Method to assess the need for re-planning HDR brachytherapy tandem and ring treatments.

High dose rate (HDR) brachytherapy procedures for cervical cancer require multiple applicator insertions for multiple (typically 5) fractions of a single plan, which carries a risk for variability in applicator position between fractions. Due to applicator displacement relative to patient anatomy, the dose to nearby organs-at-risk (OARs) may vary significantly from one fraction to the next. The purpose of this study was to evaluate the effect of changes in HDR tandem and ring (T&R) applicator position on doses to nearby OARs and to present a quick and simple method to estimate doses to OARs inter-fractionally without having to perform a re-plan. Ninety CT image sets for 20 patients, ages 44 to 86, undergoing T&R-based HDR for cervical cancer were used retrospectively for this study. Measures of applicator positional and angular changes relative to the bony anatomy were obtained using image fusion in MIM software, between the planning CT (plan CT) and the CT on the treatment day (CT-TX). Dosimetric data were determined, also using MIM software, using the original (first fraction) dose distribution applied to organs at risk (rectum and bladder), transferred via rigid registration from the plan CT to each CT-TX. Bladder and rectum contours were also transferred from each plan CT to each CT-TX and were tweaked manually to match anatomy on each CT-TX and examined visually for appropriateness. Differences in translation and rotation of the T&R applicator between the planning CT and subsequent individual fractions were recorded and plotted against dose differences between each fraction of treatment and the original (first) fraction. Absolute dose (D2cc) and volume (V50) differences vs positional shifts were calculated and plotted, and the Pearson Product-Moment correlation coefficient between dose parameters and measured positional shifts was determined. Average dosimetric differences between planned dose and subsequent fractional doses obtained through rigid registration were 1.48 ± 1.92 Gy, 14.91 ± 11.92 cm3, 0.56 ± 0.93 Gy, and 1.77 ± 2.18 cm3 for Bladder D2cc, Bladder V50, Rectum D2cc, and Rectum V50, respectively. Correlation between Bladder V50 and sagittal plane rotation gave an r2 of 0.4, showing the most correlation of all parameters studied. Bladder dose and volume increased by a maximum of about 2.7 Gy and 50 cm3 overall for Bladder D2cc and Bladder V50, respectively. Bladder V50 was most sensitive to T&R applicator displacements. We have quantified the effects of applicator positional changes on dose changes for the bladder and rectum. Even large changes in applicator position between fractions did not result in significant changes in dose to these normal tissues, indicating that adaptive re-planning is not necessary.

Neoadjuvant Reirradiation for Radiation Therapy-Associated Angiosarcoma of the Breast.

PURPOSE: Radiation-associated angiosarcoma of the breast (RAASB) is a rare side effect after breast radiation and has been associated with poor outcomes. At this time, there is no consensus regarding management of RAASB, and the role of reirradiation remains controversial. We present our modern institutional outcomes in managing RAASB with incorporation of neoadjuvant hyperfractionated reirradiation. METHODS AND MATERIALS: Patients identified were treated between 2016 and 2020 with inclusion of any histologically proven RAASB without metastatic disease at diagnosis, while excluding those with a history of radiation therapy outside of the breast/chest wall or other sarcoma histologies. Major wound complications were defined as requiring wound care and/or wound vacuum or return to the operating room for wound repair at any time after surgery. RESULTS: Eight patients were identified, and the median follow-up was 34 months. Median time to RAASB development was 8 years from initial radiation therapy. With respect to RAASB management, all underwent surgery and neoadjuvant reirradiation therapy, and all but 1 patient received taxol-based chemotherapy. At last follow-up, 7 patients remained free of disease, and 1 patient died with distant disease. With respect to acute toxicity after reirradiation, all patients developed at least acute grade 2 toxicities. Five of the 8 patients developed a major wound complication. CONCLUSIONS: Our institutional analysis suggests excellent local control and survival outcomes for RAASB treated with neoadjuvant hyperfractionated reirradiation, surgery, and taxol-based chemotherapy. However, major wound complications represent a major challenge with this approach. Future studies should consider how best to improve the therapeutic ratio while maintaining high rates of local control and survival.

Five Fraction Accelerated Partial Breast Irradiation Versus Intraoperative Radiation Therapy for Early-Stage Breast Cancer.

PURPOSE/OBJECTIVE(S): Accelerated partial breast irradiation (PBI) delivered in 5 fractions with intensity modulated radiation therapy (IMRT) has been shown to have comparable clinical outcomes to whole breast irradiation with reduced toxicity profiles. In contrast, intraoperative radiation therapy (IORT) offers patients the potential to complete adjuvant radiation therapy in a single treatment. While early data were promising, concerns exist regarding long-term rates of local recurrence after IORT. We present a comparison of 5 fraction PBI versus IORT. MATERIALS/METHODS: We performed a retrospective review of 473 patients with early-stage breast cancer treated at a single institution from 2011 to 2021 with 258 receiving PBI and 215 receiving IORT. PBI patients received 30 Gy in 5 fractions delivered with IMRT. IORT patients received 20 Gy in 1 fraction prescribed to the applicator surface at surgery using the low-energy TARGIT technique. RESULTS: Mean age was 71 years old (IQR:67-74) for IORT patients and 67 years old (IQR:62-72) for PBI patients. Median follow up was 5.7 years (IQR:4.2-7.0) for IORT patients and 2.4 years (IQR:1.8-3.3) for PBI patients (P < .001). Recurrence at any time (locoregional and distant) was seen in 7.9% (n = 17) of patients receiving IORT as compared to 0.8% (n = 2) of patients receiving PBI. IORT was associated with reduced rates of locoregional relapse free survival at 5 years (93.6% vs. 99.4%, P = .05) with no difference in overall survival(92.8% vs. 95.1%, P = .99). CONCLUSION: Low-energy TARGIT IORT was associated with higher rates of locoregional recurrence compared to PBI. These outcomes, consistent with other series and current guidelines, suggest a limited role for low-energy IORT as monotherapy.

Intraoperative Radiation Therapy for Early-Stage Breast Cancer: Updated Outcomes from a Single-Institution Experience.

BACKGROUND: Increasingly, data have supported the use of partial-breast irradiation (PBI) for low-risk patients after breast-conserving surgery, with techniques allowing for completion of treatment in 1-3 weeks. Intraoperative radiation therapy (IORT) is an alternative to PBI. Our institution had used low-energy photon IORT (TARGIT) for more than a decade. The initial results demonstrated a 2% local recurrence rate with a short follow-up period of 2 years. This report presents updated outcomes during with 5-year follow-up. METHODS: A review of an institutional review board (IRB)-approved institutional registry was performed. The review identified 215 patients with early-stage breast cancer (stages 0-IIA) who received IORT. At the time of surgery, IORT was delivered with 20 Gy in a single fraction, with 5.1% (n = 11) of patients receiving additional whole-breast irradiation (WBI). RESULTS: The mean age at diagnosis was 71 years (range, 49-98 years), and the median follow-up was 5.7 years (interquartile range [IQR], 4.2-7.0 years). Of the 215 patients, 2.8% (n = 6) had ductal carcinoma in situ (DCIS), 90.7% (n = 195) had T1 disease, and 6.5% (n = 14) had T2 disease. Endocrine therapy was prescribed for 79% and chemotherapy for 1.4% of the patients. The 5-year rates were 5.3% for local recurrence, 6.4% for locoregional recurrence, and 2.7% for distant metastases. At 5 years, 93% of the patients were alive. CONCLUSIONS: The 5-year outcomes with TARGIT IORT demonstrated high rates of local recurrence, exceeding those seen with alternative modern approaches. The local recurrence outcomes with IORT are more consistent with studies omitting radiation following breast-conserving surgery, using endocrine therapy alone. Consistent with current guidelines and previous data, TARGIT IORT should not be used as monotherapy outside prospective clinical trials.

Implementing failure mode and effect analysis to improve the safety of volumetric modulated arc therapy for total body irradiation.

PURPOSE: Volumetric-modulated arc therapy for total body irradiation (VMAT-TBI) is a novel radiotherapy technique that has been implemented at our institution. The purpose of this work is to investigate possible failure modes (FMs) in the treatment process and to develop a quality control (QC) program for VMAT-TBI following TG-100 guidelines. METHODS: We formed a multidisciplinary team to map out the complete treatment process of VMAT-TBI following the AAPM TG-100 guidelines. This process map gives a visual representation of the VMAT-TBI workflow from the CT simulation, image processing, contouring, treatment planning, to treatment delivery. From the process map, potential FMs were identified. The occurrence (O), detectability (D), and severity of impact (S) of each FM were assigned according to scoring criteria (1-10) by the multidisciplinary team. A risk priority number (RPN) was calculated from average O, S, and D of each FM (RPN = O x S x D). High risk FMs were identified as 20% of the FMs having the highest RPN scores. After the FMEA analysis, fault-tree analysis (FTA) was performed for each major step of the treatment process to determine the effects of potential failures to the treatment outcome. Effective QC methods were identified to prevent the high risk failures and to improve the safety of the VMAT-TBI program. RESULTS: We identified a total of 55 sub-processes and 128 FMs from the VMAT-TBI workflow. The top five high-risk FMs were: (1) Prescription and/or OAR constraints changed during planning and not communicated to the planner, (2) Patient moves or breathes too heavily during the upper body CT scan (3) Patient moves during the lower body CT scan, (4) Treatment planning system not calculating total body DVH metrics correctly for TBI, (5) Improper optimization criteria used or not sufficient optimization, resulting in suboptimal dose coverage, OAR sparing or excessive hotspots during treatment planning. Two FMs have average severity scores ≥8: Incorrect PTV subdivision/isocenter placement and Prescription and/or OAR constraints changed during planning and not communicated to the planner. Quality assurance and QC interventions including staff training, standard operating procedures, and quality checklists were implemented based on the FMEA and FTA. CONCLUSION: FM and effect analysis was performed to identify high-risk FMs of our VMAT-TBI program. FMEA and FTA were effective in identifying potential FMs and determining the best quality management (QM) measures to implement in the VMAT-TBI program.

Coronary intravascular brachytherapy for in-stent restenosis: A review of the contemporary literature.

Intracoronary stent restenosis (ISR) is a clinically relevant challenge in the modern era. Heterogeneity in patient- and lesion-specific factors can further compound this clinical challenge. Coronary intravascular brachytherapy (IVBT) was the standard therapeutic approach for ISR prior to the advent of drug-eluting stents (DES). Despite prospective data describing the superiority of DES over IVBT for treating de novo ISR, IVBT remains a treatment option for patients with complex disease. The purpose of this review is to evaluate the historical and contemporary literature surrounding IVBT in order to elucidate its role in modern cardiac care and to describe opportunities for future investigations to improve patient selection. Herein, we provide a review of the contemporary literature describing IVBT as a safe and effective treatment option for patients with recurrent, refractory ISR after multilayer DES and no good surgical or mechanical option. Combination therapy with emerging technologies such as DCBs may further increase efficacy.

Stereotactic body radiotherapy for the treatment of oligometastatic gynecological malignancy in the abdomen and pelvis: A single-institution experience.

PURPOSE/OBJECTIVES: Metastasis-directed therapy with stereotactic body radiotherapy (SBRT) in the setting of oligometastatic disease is a rapidly evolving paradigm given ongoing improvements in systemic therapies and diagnostic modalities. However, SBRT to targets in the abdomen and pelvis is historically associated with concerns about toxicity. The purpose of this study was to evaluate the safety and efficacy of SBRT to the abdomen and pelvis for women with oligometastases from primary gynecological tumors. MATERIALS/METHODS: From our IRB-approved registry, all patients who were treated with SBRT between 2014 and 2020 were identified. Oligometastatic disease was defined as 1 to 5 discrete foci of clinical metastasis radiographically diagnosed by positron emission tomography (PET) and/or computerized tomography (CT) imaging. The primary endpoint was local control at 12 months. Local and distant control rates were estimated using the Kaplan-Meier method. Time intervals for development of local progression and distant progression were calculated based on follow up visits with re-staging imaging. Acute and late toxicity outcomes were determined based on Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. RESULTS: We identified 34 women with 43 treated lesions. Median age was 68 years (range 32-82), and median follow up time was 12 months (range 0.2-54.0). Most common primary tumor sites were ovarian (n=12), uterine (n=11), and cervical (n=7). Median number of previous lines of systemic therapy agents at time of SBRT was 2 (range 0-10). Overall, SBRT was delivered to 1 focus of oligometastasis in 29 cases, 2 foci in 2 cases, 3 foci in 2 cases, and 4 foci in 1 case. All patients were treated comprehensively with SBRT to all sites of oligometastasis. Median prescription dose was 24 Gy (range 18-54 Gy) in 3 fractions (range 3-6) to a median prescription isodose line of 83.5% (range 52-95). Local control by lesion at 12 and 24 months was 92.5% for both time points. Local failure was observed in three treated sites among two patients, two of which were at 11 months in one patient, and the other at 30 months. Systemic control rate was 60.2% at 12 months. Overall survival at 12 and 24 months was 85% and 70.2%, respectively. Acute grade 2 toxicities included nausea (n=3), and there were no grade > 3 acute toxicities. Late grade 1 toxicities included diarrhea (n=1) and fatigue (n=1), and there were no grade > 2 toxicities. CONCLUSION: SBRT to oligometastatic gynecologic malignancies in the abdomen and pelvis is feasible with encouraging preliminary safety and local control outcomes. This approach is associated with excellent local control and low rates of toxicity during our follow-up interval. Further investigations into technique, dose-escalation and utilization are warranted.

TARGIT-R (Retrospective): 5-Year Follow-Up Evaluation of Intraoperative Radiation Therapy (IORT) for Breast Cancer Performed in North America.

BACKGROUND: Intraoperative radiation therapy (IORT) has been investigated for patients with low-risk, early-stage breast cancer. The The North American experience was evaluated by TARGIT-R (retrospective) to provide outcomes for patients treated in "real-world" clinical practice with breast IORT. This analysis presents a 5-year follow-up assessment. METHODS: TARGIT-R is a multi-institutional retrospective registry of patients who underwent lumpectomy and IORT between the years 2007 and 2013. The primary outcome of the evaluation was ipsilateral breast tumor recurrence (IBTR). RESULTS: The evaluation included 667 patients with a median follow-up period of 5.1 years. Primary IORT (IORT at the time of lumpectomy) was performed for 72%, delayed IORT (after lumpectomy) for 3%, intended boost for 8%, and unintended boost (primary IORT followed by whole-breast radiation) for 17% of the patients. At 5 years, IBTR was 6.6% for all the patients, with 8% for the primary IORT cohort and 1.7% for the unintended-boost cohort. No recurrences were identified in the delayed IORT or intended-boost cohorts. Noncompliance with endocrine therapy (ET) was associated with higher IBTR risk (hazard ratio [HR], 3.67). Patients treated with primary IORT who were complaint with ET had a 5-year IBTR rate of 3.9%. CONCLUSION: The local recurrence rates in this series differ slightly from recent results of randomized IORT trials and are notably higher than in previous published studies using whole-breast radiotherapy for similar patients with early-stage breast cancer. Understanding differences in this retrospective series and the prospective trials will be critical to optimizing patient selection and outcomes going forward.

Use of a Radiation Tumor Bed Boost After Breast-Conserving Surgery and Whole-Breast Irradiation: Time Trends and Correlates.

PURPOSE: We sought to evaluate time trends and correlates of the use of a radiation tumor bed boost (TBB) after breast-conserving surgery and either conventional or hypofractionated whole-breast irradiation (CWBI or HWBI) for patients with early stage breast cancer. METHODS AND MATERIALS: The National Cancer Database was queried for patients diagnosed between 2012 and 2016. We evaluated the utilization of TBB before and after publication of the Society of Surgical Oncology-American Society for Radiation Oncology margin guidelines in relation to sociodemographic variables, treatment facility, tumor characteristics, and whole-breast fractionation. RESULTS: The population included 380,387 patients, of whom 76.7% received a TBB. Utilization of TBB decreased over time (2012-2013: 79.2%; 2014: 76.6%; 2015-2016: 74.7%; P < .001); this was seen for most subgroups evaluated. Rates of TBB differed by facility type and region. There was a decrease in TBB use in patients treated with CWBI over time (2012-2013: 84.9%; 2014: 83.5%; 2015-2016: 82.3%; P < .001) but an increase among patients treated with HWBI (2012-2013: 55.5%; 2014: 60.7%; 2015-2016: 65.1%; P < .001); this was also seen for low-risk patients (age >70 years, negative margins). Among patients undergoing HWBI, TBB was more frequently used when 15 fractions were used compared with 16 fractions (76.8% vs 59.1%; P < .001). CONCLUSIONS: The use of TBB decreased over time, coinciding with the publication of new margin guidelines, for patients receiving CWBI and those with negative margins, but TBB use increased for patients treated with HWBI. Hence, fractionation regimen is a critical variable in analyzing changes over time in the practice patterns of TBB.

Outcomes with intraoperative radiation therapy for early-stage breast cancer.

Adjuvant radiation therapy has been associated with improved local control following breast-conserving surgery. Traditionally, treatment has been delivered with whole breast irradiation over 3-6 weeks or partial breast irradiation over 1-3 weeks. However, intraoperative radiation therapy (IORT) has emerged as a technique that delivers a single dose of radiotherapy at the time of surgery for early-stage breast cancers. We report initial outcomes and acute toxicities with intraoperative radiation from a single institution. Patients with DCIS or Stage I-II breast cancer who underwent lumpectomy and sentinel lymph node biopsy (nodal sampling excluded in some cases) were included. All patients in this analysis were treated with IORT as at the time of surgery, 20 Gy in 1 fraction with 50 kV x-ray. Patients were treated at a single institution between 2011 and 2019. Follow-up was per standard institutional protocol. Two hundred and one patients were included in the analysis, with a median follow-up of 23 months (range: 0-73 months). Median age was 71 years old. Overall, 4 (2.0%) patients had DCIS, 186 (92.5%) patients had Stage 1 disease, and 11 patients had (5.5%) Stage 2 disease. All patients were estrogen receptor-positive, 175 (87.9%) progesterone receptor-positive, and 1 (0.5%) HER2 amplified. The crude rate of local recurrence was 2.0% (n = 4) and distant metastasis rate was 0.5% (n = 1). The rate of arm lymphedema was 0.5% (n = 1) and chronic telangiectasia rate was 1.1% (n = 2). Intraoperative radiation therapy, in a cohort of low-risk patients, demonstrated low rates of recurrence and reproducibility in a multi-disciplinary setting. Further follow-up, analysis of patient satisfaction and cosmesis, and comparison to whole breast irradiation and partial breast techniques is necessary in order to further validate these findings.

Initial outcomes with image-guided partial breast irradiation delivered with intensity-modulated radiation therapy.

Patients were treated at a single institution to a dose of 30 Gy in five fractions delivered every other day using image-guided intensity modulated radiation therapy (IMRT) partial breast irradiation. A total of 34 patients were treated with a median follow-up of 4.6 months. The rate of acute Grade 1 dermatitis was 23.5% (n = 8), and Grade 1 fatigue was 17.6% (n = 6), with no Grade 2 or higher acute toxicities. The rate of chronic Grade 1 dermatitis was 25.0% (n = 6), Grade 1 fat necrosis 4.2% (n=1), with no patients demonstrating other chronic toxicities. Image-guided APBI delivered with IMRT is associated with low rates of acute and chronic toxicity though additional follow-up is warranted.

Cost and Cost-Effectiveness of Image Guided Partial Breast Irradiation in Comparison to Hypofractionated Whole Breast Irradiation.

PURPOSE: Hypofractionated whole breast irradiation (HWBI) and accelerated partial breast irradiation (APBI) represent two adjuvant radiation therapy options after breast-conserving surgery. We performed a cost and cost-effectiveness analysis of an external beam image guided APBI technique compared with HWBI. METHODS AND MATERIALS: HWBI was defined as 40 Gy in 15 fractions to the whole breast with or without a 10-Gy/5-fraction boost. APBI was 30 Gy in 5 fractions per Livi et al and was evaluated as both intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy. The decision analytical model measured effectiveness in quality-adjusted life years. Micro-costing was conducted to estimate the true cost of the different treatment regimens, and incremental cost-effectiveness analysis was performed. RESULTS: Based on micro-costing, the cost of HWBI was $4551 with boost and $3666 without boost, compared with $2966 for APBI. Including indirect costs, HWBI with boost cost $6160, HWBI without boost cost $4940, and APBI cost $3569. Cost savings for APBI compared with HWBI with and without boost was $1585 and $700 based on direct costs and $2591 and $1371 including indirect costs. APBI was also more effective, at 0.2300 quality-adjusted life years compared with 0.2289 for HWBI with or without boost. Thus, APBI was both less costly and more effective. Basing cost on Medicare reimbursement (IMRT) leads to APBI again dominating HWBI, but basing cost for APBI on reimbursement billed as stereotactic body radiation therapy leads to HWBI being far more cost-effective. CONCLUSIONS: Image guided partial breast irradiation is less costly to deliver and has slightly improved efficacy compared with HWBI, with or without a boost. IMRT APBI should be considered a standard-of-care option in appropriately selected patients based on efficacy and value.

Oncotype testing in patients undergoing intraoperative radiation for breast cancer.

Oncotype DX recurrence score (RS) predicts risk of distant disease recurrence, and can guide chemotherapy recommendations in hormone positive, human epidermal growth factor 2-negative, early stage breast cancer. The present study aimed to evaluate the pattern of oncotype testing, RS and adjuvant treatment in patients undergoing intraoperative radiotherapy (IORT). Single center prospective data registry was queried for patients receiving IORT between October 2011 and February 2017. Patient demographics, tumor characteristics, RS, systemic therapy and recurrence information were analyzed. A total of 150 women with mean age of 70.8 years were included. The majority had invasive ductal cancer (60.6%) with 1.0 cm average tumor size and no lymph node involvement (99%). Oncotype testing was performed in 36 patients (24.3%). Low risk score (<18) was confirmed in 19 women (53%); intermediate risk score (18-30) in 16 women (44%); and high risk score (>30) in one woman (3%). Patients with RS testing had significantly increased tumor sizes (1.2 vs. 1.0 cm; P<0.001) and were younger (68.5 vs. 71.3 years; P=0.02) compared with those not tested. A total of 4/150 patients (2.6%) received chemotherapy; two received chemotherapy based on RS testing. Based on the current selection criteria for IORT, oncotype testing rarely results in a high-risk score or utilization of chemotherapy for IORT patients. The present study supports selective use of RS testing in IORT patients and confirms that biologically low-risk patients are being selected for IORT based on current guidelines.

Principles and practice of high-dose rate penile brachytherapy: Planning and delivery techniques.

PURPOSE: To allow for organ preservation, high-dose rate (HDR) brachytherapy may be used in the treatment of localized penile cancer. Penile cancer is a rare malignancy that accounts for <1% of cancers in men in the United States. The standard treatment for localized disease is partial amputation of the penis. However, patients with T1b or T2 disease <4 cm in maximum dimension and confined to the glans penis may be treated with brachytherapy as an organ-sparing approach. Previous works have described the technique involved for low-dose rate brachytherapy; however, we detail the techniques involved with HDR brachytherapy. METHODS AND MATERIALS: Circumcision should precede brachytherapy. Interstitial brachytherapy needles are placed in the operating room under general anesthesia with the goal to allow for appropriate target coverage. Target definition is done via computed tomography-based simulation and planning. Radiation is delivered using a prescription dose of 3840 cGy in 12 fractions twice daily over a course of 6 days. RESULTS: Acute toxicities peak upon completion of the radiation therapy and may include dermatitis, sterile urethritis, and adhesions in the urethra. These toxicities are reversible and generally take 2 to 3 months to heal. The two most common and significant late complications of radiation therapy for penile cancer are soft tissue necrosis and meatal stenosis. An increased risk of necrosis has been reported with T3 tumors and higher-volume implants (>30 cm3). Erectile function is generally maintained because the erectile tissues including the penile shaft and corpora have not been irradiated. CONCLUSIONS: Organ preservation is feasible using HDR brachytherapy with favorable acute and late toxicities.

Most patients are eligible for an alternative to conventional whole breast irradiation for early-stage breast cancer: A National Cancer Database Analysis.

We evaluated the proportion of patients eligible for alternatives to standard whole breast irradiation (WBI) following breast-conserving surgery using the National Cancer Database (NCDB). Using the 2016 dataset, Stage I-III patients were identified. Eligibility for hypofractionated WBI (HFRT), accelerated partial breast irradiation (APBI) and endocrine therapy (ET-alone) was defined using eligibility from large clinical trials as well as consensus guidelines. For patients with pN0 breast cancer, 20.6% and 37.0% were eligible for ET-alone based on the CALGB 9343/PRIME-II trials, respectively. In terms of HFRT, 72.5% and 50.4% were eligible based on IMPORT LOW/ASTRO HFRT guidelines, respectively. Based on IMPORT LOW/GEC-ESTRO trial/ASTRO guidelines/ABS guidelines/GEC-ESTRO guidelines, 72.5%, 86.1%, 39.0%, 72.5%, 45.7%, respectively, were eligible for APBI. Of those who qualify for HFRT per ASTRO guidelines, approximately 90% were eligible for APBI and 50% for ET-alone. This analysis shows that a large proportion of patients with node-negative breast cancer are eligible for HFRT, APBI and/or ET-alone after breast-conserving surgery.

Dosimetric differences between local failure and local controlled non-small cell lung cancer patients treated with stereotactic body radiotherapy: A matched-pair study.

INTRODUCTION: Concerns were raised about the accuracy of pencil beam (PB) calculation and potential underdosing of medically inoperable non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). From our institutional series, we designed a matched-pair study where each local failure and controlled patient was matched based upon several clinical factors, to investigate the dose difference between the matched-pair. METHODS: Eighteen pairs of NSCLC patients, treated with 50 Gy in five fractions, were selected. These patients were matched based on treatment intent, tumour size, histology and clinical follow-up. All PB calculated clinical plans were retrospectively recalculated with a MC algorithm. The D99 and DMean of the gross tumour volume (GTV) and D95 and DMean of the planning tumour volume (PTV) from PB and Monte Carlo (MC) calculation were compared between local failures and controls using the Mann-Whitney test. RESULTS: The mean PB calculated D95 of PTV was 50.4 Gy for both failures and controls (P = 0.85), indicating no planning differences between the groups. From MC calculations, the mean (±SD) of GTV D99 , GTV DMean , PTV D95 , PTV DMean were 47.6 ± 2.6/46.3 ± 2.4, 50.4 ± 2.1/49.8 ± 1.6, 44.4 ± 2.7/43.6 ± 3.1, 48.7 ± 2.4/48.2 ± 2.4 Gy for failure/controlled groups, respectively, and there was no significant difference between two groups (all P > 0.1). The dose differences between MC and PB calculations were in agreement with other literatures and there was no significant difference between two groups. CONCLUSIONS: While PB algorithms may overestimate tumour doses relative to MC algorithms, our matched-pair study did not find dose differences between local failure and local controlled cases.

Evaluating Candidacy for Hypofractionated Radiation Therapy, Accelerated Partial Breast Irradiation, and Endocrine Therapy After Breast Conserving Surgery: A Surveillance Epidemiology and End Results (SEER) Analysis.

PURPOSE/OBJECTIVE(S): After breast conserving surgery, adjuvant radiation therapy represents the standard of care for most patients. However, multiple options exist beyond standard fractionated whole breast irradiation including hypofractionated whole breast irradiation (HFRT), accelerated partial breast irradiation (APBI), and endocrine therapy (ET) alone, which can limit treatment duration, and potentially reduce morbidity and cost. Limited data are available on the percentage of patients eligible for these alternatives; therefore, a Surveillance Epidemiology and End Results (SEER) analysis was performed to assess candidacy for these alternative options in women with early stage breast cancer. MATERIALS AND METHODS: Women treated for breast cancer between the years of 2010 and 2012 were identified in the SEER database. Patients with unknown staging, metastatic disease, T3/T4 disease, and ≥N1 disease were excluded. Patients were defined as eligible for HFRT based on the American Society for Radiation Oncology (ASTRO) consensus guidelines and randomised trial testing intensity modulated and partial organ radiotherapy following breast conservation surgery for early breast cancer (IMPORT LOW) trial criteria, APBI based on the ASTRO, American Brachytherapy Society and the Groupe Européen de Curiethérapie of European Society for Therapeutic Radiotherapy and Oncology (GEC-ESTRO) consensus guidelines, and GEC-ESTRO APBI and IMPORT LOW trial criteria, and ET alone based on the Cancer and Leukemia Group B 9343 and Post-operative Radiotherapy in Minimum Risk Elderly II inclusion criteria. RESULTS: A total of 108,484 women with early stage breast cancer who met the aforementioned inclusion criteria were identified. Of these patients, 86,896 (80.1%) were eligible for HFRT based on ASTRO consensus guidelines and 81,459 (75.0%) based on IMPORT LOW trial criteria. Regarding APBI, 44,797 (41.2%), 81,020 (74.6%), 81,020 (74.6%) were eligible according to ASTRO, ABS, GEC-ESTRO consensus guidelines, respectively, 97,301 (89.7%) patients according to the GEC-ESTRO trial criteria, and 81,459 (75.0%) patients according to the IMPORT LOW trial criteria. For ET alone, 23,006 (21.2%) were eligible according to Cancer and Leukemia Group B 9343 criteria and 42,104 (38.8%) according to Post-operative Radiotherapy in Minimum Risk Elderly II criteria. CONCLUSIONS: This SEER analysis demonstrates that a substantial proportion of women with early stage breast cancer are eligible for HFRT, APBI, or ET alone after breast conserving surgery according to consensus guidelines and prospective trial criteria. With incorporation of additional pathologic, dosimetric, and chemotherapy data, quality assurance pathways may use such data to help ensure patients are receiving appropriate risk stratified treatment recommendations.

Intraoperative Radiation for Breast Cancer with Intrabeam™: Factors Associated with Decreased Operative Times in Patients Having IORT for Breast Cancer.

INTRODUCTION: Intraoperative radiation with Intrabeam™ (IORT) for breast cancer is a newer technology recently implemented into the operating room (OR). This procedure requires time and coordination between the surgeon and radiation oncologist, who both perform their treatments in a single operative setting. We evaluated the surgeons at our center, who perform IORT and their OR times to examine changes in OR times following implementation of this new surgical procedure. We hypothesized that IORT is a technique for which timing could be improved with the increasing number of cases performed. METHODS: A prospectively maintained IRB approved database was queried for OR times (incision and close) in patients who underwent breast conserving surgery (BCS), sentinel lymph node biopsy with and without IORT using the Intrabeam™ system at our institution from 2011 to 2015. The total OR times were compared for each surgeon individually and over time. Next, the OR times of each surgeon were compared to each other. Continuous variables were summarized and then a prediction model was created using IORT time, OR time, surgeon, and number of cases performed. RESULTS: There were five surgeons performing IORT at our institution during this time period with a total of 96 cases performed. There was a significant difference observed in baseline surgeon-specific OR time for BSC (p = 0.03) as well as for BCS with IORT (p < 0.05), attributable to surgeon experience. The average BCS times were faster than the BCS plus IORT procedure times for all surgeons. The overall mean OR time for the entire combined surgical and radiation procedure was 135.5 min. The most common applicator sizes used were the 3.5 and 4 cm, yielding an average 21 min IORT time. Applicator choice did not differ over time (p = 0.189). After adjusting for IORT time and surgeon, the prediction model estimated that surgeons decreased the total BCS plus IORT OR time at a rate of -4.5 min per each additional 10 cases performed. CONCLUSION: Surgeon experience and applicator size are related to OR times for performing IORT for breast cancer. OR time for IORT in breast cancer treatment can be improved over time, even among experienced surgeons.

Extranodal Marginal Zone Lymphoma of Ocular Adnexa: Outcomes following Radiation Therapy.

AIM: The aim of this study was to report outcomes following radiation therapy in patients with biopsy-proven extranodal marginal zone lymphoma of the ocular adnexa and uvea. METHODS: Records from a single institution were retrospectively reviewed from January 1997 to December 2015. The mean follow-up duration was 38 months (range 0-194). Radiation therapy was administered to 77 eyes (60 patients); 57 of the 77 eyes (74%) were treated with radiation only (range 20-36 Gy, median 15 fractions). Radiation cataract, radiation retinopathy, and optic neuropathy assessments were performed on all eyes treated with radiation. RESULTS: 100% of the 47 patients treated with radiation therapy only had local control with an average dose of 26.5 Gy (median 25.2 [range 20-36] Gy; 150-200 cGy per fraction). Four patients lost 2 lines or more of vision after radiation. The most common complication of radiation therapy was cataract formation/progression in 19 eyes (25%). Radiation retinopathy was observed only in 1 patient (1%). CONCLUSION: Our results confirm that radiation therapy (median 25 Gy) for extranodal marginal zone lymphoma of the ocular adnexa is associated with high local control and low risk of visually significant complications.

Are Patients Traveling for Intraoperative Radiation Therapy?

PURPOSE: One benefit of intraoperative radiation therapy (IORT) is that it usually requires a single treatment, thus potentially eliminating distance as a barrier to receipt of whole breast irradiation. The aim of this study was to evaluate the distance traveled by IORT patients at our institution. METHODS: Our institutional prospective registry was used to identify IORT patients from 10/2011 to 2/2017. Patient's home zip code was compared to institution zip code to determine travel distance. Characteristics of local (<50 miles), regional (50-100 miles), and faraway (>100 miles) patients were compared. RESULTS: 150 were patients included with a median travel distance of 27 miles and mean travel distance of 121 miles. Most were local (68.7%), with the second largest group living faraway (20.0%). Subset analysis of local patients demonstrated 20.4% traveled <10 miles, 34.0% traveled 10-20 miles, and 45.6% traveled 20-50 miles. Six patients traveled >1000 miles. The local, regional, and faraway patients did not differ with respect to age, race, tumor characteristics, or whole breast irradiation. CONCLUSIONS: Breast cancer patients are traveling for IORT, with 63% traveling >20 miles for care. IORT is an excellent strategy to promote breast conservation in selected patients, particularly those who live remote from a radiation facility.