Search

Randomized clinical trials have shown that regional nodal irradiation (RNI) in patients with unselected N1 breast cancer improves breast cancer-specific survival. However, the benefit of RNI in women with biologically low-risk N1 breast cancer is uncertain. We conducted a population-based study to determine whether RNI is associated with improved breast cancer recurrence-free interval (BCRFI) in this population.Patients aged 40 to 79 years with pT1-2 pN1 (node-positive) breast cancer diagnosed between 2005 and 2014 were identified. The inclusion criteria were modeled off of the TAILOR RT study, which is a randomized noninferiority clinical trial designed to assess the value of RNI in patients with low-risk N1 disease. Eligible patients had breast-conserving surgery or mastectomy and axillary lymph node dissection with 1 to 3 positive nodes, breast-conserving surgery and sentinel lymph node biopsy with 1 to 2 positive nodes, or mastectomy and sentinel lymph node biopsy with 1 positive node. Additionally, patients had luminal A breast cancers, as approximated by estrogen receptor positive (Allred 6-8/8), progesterone receptor (PR) positive (Allred 6-8/8), human epidermal growth factor receptor 2-negative, and grade 1 to 2 immunohistochemical testing. All patients were prescribed hormonal treatment. The primary endpoint of BCRFI, the time to any breast cancer recurrence or breast cancer-related death, was analyzed using a multivariate competing risks analysis.The cohort included 1169 women with a median follow-up of 9.2 years. Radiation treatments were not performed in 151 women treated with mastectomy alone, were delivered to the breast only in 133 women, and were delivered locoregionally in 885 women. Patients undergoing RNI were younger (median age: 58 vs 62 years), more likely to have 2 to 3 macroscopic lymph nodes involved, and more often received chemotherapy (all P.05). The 10-year estimate of BCRFI was 90% without RNI versus 90% with RNI (P = .5). On multivariable analysis, RNI was not a significant predictor of BCRFI (hazard ratio: 1.0; P = .9).In this retrospective analysis, RNI was not associated with improved BCRFI for women with biologically low-risk N1 breast cancer. We advocate accrual to the ongoing TAILOR RT study.

INTRODUCTION:. Local and systemic treatments for breast cancer have evolved in the past decades. This study reports the development of a modern population-based nomogram to individualize local recurrence (LR) risk estimates for patients treated with breast conservation surgery (BCS). The magnitude of benefit of adjuvant breast radiotherapy (BRT) depends on individual patient, tumor, and treatment characteristics (1). Nomograms can provide accurate predictions of LR and the absolute LR benefit of BRT that can assist patients in making informed decisions regarding BRT. This nomogram is based on a large cohort of women with prospectively captured biomarker data and modern systemic therapies including anti-human epidermal growth factor receptor 2 (HER2) therapy. METHOD:. Study Population:. The study cohort included women treated curatively for newly diagnosed breast cancer between 1st January 2005 and 31st December 2014. Inclusion criteria were: age >16 years, invasive ductal or lobular carcinoma, stage I-III, and BCS. Patients with metastatic disease, prior or synchronous contralateral breast cancer, unknown tumor or treatment characteristics, or treated with neoadjuvant therapy or mastectomy were excluded. Nomogram Development and Validation:. Age, tumor size, number of positive lymph nodes, grade, margin status, lymphovascular invasion (LVI), extensive intraductal component (EIC), estrogen receptor (ER), progesterone receptor (PR), HER2 status, use of chemotherapy, hormonal therapy, and radiotherapy with or without boost were recorded for each patient. The endpoint was LR as the first event. Fine and Gray’s competing risk model, with distant recurrence and death as competing risks, was used for the multivariable analysis, adjusting for demographics, tumor, and treatment factors. Hazard ratio (HR) and 95% confidence interval (CI) for each variable were calculated. The multivariable model forms the basis for the nomogram, which is being internally validated using the bootstrap and cross-validation. RESULTS:Of 11,310 patients, there were 429 LR (crude risk = 3.8%). The HR and 95% CIs from the Fine and Gray model for each of the variables in the nomogram are presented in the table. Age, number of positive nodes, grade, ER, LVI, margins, hormone therapy, chemotherapy, and radiotherapy were independent prognostic factors for LR. For patients treated with RT, the predicted 10-year cumulative incidence of LR ranged from 2.4% in patients with low-risk disease to 12.5% in patients with high-risk disease. CONCLUSION:A new nomogram for local recurrence, based on patients who had ER/PR/HER2 testing and who received modern systemic therapies is being developed. It will assist clinicians and patients individualize estimates of local recurrence risk and improve shared decision-making regarding the use of BRT in contemporary practice. REFERENCES:. (1)Sanghani, M., et al J Clin Oncol.,2010; 28(5), 718-722. Cox regression hazard ratios and confidence intervals for variablesCharacteristicHR95%CIp-valueAge0.980.970.99 Citation Format: Dylan Narinesingh, Alan Nichol, Pauline Truong, Lovedeep Gondara, Caroline Speers, Laveniya Kugathasan, Caroline Lohrisch, Dave Voduc, Nafisha Lalani. Bc cancer ipsilateral breast tumor recurrence (BCC IBTR) nomogram [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-07-04.

The aim of this study is to assess the Internet usage pattern amongst glioma patients and to characterize its impact in their decision-making and clinical interactions. Glioma patients attending a tertiary cancer center between June and December 2019 were invited to participate in this study. A 26-item survey consisting of closed and open-ended questions was distributed with a unique identifier. Quantitative data were analyzed with descriptive statistics using SPSS Statistical package, and qualitative data with grounded theory approach. Thirty-two patients completed the survey. Demographics varied in age, time since diagnosis, glioma type, and level of education. Eighty-one percent were identified as “Internet users” who sought online glioma information. Google was the most popular search engine (96%), with “glioma” being the most frequent search term. The selection of websites often relied on perceived credibility and top search hits. The most searched topic was prognosis (73%). The majority of patients found that online information was easy to understand, and this did not vary significantly amongst age groups. Website quality was always assessed by 60% of patients. Only 62% patients found the Internet a useful resource, and 70% patients found it facilitated their understanding. Most patients discussed their Internet findings with a physician, largely regarding concerns about reliability. There is variable glioma information available online. Patients with glioma use the Internet as a resource, with variable impact on their interactions and decision-making. This information can be used by physicians, educators, and website developers to support glioma patients’ needs.

This study aimed to investigate whether systemic therapy (ST) use surrounding radiation therapy (RT) predicts overall survival (OS) after RT for patients with brain metastases (BMs). Provincial RT and pharmacy databases were used to review all adult patients in British Columbia, Canada, who received a first course of RT for BMs between 2012 and 2016 (n = 3095). Multivariate analysis on a randomly selected subset was used to develop an OS nomogram. In comparison to the 2096 non-recipients of ST after RT, the median OS of the 999 recipients of ST after RT was 5.0 (95% Confidence interval (CI) 4.1–6.0) months longer (p

Purpose Understanding the pathways and gateways to leadership and challenges faced by individuals in such roles can inform efforts to promote diversity and equity. We sought to describe the professional experiences and personal characteristics of academic radiation oncology (RO) chairs and to evaluate whether differences exist by gender. Methods and Materials Anonymous surveys were distributed to 95 chairs of RO departments during the 2016 annual meeting of the Society of Chairs of Academic Radiation Oncology Programs. The surveys included 28 closed-ended questions and the Leadership Practices Inventory. Results were analyzed by gender using χ2 tests, rank-sum, and t tests (significance P Results A total of 72 chairs responded (61 male, 10 female, 1 declined to identify gender) for a response rate of 76%. There were no significant gender differences in age, academic rank, publications, or prior leadership positions held at the time of the first chair appointment, but female respondents held significantly greater total direct funding from extramural grants than their male counterparts (median, $1.89 million [interquartile range, $0.5-$5 million] vs $0.25 million [interquartile range, $0-$1.0 million]; P = .006). Women were more likely to have spouses employed outside the home at time of their first chair appointment than men were, with a trend toward women experiencing greater difficulty relocating. Men and women identified budgeting and resource allocation as their greatest professional challenges. There were no gender differences in the Leadership Practices Inventory–identified leadership domains or professional goals. Conclusions Female RO chairs are as equally qualified as men in terms of productivity or leadership skills, but they face distinct challenges in the context of a gender-structured society. The observation of higher grant funding among women at the time of chair appointment suggests a possible need for interventions such as unconscious bias training to ensure that selection processes do not unnecessarily hold women to a higher standard.

Purpose/Objective(s) The benefit of regional nodal irradiation (RNI) for node-positive, low-risk breast cancer is controversial. The ongoing TAILOR RT trial is enrolling breast cancer patients with 1-3 involved macroscopic nodes and a low risk Oncotype DX Recurrence Score ( Materials/Methods We interrogated a population-based database, which included all women treated for breast cancer in the province. Inclusion criteria were: age 40-79, pT1-2 pN1 (macroscopically node-positive) breast cancer, and diagnosis between 2005 and 2014. To reproduce the inclusion criteria of TAILOR RT, patients could have had breast-conserving surgery (BCS) or mastectomy & axillary lymph node dissection (ALND) with 1-3 positive nodes, BCS & sentinel lymph node biopsy (SLNB) with 1-2 positive nodes or mastectomy & SLNB with 1 positive node. To select a cohort of patients likely to have Recurrence Score Results We identified 1,169 eligible women. Median follow-up was 9.2 years. There were 885 patients who received RNI and 284 who did not undergo RNI. The RNI group was younger (median 62 versus 58 years), had a higher rate of nodal involvement, and were more likely to have received chemotherapy (all P 0.05). Conclusion RNI was not associated with improved outcomes in node-positive, low-risk breast cancers. This work underscores the importance of continued accrual onto the ongoing non-inferiority trial of RNI, TAILOR RT.

The aim of this study is to assess the Internet usage pattern amongst glioma patients and to characterize its impact in their decision-making and clinical interactions. Glioma patients attending a tertiary cancer center between June and December 2019 were invited to participate in this study. A 26-item survey consisting of closed and open-ended questions was distributed with a unique identifier. Quantitative data were analyzed with descriptive statistics using SPSS Statistical package, and qualitative data with grounded theory approach. Thirty-two patients completed the survey. Demographics varied in age, time since diagnosis, glioma type, and level of education. Eighty-one percent were identified as "Internet users" who sought online glioma information. Google was the most popular search engine (96%), with "glioma" being the most frequent search term. The selection of websites often relied on perceived credibility and top search hits. The most searched topic was prognosis (73%). The majority of patients found that online information was easy to understand, and this did not vary significantly amongst age groups. Website quality was always assessed by 60% of patients. Only 62% patients found the Internet a useful resource, and 70% patients found it facilitated their understanding. Most patients discussed their Internet findings with a physician, largely regarding concerns about reliability. There is variable glioma information available online. Patients with glioma use the Internet as a resource, with variable impact on their interactions and decision-making. This information can be used by physicians, educators, and website developers to support glioma patients' needs.

Purpose We evaluated the risk of cardiac mortality in older patients who receive adjuvant radiation therapy (RT) for stage I breast cancer to determine whether this risk persists in the modern era. Methods and Materials Using the 2000 to 2015 Surveillance, Epidemiology, and End Results program data, we performed a population-based cohort study to evaluate the association between adjuvant breast RT, tumor laterality, and cardiac-specific survival (CSS) among patients 60 and older with stage I estrogen receptor positive breast cancer who received breast-conserving surgery and RT. Results At a median follow-up of 6 years (range, 0-15.9 years), patients receiving RT for left-sided breast cancer demonstrated no difference in 5- and 10-year CSS compared with those with right-sided breast cancer (5 year 98.3% vs 98.2%, 10 year 94.3% vs 93.9%; log-rank P = .56). Cox proportional hazards regression analysis confirmed the lack of association of tumor laterality on adjusted 5-year CSS (hazard ratio [HR] = 0.96; 95% confidence interval [CI] = 0.87-1.06), breast-cancer specific survival (HR = 0.96; 95% CI = 0.85-1.09), and overall survival (HR = 0.98; 95% CI = 0.94-1.03). There was also no association of inner versus outer quadrant location on adjusted 5-year CSS for right-sided (HR = 1.06; 95% CI = 0.89-1.12) and left-sided breast cancer (HR = 0.95; 95% CI = 0.79-1.15). Conclusions With modern radiation therapy techniques, older patients who received left-sided RT for stage I estrogen-receptor positive breast cancer do not demonstrate an increased risk of cardiac mortality compared with patients with right-sided breast cancer. RT can be offered to older patients without concern for inducing cardiac-related death.

Purpose To investigate predictors of cognitive decline after whole brain radiotherapy (WBRT) for brain metastases. Methods A secondary analysis of a phase 2 clinical trial was conducted in patients who received stereotactic radiosurgery for 1–10 brain metastases and WBRT (NCT01046123). The Montreal Cognitive Assessment (MoCA) was performed at baseline and every 3 months after WBRT. Baseline T2-weighted fluid attenuation inversion recovery magnetic resonance imaging was independently assessed by two neuroradiologists for the presence of white matter hyperintensities (WMH) using the Fazekas visual rating scale. WMH were also manually segmented for volumetric analysis. Univariable and multivariable logistic regression were used to test the association between baseline variables and MoCA score decline. Results Forty-six patients survived ≥ 3 months after treatment. Age (OR 1.12 (1.04–1.21), p p = 0.02) and baseline Fazekas score ≥ 3/6 (OR 6.4, 95% CI 1.7–24.7, p Conclusion A greater decline in cognition after WBRT was observed in older patients and patients with a higher baseline WMH burden. Although this study is small and hypothesis-generating, we propose that radiation oncologists should exercise caution in prescribing WBRT if leukoencephalopathy is present on pre-treatment imaging. Trial Registration: clinicaltrials.gov identifier NCT01046123. First posted January 11, 2010. https://clinicaltrials.gov/ct2/show/NCT01046123

Brain metastases (BM) arising from head and neck cancer (HNC) are rare and not well characterized. This study aims to describe the clinicopathological features, treatments, prognostic factors, and survival in HNC patients with BM.Non-thyroid HNC patients referred to BC Cancer from 1998 to 2016 were retrospectively reviewed for BM. The Kaplan-Meier method, log-rank test, and Cox regression analysis were used to assess post-BM survival and prognostic factors.Out of 9432 HNC patients, 88 patients developed BM (0.9%, median follow-up 3.4 years). On average, the BM were diagnosed 18.5 months after the primary diagnosis and tended to arise after distant metastases to extracranial sites (85%) such as the lungs (78%). At BM presentation, 84% were symptomatic and two thirds had a poor performance status (ECOG ≥ 2, 68%). The median post-BM survival was 2.5 months (95% CI 2.1-3.3 months). On multivariable analysis, management of BM with radiotherapy (RT) alone (3.3 months, 95% CI 2.3-4.6, p = 0.005) and RT with surgery (4.4 months, 95% CI 2.8-6.9, p 0.001) was associated with longer survival compared to best supportive care alone (1.4 months, 95% CI 1.0-2.0 months). Age, sex, performance status, sub-localization of the primary HNC, presence of extracranial metastases, and number of intracranial metastases were not associated with post-BM survival (all p ≥ 0.05).This is the largest study to date in BM from HNC. BM occur late in the course of HNC and carry a poor prognosis. Treatment with intracranial radiotherapy both with and without surgery was associated with improved survival.

The predictive benefit of breast cancer molecular subtypes for systemic therapy approaches has been well established; yet, there is a paucity of data regarding their use as a predictor of radiation therapy fractionation sensitivity. The purpose of this study was to determine whether rates of local recurrence (LR) for patients treated with hypofractionated (HF) radiation therapy, in comparison to conventional fractionation, differ across breast cancer molecular subtypes in a large, prospectively collected cohort treated with modern systemic therapy.Patients who received a diagnosis of stage I-III breast cancer between 2005 and 2009 were identified. Molecular subtype was determined using the American Joint Committee on Cancer classification system (luminal-A, luminal-B, HER2+, triple negative [TN]). Multivariable Cox regression modeling was used to identify predictors of LR. LR-free-survival (LRFS) was determined using the Kaplan-Meier method and compared using the log-rank test.A total of 5868 cases were identified with a median follow-up of 10.8 years. Patients with luminal-A subtype composed 45% of the cohort (n = 2628), compared with 30% luminal-B (n = 1734), 15% HER2+ (n = 903), and 10% TN (n = 603). A total of 76% (n = 4429) of patients were treated with HF. The 10-year LRFS was 97.1% (95% confidence interval [CI], 96.6-97.6) for the whole cohort. The 10-year LRFS based on molecular subtypes was 98.3% (95% CI, 97.6-98.7) luminal-A, 96.6% (95% CI, 95.5-97.4) luminal-B, 97.0% (95% CI, 95.5-98.0) HER2+, and 93.5% (95% CI, 91.1-95.3) TN (P.001). There was no difference in the 10-year LRFS between patients treated with HF versus conventional fractionation among those with luminal-A (98.2% vs 98.4%; P = .42), luminal-B (96.6% vs 96.8%; P = .90), HER2+ (97.5% vs 95.8%; P = .12), or TN (93.9% vs 92.2%; P = .47). There was no significant interaction between subtype and fractionation regimen.These data support the routine use of hypofractionated radiation therapy regimens across all breast cancer subtypes.

Purpose: Ductal Carcinoma in Situ (DCIS) with microinvasion (MI) (< 1mm) includes a spectrum of cases with a single focus of MI and those with multiple foci (2 or more) of MI. The impact of multiple foci of MI on the risks of local recurrence (LR), invasive LR and breast cancer-specific survival (BCSS) is unknown, leading to uncertainty if DCIS with multiple foci of MI requires more aggressive treatment than those with a single focus of MI or pure DCIS. We examined the impact of multiple foci of MI, confirmed by expert pathology review, on the 15-yr risks of LR, invasive LR and breast-cancer specific survival (BCSS) in a population cohort of DCIS (+/-MI) treated with breast-conserving surgery (BCS) +/- radiotherapy (RT). Methods: The cohort includes all women diagnosed with DCIS +/- MI in Ontario from 1994-2003 treated with BCS+/-RT. Cases with prior malignancy were excluded. Treatment and outcomes were ascertained by deterministic linkage with chart validation. Cause of death was determined from the provincial cancer registry or terminal hospital admission records. Cox proportional hazards model was used to evaluate the impact of multiple foci of MI on the risks of ipsilateral invasive LR and ipsilateral DCIS LR, adjusting for significant co-variates. The 15-yr invasive local recurrence-free survival (LRFS), DCIS LRFS and 15-yr BCSS risks were calculated using the Kaplan-Meier method with differences compared using the log-rank test. Results: The cohort includes 3529 women; 2988 (85%) with pathology review are included in this analysis. 2,721 had pure DCIS (51% received RT), 267 had DCIS with MI (1 focus, N=156; multiple foci, N=111 (58% had RT)). Median follow-up was 13 years. Median age at diagnosis was 58 years. LR developed in 571 cases (21%) of pure DCIS, 33 cases (21%) with 1 focus of MI and 23 cases (27%) with multiple foci of MI. On multivariable analyses, the presence of multiple foci of MI was associated with an increased risk of invasive LR (HR=1.59, 95%CI: 1.01-2.49, p=0.04) but not DCIS LR (HR=0.89, 95%CI: 0.46, 1.76, p=0.7). Women with multiple foci of MI had higher risks of invasive LR and lower BCSS at 15 years compared to those with pure DCIS. The 15-year invasive LRFS risks for cases with pure DCIS, with 1 focus or multiple foci of MI were 85.7%, 85.6%, 74.7% for cases treated by BCS alone and 87.2%, 89.9% and 77% following BCS+RT without boost; however, women treated with boost RT had substantially higher 15-yr invasive LRFS risks than those who did not receive boost RT. The 15-yr invasive LRFS risks for those with pure DCIS, 1 or multiple foci of MI, were 89.2%, 91.3% and 95% (all p values>.05, limited by low event rate). The 15-yr BCSS risks for cases with 1 focus, multiple foci of MI or pure DCIS were 92.1%, 93.1%, 96.4% (p=.006). Conclusions: The presence of multiple foci of MI in DCIS is associated with higher 15-year risks of invasive LR and lower breast-cancer specific survival after breast-conserving therapy compared to women with pure DCIS but treatment with whole breast and boost RT can mitigate this risk. Citation Format: Rakovitch E, Sutradhar R, Lalani N, Gu S, Nofech-Mozes S, Hanna W, Fong C, Paszat L. Multiple foci of microinvasion is associated with an increased risk of invasive local recurrence and an increased risk of breast cancer mortality in women with ductal carcinoma in situ treated with breast-conserving therapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-03.

Purpose Given concerns about attrition and career outcomes of academic radiation oncologists, we sought to gather empirical evidence regarding mentorship experiences. Methods and Materials We surveyed academic radiation oncologists in the United States and Canada who were within 5 years of board certification, using a pretested questionnaire that included 14 questions evaluating the following aspects of mentorship: relationship development, peer mentorship, satisfaction with mentorship, sponsorship, relationship nature, informal interactions, mentoring roles, presence of a primary mentor, and primary mentor characteristics. We described responses and evaluated associations with gender in separate multivariable regression models that adjusted for years in practice, nature of research, possession of higher degrees, and race. Results Of 347 faculty surveyed, 221 responded (64% response rate); 66% of respondents were men. Over half of respondents indicated difficulty in identifying role models (56%, n = 124); just under half reported ease in developing mentoring relationships (49%, n = 108). Peer-mentor use was commonly reported (62%, n = 138). Most respondents (66%, n = 145) spent ≤1 hour per month meeting with mentors. Only 51% (n = 112) reported having a primary mentor. Just under half of all respondents reported being very or somewhat satisfied with their mentorship experiences (49%, n = 108). Conclusions These findings suggest a need for academic radiation oncology departments to facilitate mentorship of all junior faculty through deliberate, structured programs, with training of mentors and mentees alike. It is heartening that substantial rates of sponsorship and peer-mentorship use were reported, which may serve as the grounding for further initiatives.

Purpose A lack of diversity has been observed in radiation oncology (RO), with women and certain racial/ethnic groups underrepresented as trainees, faculty, and practicing physicians. We sought to gain a nuanced understanding of how to best promote diversity, equity, and inclusion (DEI) based on the insights of RO department chairs, with particular attention given to the experiences of the few women and underrepresented minorities (URMs) in these influential positions. Methods and Materials From March to June 2016, we conducted telephone interviews with 24 RO department chairs (of 27 invited). Purposive sampling was used to invite all chairs who were women (n = 13) or URMs (n = 3) and 11 male chairs who were not URMs. Multiple analysts coded the verbatim transcripts. Results Five themes were identified: (1) commitment to DEI promotes quality health care and innovation; (2) gaps remain despite some progress with promoting diversity in RO; (3) women and URM faculty continue to experience challenges in various career domains; (4) solutions to DEI issues would be facilitated by acknowledging realities of gender and race; and (5) expansion of the career pipeline is needed. Conclusions The chairs' insights had policy-relevant implications. Bias training should broach tokenism, blindness, and intersectionality. Efforts to recruit and support diverse talent should be deliberate and proactive. Bridge programs could engage students before their application to medical school.

Background: Ductal Carcinoma in Situ (DCIS) is a non-invasive breast cancer often treated with breast-conserving surgery (BCS) with or without radiotherapy (RT). It is unclear if the presence of microinvasion (MI) (invasion ≤1mm) is associated with an increased risk of LR (DCIS or invasive) or invasive LR compared to women with pure DCIS. In addition, the impact of multiple foci (>2) of MI compared to pure DCIS is also unknown; therefore, it is unclear if some women with MI require more aggressive treatment. We evaluated the impact of the presence of MI and the number of foci of MI on the risks of any LR and invasive LR in a population of women with DCIS with and without MI treated with BCS. Methods: The cohort includes all women diagnosed with pure DCIS or DCIS with MI in Ontario from 1994-2003 treated with BCS +/- RT. All cases had systematic pathology review to confirm the presence and number of foci of MI. Treatment and outcomes were ascertained through administrative databases and validated by chart review. Cox proportional hazards model was used to evaluate the impact of MI and the number of foci of MI (1 vs >2 foci) on the development of any LR and invasive LR compared to cases with pure DCIS. The 10-yr local recurrence-free survival (LRFS) and invasive LRFS rates were calculated using the Kaplan-Meier approach with differences compared using the log-rank test. Results: The population cohort includes 2,988 women with DCIS treated by BCS (N=2,721 pure DCIS, N= 267 DCIS with MI). Median follow-up (12 years; p=.23) and median age at diagnosis (58 years; p=.17) were similar in both groups. RT was given in 58% of cases with MI and 51% of cases with pure DCIS (p=.03). Hormonal therapy was utilized in 7.1% of women with MI and 5.3% of women with pure DCIS (p=.22). LR developed in 59 (22.1%) cases with MI and 530 (19.6%) cases of pure DCIS. Women with MI were more likely to have high nuclear grade (p 2 foci of MI (HR=1.45, 95% CI: .90-2.32) was also not associated with an increased risk of invasive LR compared to cases of pure DCIS. Among women treated with BCS alone, the 10 year LRFS rates were 80%, 75% and 73% for women with pure DCIS, 1 focus, >2 foci of MI (p=.10). The invasive LRFS rates were 89%, 91% and 85% (p=.26). Among women treated with BCS+RT, the 10 year LRFS rates were 87%, 88% and 80% (p=0.32) for women with pure DCIS, 1 focus or ≥2 foci of MI. The invasive LRFS rates were 93%, 90% and 86% (p=.44). There was no interaction between the presence of MI and RT. Conclusions: Women with DCIS with one or multiple foci of microinvasion ( Citation Format: Lalani N, Paszat L, Sutradhar R, Gu S, Fong C, Nofech-Mozes S, Hanna W, Tuck A, Youngson B, Miller N, Done SJ, Chang MC, Sengupta S, Elavathil L, Jani PA, Bonin M, Rakovitch E. The presence of one or multiple foci of microinvasion is not associated with an increased risk of local recurrence in women with ductal carcinoma in situ treated with breast conserving therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-05.

Background: Prediction of local recurrence (LR) risk after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) is needed to guide decisions regarding risks and benefits of adjuvant radiotherapy (RT). We aim to determine the optimal combination of clinical and pathological characteristics with the Oncotype DCIS Score (DS) to predict individualized 10 year risks of local recurrence (LR) after BCS (with or without RT) for DCIS and develop a web-based nomogram / risk calculator. Methods: DS (continuous, categorical risk groups low/intermediate/high) and complete clinico-pathological data (age, tumor size, nuclear grade, comedonecrosis, multifocality, margin width and receipt of breast RT) are available for 1102 cases from the Ontario population cohort of pure DCIS treated by BCS (981 cases with negative margins, 121 cases with positive margins). We examined various categorizations of discrete variables, and transformations of continuous variables, and used model selection procedures to determine the best fitting Cox proportional hazards regression model of LR according to the c-statistic, Akaike Information Criterion, and log-likelihood. We tested all two-way interactions and interactions with time. The 10-year probability of LR was calculated for each woman using the estimate of the baseline survival function and the estimate of the linear predictor, which is a function of the regression parameter estimates and specific covariate values. Model calibration will be explored by comparing observed versus predicted risk of LR, and the model's discriminative ability will be assessed by the concordance index. Model validation will be conducted via bootstrapping approaches. Results: In the best fitting main effects full model, the adjusted hazard ratios (HR) (95% confidence intervals (CI)) for LR included: intermediate/ high risk DS vs. low risk (HR =1.96 (1.39, 2.74)), age < 50 years at diagnosis vs. age>= 50 (HR = 1.62 (1.16, 2.25)), square root of tumor size (HR/mm = 1.24 (1.11, 1.38)), comedonecrosis > 30% vs. = 50, tumor size Conclusion: This prediction model combines clinical and pathological features with the DS to improve estimates of local recurrence risk after BCS alone and the absolute benefit with RT, which can improve decision making in DCIS. After calibration and validation, it will be the basis of a web-based nomogram / risk calculator. It also demonstrates the importance of molecular testing for studies of the de-escalation of therapy for DCIS. Citation Format: Paszat L, Sutradhar R, Zhou L, Lalani N, Nofech-Mozes S, Rakovitch E. Integration of clinical and pathological data with the DCIS score to predict the risk of local recurrence [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-01.

Highlights • Radiation-induced osteomyelitis near the skull base (e.g. temporal bone and high cervical vertebrae) could carry potentially lethal consequences. • Early diagnosis and timely intervention is critical. • The two cases included in this report highlight the importance of differential diagnosis and timely referral to a surgical oncologist and infectious diseases specialist for prolonged intraveous antibiotics in achieving satisfactory clinical outcomes., Osteomyelitis, infection of the bone and marrow, following high dose (chemo-)radiotherapy for head and neck cancer is uncommon and rarely seen in the cervical spine or temporal bone. Due to its proximity to critical structures, osteomyelitis in the latter regions could carry potentially important consequences. Furthermore, involvement near the skull base (e.g. temporal bone and high cervical vertebrae) presents unique challenges in diagnosis (especially in the differentiation from disease recurrence) and treatment, making early detection and timely intervention critical. In this report, we describe two cases of osteomyelitis, one involving the temporal bone and the other affecting the 2nd and 3rd cervical vertebrae, diagnosed and treated with good outcome in the setting of definitive chemoradiotherapy for locally advanced pharyngeal carcinomas. We suggest that for new or evolving post-radiotherapy osseous changes in regions that have received a high dose of radiotherapy, associated with unexpected and deteriorating spinal symptoms such as pain and spasm, radiation-related osteomyelitis should be considered in the differential diagnosis from tumor progression. Timely referral to a surgical oncologist and infectious diseases specialist is paramount in achieving satisfactory clinical outcomes.

The impact of Ductal Carcinoma in Situ (DCIS) with multiple foci of microinvasion (MI) (≤ 1 mm) on the risks of local recurrence (LR) and invasive LR is unknown, leading to uncertainty if DCIS with multiple foci of MI requires more aggressive treatment. We report a population-based analysis of the impact of multiple foci of MI, confirmed by pathology review, on the 15-year risks of LR and invasive LR treated with breast-conserving surgery (BCS) ± radiotherapy (RT). Cohort includes all women diagnosed with DCIS ± MI from 1994 to 2003 treated with BCS ± RT. Cox proportional hazards model was used to evaluate the impact of multiple foci of MI on the risks of LR and invasive LR, adjusting for covariates. The 15-year local and invasive local recurrence-free survival rates were calculated using the Kaplan–Meier method with differences compared by log-rank test. The cohort includes 2988 women treated by BCS; 2721 had pure DCIS (51% received RT), 267 had DCIS with one or more foci of MI (58% had RT). Median follow-up was 13 years. Median age at diagnosis was 58 years. On multivariable analyses, the presence of multiple foci of MI was associated with an increased risk of invasive LR (HR = 1.59, 95% CI 1.01–2.49, p = 0.04) but not DCIS LR (HR = 0.89, 95% CI 0.46, 1.76, p = 0.7). The 15-year invasive LRFS risks for cases with pure DCIS, with 1 focus or multiple foci of MI were 85.7%, 85.6%, 74.7% following treatment by BCS alone, 87.2%, 89.9%, and 77% for those treated with BCS + RT without boost and 89.2%, 91.3%, and 95% for women treated with BCS + RT and boost. The presence of multiple foci of MI in DCIS is associated with higher 15-year risks of invasive LR after breast-conserving therapy compared to women with pure DCIS but treatment with whole breast and boost RT can mitigate this risk.

Ductal carcinoma in situ of the breast comprises nearly 25 % of all diagnoses of breast cancer. The current paradigm for management of DCIS consists of breast-conserving surgery followed by post-operative radiotherapy. The goal of the treatment of DCIS is to reduce the risk of local recurrence (and invasive local recurrence) to prevent the detrimental psychological impact of recurrence and minimize the need for additional treatment. A number of clinical, pathological, and molecular variables have been identified as predictive markers of recurrence and can be used to help risk stratify women with this diagnosis. We present here a review of current markers of recurrence, risk prediction tools, and future directions.

Thymomas and thymic carcinomas are rare epithelial cell tumours arising from the thymus. Definitive surgical resection continues to be the primary approach for the management of thymomas and thymic carcinomas. However, complete resection is not always achievable due to the complexity of the mediastinal anatomy and in rare cases local recurrences may occur which are often incurable. Therefore, the use of Post-Operative Radiotherapy (PORT) may be considered with the intent of improving local control while being judicious of toxicity in the setting of prolonged clinical trajectories and proximity to critical structures. There continues to be a paucity of literature surrounding the use of PORT for thymomas and thymic carcinomas and the optimal dose has not yet been established. This review aims to summarize the current literature regarding radiotherapy indications and to explore issues surrounding radiotherapy dose-response-relationships for thymomas and thymic carcinoma. Long-term prospective studies using contemporary surgical and radiotherapy techniques are needed to further elucidate the optimal radiation approach in the management of thymic tumours.

PURPOSE We aimed to investigate whether systemic therapy (ST) use around the time of brain radiotherapy (RT) predicts overall survival for patients with brain metastases (BM). We also aimed to validate the Diagnosis-Specific Graded Prognostic Assessment (DS-GPA) in a population-based cohort. METHODS We used provincial RT and pharmacy databases to retrospectively review all adult patients in British Columbia, Canada, who received a first course of RT for BMs between 2012 and 2016. We used a randomly selected subset with complete baseline data to develop a multivariate analysis (MVA)-based nomogram including ST use to predict survival after RT and to validate the DS-GPA. RESULTS In our 3095-patient cohort, the median overall survival (OS) of the 999 recipients of ST after RT was 5.0 months (CI 4.1-6.0) longer than the OS of the 2096 non-recipients of ST after RT (p< 0.0001): targeted therapy (HR 0.42, CI 0.37-0.48), hormone therapy (HR 0.45, CI 0.36-0.55) and cytotoxic chemotherapy (HR 0.71, CI 0.64-0.79). The OS of patients who discontinued ST after RT was 0.9 months (CI 0.3-1.4) shorter than the OS of those who did not receive ST before nor after RT (p< 0.0001). A MVA in the 200-patient subset demonstrated that the traditional baseline variables: cancer diagnosis, age, performance status, presence of extracranial disease, and number of BMs predicted survival, as did the novel variables: ST use before RT and ST use after RT. The MVA-based nomogram had a bootstrap-corrected Harrell’s Concordance Index of 0.70. In the 179 patients within this subset with DS-GPA-compatible diagnoses, the DS-GPA overestimated OS by 6.3 months (CI 5.3- 9.8) (p= 0.0006). CONCLUSIONS The type and timing of ST use around RT predict survival for patients with BMs. A novel baseline variable “ST planned after RT” should be prospectively collected to validate these findings in other cohorts.

e19109 Background: Estrogen positive (ER) advanced breast cancers (ABC) are associated with a longer survival compared to other subtypes. However, clinical equipoise remains for the management of oligometastatic disease. While recent phase I and II data support the use of metastasis-directed therapy, breast cancer patients remain underrepresented and real-world outcomes for breast cancer patients with directed treatment for oligometastases is lacking. Methods: The BC Cancer Breast Cancer Outcomes Unit (BCOU) database was utilized to identify patients with ER positive breast cancer referred to BC Cancer from 2005-2014 with documented metastases. Baseline clinical, pathological and treatment data were compiled. Overall survival (OS) was compared between the group with oligometastatic disease(OM) (defined as < = 5 foci of metastases) and the group with non-oligometastatic disease (defined as > = 6 foci of metastases) using Kaplan-Meier survival curves. Key secondary endpoints included metastasis-directed treatment impact, based on the site of metastasis, local control (LC) and distant failure (DF) rate. Results: A total of 938 patients met the inclusion criteria. Of these, 191 (20.4%) had OM and 747 (79.6%) had widespread disease at 1st diagnosis of ABC. The groups were well balanced for clinical characteristics (all p > 0.05), with a median age of 59yrs (23-99). 84% were ductal carcinomas, 14% were also HER2 positive. Sites of oligometastases were bone (66.5%), liver (12.0%), brain (8.4%) and lung (5.8%). Median follow-up was 7.4 yrs. Median OS was 24 mo (95% CI 20.2, 27.8) for patients with OM and 11 mo (9.5, 12.5) for those with widespread disease (p < 0.0001). In the OM group, 114 (59.7%) of patients received metastasis-directed treatment, whereas 77 (40.3%) did not. Treatment modalities included radiation in 53.4% of patients, surgery in 8.9% of patients and stereotactic body radiotherapy (SBRT) in 3.7%. Median OS was 24 mo (18.3, 29.7) for patients who received metastasis-directed treatment and 23 mo (17.5, 28.5) for those who did not (p = 0.954). Patients with bone-only metastases had a median OS of 27mo with directed treatment and 25mo without directed-treatment (p = 0.334). Conclusions: Oligometastatic state was associated with a significantly better OS. Metastasis-directed treatment was associated with a non-significant OS difference in patients with bone-only metastases in a real world cohort. However, the impact of modern systemic treatment and SBRT methods are evolving. Large prospective randomized studies of this approach merit further study.

Purpose Given the importance of access to key resources to ensure future academic success, we seek to describe what is currently provided to junior faculty in radiation oncology. Methods and Materials We present descriptive analyses from a survey of academic radiation oncologists in the United States and Canada who were within 5 years of board certification. We used a pretested questionnaire evaluating time, space, staff, start-up funding, and compensation. Results We surveyed 347 faculty, with a response rate of 64% (n = 221). Respondents reported working an average of 56 hours per week. Most respondents (59.2%) reported that that their research time was “poorly” or “not at all” protected. Most perceived adequate access to space (75.7%) and equipment (73.6%). A substantial proportion perceived inadequate or no access to support from grant administrators (47.9%) or statisticians (55.5%). A third (33.6%) reported having a research assistant, and 22.2% received start-up research funding. Conclusions These findings suggest perceived needs for protected time, grants administration, and statistical support among junior faculty in radiation oncology.

Primary breast lymphoma (PBL) comprises

250Background: Despite maximal local therapies (MLT) (radical prostatectomy followed by radiotherapy [RT]), 20-30% of men will have incurable progression of prostate cancer (PC). Most recurrences i...

250 Background: Despite maximal local therapies (MLT) (radical prostatectomy followed by radiotherapy [RT]), 20-30% of men will have incurable progression of prostate cancer (PC). Most recurrences in this scenario are characterized by continuous PSA rises and failure of standard imaging (bone scan [BS] and computed tomography [CT]) to detect recurrence sites. We conducted a phase II trial for men with rising PSA after MLT using 18F-DCFPyL PET-MR followed by targeted ablation of PET positive foci. We report the results of our pre-defined analysis. Methods: Patients with rising PSA (0.43.0 ng/mL) after MLT, negative BS/CT and no prior salvage ADT were eligible. All patients underwent 18F-DCFPyL PET-MR followed by immediate PET-CT acquisition. Those with limited disease, where possible, underwent stereotactic ablative RT (SABR) or surgery. No ADT was used. The primary endpoint was biochemical response rate (complete [undetectable PSA] or partial [PSA decline ≥50% compared to baseline]). A Simon’s two stage study design was employed. Stage 1 included 12 response evaluable patients, requiring 1 or more responses in the absence of grade 3+ toxicities to proceed to stage 2 (additional 25 response evaluable patients). Results: After a median of 58 months (range 29-120) post MLT, 20 patients underwent PET-MR/CT to have 12 response evaluable patients. Median PSA at enrollment was 1.3 ng/mL (range 0.4-2.8). Three patients had negative PET-MR/CT, while 17 had positive scans, of which 12 (60%) were amenable to response evaluable ablation. The median number of detected lesions in those treated was 2 (range 1-5). Ten patients underwent SABR (27-30 Gy/3 fractions) and 2 had surgery. One patient (8%) had complete and 4 (33%) had partial PSA responses at a median of 3.3 months (range 2.8-6.0) after ablation, while the remaining 7 (59%) did not have biochemical response. No grade 3+ toxicities were observed. Conclusions: 18F-DCFPyL PET/MR has high detection rates in men with rising PSA after MLT. We observed favorable early results with SABR or surgery (41% RR). Trial completion will inform if this approach offers potential for cure in an early molecularly-defined PC oligometastatic state. Clinical trial information: NCT03160794.

The purpose of this study was to evaluate bilateral kidney and target translational/rotational intrafraction motion during stereotactic body radiation therapy treatment delivery of primary renal cell carcinoma and oligometastatic adrenal lesions for patients immobilized in the Elekta BodyFIX system. Bilateral kidney motion was assessed at midplane for 30 patients immobilized in a full‐body dual‐vacuum‐cushion system with two patients immobilized via abdominal compression. Intrafraction motion was assessed for 15 patients using kilovoltage cone‐beam computed tomography (kV‐CBCT) datasets (n=151) correlated to the planning CT. Patient positioning was corrected for translational and rotational misalignments using a robotic couch in six degrees of freedom if setup errors exceeded 1 mm and 1°. Absolute bilateral kidney motion between inhale and exhale 4D CT imaging phases for left–right (LR), superior–inferior (SI), and anterior–posterior (AP) directions was 1.51±1.00mm,8.10±4.33mm, and 3.08±2.11mm, respectively. Residual setup error determined across CBCT type (pretreatment, intrafraction, and post‐treatment) for x (LR), y (SI), and z (AP) translations was 0.63±0.74mm,1.08±1.38mm, and 0.70±1.00mm; while for x (pitch), y (roll), and z (yaw) rotations was 0.24±0.39°,0.19±0.34°, and 0.26±0.43°, respectively. Targets were localized to within 2.1 mm and 0.8° 95% of the time. The frequency of misalignments in the y direction was significant (p

To develop a volumetric modulated arc therapy (VMAT) treatment planning solution in the treatment of primary renal cell carcinoma and oligometastatic adrenal lesions with stereotactic body radiation therapy. Single-arc VMAT plans (n = 5) were compared with clinically delivered step-and-shoot intensity-modulated radiotherapy (IMRT) with planning target volume coverage normalized between techniques. Target volume conformity, organ-at-risk (OAR) dose, treatment time, and monitor units were compared. A VMAT planning solution, created from a combination of arc settings and optimization constraints, auto-generated treatment plans in a single optimization. The treatment planning solution was evaluated on 15 consecutive patients receiving kidney and adrenal stereotactic body radiation therapy. Treatment time was reduced from 13.0 ± 2.6 to 4.0 ± 0.9 minutes for IMRT and VMAT, respectively. The VMAT planning solution generated treatment plans with increased target homogeneity, improved 95% conformity index, and a reduced maximum point dose to nearby OARs but with increased intermediate dose to distant OARs. The conformity of the 95% isodose improved from 1.32 ± 0.39 to 1.12 ± 0.05 for IMRT and VMAT treatment plans, respectively. Evaluation of the planning solution showed clinically acceptable dose distributions for 13 of 15 cases with tight conformity of the prescription isodose to the planning target volume of 1.07 ± 0.04, delivering minimal dose to OARs. The introduction of a stereotactic body radiation therapy VMAT treatment planning solution improves the efficiency of planning and delivery time, producing treatment plans of comparable or superior quality to IMRT in the case of primary renal cell carcinoma and oligometastatic adrenal lesions.

Whole-breast radiation therapy (XRT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) may decrease the risk of local recurrence, but the optimal dose regimen remains unclear. Past studies administered 50 Gy in 25 fractions (conventional); however, treatment pattern studies report that hypofractionated (HF) regimens (42.4 Gy in 16 fractions) are frequently used. We report the impact of HF (vs conventional) on the risk of local recurrence after BCS for DCIS.All women with DCIS treated with BCS and XRT in Ontario, Canada from 1994 to 2003 were identified. Treatment and outcomes were assessed through administrative databases and validated by chart review. Survival analyses were performed. To account for systematic differences between women treated with alternate regimens, we used a propensity score adjustment approach.We identified 1609 women, of whom 971 (60%) received conventional regimens and 638 (40%) received HF. A total of 489 patients (30%) received a boost dose, of whom 143 (15%) received conventional radiation therapy and 346 (54%) received HF. The median follow-up time was 9.2 years. The median age at diagnosis was 56 years (interquartile range [IQR], 49-65 years). On univariate analyses, the 10-year actuarial local recurrence-free survival was 86% for conventional radiation therapy and 89% for HF (P=.03). On multivariable analyses, age45 years (hazard ratio [HR] = 2.4; 95% CI: 1.6-3.4; P.0001), high (HR=2.9; 95% CI: 1.2-7.3; P=.02) or intermediate nuclear grade (HR=2.7; 95% CI: 1.1-6.6; P=.04), and positive resection margins (HR=1.4; 95% CI: 1.0-2.1; P=.05) were associated with an increased risk of local recurrence. HF was not significantly associated with an increased risk of local recurrence compared with conventional radiation therapy on multivariate analysis (HR=0.8; 95% CI: 0.5-1.2; P=.34).The risk of local recurrence among individuals treated with HF regimens after BCS for DCIS was similar to that among individuals treated with conventional radiation therapy.

The addition of a tumour-bed boost following whole breast radiotherapy (RT) can reduce local recurrence, but is associated with increased toxicity. The objective of this study was to prospectively record toxicities in women treated with whole breast RT with or without a sequential boost, and determine the associated with breast-related late toxicities. This REB approved study included women with breast tumours previously treated with 50Gy/25±10Gy boost, 40Gy/16±12.5Gy boost, or 42.40Gy/16±10 boost. Breast RT was delivered using intensity modulated RT (IMRT). The tumour bed was contoured for boost treatment (delivered using a mixed photon and electron direct appositional technique). Breast-related toxicities were prospectively evaluated at 3, 6, 12, and 24 months, and were defined by CTCAE v3.0. Chemotherapy, RT dose, age, time since RT, and boost parameters were assessed for association with late toxicity. Multivariable marginal logistic regression analysis was performed on all patients and the boost cohort. From Jan 2007 to Dec 2009, 125 post-lumpectomy women were included. Fifty-eight (46%) women had breast RT only and 67 (54%) had a subsequent boost. Patients who attended and had one or more toxicities at 3, 6, 12, or 24 months were 59/94 (63%), 61/100 (61%), 51/104 (49%), and 47/104 (45%), respectively. Adjuvant chemo, age, and RT tangential dose were not significant for side-effects. The addition of a boost increased the odds of having at least one sideeffect by nearly 2-fold (OR=1.97; 95%CI: 1.14-3.4, p=.015). The odds of any side-effect did reduce over time (OR=0.67 per year; 95%CI: 0.48-0.91, p=.012). Within the boost cohort, the odds of side-effects increased with electron energies >9Mev (OR=2.66, 95%CI: 1.1-6.41); while no impact was observed with chest wall thickness, depth of seroma, hotspot, nipple in-field, and boost field size. Compared to the lower outer quadrant, upper inner (OR=4.82) and upper outer quadrant boosts (OR=3.37) increased the odds of side-effects. Whole breast RT treated with standard fractionation or hypofractionation were not significantly different with respect to late toxicity. The addition of a breast boost nearly doubled the risk of any breast-related late toxicity, with reduction in these side effects over time. Where possible, boost treatments should be tailored to avoid sensitive normal breast regions and omit high Open Access Abstract

Introduction: There is little knowledge of survivorship care specific to genitourinary (GU) cancers. To improve care delivery to this patient population, we need to clearly define physician perceptions of survivorship care. We therefore conducted a study to determine the challenges to GU cancer survivorship care in Canada.Methods: A web-based questionnaire was e-mailed to physicians treating GU cancers in Canada, including urologists, radiation oncologists, and medical oncologists. Five domains were assessed: demography, current post-cancer treatment care, perspectives on barriers to survivorship care, accessibility to survivorship resources, and perspectives about advocacy groups.Results: There were 306 responses, with 260 eligible for study. A total of 82% of physicians involve primary care practitioners (PCPs) at some point in survivorship care. Most physicians provide some form of written follow-up plan to PCPs. However, only 25% provided lifestyle recommendations and 53% included persistent and late effects of therapy. Lack of time or resources dedicated to survivorship care was the most commonly reported barrier. There was variation in accessibility to survivorship support programs among different subspecialties and regions. Advocacy groups generally were underutilized, particularly in testis cancer. Low response rate and the potential response bias are the main limitations of this survey.Conclusion: To our knowledge this is the first study to address the challenges of GU cancer survivorship care in Canada. The barriers and accessibility of survivorship care quoted in this survey may be used to improve care for this group of patients. Underutilization of advocacy groups may stimulate the advocacy groups and institutions to address its causes and solutions.

320 Background: For select muscle invasive bladder cancer (MIBC) patients, a multimodal approach using transurethral resection of the bladder tumor (TURBT) followed by concurrent cisplatin and external beam radiotherapy (EBRT) provides a curative bladder-sparing alternative to cystectomy. Our aim was to review decision making, tolerability and outcomes for patients treated in a multidisciplinary bladder clinic. Methods: Between June 1998-June 2011, MIBC patients treated with TURBT and concurrent cisplatin (40mg/m2 weekly) with EBRT (60-66Gy in 30-33 fractions to the bladder and pelvis) were identified. Post-treatment cystoscopy was performed every 3 months with regular imaging. Results: A total of 64 patients were assessed; mean age 73 (43-89), 83% were male. The decision to attempt bladder-sparing was based on patient preference (58%), nonsurgical candidate (25%), or unknown (17%). Patients received a mean 5/6 weeks of cisplatin with the most common toxicity being a 14% overall risk of grade 0-1 renal toxicity by NCIC CTC criteria. All patients completed the prescribed EBRT. No patients experienced acute toxicity requiring cystectomy or causing death. At a median follow-up of 3.5 years, 50/64 (78%) patients were alive and had their own bladders, 7/64 (11%) were alive after cystectomy for recurrence, 7/64 (11%) died. Of the 24/64 (38%) recurrences: 3/64 (5%) had positive cytology/carcinoma in-situ and received intravesicle therapy; 1/64 (2%) had local superficial recurrence and underwent TURBT; 7/64 (11%) had local invasive recurrence requiring cystectomy; 13/64 (20%) had distant recurrence, 6 received chemotherapy and 7 were observed. Estimated disease free survival was 51%, and overall survival was 90% at 3.5 years. Conclusions: Bladder-sparing therapy with concurrent cisplatin and EBRT is a well-tolerated and effective approach with outcomes comparable to cystectomy in carefully selected patients. Prospective trials are required to delineate clinical and molecular factors to further triage patients into sub-groups who may benefit from bladder sparing with neoadjuvant/adjuvant chemotherapy or molecularly-targeted agents to improve survival.