation and 28% of whom had a seizure at any point during the study period. Tumor histology was significantly associated with initial seizure risk. AED use was highly variable. In the 90-day post-SRS period, the summed total planning target volume (PTV) was independently predictive of post-SRS seizures, regardless of the fractionation scheme (single fraction vs hypofractionated) and other clinical factors. The number of supratentorial BMs was not predictive of post-SRS seizures. CONCLUSIONS: PTV is a superior predictor of post-SRS seizures relative to the number of supratentorial BMs, as it serves as a volumetric proxy for intracranial disease burden. A larger PTV, alongside tumor histology and prior seizure history, should be considered in the decision-making process for AED use following radiosurgery.

Experience of Telemedicine Visits in Radiation Oncology During the COVID-19 Pandemic: A US National Survey and Lessons Learned for Incorporating Telemedicine Post-COVID-19.

Purpose: We sought to survey the attitudes and perceptions of US radiation oncologists toward the adoption of telemedicine during the COVID-19 pandemic and offer suggestions for its integration in the postpandemic era. Methods and Materials: A 25-question, anonymous online survey was distributed nationwide to radiation oncologists. Results: One hundred and twenty-one respondents completed the survey, with 92% from academia. Overall, 79% worked at institutions that had implemented a work-from-home policy, with which 74% were satisfied. Despite nearly all visit types being conducted in-person before COVID-19, 25%, 41%, and 5% of the respondents used telemedicine for more than half of their new consultations, follow-up, and on-treatment visits, respectively, during the COVID-19 pandemic. Most (83%) reported being comfortable integrating telemedicine. Although telemedicine was appreciated as being more convenient for patients (97%) and reducing transmission of infectious agents (83%), the most commonly perceived disadvantages were difficulty in performing physical examinations (90%), patients' inability to use technology adequately (74%), and technical malfunctions (72%). Compared with in-person visits, telemedicine was felt to be inferior in establishing a personal connection during consultation (90%) and assessing for toxicity while on-treatment (88%) and during follow-up (70%). For follow-up visits, genitourinary and thoracic were perceived as most appropriate for telemedicine while gynecologic and head and neck were considered the least appropriate. Overall, 70% were in favor of more telemedicine, even after pandemic is over. Conclusions: Telemedicine will likely remain part of the radiation oncology workflow in most clinics after the pandemic. It should be used in conjunction with in-person visits, and may be best used for conducting follow-up visits in certain disease sites such as genitourinary and thoracic malignancies.

Retrospective examination of pseudoprogression in IDH mutant gliomas.

Background: Tumor surveillance of isocitrate dehydrogenase (IDH) mutant gliomas is accomplished via serial contrast MRI. When new contrast enhancement (CEnew) is detected during postsurgical surveillance, clinicians must assess whether CEnew indicates pseudoprogression (PsP) or tumor progression (TP). PsP has been better studied in IDH wild-type glioblastoma but has not been well characterized in IDH mutant gliomas. We conducted a retrospective study evaluating the incidence, predictors, natural history, and survival of PsP patients in a large cohort of IDH mutant glioma patients treated at a single institution. Methods: We identified 587 IDH mutant glioma patients treated at UCLA. We directly inspected MRI images and radiology reports to identify CEnew and categorized CEnew into TP or PsP using MRI or histopathology. Results: Fifty-six percent of patients developed CEnew (326/587); of these, 92/326 patients (28% of CEnew; 16% of all) developed PsP and 179/326 (55%) developed TP. All PsP patients had prior radiation, chemotherapy, or chemoradiotherapy. PsP was associated with longer overall survival (OS) versus TP patients and similar OS versus no CEnew. PsP differs from TP based on earlier time of onset (median 5.8 vs 17.4 months from treatment, P < .0001) and MRI features that include punctate enhancement and enhancement location. Conclusion: PsP patients represented 28% of CEnew patients and 16% of all patients; PsP patients demonstrated superior outcomes to TP patients, and equivalent survival to patients without CEnew. PsP persists for <1 year, occurs after treatment, and differs from TP based on time of onset and radiographic features. Poor outcomes after CEnew are driven by TP.

Prostate-Centric Versus Bony-Centric Registration in the Definitive Treatment of Node-Positive Prostate Cancer with Simultaneous Integrated Boost: A Dosimetric Comparison.

Purpose: To determine the effect of daily shifts based on rigid registration to intraprostatic markers on coverage of boost doses delivered to gross nodal disease for prostate cancer. Methods and Materials: Seventy-five cone beam computed tomographies (CBCTs) from 15 patients treated with definitive radiation for clinically node-positive prostate cancer underwent fiducial-based and pelvic bony-based registration to the initial planning scans. Gross tumor volumes of nodal boost targets were contoured directly on each CBCT registration. The nodal displacement (3-dimensional translation from the node centroid on planning CT to node centroid on registered CBCT) and dose coverage (minimum dose [Dmin], mean dose [Dmean], dose delivered to 95% of the gross tumor volumes [D95]) were calculated for each registration on all nodal targets. All doses for each node were normalized to its intended prescription dose (dose covering 95% of a 3 mm planning target volume [PTV] expansion). Results: Forty-one gross nodal targets were analyzed. Most boosted nodes (80.5%, 33/41) were treated with conventional fractionation using volumetric-arc radiation therapy, and 19.5% (8/41) underwent stereotactic body radiation therapy (SBRT). Dmin, Dmean, and D95 were all significantly lower with fiducial-based registration compared with bony-based registration (P < .0001). Nodal displacement was significantly higher for fiducial-based registrations (P < .0001). The 3-dimensional translation between the fiducial-based and bony-based registrations (bony-to-fiducial vector) was the most significant predictor of nodal displacement (P < .0001). On fiducial-based registrations, a 3 to 5 mm gross nodal PTV margin is sufficient in most directions; however, superior and posterior margins of 8 to 9 mm are required as a result of asymmetrical prostatic motion. Conclusions: Large and anisotropic PTV margins are likely needed to adequately dose gross nodal targets when patient setup is based on rigid registration to intraprostatic markers. Alternative approaches such as adaptive replanning may be required to overcome these limitations.

A Prospective Phase II Study of Automated Non-Coplanar VMAT for Recurrent Head and Neck Cancer: Initial Report of Feasibility, Safety, and Patient-Reported Outcomes.

This study reports the initial results for the first 15 patients on a prospective phase II clinical trial exploring the safety, feasibility, and efficacy of the HyperArc technique for recurrent head and neck cancer treatment. Eligible patients were simulated and planned with both conventional VMAT and HyperArc techniques and the plan with superior dosimetry was selected for treatment. Dosimetry, delivery feasibility and safety, treatment-related toxicity, and patient-reported quality of life (QOL) were all evaluated. HyperArc was chosen over conventional VMAT for all 15 patients and enabled statistically significant increases in dose conformity (R50% reduced by 1.2 ± 2.1, p < 0.05) and mean PTV and GTV doses (by 15.7 ± 4.9 Gy, p < 0.01 and 17.1 ± 6.0 Gy, p < 0.01, respectively). The average HyperArc delivery was 2.8 min longer than conventional VMAT (p < 0.01), and the mean intrafraction motion was ≤ 0.5 ± 0.4 mm and ≤0.3 ± 0.1°. With a median follow-up of 12 months, treatment-related toxicity was minimal (only one grade 3 acute toxicity above baseline) and patient-reported QOL metrics were favorable. HyperArc enabled superior dosimetry and significant target dose escalation compared to conventional VMAT planning, and treatment delivery was feasible, safe, and well-tolerated by patients.

Ventilation measurements using fast-helical free-breathing computed tomography.

PURPOSE: To examine the use of multiple fast-helical free breathing computed tomography (FHFBCT) scans for ventilation measurement. METHODS: Ten patients were scanned 25 times in alternating directions using a FHFBCT protocol. Simultaneously, an abdominal pneumatic bellows was used as a real-time breathing surrogate. Regions-of-interest (ROIs) were selected from the upper right lungs of each patient for analysis. The ROIs were first registered using a published registration technique (pTV). A subsequent follow-up registration employed an objective function with two terms, a ventilation-adjusted Hounsfield Unit difference and a conservation-of-mass term labeled ΔΓ that denoted the difference between the deformation Jacobian and the tissue density ratio. The ventilations were calculated voxel-by-voxel as the slope of a first-order fit of the Jacobian as a function of the breathing amplitude. RESULTS: The ventilations of the 10 patients showed different patterns and magnitudes. The average ventilation calculated from the deformation vector fields (DVFs) of the pTV and secondary registration was nearly identical, but the standard deviation of the voxel-to-voxel differences was approximately 0.1. The mean of the 90th percentile values of ΔΓ was reduced from 0.153 to 0.079 between the pTV and secondary registration, implying first that the secondary registration improved the conservation-of-mass criterion by almost 50% and that on average the correspondence between the Jacobian and density ratios as demonstrated by ΔΓ was less than 0.1. This improvement occurred in spite of the average of the 90th percentile changes in the DVF magnitudes being only 0.58 mm. CONCLUSIONS: This work introduces the use of multiple free-breathing CT scans for free-breathing ventilation measurements. The approach has some benefits over the traditional use of 4-dimensional CT (4DCT) or breath-hold scans. The benefit over 4DCT is that FHFBCT does not have sorting artifacts. The benefits over breath-hold scans include the relatively small motion induced by quiet respiration versus deep-inspiration breath hold and the potential for characterizing dynamic breathing processes that disappear during breath hold.

Simultaneous radiosurgery for multiple brain metastases: technical overview of the UCLA experience.

PURPOSE/OBJECTIVE(S): To communicate our institutional experience with single isocenter radiosurgery treatments for multiple brain metastases, including challenges with determining planning target volume (PTV) margins and resulting consequences, image-guidance translational and rotational tolerances, intra-fraction patient motion, and prescription considerations with larger PTV margins. MATERIALS/METHODS: Eight patient treatments with 51 targets were planned with various margins using Elements Multiple Brain Mets SRS treatment planning software (Brainlab, Munich, Germany). Forty-eight plans with 0 mm, 1 mm and 2 mm margins were created, including plans with variable margins, where targets more than 6 cm away from the isocenter were planned with larger margins. The dosimetric impact of the margins were analyzed with V5Gy, V8Gy, V10Gy, V12Gy values. Additionally, 12 patient motion data were analyzed to determine both the impact of the repositioning threshold and the distributions of the patient translational and rotational movements. RESULTS: The V5Gy, V8Gy, V10Gy, V12Gy volumes approximately doubled when margins change from 0 to 1 mm and tripled when change from 0 to 2 mm. With variable margins, the aggregated results are similar to results from plans using the lower of two margins, since only 12.2% of the targets were more than 6 cm away from the isocenter. With 0.5 mm re-positioning threshold, 57.4% of the time the patients are repositioned. Reducing the threshold to 0.25 mm results in 91.7% repositioning rate, due to limitations of the fusion algorithm and actual patient motion. The 90th percentile of translational movements in all directions is 0.7 mm, while the 90th percentile of rotational movements in all directions is 0.6 degrees. Median translations and rotations are 0.2 mm and 0.2 degrees, respectively. CONCLUSIONS: Based on the data presented, we have switched our modus operandi from 2 to 1 mm PTV margins, with an eventual goal of using 0.5 and 1.0 mm variable margins when an automated margin assignment method becomes available. The 0.5 mm and 0.5 degrees repositioning thresholds are clinically appropriate with small residual patient movements.

A Framework for Sharing Radiation Dose Distribution Maps in the Electronic Medical Record for Improving Multidisciplinary Patient Management.

Radiation oncology practices use a suite of dedicated software and hardware that are not common to other medical subspecialties, making radiation treatment history inaccessible to colleagues. A radiation dose distribution map is generated for each patient internally that allows for visualization of the dose given to each anatomic structure volumetrically; however, this crucial information is not shared systematically to multidisciplinary medical, surgery, and radiology colleagues. A framework was developed in which dose distribution volumes are uploaded onto the medical center's picture archiving and communication system (PACS) to rapidly retrieve and review exactly where, when, and to what dose a lesion or structure was treated. The ability to easily visualize radiation therapy information allows radiology clinics to incorporate radiation dose into image interpretation without direct access to radiation oncology planning software and data. Tumor board discussions are simplified by incorporating radiation therapy information collectively in real time, and daily onboard imaging can also be uploaded while a patient is still undergoing radiation therapy. Placing dose distribution information into PACS facilitates central access into the electronic medical record and provides a succinct visual summary of a patient's radiation history for all medical providers. More broadly, the radiation dose map provides greater visibility and facilitates incorporation of a patient's radiation history to improve oncologic decision making and patient outcomes. Keywords: Brain/Brain Stem, CNS, MRI, Neuro-Oncology, Radiation Effects, Radiation Therapy, Radiation Therapy/Oncology, Radiosurgery, Skull Base, Spine, Technology Assessment Supplemental material is available for this article. © RSNA, 2021 See also commentary by Khandelwal and Scarboro in this issue.

Missing the Near Miss: Recognizing Valuable Learning Opportunities in Radiation Oncology.

PURPOSE: "Near miss" events are valuable low-cost learning opportunities in radiation oncology as they do not result in patient harm and are more pervasive than adverse events that do. Near misses vary depending on the presence of a latent error of behavior or process, and the presence of an enabling condition predisposing the patient to harm. These nuanced distinctions across near miss types can elicit different cognitive biases affecting the recognition of near misses as learning opportunities. We define near miss types in radiation oncology and explore the differential perceptions among radiation oncology staff. METHODS AND MATERIALS: Six event types were defined based on attributes of latent error and enabling conditions: "hit," "potential hit," "almost happened," "fortuitous catch," "could have happened," and "process-based catch." These events were illustrated with an example of a patient receiving pacemaker cardiac clearance before radiation treatment. A survey assessing (1) success versus failure of an event and (2) willingness to report the event was administered to a radiation oncology department using the pacemaker example. Mean scores for each near miss type were compared. RESULTS: Ninety-five staff members (74%) completed the survey. Perceived success scores and willing-to-report scores significantly differed by near miss type (P = .042 for success ratings; P < .0001 for willingness to report). "Could have happened" events were viewed as less successful and were more likely to be reported than "almost happened" events (P < .0001). CONCLUSIONS: Cognitive biases appear to influence whether and how near miss types are recognized as report-worthy. Education of near miss types and engaging staff for quality improvement may improve recognition.

Automated Non-Coplanar VMAT for Dose Escalation in Recurrent Head and Neck Cancer Patients.

This study evaluates the potential for tumor dose escalation in recurrent head and neck cancer (rHNC) patients with automated non-coplanar volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) planning (HyperArc). Twenty rHNC patients are planned with conventional VMAT SBRT to 40 Gy while minimizing organ-at-risk (OAR) doses. They are then re-planned with the HyperArc technique to match these minimal OAR doses while escalating the target dose as high as possible. Then, we compare the dosimetry, tumor control probability (TCP), and normal tissue complication probability (NTCP) for the two plan types. Our results show that the HyperArc technique significantly increases the mean planning target volume (PTV) and gross tumor volume (GTV) doses by 10.8 ± 4.4 Gy (25%) and 11.5 ± 5.1 Gy (26%) on average, respectively. There are no clinically significant differences in OAR doses, with maximum dose differences of <2 Gy on average. The average TCP is 23% (± 21%) higher for HyperArc than conventional plans, with no significant differences in NTCP for the brainstem, cord, mandible, or larynx. HyperArc can achieve significant tumor dose escalation while maintaining minimal OAR doses in the head and neck-potentially enabling improved local control for rHNC SBRT patients without increased risk of treatment-related toxicities.

High-Dose Rate Interstitial Spine Brachytherapy Using an Intraoperative Mobile Computed Tomography-Guided Surgical Navigation System.

BACKGROUND: Up to 15% of previously irradiated metastatic spine tumors will progress. Re-irradiation of these tumors poses a significant risk of exceeding the radiation tolerance to the spinal cord. High-dose rate (HDR) brachytherapy is a treatment alternative. OBJECTIVE: To develop a novel HDR spine brachytherapy technique using an intraoperative computed tomography-guided navigation (iCT navigation). METHODS: Patients with progressive metastatic spine tumors were included in the study. HDR brachytherapy catheters were placed under iCT navigation. CT-based planning with magnetic resonance imaging fusion was performed to ensure conformal dose delivery to the target while sparing normal tissue, including the spinal cord. Patients received single fraction radiation treatment. RESULTS: Five patients with thoracolumbar tumors were treated with HDR brachytherapy. Four patients previously received radiotherapy to the same spinal level. Preimplant plans demonstrated median clinical target volume (CTV) D90 of 116.5% (110.8%-147.7%), V100 of 95.7% (95.5%-99.6%), and Dmax of 8.08 Gy (7.65-9.8 Gy) to the spinal cord/cauda equina. Postimplant plans provided median CTV D90 of 113.8% (93.6%-120.1%), V100 of 95.9% (87%-99%), and Dmax of 9.48 Gy (6.5-10.3 Gy) to cord/cauda equina. Patients who presented with back pain (n = 3) noted symptomatic improvement at a median follow-up of 22 d after treatment. Four patients demonstrated local tumor control of spinal metastatic tumor at a median follow-up of 92 d after treatment. One patient demonstrated radiographic evidence of local tumor progression 2.7 mo after treatment. CONCLUSION: HDR spine brachytherapy with iCT navigation is a promising treatment alternative to induce local tumor control and reduce pain symptoms associated with metastatic spine disease.