A Radiation Therapy Contouring Atlas for Delineation of the Level I and II Axillae in the Prone Position: A Single-Institution Experience.

PURPOSE: With transition from supine to prone position, tenting of the pectoralis major occurs, displacing the muscle from the chest wall and shifting the level I and II axillary spaces. For patients for whom we aim to treat the level I and II axillae using the prone technique, accurate delineation of these nodal regions is necessary. Although different consensus guidelines exist for delineation of nodal anatomy in supine position, to our knowledge, there are no contouring guidelines in the prone position that account for this change in nodal anatomy. METHODS AND MATERIALS: The level I and II nodal contours from the Radiation Therapy Oncology Group (RTOG) breast cancer supine atlas were adapted for prone position by 2 radiation oncologists and a breast radiologist based on anatomic changes observed from supine to prone positioning on preoperative diagnostic imaging. Forty-three patients from a single institution treated with prone high tangents from 2012 to 2018 were identified as representative cases to delineate the revised level I and II axillae on noncontrast computed tomography (CT) scans obtained during radiation simulation. The revised nodal contours were reviewed by an expanded expert multidisciplinary panel including breast radiologists, radiation oncologists, and surgical oncologists for consistency and reproducibility. RESULTS: Consensus was achieved among the panel in order to create modifications from the RTOG breast atlas for CT-based contouring of the level I and II axillae in prone position using bone, muscle, and skin as landmarks. This atlas provides representative examples and accompanying descriptions for the changes described to the caudal and anterior borders of level II and the anterior, posterior, medial, and lateral borders of level I. A step-by-step guide is provided for properly identifying the revised anterior border of the level I axilla. CONCLUSIONS: The adaptations to the RTOG breast cancer atlas for prone positioning will enable radiation oncologists to more accurately target the level I and II axillae when the axillae are targets in addition to the breast.

Disparities in Access to Radiotherapy Among Hispanic/Latinx Populations in the United States: How Far Have We Left to Go?

OBJECTIVES: The Hispanic/Latinx population has consistently faced disparities in oncology access and outcomes with cancer being the leading cause of death in this population. We evaluate recent research in radiation therapy disparities among the Hispanic/Latinx population in the United States since our seminal analysis from 2017. METHODS: A PubMed literature search was conducted for articles published from January 2017 through March 2023. Four term combinations were utilized, including: (1) "Hispanic" and "Radiotherapy" and "Disparities", (2) "Latino" and "Radiotherapy" and "Hispanic", (3) "Hispanic" and "Radiation" and "Disparities", and (4) "Latino" and "Radiation" and "Disparities." Included studies were those taking place in the United States, examined radiation oncology care, and examined health disparities. RESULTS: Fifty-eight of 245 articles returned met inclusion criteria and spanned 6 disparity-types: (1) Stage at Presentation, (2) Time to Treatment Initiation & Completion, (3) Receipt of Treatment and Guideline-Concordant Care, (4) Geography, (5) Clinical Trial Access and (6) Insurance Barriers and Treatment Center Type. The most common disparity was receipt of treatment and guideline-concordant care (n=39 studies), demonstrating that the Hispanic/Latinx population was less likely to receive guideline-concordant treatment or treatment at all. In additon, studies identified disparities in time to treatment and completion (n=12), geography (n=5), clinical trial access (n=3), and insurance and treatment center access (n=5). CONCLUSIONS: Disparities in radiotherapy access remain prominent for the Hispanic/Latinx population through a multitude of barriers, despite increasing interest in disparities research. Continued health care disparities research with tangible interventions are needed in radiation oncology to properly understand and address this problem.

Risk of Radiation Dermatitis in Patients With Skin of Color Who Undergo Radiation to the Breast or Chest Wall With and Without Regional Nodal Irradiation.

PURPOSE: Acute radiation dermatitis (ARD) is common after radiation therapy for breast cancer, with data indicating that ARD may disproportionately affect Black or African American (AA) patients. We evaluated the effect of skin of color (SOC) on physician-reported ARD in patients treated with radiation therapy. METHODS AND MATERIALS: We identified patients treated with whole breast or chest wall ± regional nodal irradiation or high tangents using 50 Gy in 25 fractions from 2015 to 2018. Baseline skin pigmentation was assessed using the Fitzpatrick scale (I = light/pale white to VI = black/very dark brown) with SOC defined as Fitzpatrick scale IV to VI. We evaluated associations among SOC, physician-reported ARD, late hyperpigmentation, and use of oral and topical treatments for RD using multivariable models. RESULTS: A total of 325 patients met eligibility, of which 40% had SOC (n = 129). On multivariable analysis, Black/AA race and chest wall irradiation had a lower odds of physician-reported grade 2 or 3 ARD (odds ratio [OR], 0.110; 95% confidence interval [CI], 0.030-0.397; P = .001; OR, 0.377; 95% CI, 0.161-0.883; P = .025), whereas skin bolus (OR, 8.029; 95% CI, 3.655-17.635; P = 0) and planning target volume D0.03cc (OR, 1.001; 95% CI, 1.000-1.001; P = .028) were associated with increased odds. On multivariable analysis, SOC (OR, 3.658; 95% CI, 1.236-10.830; P = .019) and skin bolus (OR, 26.786; 95% CI, 4.235-169.432; P = 0) were associated with increased odds of physician-reported late grade 2 or 3 hyperpigmentation. There was less frequent use of topical steroids to treat ARD and more frequent use of oral analgesics in SOC versus non-SOC patients (43% vs 63%, P < .001; 50% vs 38%, P = .05, respectively). CONCLUSIONS: Black/AA patients exhibited lower odds of physician-reported ARD. However, we found higher odds of late hyperpigmentation in SOC patients, independent of self-reported race. These findings suggest that ARD may be underdiagnosed in SOC when using the physician-rated scale despite this late evidence of radiation-induced skin toxicity.

Breast Cancer Screening in Survivors of Childhood Cancer.

Women who survived childhood cancers or cancers at a young age are at high risk for breast cancer later in life. The accentuated risk is notable among those treated at a young age with a high radiation dose but also extends to survivors treated with therapies other than or in addition to radiation therapy. The predisposing risk factors are complex. Advances in radiation therapy continue to curtail exposure, yet the risk of a second cancer has no dose threshold and a long latency period, and concurrent use of chemotherapy may have an additive effect on long-term risk of cancer. Early screening with annual mammography and MRI is recommended for chest radiation exposure of 10 Gy or greater, beginning 8 years after treatment or at age 25 years, whichever is later. However, there is a lack of recommendations for those at high risk without a history of radiation therapy. Because mortality after breast cancer among survivors is higher than in women with de novo breast cancer, and because there is a higher incidence of a second asynchronous breast cancer in survivors than that in the general population, regular screening is essential and is expected to improve mortality. However, awareness and continuity of care may be lacking in these young patients and is reflected in their poor screening attendance. The transition of care from childhood to adulthood for survivors requires age-targeted and lifelong strategies of education and risk prevention that are needed to improve long-term outcomes for these patients. © RSNA, 2023 See the invited commentary by Chikarmane in this issue. Quiz questions for this article are available through the Online Learning Center.

Early effectiveness and toxicity outcomes of reirradiation after breast conserving surgery for recurrent or new primary breast cancer.

PURPOSE: Breast reirradiation (reRT) after breast conserving surgery (BCS) has emerged as a viable alternative to mastectomy for women presenting with recurrent or new primary breast cancer. There are limited data on safety of different fractionation regimens. This study reports safety and efficacy among women treated with repeat BCS and reRT. METHODS AND MATERIALS: Patients who underwent repeat BCS followed by RT from 2015 to 2021 at 2 institutions were analyzed. Univariate logistic regression models were used to identify predictors of acute and late toxicities. Kaplan-Meier estimates were used to evaluate overall survival (OS), distant metastasis-free survival (DMFS) and locoregional recurrence-free survival (LR-RFS). RESULTS: Sixty-six patients were reviewed with median follow-up of 16 months (range: 3-60 months). At time of first recurrence, 41% had invasive carcinoma with a ductal carcinoma in situ (DCIS) component, 41% had invasive carcinoma alone and 18% had DCIS alone. All were clinically node negative. For the reirradiation course, 95% received partial breast irradiation (PBI) (57.5% with 1.5 Gy BID; 27% with 1.8 Gy daily; 10.5% with hypofractionation), and 5% received whole breast irradiation (1.8-2 Gy/fx), all of whom had received PBI for initial course. One patient experienced grade 3 fibrosis, and one patient experienced grade 3 telangiectasia. None had grade 4 or higher late adverse events. We found no association between the fractionation of the second course of RT or the cumulative dose (measured as EQD2) with acute or late toxicity. At 2 years, OS was 100%, DMFS was 91.6%, and LR-RFS was 100%. CONCLUSION: In this series of patients with recurrent or new primary breast cancer, a second breast conservation surgery followed by reirradiation was effective with no local recurrences and an acceptable toxicity profile across a range of available fractionation regimens at a median follow up of 16 months. Longer follow up is required.

Definitive Radiation With Nodal Boost for Patients With Locally Advanced Breast Cancer.

PURPOSE: The optimal local therapy of patients with nodal disease in supraclavicular (SCV), internal mammary nodes (IMN) and level III axilla is not well studied. We aimed to evaluate the outcomes of patients with breast cancer and advanced nodal disease that received a nodal boost. METHODS AND MATERIALS: This retrospective study included 79 patients with advanced nodal disease who underwent adjuvant radiation with a nodal boost to the SCV, IMNs, and/or axilla. All patients had radiographic changes after systemic therapy concerning for gross nodal disease. Overall survival, disease-free survival (DFS), and local recurrence-free survival were estimated using the Kaplan-Meier method. RESULTS: All patients received an initial 50 Gy to the breast/chest wall and regional nodes, of whom 46.8% received an IMN boost, 38.0% axillary (ax)/SCV boost, and 15.2% both IMN and ax/SCV boost (IMN + ax/SCV). Most patients had hormone receptor positive (74.7%) and human epidermal growth factor receptor 2 negative disease (83.5%). In addition, 12.7% of patients had clinical (c) N2 disease, 21.5% cN3A disease, 51.9% cN3B disease, and 5.1% cN3C disease. Most patients received chemotherapy (97.5%). The median nodal boost dose was 10 Gy (range, 10-20 Gy), with 21.6% of IMN, 16.7% of ax/SCV, and 16.7% of IMN + ax/SCV receiving 14 to 20 Gy. With a median follow up of 30 months, the 3-year local recurrence-free survival, DFS, and overall survival rates were 94.5%, 86.3%, and 93.8%, respectively. Crude rates of failure were 13.9% (10.1% distant failure [DF] alone; 3.8% DF + locoregional failure [LRF]). Rates of failure by boost group were 13.3% for ax/SCV (10.0% DF alone; 3.3% DF + LRF), 5.4% for IMN (2.7% DF alone, 2.7% DF + LRF), and 41.7% for IMN + ax/SCV (33.3% DF, 8.3% DF + LRF). There were no LRFs without DFs. The median time to failure was 22.8 months (interquartile range, 18-34 months). Clinical tumor size and IMN + ax/SCV versus IMN or ax/SCV alone was associated with worse DFS (hazard ratio [HR]: 9.78; 95% confidence interval [CI], 2.07-46.2; P = .004 and HR: 9.49; 95% CI, 2.67-33.7; P = .001, respectively). On multivariate analysis, IMN + ax/SCV versus IMN or ax/SCV alone retained significance (HR: 4.80; 95% CI, 1.27-18.13; P = .02). CONCLUSIONS: In this population of patients with locally advanced breast cancer, the majority of failures were distant with no isolated LRFs. Failures were the highest in the IMN + ax/SCV group (∼40%). Further treatment escalation is necessary for these patients.

Radiation-induced skin changes after breast or chest wall irradiation in patients with breast cancer and skin of color: a systematic review.

INTRODUCTION: The purpose of this study is to systematically review data pertaining to breast cancer and radiation-induced skin reactions in patients with skin of color (SOC), as well as data pertaining to objective measurements of skin pigmentation in the assessment of radiation dermatitis (RD). METHODS AND MATERIALS: We conducted a systematic review utilizing MEDLINE electronic databases to identify published studies until August 2022. Key inclusion criteria included studies that described RD in breast cancer with data pertaining to skin of color and/or characterization of pigmentation changes after radiation. RESULTS: We identified 17 prospective cohort studies, 7 cross-sectional studies, 5 retrospective studies and 4 randomized controlled trials. Prospective cohort and retrospective series demonstrate worse RD in African American (AA) patients using subjective physician-graded scales. There is more limited data in patients representing other non-White racial subgroups with SOC. 2 studies utilize patient reported outcomes and 15 studies utilize objective methods to characterize pigmentation change after radiation. There are no prospective and randomized studies that objectively describe pigmentation changes with radiotherapy in SOC. CONCLUSIONS: AA patients appear to have worse RD outcomes, though this is not uniformly observed across all studies. There are no studies that describe objective measures of RD and include baseline skin pigmentation as a variable, limiting the ability to draw uniform conclusions on the rate and impact of RD in SOC. We highlight the importance of objectively characterizing SOC and pigmentation changes before, during and after radiotherapy to understand the incidence and severity of RD in SOC.

Insights into the Social Determinants of Health in Older Adults.

In this paper, we review the social determinants of health in older adults and their complex interrelationship with medical diseases. Also, we provide recommendations to address these determinants in the integrated healthcare plan. The social determinants in older adults and its influence in health outcomes have been studied for decades. There is solid evidence for the interrelationship between social factors and the health of individuals and populations; however, these studies are unable to define their complex interrelatedness. Health is quite variable and depends on multiple biological and social factors such as genetics, country of origin, migrant status, etc. On the other hand, health status can affect social factors such as job or education. Addressing social determinants of health in the integrated healthcare plan is important for improving health outcomes and decreasing existing disparities in older adult health. We recommend a person-centered approach in which individualized interventions should be adopted by organizations to improve the health status of older adults at the national and global level. Some of our practical recommendations to better address the social determinants of health in clinical practice are EHR documentation strategies, screening tools, and the development of linkages to the world outside of the clinic and health system, including social services, community activities, collaborative work, and roles for insurance companies.

Radiation in Early-Stage Breast Cancer: Moving beyond an All or Nothing Approach.

Radiotherapy omission is increasingly considered for selected patients with early-stage breast cancer. However, with emerging data on the safety and efficacy of radiotherapy de-escalation with partial breast irradiation and accelerated treatment regimens for low-risk breast cancer, it is necessary to move beyond an all-or-nothing approach. Here, we review existing data for radiotherapy omission, including the use of age, tumor subtype, and multigene profiling assays for selecting low-risk patients for whom omission is a reasonable strategy. We review data for de-escalated radiotherapy, including partial breast irradiation and acceleration of treatment time, emphasizing these regimens' decreasing biological and financial toxicities. Lastly, we review evidence of omission of endocrine therapy. We emphasize ongoing research to define patient selection, treatment delivery, and toxicity outcomes for de-escalated adjuvant therapies better and highlight future directions.

A Prospective Trial to Compare Deep Inspiratory Breath Hold With Prone Breast Irradiation.

PURPOSE: To compare heart and lung doses for adjuvant whole breast irradiation (WBI) between radiation plans generated supine with deep inspiratory breath hold (S-DIBH) and prone with free-breathing (P-FB) and examine the effect of breast volume (BV) on dosimetric parameters. METHODS AND MATERIALS: Patients with left breast ductal carcinoma in situ or invasive cancer receiving adjuvant WBI were enrolled on a single-institutional prospective protocol. Patients were simulated S-DIBH and P-FB; plans were generated using both scans. Wilcoxon signed-rank and rank-sum tests were used to compare intrapatient differences between plans for the entire cohort and within BV groups defined by tertiles. RESULTS: Forty patients were enrolled. Thirty-four patients are included in the analysis owing to patient withdrawal or inability to hold breath. With WBI dose of 4005 to 4256 cGy, mean heart dose (MHD) was 80 cGy in S-DIBH and 77 cGy in P-FB (P = .08). Mean ipsilateral lung dose (MLD) was 453 cGy in S-DIBH and 45 cGy in P-FB (P < .0001). Mean and max left anterior descending artery doses were 251 cGy and 551 cGy in S-DIBH, respectively (P = .1), and 324 cGy and 993 cGy in P-FB, respectively (P = .3). Hot spot and separation were 109% and 22 cm in S-DIBH, respectively, and 107% and 16 cm in P-FB, respectively (P < .0001). For patients with smallest BV, S-DIBH improved MHD and left anterior descending artery doses; for those with largest BV, P-FB improved cardiac dosimetry. With increasing BV, there was an increasing advantage of P-FB for MHD (P = .05), and max (P = .03) and mean (P = .02) left anterior descending artery doses, and the reduction in MLD, hot spot, and separation with P-FB increased (P < .05). CONCLUSIONS: MHD did not differ between P-FB and S-DIBH, whereas MLD was significantly lower with P-FB. Analysis according to breast volume revealed improved cardiac dosimetry with S-DIBH for women with smallest BV and improved cardiac dosimetry with P-FB for women with larger BV, thereby providing a dosimetric rationale for using breast size to help determine the optimal positioning for WBI.

Ipsilateral breast tumor recurrence in early stage breast cancer patients treated with breast conserving surgery and adjuvant radiation therapy: Concordance of biomarkers and tumor location from primary tumor to in-breast tumor recurrence.

BACKGROUND: Patients with an in-breast tumor recurrence (IBTR) after breast-conserving therapy have a high risk of distant metastasis and disease-related mortality. Classifying clinical parameters that increase risk for recurrence after IBTR remains a challenge. AIM: To describe primary and recurrent tumor characteristics in patients who experience an IBTR and understand the relationship between these characteristics and disease outcomes. METHODS: Patients with stage 0-II breast cancer treated with lumpectomy and adjuvant radiation were identified from institutional databases of patients treated from 2003-2017 at our institution. Overall survival (OS), disease-free survival, and local recurrence-free survival (LRFS) were estimated using the Kaplan Meier method. We identified patients who experienced an isolated IBTR. Concordance of hormone receptor status and location of tumor from primary to recurrence was evaluated. The effect of clinical and treatment parameters on disease outcomes was also evaluated. RESULTS: We identified 2164 patients who met the eligibility criteria. The median follow-up for all patients was 3.73 [interquartile range (IQR) 2.27-6.07] years. Five-year OS was 97.7% (95%CI: 96.8%-98.6%) with 28 deaths; 5-year LRFS was 98.0% (97.2-98.8) with 31 IBTRs. We identified 37 patients with isolated IBTR, 19 (51.4%) as ductal carcinoma in situ and 18 (48.6%) as invasive disease, of whom 83.3% had an in situ component. Median time from initial diagnosis to IBTR was 1.97 (IQR: 1.03-3.5) years. Radiotherapy information was available for 30 of 37 patients. Median whole-breast dose was 40.5 Gy and 23 patients received a boost to the tumor bed. Twenty-five of thirty-two (78.1%) patients had concordant hormone receptor status, HER-2 receptor status, and estrogen receptor (ER) (P = 0.006) and progesterone receptor (PR) (P = 0.001) status from primary to IBTR were significantly associated. There were no observed changes in HER-2 status from primary to IBTR. The concordance between quadrant of primary to IBTR was 10/19 [(62.2%), P = 0.008]. Tumor size greater than 1.5 cm (HR = 0.44, 95%CI: 0.22-0.90, P = 0.02) and use of endocrine therapy upfront (HR = 0.36, 95%CI: 0.18-0.73, P = 0.004) decreased the risk of IBTR. CONCLUSION: Among patients with early stage breast cancer who had breast conserving surgery treated with adjuvant RT, ER/PR status and quadrant were highly concordant from primary to IBTR. Tumor size greater than 1.5 cm and use of adjuvant endocrine therapy were significantly associated with decreased risk of IBTR.

Radiation effect on late cardiopulmonary toxicity: An analysis comparing supine DIBH versus prone techniques for breast treatment.

Two commonly used whole breast irradiation (WBI) techniques, deep inspiration breath hold (DIBH) and prone positioning, are compared with regard to dosimetry and estimated late cardiac morbidity and secondary lung cancer mortality using published models. Forty patients with left-sided DCIS or breast cancer who underwent lumpectomy and required adjuvant WBI were enrolled on a prospective trial comparing supine DIBH (S-DIBH) with prone free breathing (P-FB) planning. Patients underwent CT simulation in both positions; two plans were generated for each patient. Comparative dosimetry was available for 34 patients. Mean cardiac and lung doses were calculated. Risk of death from ischemic heart disease (IHD), risk of at least one acute coronary event (ACE), and lung cancer mortality were estimated from published data. Difference between S-DIBH and P-FB plans was compared using paired two-tailed t test. Estimated mean risk of death from IHD by age 80 was 0.1% (range 0.0%-0.2%) for both plans (P = 1.0). Mean risk of at least one ACE was 0.3% (range 0.1%-0.6%) for both plans (P = .6). Mean lung cancer mortality risk was 1.4% (range 0.5%-15.4%) for S-DIBH and 1.0% (range 0.4%-9.8%) for P-FB (P = .008). Excess lung cancer mortality due to radiation was 0.5% (range 0.1%-6.0%) with S-DIBH and 0.0% (range 0.0%-0.4%) with P-FB (P = .008). Both S-DIBH and P-FB provide excellent cardiac sparing. Prone positioning results in lower lung dose than S-DIBH and leads to an absolute decrease of 0.5% in excess lung cancer mortality for patients receiving WBI.

The pervasive crisis of diminishing radiation therapy access for vulnerable populations in the United States-part 3: Hispanic-American patients.

PURPOSE: Health disparities have profoundly affected underrepresented minorities throughout the United States, particularly with regard to access to evidence-based interventions such as surgery or medication. The degree of disparity in access to radiation therapy (RT) for Hispanic-American patients with cancer has not been previously examined in an extensive manner. METHODS AND MATERIALS: An extensive literature search was performed using the PubMed database to examine studies investigating disparities in RT access for Hispanic-Americans. RESULTS: A total of 34 studies were found, spanning 10 organ systems. Disparities in access to RT for Hispanic-Americans were most prominently studied in cancers of the breast (15 studies), prostate (4 studies), head and neck (4 studies), and gynecologic system (3 studies). Disparities in RT access for Hispanic-Americans were prevalent regardless of the organ system studied and were compounded by limited English proficiency and/or birth outside of the United States. A total of 26 of 34 studies (77%) involved analysis of a population-based database, such as Surveillance, Epidemiology and End Result (15 studies); Surveillance, Epidemiology and End Result-Medicare (4 studies); National Cancer Database (3 studies); or a state tumor registry (4 studies). CONCLUSIONS: Hispanic-Americans in the United States have diminished RT access compared with Caucasian patients but are less likely to experience concomitant disparities in mortality than other underrepresented minorities that experience similar disparities (ie, African-Americans). Hispanic-Americans who are born outside of the United States and/or have limited English proficiency may be more likely to experience substandard RT access. These results underscore the importance of finding nationwide solutions to address such inequalities that hinder Hispanic-Americans and other underrepresented minorities throughout the United States.

Hypofractionated Whole-Breast Irradiation in Women Less Than 50 Years Old Treated on 4 Prospective Protocols.

PURPOSE: Hypofractionated whole-breast radiation therapy (RT) has proved to be equivalent to conventionally fractionated RT in multiple randomized trials. There is controversy regarding its use in younger women because of their underrepresentation in trials and the concern for late toxicity. We evaluated disease control and cosmetic outcomes in patients aged <50 years treated with hypofractionated RT in 4 prospective single-institutional trials. METHODS AND MATERIALS: From 2003 to 2015, 1313 patients were enrolled in 4 prospective protocols investigating the use of adjuvant hypofractionated RT after breast-conserving surgery with a daily or weekly concomitant boost. We identified the records of 348 patients aged <50 years at consultation for this analysis. Overall survival, disease-free survival, and local recurrence-free survival were estimated using the Kaplan-Meier method by study and across studies using meta-analytic methods. The late effects of RT, clinician-rated cosmesis, and patient-rated cosmesis were also evaluated. RESULTS: With a median follow-up period of 66.9 months, the overall survival rate was 99.6%, the disease-free survival rate was 96.3%, and the local recurrence-free survival rate was 97.7% at 3 years. Clinician-rated cosmesis (n = 242) was excellent or good in 93.4% of cases and fair or poor in 6.6%. Patient-rated cosmesis (n = 259) was excellent or good in 86.1% and fair or poor in 13.9%. When patients rated themselves differently than their physicians, patients more often rated themselves poorly compared with their physicians (P = .0044, Cochran-Mantel-Haenszel test). CONCLUSIONS: At a median follow-up of 5 years, an analysis of patients aged <50 years demonstrated that hypofractionated RT was safe and effective, with good to excellent cosmesis as assessed by both clinicians and patients.

Cost in perspective: direct assessment of American market acceptability of Co-60 in gynecologic high-dose-rate brachytherapy and contrast with experience abroad.

PURPOSE: While Ir-192 remains the mainstay isotope for gynecologic high-dose-rate (HDR) brachytherapy in the U.S., Co-60 is used abroad. Co-60 has a longer half-life than Ir-192, which may lead to long-term cost savings; however, its higher energy requires greater shielding. This study analyzes Co-60 acceptability based on a one-time expense of additional shielding and reports the financial experience of Co-60 in Peru's National Cancer Institute, which uses both isotopes. MATERIAL AND METHODS: A nationwide survey was undertaken assessing physician knowledge of Co-60 and willingness-to-pay (WTP) for additional shielding, assuming a source more cost-effective than Ir-192 was available. With 440 respondents, 280 clinicians were decision-makers and provided WTPs, with results previously reported. After completing a shielding report, we estimated costs for shielding expansion, noting acceptability to decision makers' WTP. Using activity-based costing, we note the Peruvian fiscal experience. RESULTS: Shielding estimates ranged from $173,000 to $418,000. The percentage of respondents accepting high-density modular or lead shielding (for union and non-union settings) were 17.5%, 11.4%, 3.9%, and 3.2%, respectively. Shielding acceptance was associated with greater number of radiation oncologists in a respondent's department but not time in practice or the American Brachytherapy Society membership. Peru's experience noted cost savings with Co-60 of $52,400 annually. CONCLUSIONS: By comparing the cost of additional shielding for a sample institution's HDR suite with radiation oncologists' WTP, this multi-institutional collaboration noted < 20% of clinicians would accept additional shielding. Despite low acceptability in the US, Co-60 demonstrates cost-favorability in Peru and may similarly in other locations.

Factors influencing the utilization of prophylactic cranial irradiation in patients with limited-stage small cell lung cancer.

PURPOSE: Brain metastases are common in patients with limited-stage small cell lung cancer (LS-SCLC) due to the inability of most chemotherapeutics to penetrate the blood-brain barrier. Prophylactic cranial irradiation (PCI) is therefore recommended for use in patients with a good response to concurrent chemoradiotherapy. However, PCI is not always delivered; therefore, we investigated the reasons for PCI omission in patients who underwent therapy with curative intent. METHODS AND MATERIALS: We retrospectively reviewed all patients with LS-SCLC who were treated with curative intent at our institution. Overall survival and cumulative incidence of brain metastasis were estimated by the Kaplan-Meier method. The Pearson χ2 test and Mann-Whitney U test were used to examine factors associated with PCI use, and prognostic factors were analyzed with Cox proportional hazards modeling. RESULTS: We examined 208 patients who were treated for LS-SCLC at our institution. A total of 115 patients (55%) received PCI. The most common documented reason for PCI omission was patient refusal due to neurotoxicity concerns (38%). Physician assessment of being medically unfit (33%) and of advanced age (8%) were the second and third most common reasons, respectively. Karnofsky performance status and clinical American Joint Committee on Cancer stage but not PCI were significantly associated with overall survival. Only clinical stage remained an independent factor on multivariate analysis. CONCLUSIONS: Approximately half of patients with LS-SCLC ultimately receive PCI, generally for guideline-recommended reasons. The most common reason for PCI omission was patient concerns regarding neurotoxicity. Efforts to decrease PCI neurotoxicity, including hippocampal-sparing radiation and memantine use, may increase the use of this survival-improving intervention in eligible patients with LS-SCLC.

Effect of Breast Irradiation on Cardiac Disease in Women Enrolled in BCIRG-001 at 10-Year Follow-Up.

PURPOSE: To investigate cardiac toxicity associated with breast radiation therapy (RT) at 10-year follow-up in BCIRG-001, a phase 3 trial comparing adjuvant anthracycline chemotherapy (fluorouracil, doxorubicin, and cyclophosphamide) with anthracycline-taxane chemotherapy (docetaxel, doxorubicin, and cyclophosphamide) in women with lymph node-positive early breast cancer. METHODS AND MATERIALS: Prospective data from all 746 patients in the control arm (fluorouracil, doxorubicin, and cyclophosphamide) of BCIRG-001 at 10-year follow-up were obtained from Project Data Sphere. Cardiac toxicities examined included myocardial infarction (MI), heart failure (HF), arrhythmias, and relative and absolute left ventricular ejection fraction decrease of >20% from baseline. Toxicities were compared between patients who received RT versus no RT, left-sided RT versus no RT, and internal mammary nodal RT versus no RT. RESULTS: Of the 746 patients, 559 (75%) received RT to a median dose of 50 Gy. Myocardial infarction occurred in 3 RT patients (0.5%) versus 6 no-RT patients (3%) (P=.01). Heart failure was seen in 15 RT patients (2.7%) versus 3 no-RT patients (1.6%) (P=.6). Among these, 35 RT patients (18%) had a left ventricular ejection fraction relative decrease of >20% baseline versus 7 (10%) who did not receive RT (P=.1). Arrhythmias were more common in RT patients (3.2%) versus no-RT patients (0%) (P=.01). On univariable and multivariable analysis HF was not significantly associated with RT, and MI was negatively associated with RT. CONCLUSIONS: In this retrospective analysis of prospective toxicity outcomes, there is an increased risk of arrhythmias but no clear evidence of significantly increased risk of MI or HF at 10 years in lymph node-positive women treated with breast RT and uniform adjuvant doxorubicin-based chemotherapy. Given the low incidence of these outcomes, studies with larger numbers are needed to confirm our findings.

Patterns of failure in limited-stage small cell lung cancer: Implications of TNM stage for prophylactic cranial irradiation.

BACKGROUND AND PURPOSE: The relationship between tumor-node-metastasis (TNM) stage and patterns of failure in limited-stage small cell lung cancer (LS-SCLC) remains unclear. We hypothesized that TNM stage predicts brain metastasis risk, and could inform the use of prophylactic cranial irradiation. MATERIAL AND METHODS: We reviewed 283 patients with stage I-IIIB SCLC. Competing-risks regression was used to analyze local, distant, and brain failure. Multivariate analysis was used to evaluate the effect of treatment and clinical factors on failure and OS. RESULTS: Patients with stage I or II SCLC (35% of cohort) had significantly better survival and lower risk of distant and brain metastasis, compared with stage III patients. The 5-year cumulative incidence of brain metastasis for stage I/II and III were 12% and 26%, respectively. Stage had no correlation with local failure. On multivariate analysis, stage was independently prognostic for survival, distant metastasis risk, and brain metastasis risk. CONCLUSIONS: TNM staging predicts likelihood of distant metastasis, brain metastasis, and survival in LS-SCLC. This supports the routine use of TNM staging in clinical practice. The lower risk of brain metastasis in stage I and II SCLC suggests that prophylactic cranial irradiation could play a more limited role in treatment of early-stage disease.

A national survey of HDR source knowledge among practicing radiation oncologists and residents: Establishing a willingness-to-pay threshold for cobalt-60 usage.

PURPOSE: Ir-192 is the predominant source for high-dose-rate (HDR) brachytherapy in United States markets. Co-60, with longer half-life and fewer source exchanges, has piloted abroad with comparable clinical dosimetry but increased shielding requirements. We sought to identify practitioner knowledge of Co-60 and establish acceptable willingness-to-pay (WTP) thresholds for additional shielding requirements for use in future cost-benefit analysis. METHODS AND MATERIALS: A nationwide survey of U.S. radiation oncologists was conducted from June to July 2015, assessing knowledge of HDR sources, brachytherapy unit shielding, and factors that may influence source-selection decision-making. Self-identified decision makers in radiotherapy equipment purchase and acquisition were asked their WTP on shielding should a more cost-effective source become available. RESULTS: Four hundred forty surveys were completed and included. Forty-four percent were ABS members. Twenty percent of respondents identified Co-60 as an HDR source. Respondents who identified Co-60 were significantly more likely to be ABS members, have attended a national brachytherapy conference, and be involved in brachytherapy selection. Sixty-six percent of self-identified decision makers stated that their facility would switch to a more cost-effective source than Ir-192, if available. Cost and experience were the most common reasons provided for not switching. The most common WTP value selected by respondents was <$25,000. CONCLUSIONS: A majority of respondents were unaware of Co-60 as a commercially available HDR source. This investigation was novel in directly assessing decision makers to establish WTP for shielding costs that source change to Co-60 may require. These results will be used to establish WTP threshold for future cost-benefit analysis.