Margin Guidelines Research Articles

Analysis of left ventricle regional myocardial motion for cardiac radioablation: Left ventricular motion analysis.

Left ventricle (LV) regional myocardial displacement due to cardiac motion was assessed using cardiovascular magnetic resonance (CMR) cine images to establish region-specific margins for cardiac radioablation treatments. CMR breath-hold cine images and LV myocardial tissue contour points were analyzed for 200 subjects, including controls (n=50) and heart failure (HF) patients with preserved ejection fraction (HFpEF, n=50), mid-range ejection fraction (HFmrEF, n=50), and reduced ejection fraction (HFrEF, n=50). Contour points were divided into segments according to the 17-segment model. For each patient, contour point displacements were determined for the long-axis (all 17 segments) and short-axis (segments 1-12) directions. Mean overall, tangential (longitudinal or circumferential), and normal (radial) displacements were calculated for the 17 segments and for each segment level. The greatest overall motion was observed in the control group-long axis: 4.5±1.2mm (segment 13 [apical anterior] epicardium) to 13.8±3.0mm (segment 6 [basal anterolateral] endocardium), short axis: 4.3±0.8mm (segment 9 [mid inferoseptal] epicardium) to 11.5±2.3mm (segment 1 [basal anterior] endocardium). HF patients exhibited lesser motion, with the smallest overall displacements observed in the HFrEF group-long axis: 4.3±1.7mm (segment 13 [apical anterior] epicardium) to 10.6±3.4mm (segment 6 [basal anterolateral] endocardium), short axis: 3.9±1.3mm (segment 8 [mid anteroseptal] epicardium) to 7.4±2.8mm (segment 1 [basal anterior] endocardium). This analysis provides an estimate of epicardial and endocardial displacement for the 17 segments of the LV for patients with normal and impaired LV function. This reference data can be used to establish treatment planning margin guidelines for cardiac radioablation. Smaller margins may be used for patients with higher degree of impaired heart function, depending on the LV segment.

Assessment of Standard Surgical Excision Efficacy and Analysis of Recurrence-Associated Factors in 343 Cases of Nasal Basal Cell Carcinoma: A Single-Center Retrospective Study.

In Caucasians, basal cell carcinoma, the predominant non-melanoma skin cancer type, poses challenges for surgeons due to anatomical and aesthetic concerns, particularly when located on the nose. The study aimed to evaluate tumor distribution, size, morphological subtypes, surgical outcomes, radicality levels, and their correlation with recurrence rates. A retrospective analysis encompassed 343 cases of nasal skin cancer over a four-year period from 1 January 2019 to 31 December 2022. The research cohort comprised 252 female and 91 male participants, averaging 75.2 years old. Tumors were most found on the left sidewall of the nose (25.4%) and the dorsum (24.8%). The infiltrative morphological subtype was predominant (70.8%). Standard surgical excision with fasciocutaneous plastic was the preferred surgical procedure. Radical excision, defined by the absence of tumor cells in a resection margin, was accomplished in 79.0% of lesions, whereas 16.9% demonstrated incomplete excision, signifying the presence of tumor cells in the resection margin. Non-radically excised tumors exhibited a significantly higher recurrence rate (24.1%) compared to those with radical excision (6.3%). In nasal reconstruction, diverse surgical techniques are essential for precise adaptation based on factors like tumor characteristics and patient needs. Despite surgeons' careful adherence to excision margin guidelines, the possibility of non-radical outcome cannot be eliminated.

Impact of SSO-ASTRO Margin Guidelines on Re-excision Rate in Breast-conserving Surgery: A Single-center Experience.

Breast-conserving surgery (BCS) has been historically linked with a high rate of re-excision. To address this issue, the Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO) developed consensus guidelines in 2014 to standardize practices and improve clinical outcomes for BCS patients. In our tertiary cancer care hospital, we assessed the impact of these guidelines on the re-excision rate following BCS. We conducted a retrospective study on breast cancer patients who underwent BCS at the Shaukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, Pakistan. The study compared the re-excision rate before the implementation of the SSO-ASTRO consensus guidelines (November 2015-July 2017) and after the implementation (January 2018-August 2019). Margins were considered positive if "ink on tumor" was present and negative if "no ink on tumor" was present. Fisher's exact test or Chi-square test was used to compare the re-excision rates between the pre- and post-guideline periods. A total of 919 patients were identified, with 533 from the pre-guideline period and 386 from the post-guideline period. Of the 919 patients, 31 with ductal carcinoma in situ (DCIS) were excluded from the re-excision analysis because the guidelines were not implemented on the DCIS. Furthermore, the overall rate of re-excision in our data was 4.3%. The re-excision rate decreased from 71.1% to 28.9% (P ≤ 0.05) following the adoption of the guidelines. We observed a statistically significant decrease in the re-excision rate after implementing the SSO-ASTRO guidelines. Implementation of the SSO-ASTRO margin guidelines led to a notable decrease in the overall re-excision rate in our data set. These findings suggest that continued adherence to the guidelines may lead to a further reduction in the re-excision rate in the future.

The Impact of Breast-Conserving Surgery Re-excision on Patient-Reported Outcomes Using the BREAST-Q.

Approximately 14% of women undergoing breast-conserving surgery (BCS) require re-excision to achieve negative margins following the Society of Surgical Oncology (SSO) and American Society for Radiation Oncology (ASTRO) margin guidelines, which may influence patient-reported outcomes (PROs). Few studies have assessed the impact of re-excision on PROs following BCS. Women with stage 0-III breast cancer undergoing BCS who completed a BREAST-Q PRO measure from 2010 to 2016 were identified from a prospective database. Baseline characteristics were compared between women who underwent one BCS and those who underwent ≥ 1 re-excision surgery for positive margins (R-BCS). Linear mixed models were used to analyze associations between number of excisions and BREAST-Q scores over time. Of 2543 eligible women, 1979 (78%) had one BCS and 564 (22%) had R-BCS. Younger age, lower BMI, surgery pre-SSO Invasive Guidelines issuance, ductal carcinoma in situ (DCIS), multifocal disease, radiation therapy receipt, and endocrine therapy omission were more common in the R-BCS group. Breast satisfaction and sexual well-being were lower in the R-BCS group 2years postoperatively. There were no differences in psychosocial well-being between groups over 5 years. On multivariable analysis, re-excision was associated with lower breast satisfaction and sexual well-being (p= 0.007 and p= 0.049, respectively), but there was no difference in psychosocial well-being (p= 0.250). Women with R-BCS had lower breast satisfaction and sexual well-being 2 years postoperatively, but this difference did not remain long term. Psychosocial well-being in women who underwent one BCS were largely comparable over time to the R-BCS group. These findings may help in counseling women who are concerned about satisfaction and quality-of-life outcomes with BCS if re-excision is necessary.

Quantification of Organ Motion in Male and Female Patients Undergoing Long-Course Radiation Therapy for Rectal Cancer in the Supine Position

PurposePrevious studies have reported data on the internal rectal motion of patients with rectal cancer treated in the prone position. With the introduction of intensity modulated techniques, more patients are treated in the more reproducible supine position. Data informing specific margins for this treatment position are sparse, as are data comparing rectal motion characteristics and factors in male and female patients. The purpose of this retrospective study was to quantify and compare the interfractional rectal movement characteristics of male and female patients with rectal cancer treated with long-course chemoradiation therapy in the supine position. The data will aid the generation of internal target volume margins accounting for this organ's internal physiological movements. Methods and MaterialsCone beam computed tomography (CBCT) images were acquired from 19 male and 16 female patients with rectal cancer on the first 3 days of treatment and weekly thereafter. The rectum, bladder, and femoral heads were delineated on the planning CT (PCT) and 6 CBCT for each patient. Overall, 245 images were analyzed. All patients were treated with a full bladder. The rectum was divided into three 5-cm segments (upper, mid, and lower). The motion of the rectum was quantified by documenting the anteroposterior and lateral distances as measured using fixed anatomic landmarks, namely from the anterior aspect of the sacrum and mid-left femoral head, respectively. These measurements were taken at 1-cm intervals from the inferior border of L5 vertebrae. The sigmoid was excluded from these measurements. Estimations of systematic and random physiological movement error were determined and margins were calculated. ResultsTwo hundred forty-five image sets (19 PCT + 114 CBCT for male, 16 PCT + 96 CBCT for female) on patients who had undergone long-course radiation therapy were analyzed. Rectal tumor location was 31% in the inferior rectum, 46% in the mid rectum, and 23% in the superior rectum. Random rectal motion (mean of the per-patient standard deviation [σ]) was largest for the upper and mid rectum in the anterior direction. There were statistically significant differences in σ between male and female patients in the left lateral motion of the mid and inferior rectum as well as the anterior, posterior, and right motion of the inferior rectum (mid left: P < .0005; lower left: P < .0005; lower posterior: P = .001; lower anterior: P = .032; lower right: P = .001). Suggested internal target volume margin guidelines are therefore nonisotropic and vary per segment of rectum and sex. ConclusionsIn our present study, interfractional rectal motion is shown to be significantly different between male and female patients. Our data suggest that the use of asymmetrical sex-specific margins in patients with rectal cancer treated in the supine position should be considered.

ASO Visual Abstract: Preoperative MRI and Its Impact on Surgical Outcomes in Patients with Triple Negative Breast Cancer Treated with Primary Surgery: Did New Margin Guidelines or Cavity Shave Margins Practice Diminish the Role of Preoperative MRI?

ASO Visual Abstract: Preoperative MRI and Its Impact on Surgical Outcomes in Patients with Triple Negative Breast Cancer Treated with Primary Surgery: Did New Margin Guidelines or Cavity Shave Margins Practice Diminish the Role of Preoperative MRI?

Preoperative MRI and Its Impact on Surgical Outcomes in Patients with Triple Negative Breast Cancer Treated with Primary Surgery: Did New Margin Guidelines or Cavity Shave Margins Practice Diminish the Role of Preoperative MRI?

Results of an earlier retrospective study from our institution suggested that patients with triple negative breast cancer (TNBC) who had preoperative MRI may have had an improved local recurrence rate (LRR) after breast conserving surgery (BCS). We aimed to clarify the impact of preoperative MRI on surgical outcomes in an expanded TNBC cohort treated by BCS in a contemporary era. Our study cohort comprised 648 patients with TNBC who underwent BCS between 2009 and 2018. Demographic and clinical characteristics were compared between those with (n=292, 45.1%) and without (n=356, 54.9%) preoperative MRI. Multivariable logistic regression was performed to assess the association of preoperative MRI with surgical outcomes. The crude LRR of 3.5% was lower than previously reported. Univariable analyses demonstrated that the LRR and re-excision rates in the MRI and no-MRI groups were 3.4 and 3.7%, 21.6% and 27.2%, p=0.876 and p=0.10, respectively. Multivariable logistic regression analyses demonstrated that preoperative MRI was not associated with a lower LRR: odds ratio (OR)=1.42 (p=0.5). During our study period, new margin guidelines and shave margins practice were adopted in 2014 and 2015. To account for their effects, the year of diagnosis/surgery and other clinical variables were adjusted in multivariable logistic regression and inverse probability weighting models to demonstrate that preoperative MRI remained associated with a lower re-excision risk, OR 0.56, p=0.04l; and a lower re-excision rate, 23.15% versus 36.0%, p<0.01, respectively. Our findings suggested that patients with TNBC anticipating BCS may benefit from preoperative MRI.

382 Compliance With Current Excision Margin Guidelines for Non-Melanoma Skin Cancer: Do We Make the Cut?

Abstract Aim Non-melanoma skin cancers (NMSC) are the most common malignancies worldwide, with basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) constituting an ever-growing clinical burden within Plastic &amp; Reconstructive Surgery. In this 3-cycle Quality Improvement (QI) initiative we sought to evaluate and improve our unit’s compliance with British Association of Dermatology (BAD) guidance on excision margins for NMSCs. Method Following results from two Plan-Do-Study-Act (PDSA) cycles, a third retrospective review of clinic letters, operative notes and histopathology reports was undertaken to identify NMSCs that were excised during May 2021 and assess compliance with recommended excision margins according to risk stratification. Results The dissemination of cycle 1 findings at departmental meetings, as well as the implementation of guideline posters and operative note templates conferred a significant improvement in both clinical documentation (12% to 100%) and local compliance with excision margin guidelines for BCCs (53% to 71%) and SCCs (50% to 79%). Following the adoption of new BAD guidelines on SSC margins in early 2021, a third cycle comprising 42 lesions demonstrated a sustained improvement in clinical documentation (100%) after a 7-month period and similar guideline compliance rates for both BCC (67%) and SCC (78%). Conclusions Adequate excision margins in cutaneous malignant pathology are vital to ensure complete removal, thus minimising the risk of recurrence. Although improvement across the PDSA cycles has been sustained despite the introduction of new SCC margin guidelines, we aim to introduce further interventions such as a knowledge and practice survey to continue improving excision margin compliance.

Abstract P4-09-02: The impact of breast conserving surgery re-excision on patient-reported outcomes using the BREAST-Q

Abstract Introduction: Although SSO/ASTRO consensus margin guidelines have led to decrease rate of re-excision, some women require additional surgery. Re-excision surgery may cause psychosocial stress and impact cosmetic outcomes and breast satisfaction. The purpose of this study was to assess patient-reported outcomes using the BREAST-Q breast satisfaction, psychosocial wellbeing, and sexual wellbeing subscales for women with breast cancer following index breast-conserving surgery (BCS). Methods: Women with stage 0 to 3 breast cancer undergoing BCS who completed a BREAST-Q from 2010 to 2016 were identified by retrospective review of a prospective database. The BREAST-Q breast conserving therapy module was used to assess outcomes between women with 1 BCS and those with ≥1 re-excision surgery (R-BCS). Baseline characteristics were compared, and linear mixed models were used to analyze associations with BREAST-Q scores over time. Results: Our study group was initially composed of 2570 women that was narrowed to 2549 women after excluding 21 who ultimately underwent mastectomy; 1982 (78%) had 1 BCS and 567 (22%) had ≥1 R-BCS. The median age of the cohort was 57 years (range 26-97). Women with 1 BCS were more likely to be older (p&amp;lt;0.001), have a higher BMI (p=0.01), present with invasive carcinoma (p=0.03), have unifocal disease (p&amp;lt;0.001), undergo surgery post-release of SSO Invasive Guidelines (p&amp;lt;0.001), receive endocrine therapy (p=0.006), and less likely to receive radiation therapy (p=0.02) compared to those with ≥1 R-BCS. At 2-years post-operative, women with ≥1 R-BCS compared to 1 BCS were noted to have lower average breast satisfaction and sexual well-being scores (76.0 vs. 71.8 [p=0.03] and 70.2 vs. 64.0 [p=0.01], respectively). No difference in psychosocial well-being scores existed for up to 5 years of post-operative follow-up. Multivariable linear regression confirmed that undergoing ≥1. R-BCS is a risk factor for decreased breast satisfaction and sexual well-being at 2 years postoperative. On multivariable analysis, re-excision was found to be associated with lower breast satisfaction and sexual well-being scores. (p=0.01 and p=0.02, respectively), while it was not associated with a change in psychosocial wellbeing score (p=0.07). Factors such as Race, BMI, and marital status were not associated with any difference across all subscales (all p&amp;gt;0.1). Chemotherapy and radiotherapy were associated with lower scores across all subscales (Table). Younger age was associated with lower psychosocial and sexual well-being scores (both p&amp;lt;0.001), and endocrine therapy was associated with a lower sexual well-being score (p=0.01). Conclusions: Psychosocial well-being in women with 1 BCS for breast cancer were largely comparable over time to those who underwent ≥1 R-BCS. At 2 years post-operative, women with 1-BCS had lower breast satisfaction and sexual well-being, but this difference did not remain at later time periods. These findings may help in counseling women who are concerned of satisfaction and quality of life outcomes with BCS if breast re-excision was necessary. Multivariable analysis of BREAST-Q Subscale scoresEstimateStandard Errorp valueBreast SatisfactionAge at surgery-0.0690.0480.147BMI-0.1380.0810.088Chemotherapy-2.5421.0260.015Adjuvant radiation-3.4371.5830.031Hormonal therapy-0.6511.1700.119≥1 R-BCS vs. 1 BCS-2.5420.8840.008Psychosocial well-beingAge at surgery0.1980.043&amp;lt;0.001BMI-0.079-0.0790.287 Chemotherapy-3.2090.9330.001Adjuvant radiation-4.5091.4600.004Hormonal therapy0.2081.0740.528≥1 R-BCS vs. 1 BCS-1.4450.7930.059Sexual well-beingAge at surgery0.2700.072&amp;lt;0.001BMI-0.1140.1180.337Chemotherapy-4.7131.428&amp;lt;0.001Adjuvant radiation-7.6292.493&amp;lt;0.001Hormonal therapy-1.1801.7080.008≥1 R-BCS vs. 1 BCS-2.9661.2190.015 Citation Format: Regina Matar, Meghan Flanagan, Sarah Fuzesi, Kathyrn Haglich, Shen Yin, Varadan Sevilimedu, Jonas Nelson, Mary L. Gemignani. The impact of breast conserving surgery re-excision on patient-reported outcomes using the BREAST-Q [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 P4-09-02.

ADR ON DISPUTE BETWEEN A CLIENT AND TRADING MEMBER AT THE LEADING STOCK EXCHANGE IN INDIA: A CASE STUDY

This case is an appeal matter with the Leading Stock Exchange of India Ltd (LSE) with regard to a dispute between a client and a trading member of the LSE. The Appellant contended that the award passed by the arbitrator had not taken into account the evidence, documents and rules of stock exchange properly while determining the case matter and passed the award. Appellant challenged the Award on the grounds that the award was beyond the scope of submissions to the arbitration, non-application of mind, and ignorance of established judicial principles. The Appellate Member has to determine whether there had been any lapses on the part of the arbitration in applying the trading rules and procedures of the Exchange while analyzing the matter, determining the case and passing the award. Based on that, the Appellant Arbitral Tribunal had to decide whether to set aside the award passed by the sole arbitrator, modify the award or uphold it. The findings and conclusions provide inputs for the development of an appropriate regulatory framework for the Futures Market. However, the results may be generalized only in the emerging markets environment. Hence, researchers are suggested to study margin guidelines of futures market, appreciate the dynamics of futures market and apply the same in their future research in India and abroad.

Melanoma trials that defined surgical management: Overview of trials that established NCCN margin guidelines.

Since the observation that clearance of all visible and microscopic tumors from cutaneous melanoma is critical to prevent a recurrence, wide surgical margins have been central to surgical dogma. In the last several decades, more conservative margin widths have been vigorously studied by surgical investigators to lessen wound complications, the need for reconstruction, and healthcare costs. This review summarizes surgeon-led clinical trials that define current guidelines and highlights the challenges to initiate and perform trials today.

1632 Improving Excision Margins in Skin Oncology

Abstract Aim There are 152,000 new non-melanoma skin cancer (NMSC) cases in the UK every year, and excision and reconstruction of basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) form a significant part of the clinical workload in plastic surgery. In this quality improvement project, we aimed to identify and improve our unit’s compliance of guidelines for excision margins for NMSCs. Method A retrospective audit was undertaken in June 2020 to determine compliance with British Association of Dermatology and local guidelines on excision margins for NMSCs. A repeat audit was undertaken in October 2020 following quality improvement interventions. Results The first audit cycle examined 66 lesions in total. Guidelines were met in 53% (BCCs) and 50% (SCCs) of lesions. 12% of lesions had unclear documentation of margins. 16 lesions had margins that were too small as according to the risk factors present. These findings were presented to the department, and a new operative note template specifically designed for skin oncology was launched. Key audit findings were displayed along with the guidelines on posters. A repeat cycle was undertaken in October 2020, which examined 52 lesions. Significant improvement was seen with 100% documentation, and excision margin guideline compliance rate of 71% (BCCs) and 79% (SCCs). Conclusions Adequate excision margins in skin oncology is vital to ensure complete excision and to minimise the risk of recurrence. Our project demonstrates significant improvement in excision margin compliance through the launch of a specific operative note template and information posters.

Head and Neck Melanoma: What is the Goal for Margins?

Head and Neck Melanoma: What is the Goal for Margins?

Breast Conserving Surgery: Has the Standard of Care Enhanced Outcomes for Patients?

Breast Conserving Surgery (BCS) is a rapidly emerging field increasingly adopted to facilitate breast conservation and preserve breast aesthetics. Since the publication of the Randomized Controlled Trials (RCTs) of Breast Conserving Surgery versus mastectomy in early breast cancer, the adoption of BCS for breast cancer patients’ surgical management has been comprehensive. A computerized bibliographic search was performed on PubMed/MEDLINE, Embase, Google Scholar and Cochrane library databases. This article aims to perform a thorough review of new data regarding invasive cancer and margins while evaluating patient outcomes related to BCS after neoadjuvant chemotherapy focusing on margins, imaging evaluation, the extent of resection, and local regional recurrence outcomes. The growth pattern and biopsy of Ductal Carcinoma In Situ (DCIS) differ from invasive cancer, impacting margins. It is essential to understand how the Society of Surgical Oncology (SSO) DCIS margin guideline has influenced practice. Early breast cancer surgical management should be unique to each patient, driven by evidence-based medicine, and focused on specific clinical, histological, and molecular characteristics of the tumor. Conclusion: The current management for early breast cancer should be tailored and evidence-based to each patient based on the clinical, histological and molecular characteristics of the tumor. Presumably, the standard of care in BCS has enhanced the outcomes for this patient population. This review made by peers will help surgeons to stay up to date with the current literature and help them manage breast cancer while improving multiple clinical parameters such as Disease-Free Survival (DFS), Recurrence-Free Survival (RFS) and most importantly Overall Survival (OS).

Similar rates of residual disease in patients with DCIS within 2mm of lumpectomy margin regardless of the presence of invasive carcinoma.

The 2014 Society of Surgical Oncology/American Society for Radiation Oncology (SSO/ASTRO) breast-conserving surgery (BCS) margin guidelines for invasive cancer recommended "no ink on tumor" as an adequate margin width. However, 2016 SSO/ASTRO margin guidelines for pure DCIS recommended a 2mm margin. Thus, management of a margin with DCIS > 0mm but < 2mm differs based on presence or absence of invasive carcinoma. We compared rates of residual disease in patients with pure DCIS to patients with invasive cancer with DCIS. BCS with complete shaved cavity margins (SCM) for invasive carcinoma or pure DCIS from 2004 to 2006 at our institution was reviewed. Margin width was measured on the main specimen and the presence of carcinoma in the SCM was used as a surrogate for residual disease in the cavity. Rates of residual disease were determined for varying margin widths of invasive carcinoma and DCIS. Of 329 BCS patients, 123 (37%) patients had pure DCIS and 206 (63%) had invasive cancer with DCIS. In the pure DCIS cohort, 61 patients had DCIS between 0 and 2mm from the inked margin; 32 (52%) of which had residual disease in the SCM. In the invasive cancer plus DCIS cohort, 92 had DCIS between 0 and 2mm from the inked margin; 39 (42%) of which had residual disease in the SCM (p = 0.221). Rates of residual disease are similar in patients treated with lumpectomy for pure DCIS and those with invasive carcinoma with DCIS when DCIS is found between 0 and 2mm from the inked margin.

Quantification of Rectal Motion in Male and Female Patients Undergoing Long Course Radiotherapy for Rectal Cancer in the Supine Position

Previous studies have reported data on internal rectal motion of rectal cancer patients treated in the prone position. With the introduction of intensity modulated techniques, more patients are treated in the supine position. Data informing specific margins for this treatment position is sparse as is data comparing rectal motion characteristics and factors in male and female patients. The purpose of this retrospective study is to quantify and compare the inter-fractional rectal movement characteristics of male and female rectal cancer patients treated with long course chemo radiotherapy in the supine position. As well as to generate Internal Target Volume (ITV) margins accounting for this organ’s internal physiological movements. Cone Beam Computer Tomography (CBCT) images were acquired from 20 male and 17 female rectal cancer patients on the first 3 days of treatment and weekly thereafter. The rectum, bladder and femoral heads were delineated on the planning CT (PCT) and six CBCT for each patient. Overall, 249 images were analyzed. The site of disease varied along the rectum. All patients were treated with a full bladder. The rectum was divided into three 5cm segments (inf, med, and sup) The motion of the rectum was quantified by documenting the anteroposterior and lateral distances as measured using fixed anatomical landmarks namely from the anterior aspect of the sacrum and mid-left femoral head, respectively. These measurements were taken at 1-cm intervals from the inferior border of L5. Sigmoid was excluded from these measurements. Estimate of systemic and random physiological movement error was determined, and margins were calculated using the Van Herk formula. 249 CBCT data sets (120 male, 102 female) on patients who had undergone long course chemotherapy were analyzed. The mean of the per-patient standard deviation (σ) was largest for the mid rectum in all directions (Anterior, Left and Right) except for the posterior motion of the lower rectal wall. There were statistically significant differences in σ between males and females in the lateral directions in all three rectal segments. Suggested ITV margin guidelines are therefore non-isotropic and vary per segment of rectum and sex. Table 1 shows the ITV margins calculated based on this study’s patient population. In our present study, rectal motion is shown to be significantly different between males and females. Our data suggests using asymmetrical sex specific margins in all patients should be considered.Abstract 3377; TableFEMALE ITV MARGINSUP [cm]MID [cm]INF [cm]POST1.940.931.39ANT1.751.671.56LEFT1.691.471.03RIGHT1.941.61.22MALE ITV MARGINSUP [cm]MID [cm]INF [cm]POST1.260.990.89ANT1.411.451.19LEFT0.961.060.85RIGHT1.291.161.06 Open table in a new tab

Implementing Society of Surgical Oncology and the American Society for Radiation Oncology Margin Guidelines to Reduce Reoperations After Lumpectomy for Early Breast Cancer

Implementing Society of Surgical Oncology and the American Society for Radiation Oncology Margin Guidelines to Reduce Reoperations After Lumpectomy for Early Breast Cancer

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

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. 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. 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). 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.

Noncompliance with surgical margin guidelines is associated with histologic margin positivity: A retrospective case-control study

To the Editor: Variable recurrence and metastasis rates are noted following standard surgical excision (SSE) with postoperative margin assessment for cutaneous squamous cell carcinoma (cSCC).1-4 The National Comprehensive Cancer Network (NCCN) cSCC guidelines postulate that this variability could be due to differences in margin sizes and whether clear histologic margins are achieved. The NCCN recommends 4-6-mm surgical margins for low-risk cSCC.3 This study aims first to determine whether NCCN guideline–compliant surgical margin (GCM) selection and margin documentation are associated with improved tumor clearance and second to examine the factors associated with GCM.

ASO Author Reflections: Evolving Paradigms in the Treatment of DCIS: Impact of the SSO-ASTRO Margin Guidelines.

ASO Author Reflections: Evolving Paradigms in the Treatment of DCIS: Impact of the SSO-ASTRO Margin Guidelines.