Patient Education Practices and Preferences of Radiation Oncologists and Interprofessional Radiation Therapy Care Teams: A Mixed-Methods Study Exploring Strategies for Effective Patient Education Delivery.

PURPOSE: Patients' understanding of radiation therapy (RT) and data regarding optimal approaches to patient education (PE) within radiation oncology (RO) are limited. We aimed to evaluate PE practices of radiation oncologists and interprofessional RT care team members to inform recommendations for delivering inclusive and accessible PE. METHODS AND MATERIALS: An anonymous survey was administered to all Radiation Oncology Education Collaborative Study Group members (10/5/22-11/23/22). Respondent demographics, individual practices/preferences, and institutional practices were collected. Qualitative items explored strategies, challenges, and desired resources for PE. Descriptive statistics summarized survey responses. The Fisher exact test compared PE practices by respondent role and PE timing. Thematic analysis was used for qualitative responses. RESULTS: One hundred thirteen Radiation Oncology Education Collaborative Study Group members completed the survey (28.2% response rate); RO attendings comprised 68.1% of respondents. Most practiced in an academic setting (85.8%) in North America (80.5%). Institution-specific materials were the most common PE resource used by radiation oncologists (67.6%). Almost half (40.2%) reported that their PE practices differed based on clinical encounter type, with paper handouts commonly used for in-person and multimedia for telehealth visits. Only 57.7% reported access to non-English PE materials. PE practices among radiation oncologists differed according to RT clinical workflow timing (consultation versus simulation versus first RT, respectively): one-on-one teaching: 88.5% versus 49.4% versus 56.3%, P < .01, and paper handouts: 69.0% versus 28.7% versus 16.1%, P < .01. Identified challenges for PE delivery included limited time, administrative barriers to the development or implementation of new materials or practices, and a lack of customized resources for tailored PE. Effective strategies for PE included utilization of visual diagrams, multimedia, and innovative education techniques to personalize PE delivery/resources for a diverse patient population, as well as fostering interprofessional collaboration to reinforce educational content. CONCLUSIONS: Radiation oncologists and interprofessional RO team members engage in PE, with most using institution-specific materials often available only in English. PE practices differ according to clinical encounter type and RT workflow timing. Increased adoption of multimedia materials and partnerships with patients to tailor PE resources are needed to foster high-quality, patient-centered PE delivery.

Psychosocial Factors That Influence a Woman's Decision to Enroll in a Clinical Trial: Implications on How to Improve Clinical Trial Enrollment Among Black Women.

PURPOSE: Black women with breast cancer often present with more aggressive disease compared with other races, contributing to an increased risk of cancer mortality. Despite this inequity, Black women remain severely underrepresented in breast cancer clinical trials. We aim to characterize factors that influence a woman's decision to enroll in a clinical trial, with the goal of identifying clinical interventions to aid in the recruitment of vulnerable groups. METHODS AND MATERIALS: A cross-sectional, descriptive study was conducted using a questionnaire adapted from 2 prevalidated surveys investigating factors influencing clinical trial enrollment. The survey was administered to women with curable breast cancer during a single follow-up visit at 4 different sites within a university medical system where all patients are screened for clinical trial eligibility. Chi-square tests and Mann-Whitney U tests were used to assess associations or differences between the populations. RESULTS: One hundred ninety-four out of 209 women completed the survey, giving a compliance rate of 93%. Twenty-six percent of women self-identified as Black, most women were located at community sites (67.1%), most women had diagnoses of early-stage disease (I: 57.7%, II: 29.4%), and 81% of women had some collegiate-level education. Black women were younger at diagnosis (P = .005) and less likely to be married (P = .012) but more often lived with family members (P = .003) and had a lower median income (P < .001). According to the survey, Black women were less likely to trust their care team (P = .032), more likely to believe that research ultimately harms minorities (P < .001), and had a stronger belief in God's will determining illness and wellness (P < .001). Recurring themes of trust in the health care team, patient education, and advancement of cancer treatments were discussed in the focus groups. CONCLUSIONS: Failure to offer clinical trials and mistrust in research institutions may pose the greatest hindrances to the enrollment of Black women in clinical trials. Empowering women through education and fostering trustworthy relationships can encourage greater clinical trial participation.

The AAPM/ASTRO 2023 Core Physics Curriculum for Radiation Oncology Residents.

PURPOSE: The American Association of Physicists in Medicine Radiation Oncology Medical Physics Education Subcommittee (ROMPES) has updated the radiation oncology physics core curriculum for medical residents in the radiation oncology specialty. METHODS AND MATERIALS: Thirteen physicists from the United States and Canada involved in radiation oncology resident education were recruited to ROMPES. The group included doctorates and master's of physicists with a range of clinical or academic roles. Radiation oncology physician and resident representatives were also consulted in the development of this curriculum. In addition to modernizing the material to include new technology, the updated curriculum is consistent with the format of the American Board of Radiology Physics Study Guide Working Group to promote concordance between current resident educational guidelines and examination preparation guidelines. RESULTS: The revised core curriculum recommends 56 hours of didactic education like the 2015 curriculum but was restructured to provide resident education that facilitates best clinical practice and scientific advancement in radiation oncology. The reference list, glossary, and practical modules were reviewed and updated to include recent literature and clinical practice examples. CONCLUSIONS: ROMPES has updated the core physics curriculum for radiation oncology residents. In addition to providing a comprehensive curriculum to promote best practice for radiation oncology practitioners, the updated curriculum aligns with recommendations from the American Board of Radiology Physics Study Guide Working Group. New technology has been integrated into the curriculum. The updated curriculum provides a framework to appropriately cover the educational topics for radiation oncology residents in preparation for their subsequent career development.

From Beaming Cancer to Beaming Parent: Paternity Leave Experiences in Radiation Oncology.

PURPOSE: Although supported by most men and women, paternity leave is heavily underused across industries owing in part to external pressures and inconsistent availability. The goal of this study was to assess the use of paternity leave in radiation oncology (RO) practices and identify any associated barriers. METHODS AND MATERIALS: A 36-item survey was distributed via e-mail to 536 male domestic RO attending and resident physicians. Questions assessed paternity leave policies, use, and departmental support. Data were collected using Research Electronic Data Capture from January to February 2021. Descriptive statistics were obtained for analysis, and logistic regression was performed to analyze the association between practice type and presence of policy. RESULTS: The survey response rate was 20% (n = 108), with 98% of participants completing all applicable questions. Respondents included 63 attending physicians (58%) and 45 resident physicians (42%). The median age of all respondents was 35 years. Among all participants, 51 (47%) stated their practice had a formal paternity leave policy. The median time allowed for leave was 4 weeks (range, 0.5 weeks to unlimited), whereas the median time taken was 2 weeks (range, 0.5-12 weeks). Sixteen men felt pressure to take less leave than what was allowed by their policy, and 46% of men stated that in retrospect, they would have taken more time off for paternity leave. CONCLUSIONS: To the authors' knowledge, this is the first study to investigate the use of paternity leave in RO practices in the United States. Integrating expanded family leave policies, including specifically allowing for paternity leave and accompanying these policies with cultural changes acknowledging the importance of family leave, would be beneficial to improving quality of life and work-life balance for parents.

Correlation of treatment time to target volume for GammaPod treatments: A simple second calculation.

PURPOSE: The GammaPod is a novel device for stereotactic breast treatments that employs 25 rotating Co-60 sources while the patient is continuously translated in three axes to deliver a highly conformal dose to the target. There is no commercial software available for independent second calculations. The purpose of this study is to determine an efficient way to estimate GammaPod treatment times based on target volume and use it as a second calculation for patient-specific quality assurance. METHODS: Fifty-nine GammaPod (Xcision Medical Systems, LLC.) breast cancer patient treatments were used as the fitting dataset for this study. Similar to the Curie-seconds concept in brachytherapy, we considered dose-rate × time/(prescribed dose) as a function of target volumes. Using a MATLAB (Mathworks, Natick, MA, USA) script, we generated linear (with 95% confidence interval (CI)) and quadratic fits and tested the resulting equations on an additional set of 30 patients. RESULTS: We found a strong correlation between the dose-rate × time/(prescribed dose) and patients' target volumes for both the linear and quadratic models. The linear fit was selected for use and using the polyval function in MATLAB, a 95% CI graph was created to depict the accuracy of the prediction for treatment times. Testing the model on 30 additional patients with target volumes ranging from 20 to 188 cc yielded treatment times from 10 to 25 min that in all cases were within the predicted CI. The average absolute difference between the predicted and actual treatment times was 1.0 min (range 0-3.3 min). The average percent difference was 5.8% (range 0%-18.4%). CONCLUSION: This work has resulted in a viable independent calculation for GammaPod treatment times. This method has been implemented as a spreadsheet that is ready for clinical use to predict and verify the accuracy of breast cancer treatment times.

Phase II trial of proton therapy versus photon IMRT for GBM: secondary analysis comparison of progression-free survival between RANO versus clinical assessment.

BACKGROUND: This secondary image analysis of a randomized trial of proton radiotherapy (PT) versus photon intensity-modulated radiotherapy (IMRT) compares tumor progression based on clinical radiological assessment versus Response Assessment in Neuro-Oncology (RANO). METHODS: Eligible patients were enrolled in the randomized trial and had MR imaging at baseline and follow-up beyond 12 weeks from completion of radiotherapy. "Clinical progression" was based on a clinical radiology report of progression and/or change in treatment for progression. RESULTS: Of 90 enrolled patients, 66 were evaluable. Median clinical progression-free survival (PFS) was 10.8 (range: 9.4-14.7) months; 10.8 months IMRT versus 11.2 months PT (P = .14). Median RANO-PFS was 8.2 (range: 6.9, 12): 8.9 months IMRT versus 6.6 months PT (P = .24). RANO-PFS was significantly shorter than clinical PFS overall (P = .001) and for both the IMRT (P = .01) and PT (P = .04) groups. There were 31 (46.3%) discrepant cases of which 17 had RANO progression more than a month prior to clinical progression, and 14 had progression by RANO but not clinical criteria. CONCLUSIONS: Based on this secondary analysis of a trial of PT versus IMRT for glioblastoma, while no difference in PFS was noted relative to treatment technique, RANO criteria identified progression more often and earlier than clinical assessment. This highlights the disconnect between measures of tumor response in clinical trials versus clinical practice. With growing efforts to utilize real-world data and personalized treatment with timely adaptation, there is a growing need to improve the consistency of determining tumor progression within clinical trials and clinical practice.

A prospective phase II randomized trial of proton radiotherapy vs intensity-modulated radiotherapy for patients with newly diagnosed glioblastoma.

BACKGROUND: To determine if proton radiotherapy (PT), compared to intensity-modulated radiotherapy (IMRT), delayed time to cognitive failure in patients with newly diagnosed glioblastoma (GBM). METHODS: Eligible patients were randomized unblinded to PT vs IMRT. The primary endpoint was time to cognitive failure. Secondary endpoints included overall survival (OS), intracranial progression-free survival (PFS), toxicity, and patient-reported outcomes (PROs). RESULTS: A total of 90 patients were enrolled and 67 were evaluable with median follow-up of 48.7 months (range 7.1-66.7). There was no significant difference in time to cognitive failure between treatment arms (HR, 0.88; 95% CI, 0.45-1.75; P = .74). PT was associated with a lower rate of fatigue (24% vs 58%, P = .05), but otherwise, there were no significant differences in PROs at 6 months. There was no difference in PFS (HR, 0.74; 95% CI, 0.44-1.23; P = .24) or OS (HR, 0.86; 95% CI, 0.49-1.50; P = .60). However, PT significantly reduced the radiation dose for nearly all structures analyzed. The average number of grade 2 or higher toxicities was significantly higher in patients who received IMRT (mean 1.15, range 0-6) compared to PT (mean 0.35, range 0-3; P = .02). CONCLUSIONS: In this signal-seeking phase II trial, PT was not associated with a delay in time to cognitive failure but did reduce toxicity and patient-reported fatigue. Larger randomized trials are needed to determine the potential of PT such as dose escalation for GBM and cognitive preservation in patients with lower-grade gliomas with a longer survival time.

Proton therapy reduces the likelihood of high-grade radiation-induced lymphopenia in glioblastoma patients: phase II randomized study of protons vs photons.

BACKGROUND: We investigated differences in radiation-induced grade 3+ lymphopenia (G3+L), defined as an absolute lymphocyte count (ALC) nadir of <500 cells/µL, after proton therapy (PT) or X-ray (photon) therapy (XRT) for patients with glioblastoma (GBM). METHODS: Patients enrolled in a randomized phase II trial received PT (n = 28) or XRT (n = 56) concomitantly with temozolomide. ALC was measured before, weekly during, and within 1 month after radiotherapy. Whole-brain mean dose (WBMD) and brain dose-volume indices were extracted from planned dose distributions. Univariate and multivariate logistic regression analyses were used to identify independent predictive variables. The resulting model was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: Rates of G3+L were lower in men (7/47 [15%]) versus women (19/37 [51%]) (P < 0.001), and for PT (4/28 [14%]) versus XRT (22/56 [39%]) (P = 0.024). G3+L was significantly associated with baseline ALC, WBMD, and brain volumes receiving 5‒40 Gy(relative biological effectiveness [RBE]) or higher (ie, V5 through V40). Stepwise multivariate logistic regression analysis identified being female (odds ratio [OR] 6.2, 95% confidence interval [CI]: 1.95‒22.4, P = 0.003), baseline ALC (OR 0.18, 95% CI: 0.05‒0.51, P = 0.003), and whole-brain V20 (OR 1.07, 95% CI: 1.03‒1.13, P = 0.002) as the strongest predictors. ROC analysis yielded an area under the curve of 0.86 (95% CI: 0.79-0.94) for the final G3+L prediction model. CONCLUSIONS: Sex, baseline ALC, and whole-brain V20 were the strongest predictors of G3+L for patients with GBM treated with radiation and temozolomide. PT reduced brain volumes receiving low and intermediate doses and, consequently, reduced G3+L.

Timing of esophagectomy after neoadjuvant chemoradiation treatment in squamous cell carcinoma.

BACKGROUND: Time interval between neoadjuvant (combined) chemotherapy and radiation (nCRT) and surgery has been linked to pathologic response rates and outcomes in patients with various solid cancers. The optimal timing between nCRT and esophagectomy in patients with esophageal squamous cell carcinoma (SCC), however, is not known. Our aim was to analyze the relation between elapsed time from completion of nCRT to esophagectomy and postsurgical mortality and overall survival. METHODS: We reviewed the National Cancer Database for patients with SCC (n = 1,244) of the esophagus diagnosed between 2003 and 2011 who were treated with nCRT followed by esophagectomy within 26 weeks after completion of nCRT. RESULTS: Thirty-day mortality was 5.6% and 90-day mortality was 11.1%. The duration of post-nCRT interval was not a predictor of 30-day and 90-day postoperative mortality in multivariate models, but 30-day postoperative mortality was predictable based on increasing Charlson-Deyo comorbidities (adjusted odds ratio [aOR] 1.77, P = .054) and improved in academic institutions (aOR 0.66, P = .005). Similar findings were found for 90-day mortality (comorbidity index aOR 1.58, P = .046) and for treatment at an academic facility (0.82, P = .062). In a multivariate survival analysis, the duration of the post-nCRT interval was not found to be a predictor of overall survival (P = .769), whereas increasing age (hazard ratio [HR] 1.02, P = .005), increasing comorbidity score (HR 1.38, P = .005), treatment at an academic hospital (HR 0.84, P = .001), and post-treatment nodal status (HR 1.73, P < .001) were predictors. CONCLUSION: Perioperative mortality and overall survival are not affected by the time interval between completion of nCRT and esophagectomy among patients with SCC histology.

Robust treatment comparison based on utilities of semi-competing risks in non-small-cell lung cancer.

A design is presented for a randomized clinical trial comparing two second-line treatments, chemotherapy versus chemotherapy plus reirradiation, for treatment of recurrent non-small-cell lung cancer. The central research question is whether the potential efficacy benefit that adding reirradiation to chemotherapy may provide justifies its potential for increasing the risk of toxicity. The design uses two co-primary outcomes: time to disease progression or death, and time to severe toxicity. Because patients may be given an active third-line treatment at disease progression that confounds second-line treatment effects on toxicity and survival following disease progression, for the purpose of this comparative study follow-up ends at disease progression or death. In contrast, follow-up for disease progression or death continues after severe toxicity, so these are semi-competing risks. A conditionally conjugate Bayesian model that is robust to misspecification is formulated using piecewise exponential distributions. A numerical utility function is elicited from the physicians that characterizes desirabilities of the possible co-primary outcome realizations. A comparative test based on posterior mean utilities is proposed. A simulation study is presented to evaluate test performance for a variety of treatment differences, and a sensitivity assessment to the elicited utility function is performed. General guidelines are given for constructing a design in similar settings, and a computer program for simulation and trial conduct is provided.

Body mass index and blood glucose in psychiatric and general practice populations.

Aims and method Using a retrospective observational approach, we aimed to discern whether there was a difference in metabolic parameters between psychiatric and general practice populations in the same locality. Second, we aimed to establish differences in metabolic parameters of patients taking olanzapine, clozapine or aripiprazole. Results Patients with psychiatric illness had a body mass index (BMI) comparable to that of the general practice population (28.7 v. 29.7 kg/m(2)), but blood glucose was significantly lower in the general practice population (4.8 v. 6.1 mmol/L). Olanzapine was associated with the lowest BMI (26.1 kg/m(2)) and aripiprazole the highest (32.2 kg/m(2)), with no difference in blood glucose between antipsychotics. Clinical implications Awareness of environmental factors and how they affect individuals is important and medications are not the only cause of metabolic effects. There may be a channelling bias present, meaning practitioners are cognisant of potential metabolic effects prior to prescribing. Overall monitoring of physical health is important regardless of potential cause.

Effectiveness of long-acting antipsychotics in clinical practice: 2. Effects of antipsychotic polypharmacy on risperidone long-acting injection and zuclopenthixol decanoate.

OBJECTIVES: Antipsychotic polypharmacy (APP) is common clinical practice. Theoretically, APP runs the risk of additional side effects, drug interactions, adherence and cost. A limited evidence base is emerging to support the effectiveness of APP in clinical practice. Our companion paper highlighted the extent of APP alongside commonly prescribed long-acting antipsychotic injections (LAIs). We aimed to examine the effects of APP on discontinuation rates and Clinical Global Impression (CGI) outcomes in patients commenced on risperidone long-acting injection (RLAI) and zuclopenthixol decanoate. METHOD: LAI-naïve patients commenced on RLAI (n = 102) and zuclopenthixol decanoate(n = 105) were identified using our electronic patient record (running from 2002) within NHS Lanarkshire, Scotland, UK. This was a retrospective, electronic case note review with an 18-month follow up. Patient groups were divided into those receiving the LAI as the sole antipsychotic and those who were receiving additional oral antipsychotic polypharmacy (APP) for at least 50% of the duration of the treatment with their LAI. Kaplan-Meier statistics were calculated for discontinuation rates. CGI severity and improvement scores were retrospectively assigned by the investigating team. RESULTS: Antipsychotic polypharmacy occurred with RLAI (37%) and zuclopenthixol decanoate (46%) and was associated with lower discontinuation rates (statistical significant with zuclopenthixol for any cause and adverse effects discontinuation). APP had no adverse outcomes on hospital admissions or CGI ratings. Patients on APP did not have more severe, chronic or treatment resistant illnesses. CONCLUSIONS: For RLAI and zuclopenthixol decanoate, APP had some favourable outcomes when examining discontinuation rates for any cause, and adverse effects. This was unexpected as we had considered APP would signal illness chronicity and severity and be associated with increased adverse effects resulting in early discontinuation. APP had no adverse outcomes on assigned CGI improvement or mean end-point severity ratings for RLAI and zuclopenthixol decanoate.

Effectiveness of long-acting antipsychotics in clinical practice : 1. A retrospective, 18-month follow up and comparison between paliperidone palmitate, risperidone long-acting injection and zuclopenthixol decanoate.

OBJECTIVES: In the UK, nine different compounds are available as long-acting antipsychotic injections (LAIs). There are few clinical guidelines for determining which LAIs are most effective in specific patient groups. To measure the clinical effectiveness of LAIs we aimed to determine the now-established concept of antipsychotic discontinuation rates and measure Clinical Global Impression (CGI) outcomes. METHOD: The population (n was approximately 560,000) was a secondary care NHS adult mental health service in Lanarkshire, Scotland, UK. This was a retrospective, electronic case note search of LAI-naïve patients commenced on paliperidone palmitate (n = 31), risperidone long-acting injection (RLAI) (n = 102) or zuclopenthixol decanoate (n = 105), with an 18-month follow up. Kaplan-Meier survival statistics for discontinuation rates and hospital admission were calculated. CGI severity and improvement scores were retrospectively assigned by the investigating team. RESULTS: Paliperidone palmitate performed less favourably than risperidone long-acting injection (RLAI) or zuclopenthixol decanoate. Paliperidone palmitate had higher discontinuation rates due to any cause, inefficacy and increased hospitalization risk. Paliperidone palmitate had the smallest proportion of patients assigned a clinically desirable CGI-I score of 1 (very much improved) or 2 (much improved). CONCLUSIONS: Paliperidone palmitate had less favourable discontinuation and CGI outcomes compared with RLAI and zuclopenthixol decanoate. This could not be adequately explained by patients in the paliperidone group being more chronically or severely unwell, nor by the presence of comorbidities such as alcohol or substance misuse, or by the use of lower mean dosages compared with RLAI or zuclopenthixol decanoate. We considered that prescribers are familiarizing themselves with paliperidone and outcomes may improve over time.

Definitive reirradiation for locoregionally recurrent non-small cell lung cancer with proton beam therapy or intensity modulated radiation therapy: predictors of high-grade toxicity and survival outcomes.

PURPOSE: Intrathoracic recurrence of non-small cell lung cancer (NSCLC) after initial treatment remains a dominant cause of death. We report our experience using proton beam therapy and intensity modulated radiation therapy for reirradiation in such cases, focusing on patterns of failure, criteria for patient selection, and predictors of toxicity. METHODS AND MATERIALS: A total of 102 patients underwent reirradiation for intrathoracic recurrent NSCLC at a single institution. All doses were recalculated to an equivalent dose in 2-Gy fractions (EQD2). All patients had received radiation therapy for NSCLC (median initial dose of 70 EQD2 Gy), with median interval to reirradiation of 17 months and median reirradiation dose of 60.48 EQD2 Gy. Median follow-up time was 6.5 months (range, 0-72 months). RESULTS: Ninety-nine patients (97%) completed reirradiation. Median local failure-free survival, distant metastasis-free survival (DMFS), and overall survival times were 11.43 months (range, 8.6-22.66 months), 11.43 months (range, 6.83-23.84 months), and 14.71 (range, 10.34-20.56 months), respectively. Toxicity was acceptable, with rates of grade ≥3 esophageal toxicity of 7% and grade ≥3 pulmonary toxicity of 10%. Of the patients who developed local failure after reirradiation, 88% had failure in either the original or the reirradiation field. Poor local control was associated with T4 disease, squamous histology, and Eastern Cooperative Oncology Group performance status score >1. Concurrent chemotherapy improved DMFS, but T4 disease was associated with poor DMFS. Higher T status, Eastern Cooperative Oncology Group performance status ≥1, squamous histology, and larger reirradiation target volumes led to worse overall survival; receipt of concurrent chemotherapy and higher EQD2 were associated with improved OS. CONCLUSIONS: Intensity modulated radiation therapy and proton beam therapy are options for treating recurrent non-small cell lung cancer. However, rates of locoregional recurrence and distant metastasis are high, and patients should be selected carefully to maximize the benefit of additional aggressive local therapy while minimizing the risk of adverse side effects.

MRI-based sector analysis enhances prostate palladium-103 brachytherapy quality assurance in a phase II prospective trial of men with intermediate-risk localized prostate cancer.

PURPOSE: Palladium-103 ((103)Pd) may be superior to other isotopes in brachytherapy for localized intermediate-risk prostate cancer because of its relatively short half-life, higher initial dose rate, and greater dose heterogeneity within the target volume; these properties also underscore the need for accurate target delineation and postimplant quality assurance. We assessed the use of prostate sector analysis based on MRI for quality assurance after (103)Pd monotherapy. METHODS AND MATERIALS: Fifty men with intermediate-risk prostate cancer underwent (103)Pd monotherapy in a prospective phase II trial at MD Anderson Cancer Center. Dosimetric analyses on day 30 after the implant were done using both CT and fused CT/MRI scans. Dosimetric variables were assessed for the entire prostate and for each of three or six sectors. Volumes and dosimetric variables were compared with paired t tests. RESULTS: Postimplant dosimetric variables for the entire prostate were significantly different on CT vs. CT/MRI (p = 0.019 for V100 and p < 0.01 for D90). Prostate volumes were smaller on the CT/MRI scans (p < 0.00001). The base sector contributed the greatest difference, with doses based on CT/MRI lower than those based on CT (p < 0.01 for V100 and D90). To date, these lower base doses have not affected biochemical outcomes for patients with disease in prostate base biopsy samples. CONCLUSIONS: CT/MRI is more precise than CT for prostate volume delineation and dosimetric quality assessment and thus provides superior heterogeneity control assessment after (103)Pd monotherapy implants.

Feasibility of proton beam therapy for reirradiation of locoregionally recurrent non-small cell lung cancer.

BACKGROUND AND PURPOSE: Options are limited for patients with intrathoracic recurrence of non-small cell lung cancer (NSCLC) who previously received radiation. We report our 5-year experience with the toxicity and efficacy of proton beam therapy (PBT) for reirradiation. MATERIALS AND METHODS: Thirty-three patients underwent PBT reirradiation for intrathoracic recurrent NSCLC at a single institution. All patients had had RT for NSCLC (median initial dose 63 Gy in 33 fractions), with median interval to reirradiation of 36 months. Median reirradiation dose was 66 Gy (RBE) in 32 fractions. Toxicity was scored with CTCAE v4.0, and survival outcomes were estimated using Kaplan-Meier. RESULTS: Thirty-one patients (94%) completed reirradiation. At a median 11 months' follow-up, 1-year rates of overall survival, progression-free survival, locoregional control, and distant metastasis-free survival were 47%, 28%, 54%, and 39%. Rates of severe (grade ≥3) toxicity were 9% esophageal, 21% pulmonary; 1 patient had grade 4 esophagitis, and 2 had grade 4 pulmonary toxicity. Nine patients experienced a second in-field failure. CONCLUSIONS: PBT is an option for treating recurrent NSCLC. However, the rates of locoregional recurrence and distant metastasis are high and the potential for toxicity significant. The risks and benefits of PBT must be carefully weighed in each case.

Aortic dose constraints when reirradiating thoracic tumors.

BACKGROUND AND PURPOSE: Improved radiation delivery and planning has allowed, in some instances, for the retreatment of thoracic tumors. We investigated the dose limits of the aorta wherein grade 5 aortic toxicity was observed after reirradiation of lung tumors. MATERIAL AND METHODS: In a retrospective analysis, 35 patients were identified, between 1993 and 2008, who received two rounds of external beam irradiation that included the aorta in the radiation fields of both the initial and retreatment plans. We determined the maximum cumulative dose to 1 cm(3) of the aorta (the composite dose) for each patient, normalized these doses to 1.8 Gy/fraction, and corrected them for long-term tissue recovery between treatments (NIDR). RESULTS: The median time interval between treatments was 30 months (range, 1-185 months). The median follow-up of patients alive at analysis was 42 months (range, 14-70 months). Two of the 35 patients (6%) were identified as having grade 5 aortic toxicities. There was a 25% rate of grade 5 aortic toxicity for patients receiving composite doses ≥120.0 Gy (vs. 0% for patients receiving <120.0 Gy) (P=0.047). CONCLUSIONS: Grade 5 aortic toxicities were observed with composite doses ≥120.0 Gy (NIDR ≥90.0 Gy) to 1cm(3) of the aorta.