MRIO: the Magnetic Resonance Imaging Acquisition and Analysis Ontology

Magnetic resonance imaging of the brain is a useful tool in both the clinic and research settings, aiding in the diagnosis and treatments of neurological disease and expanding our knowledge of the brain. However, there are many challenges inherent in managing and analyzing MRI data, due in large part to the heterogeneity of data acquisition. To address this, we have developed MRIO, the Magnetic Resonance Imaging Acquisition and Analysis Ontology. MRIO provides well-reasoned classes and logical axioms for the acquisition of several MRI acquisition types and well-known, peer-reviewed analysis software, facilitating the use of MRI data. These classes provide a common language for the neuroimaging research process and help standardize the organization and analysis of MRI data for reproducible datasets. We also provide queries for automated assignment of analyses for given MRI types. MRIO aids researchers in managing neuroimaging studies by helping organize and annotate MRI data and integrating with existing standards such as Digital Imaging and Communications in Medicine and the Brain Imaging Data Structure, enhancing reproducibility and interoperability. MRIO was constructed according to Open Biomedical Ontologies Foundry principles and has contributed several classes to the Ontology for Biomedical Investigations to help bridge neuroimaging data to other domains. MRIO addresses the need for a "common language" for MRI that can help manage the neuroimaging research, by enabling researchers to identify appropriate analyses for sets of scans and facilitating data organization and reporting.

SBRT for Liver Tumors: What the Interventional Radiologist Needs to Know

This review summarizes the clinical evidence supporting the utilization of stereotactic body radiotherapy (SBRT) for liver tumors, including hepatocellular carcinoma, liver metastases, and cholangiocarcinoma. Emerging prospective evidence has demonstrated the benefit and low rates of toxicity across a broad range of clinical contexts. We provide an introduction for the interventional radiologist, with a discussion of underlying themes such as tumor dose-response, mitigation of liver toxicity, and the technical considerations relevant to performing liver SBRT. Ultimately, we recommend that SBRT should be routinely included in the armamentarium of locoregional therapies for liver malignancies, alongside those liver-directed therapies offered by interventional radiology.

Online Correction of Intrafraction Motion during Volumetric Modulated Arc Therapy for Prostate Radiotherapy: A Cohort Study Quantifying the Frequency of Shifts and Analysis of Men at Highest Risk

PURPOSE/OBJECTIVE(S)

We have previously described our early experience using fiducial markers to correct for intrafraction motion during radiation therapy (RT) to the prostate using the TrueBeam Advanced imaging package. We sought to further characterize the utility of this approach in a larger cohort, and analyze factors associated with intrafraction motion.

MATERIALS/METHODS

A total of 132 men with fiducial markers treated with RT for intact prostate cancer at a single center were treated with a VMAT technique using 2-3 arcs. All patients underwent planning CT after a rectal enema and same day placement of 3 fiducial markers (Gold Anchor). Triggered kV images were acquired every 10 seconds using an onboard imaging system. Intrafraction motion correction was considered if any two fiducial markers were observed beyond a 3 mm tolerance margin. A manual 2D-3D match was performed using the fiducial markers from the single triggered kV image to obtain a couch shift. Shift data were extracted from the record and verify system and expressed as a single 3-dimensional translation. Shift percent was defined as the number of instances of a >3 mm intrafraction correction divided by the total number of fractions for a given patient. Clinical variables were evaluated, including body mass index, hormone therapy (ADT), prostate, rectal bladder volumes, and rectal width (transverse dimension of rectum at the mid-gland of prostate on simulation CT).

RESULTS

Across 2659 fractions, intrafraction motion correction was performed 582 times, in 463 fractions (17%). 101/132 patients (77%) had at least one shift during their treatment course, and 48/132 patients (36%) had shifts with an average magnitude of at least 5 mm. The median shift was 3.6 mm (range, 0-2.4 cm; IQR, 1.5-5.4 mm). 25% of men had a shift percent >20% (SP>20%). Univariate analysis revealed that only larger rectal volume or width, smaller prostate size, and use of ADT were associated with SP>20% (p<0.05). Men with rectal width in the top quartile (>3.6 cm) were more likely to have intrafraction motion corrected with SP>20% (47% vs 18%, p = 0.0016), and similarly men with rectal volume in the top quartile (>112 cc) were more likely to have SP>20% (44% vs 19%, p = 0.0067). On multivariate analysis, only rectal parameters (e.g., top quartile rectal width, HR 3.9, p = 0.0024) were correlated with a higher frequency of intrafraction motion.

CONCLUSION

Intrafraction motion occurs in a significant percentage of men undergoing prostate RT with VMAT, and is correctable utilizing a common feature. On multivariate analysis, rectal volume and width were associated with larger shift percent. Treatment approaches which do not account for intrafraction motion should consider including methods of immobilization, or larger PTV margins in order to avoid marginal miss of the prostate.

MRIO: The Magnetic Resonance Imaging Acquisition and Analysis Ontology

Objective

Magnetic resonance imaging of the brain is a useful tool in both the clinic and research settings, aiding in the diagnosis and treatments of neurological disease and expanding our knowledge of the brain. However, there are many challenges inherent in managing and analyzing MRI data, due in large part to the heterogeneity of data acquisition.

Materials and Methods

To address this, we have developed MRIO, the Magnetic Resonance Imaging Acquisition and Analysis Ontology.

Results

MRIO provides well-reasoned classes and logical axioms for the acquisition of several MRI acquisition types and well-known, peer-reviewed analysis software, facilitating the use of MRI data. These classes provide a common language for the neuroimaging research process and help standardize the organization and analysis of MRI data for reproducible datasets. We also provide queries for automated assignment of analyses for given MRI types.

Discussion

MRIO aids researchers in managing neuroimaging studies by helping organize and annotate MRI data and integrating with existing standards such as Digital Imaging and Communications in Medicine and the Brain Imaging Data Structure, enhancing reproducibility and interoperability. MRIO was constructed according to Open Biomedical Ontologies Foundry principals and has contributed several terms to the Ontology for Biomedical Investigations to help bridge neuroimaging data to other domains.

Conclusion

MRIO addresses the need for a "common language" for MRI that can help manage the neuroimaging research, by enabling researchers to identify appropriate analyses for sets of scans and facilitating data organization and reporting.

Racial/Ethnic Differences and Trends in Pathologic Complete Response Following Neoadjuvant Chemotherapy for Breast Cancer

Simple Summary

Despite improving rates of pathologic complete response (pCR; the absence of invasive cancer at the time of surgery) among patients with breast cancer who underwent chemotherapy prior to surgery, racial and ethnic minority groups were under-represented in clinical trials. Our study used a large cancer registry database in the United States to evaluate the temporal trend of pCR and patterns of pCR and survival outcomes among diverse racial and ethnic groups. It suggested that although pCR rates improved over time for all groups, pCR rates and survival outcomes varied significantly. For instance, compared to non-Hispanic White women, Black women were less likely to have pCR for triple negative and hormone receptor (HR)-negative, human epidermal growth factor receptor 2 (HER2)-positive tumors, but more likely for HR-positive, HER2-negative tumors. Given such heterogeneous outcomes among various racial and ethnic minority groups, further investigations would be warranted to optimize outcomes among such underserved populations.

Abstract

The purpose of this study was to evaluate nationwide trends in pathologic complete response (pCR) and its racial variations for breast cancer. The National Cancer Database was queried for women from 2010 to 2017 with non-metastatic breast cancer who underwent neoadjuvant chemotherapy. The primary endpoints, pCR and overall survival, were evaluated using Cochran-Armitage test, logistic, and Cox regression multivariable analyses. A total of 104,161 women were analyzed. Overall, pCR improved from 2010 to 2017 (15.1% to 27.2%, trend p < 0.001). Compared to non-Hispanic White (NHW) women, Hispanic White (HW) women were more likely to have pCR for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-positive tumors (adjusted odds ratio (aOR) 1.29, 95% confidence interval (CI) 1.08–1.53, p = 0.005). Black women were less likely to have pCR for HR-HER2+ tumors (aOR 0.81, 95% CI 0.73–0.89, p < 0.001) and triple negative (aOR 0.82, 95% CI 0.77–0.87, p < 0.001) tumors, but more likely for HR+HER2- tumors (aOR 1.13, 95% CI 1.03–1.24, p = 0.009). Among patients who achieved pCR, Asian or Pacific Islander (API) women were associated with better survival (adjusted hazards ratio (aHR) 0.52, 95% CI 0.33–0.82, p = 0.005) than NHW women. Despite positive trends in pCR rates, the likelihood of pCR and survival outcomes may be intricately dependent on racial/ethnic groups and tumor receptor subtypes.

Evaluation of risk-stratification using gene expression assays in patients with breast cancer receiving neoadjuvant chemotherapy

576

Background: Among patients with hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer, several prospective studies investigated various gene expression assays, such as 21-gene recurrence score (21 RS) and 70-gene signature (70 GS), to identify a subgroup of patients with pathologic complete response (pCR) from neoadjuvant chemotherapy. However, in the absence of large prospective trials to validate such findings, the National Comprehensive Cancer Network guideline does not recommend the routine adoption of such assays in the setting of neoadjuvant therapies. To address this knowledge gap, we performed an observational cohort study to compare pCR and survival outcomes based on these assays. Methods: The National Cancer Database (NCDB) was queried for female patients diagnosed between 2010 and 2017 with stage I-III breast cancer who underwent neoadjuvant chemotherapy and either 70 GS or 21 RS. Logistic multivariable analysis (MVA) was performed to identify variables associated with pCR. Cox MVA was performed to evaluate overall survival (OS). Subgroup analyses were performed among patients with favorable hormone receptor status (hormone receptor-positive, HER2-negative) and with RS ≥26 instead of RS ≥31. Results: A total of 3,009 patients met our inclusion criteria, with 2,075 (n = 1,287 for RS < 31, n = 788 for RS ≥31) and 934 (n = 175 for low risk, n = 759 for high risk) patients who underwent 21 RS and 70 GS, respectively. The median follow up was 48.0 months (interquartile range 32.2-66.7). On logistic MVA for all patients, those with a high risk from 70 GS or with RS ≥31 were more likely to have pCR. When compared to RS ≥31, a high risk from 70 GS was not associated with pCR. However, among those with favorable hormone receptor status, similar findings were noted, except that those with a high risk group from 70 GS were less likely to have pCR compared to those with RS ≥31. On Cox MVA for all patients, pCR was associated with improved OS. While RS ≥31 was associated with worse mortality, a high risk from 70 GS was not. No interaction was observed between pCR and risk groups for OS in both groups (interaction p = 0.23 for 70 GS, p = 0.66 for 21 RS). When analyses were repeated using a high risk group from 21 RS defined as RS ≥26, similar findings were noted, except that having favorable hormone receptor status and RS ≥26 was not associated with pCR when compared to the high risk from 70 GS. Conclusions: To our knowledge, this is the largest study using a nationwide oncology database suggesting that high recurrence risk groups in both assays were associated with pCR and that pCR was associated with improved survival. For those with favorable hormone receptor status, RS ≥31 may be a more selective prognostic marker. Further studies would be warranted to investigate the role of gene expression assays in the setting of neoadjuvant chemotherapy.

Racial differences and trends in pathologic complete response following neoadjuvant chemotherapy for breast cancer

575

Background: Given improvements in systemic therapy, pathologic complete response (pCR) rates following neoadjuvant chemotherapy were over 60% in breast cancer patients in recent clinical trials, especially in human epidermal growth factor receptor 2 (HER2)-positive and triple negative cases. While racial minority groups were associated with worse survival outcomes despite receiving standard of care in prospective studies, they were under-represented in clinical trials. To address this knowledge gap, we performed an observational cohort study to evaluate pCR and survival outcomes stratified by racial and ethnic groups. Methods: The National Cancer Database (NCDB) was queried for female patients with stage I-III breast cancer diagnosed between 2010 and 2017 treated with neoadjuvant chemotherapy followed by surgery. Cochran-Armitage test was used to analyze the trend of pCR over time. Logistic multivariable analysis (MVA) was used to identify variables associated with pCR defined as ypT0/isN0. Cox MVA was used to analyze the overall survival (OS) benefit. Results: A total of 105,804 patients (n = 72,631 for non-Hispanic white [NHW], n = 7,632 for Hispanic white [HW], n = 19,505 for black, n = 4,393 for Asian or Pacific Islander [API], n = 1,643 for other race) were included for analysis. Median follow up was 49.2 months (interquartile range 32.7-71.3). Overall pCR rate increased from 15.1% in 2010 to 27.2% in 2017, largely driven by API women (15.7% to 31.6%) and hormone receptor (HR)-HER2+ tumors (28.6% to 53.1%; all trend p < 0.001). On logistic MVA, when compared to NHW women, HW women were more likely to have pCR for HR-HER2+ (adjusted odds ratio [aOR] 1.18, p = 0.02) and HR+HER2+ tumors (aOR 1.29, p = 0.005), while black women were more likely to have pCR for HR+HER2- tumors (aOR 1.13, p = 0.01) and less likely for HR-HER2+ (aOR 0.80, p < 0.001) and triple negative tumors (aOR 0.82, p < 0.001). API women were more likely to have pCR for HR-HER2+ tumors compared to NHW women (aOR 1.17, p = 0.04). On Cox MVA, when compared to NHW women, HW (ypT+N0: adjusted hazards ratio [aHR] 0.75, p < 0.001; ypN+: aHR 0.79, p < 0.001) and API women (ypT0/isN0: aHR 0.52, p = 0.005; ypT+N0: aHR 0.63, p < 0.001; ypN+: aHR 0.86, p = 0.03) were associated with improved OS, while black women were associated with worse OS for ypN+ only (aHR 1.18, p < 0.001). Conclusions: To our knowledge, this is the largest study using a nationwide oncology database suggesting the improving trend of pCR rate over time for all racial cohorts. In our study, when compared to NHW, HW and API women were more likely to have pCR for select HER2+ tumors, while black women were less likely to have pCR for HR-HER2+ and triple negative tumors but not for HR+HER2- tumors. HW and API women were associated with improved survival in the setting of any residual disease compared to NHW women, while black women were associated with worse survival only for residual nodal disease.

Ontologies in radiation oncology

Ontologies are a formal, computer-compatible method for representing scientific knowledge about a given domain. They provide a standardized vocabulary, taxonomy and set of relations between concepts. When formatted in a standard way, they can be read and reasoned upon by computers as well as by humans. At the 2019 International Conference on the Use of Computers in Radiation Therapy, there was a session devoted to ontologies in radiation therapy. This paper is a compilation of the material presented, and is meant as an introduction to the subject. This is done by means of a didactic introduction to the topic followed by a series of applications in radiation therapy. The goal of this article is to provide the medical physicist and related professionals with sufficient background that they can understand their construction as well as their practical uses.

An ontology for representing hematologic malignancies: the cancer cell ontology

BACKGROUND

Within the cancer domain, ontologies play an important role in the integration and annotation of data in order to support numerous biomedical tools and applications. This work seeks to leverage existing standards in immunophenotyping cell types found in hematologic malignancies to provide an ontological representation of them to aid in data annotation and analysis for patient data.

RESULTS

We have developed the Cancer Cell Ontology according to OBO Foundry principles as an extension of the Cell Ontology. We define classes in Cancer Cell Ontology by using a genus-differentia approach using logical axioms capturing the expression of cellular surface markers in order to represent types of hematologic malignancies. By adopting conventions used in the Cell Ontology, we have created human and computer-readable definitions for 300 classes of blood cancers, based on the EGIL classification system for leukemias, and relying upon additional classification approaches for multiple myelomas and other hematologic malignancies.

CONCLUSION

We have demonstrated a proof of concept for leveraging the built-in logical axioms of the ontology in order to classify patient surface marker data into appropriate diagnostic categories. We plan to integrate our ontology into existing tools for flow cytometry data analysis to facilitate the automated diagnosis of hematologic malignancies.

OSCI: standardized stem cell ontology representation and use cases for stem cell investigation

Background

Stem cells and stem cell lines are widely used in biomedical research. The Cell Ontology (CL) and Cell Line Ontology (CLO) are two community-based OBO Foundry ontologies in the domains of in vivo cells and in vitro cell line cells, respectively.

Results

To support standardized stem cell investigations, we have developed an Ontology for Stem Cell Investigations (OSCI). OSCI imports stem cell and cell line terms from CL and CLO, and investigation-related terms from existing ontologies. A novel focus of OSCI is its application in representing metadata types associated with various stem cell investigations. We also applied OSCI to systematically categorize experimental variables in an induced pluripotent stem cell line cell study related to bipolar disorder. In addition, we used a semi-automated literature mining approach to identify over 200 stem cell gene markers. The relations between these genes and stem cells are modeled and represented in OSCI.

Conclusions

OSCI standardizes stem cells found in vivo and in vitro and in various stem cell investigation processes and entities. The presented use cases demonstrate the utility of OSCI in iPSC studies and literature mining related to bipolar disorder.

Comparison of adjuvant chemotherapy, chemoradiation, and chemotherapy followed by chemoradiation for resected stage I-II pancreatic cancer

372

Background: Prior National Cancer Database (NCDB) studies have demonstrated an overall survival (OS) benefit for adjuvant concurrent chemoradiation (CRT) compared to chemotherapy alone. Given the more recent adoption of postoperative chemotherapy followed by concurrent chemoradiation (C+CRT), this NCDB analysis evaluates the clinical outcomes of C+CRT compared to CRT alone or adjuvant chemotherapy alone (C) for resected pancreatic cancer. Methods: The NCDB was queried for primary stage I-II, cT1-3N0-1M0, resected pancreatic adenocarcinoma treated with adjuvant C, CRT, or C+CRT (2004-2015). Patients treated with C+CRT were compared with those treated with C (cohort C) or with CRT (cohort CRT). The primary endpoint was overall survival (OS). Baseline patient, tumor, and treatment characteristics were examined. Kaplan-Meier analysis, multivariable Cox proportional hazards method, forest plot, and propensity score matching were used. Results: Among 5667 patients (n = 3031 for C, n = 1307 for CRT, n = 1329 for C+CRT), median follow-up was 34.7 months, 45.2 months, and 39.7 months for the C, CRT, and C+CRT cohorts, respectively. In the multivariable analysis for all patients, C (HR 1.31, p < 0.001) and CRT (HR 1.24, p < 0.001) were associated with worse mortality compared to C+CRT. Treatment interactions were seen among pathologically node positive disease. C+CRT was favored in 1-3 (HR 0.74, p < 0.001) and 4+ (HR 0.75, p < 0.001) positive lymph node disease when compared to C or CRT alone, but none of the treatment options were significantly favored in node negative disease (HR 0.96, p = 0.67). Using 1:1 propensity score matching, 2152 patients for cohort C and 1774 patients for cohort CRT were matched. C+CRT remained significant for improved OS for both cohort C (median OS 23.3 vs 20.0 months, p < 0.001) and cohort CRT (median OS 23.4 vs 20.8 months, p < 0.001). Conclusions: This NCDB study using propensity score matched analysis demonstrates an OS benefit for C+CRT compared to C or CRT alone following surgical resection of pancreatic cancer. Most of this benefit is in patients with positive lymph nodes.

Outcome analysis of chemotherapy duration for resected stage I-II and unresected stage III pancreatic cancer

375

Background: For resected early-stage pancreatic cancer, RTOG 9704 has evaluated the outcome of 3 weeks of adjuvant chemotherapy (C) followed by chemoradiation (CRT) and post-CRT C. For locally advanced pancreatic cancer, a recent literature review showed that the typical duration for induction C is between 1 and 6 months prior to CRT. The ideal duration of C prior to CRT remains unclear. This National Cancer Database (NCDB) study was performed to identify the optimal duration of C prior to CRT in patients with pancreatic cancer. Methods: The NCDB was queried for primary stage I-II, cT1-3N0-1M0, resected and stage III, cT4N0-1M0, unresected pancreatic adenocarcinoma treated with C+CRT (2004-2015). Cohorts I-II and III included stage I-II and stage III cases, respectively. In each cohort, the patients were stratified by the short (short C) and long duration (long C) of chemotherapy based on their median durations (70 and 90 days between the onset of chemotherapy and radiation for cohorts I-II and III, respectively). Baseline patient, tumor, and treatment characteristics were examined. The primary endpoint was overall survival (OS). Kaplan-Meier analysis, multivariable Cox proportional hazards method, and propensity score matching were used. Results: Among 1,577 patients, cohort I-II had 839 patients (n = 409 with short C, n = 430 with long C) and cohort III had 738 patients (n = 360 with short C, n = 378 with long C). Median follow-up was 39.5 months and 24.3 months for cohorts I-II and III, respectively. The long C group showed improved OS in the multivariable analysis in both cohort I-II (HR 0.72, p < 0.001) and cohort III (HR 0.83, p = 0.025). Using 1:1 propensity score matching, a total of 610 patients for cohort I-II and 542 patients for cohort III were matched. After matching, long C remained statistically significant for improved OS compared with short C in both cohort I-II (median OS 26.1 vs 21.9 months, p = 0.003) and cohort III (median OS 16.7 vs 14.2 months, p = 0.021). Conclusions: Our NCDB study using propensity score matched analysis showed a survival benefit in the use of longer duration chemotherapy compared to shorter duration chemotherapy for both resected stage I-II and unresected stage III pancreatic cancer.

Comparison of concurrent chemoradiation with stereotactic body radiation therapy versus conventionally fractionated radiation therapy following induction chemotherapy for unresected locally advanced pancreatic cancer

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Background: Induction chemotherapy (iC) followed by concurrent chemoradiation has been shown to improve overall survival (OS) for locally advanced pancreatic cancer (LAPC). A recent National Cancer Data Base (NCDB) analysis has also shown improved OS with the use of stereotactic body radiation therapy (SBRT) versus conventionally fractionated radiation therapy (CFRT). This NCDB analysis evaluated outcomes of concurrent chemoradiation with SBRT compared to CFRT, following iC. Methods: The NCDB was queried for primary stage III, cT4N0-1M0 unresected pancreatic adenocarcinoma treated with concurrent chemoradiation following iC (2004-2015). CFRT was defined as 1.8-2.5 Gy per fraction up to a total dose of 45-70 Gy, whereas SBRT was defined as > 4.0 Gy per fraction up to a total dose of 20-60 Gy. Baseline patient, tumor, and treatment characteristics were examined. The primary endpoint was overall survival (OS). Kaplan-Meier analysis, Cox proportional hazards method, logistic regression, and propensity score matching were used. Results: Among 872 patients, 738 patients underwent CFRT and 134 patients received SBRT. Median follow-up was 24.3 months and 22.9 months for the CFRT and SBRT cohorts, respectively. The use of SBRT showed improved survival in the multivariable analysis compared to CFRT (HR 0.78, p = 0.025). Using 1:1 propensity score matching, a total of 240 patients were matched, with 120 patients in each cohort. The receipt of SBRT remained statistically significant for improved OS, including median OS (18.1 months vs 15.9 months) and 2-year OS (37.3% vs 25.5%) compared to the CFRT (p = 0.0040). Conclusions: This NCDB analysis shows a significant survival benefit with the use of SBRT versus CFRT, in the setting of definitive management for LAPC following iC. Further prospective studies evaluating the use of SBRT in the definitive treatment of this challenging population are warranted.

Adjuvant chemotherapy followed by concurrent chemoradiation is associated with improved survival for resected stage I-II pancreatic cancer

Background

This National Cancer Database (NCDB) analysis evaluates the clinical outcomes of postoperative chemotherapy followed by concurrent chemoradiation (C + CRT) compared to concurrent chemoradiation (CRT) alone or adjuvant chemotherapy alone (C) for resected pancreatic cancer.

Methods

The NCDB was queried for primary stage I‐II, cT1‐3N0‐1M0, resected pancreatic adenocarcinoma treated with adjuvant C, CRT, or C + CRT (2004‐2015). Patients treated with C + CRT were compared with those treated with C (cohort C) and CRT (cohort CRT). Baseline patient, tumor, and treatment characteristics were examined. Kaplan‐Meier analysis, multivariable Cox proportional hazards method, forest plot, and propensity score matching were used.

Results

Among 5667 patients, median follow‐up was 34.7, 45.2, and 39.7 months for the C, CRT, and C + CRT cohorts, respectively. By multivariable analysis for all patients, C and CRT had worse OS compared to C + CRT. Treatment interactions were seen among pathologically node‐positive disease. C + CRT was favored in 1‐3 and 4+ positive lymph node diseases when compared to C or CRT alone, but none of the treatment options were significantly favored in node negative disease. Using propensity score matching, 2152 patients for cohort C and 1774 patients for cohort CRT were matched. C + CRT remained significant for improved OS for both cohort C (median OS 23.3 vs 20.0 months) and cohort CRT (median OS 23.4 vs 20.8 months).

Conclusion

This NCDB study using propensity score matched analysis suggests an OS benefit for C + CRT compared to C or CRT alone following surgical resection of pancreatic cancer, particularly for patients with pathologically positive lymph nodes.

Long-term outcomes of interventions for radiation-induced xerostomia: A review

Xerostomia, or dry mouth, is a significant problem affecting quality of life in patients treated with radiation therapy for head and neck cancer. Strategies for reduction of xerostomia burden vary widely, with options including: sialagogue medications, saliva substitutes, acupuncture, vitamins, hyperbaric oxygen, submandibular gland transfer, and acupuncture or associated treatments. In this review, we sought to evaluate long-term outcomes of patients treated with various interventions for radiation-induced xerostomia. A literature search was performed using the terms "xerostomia" and "radiation" or "radiotherapy"; all prospective clinical trials were evaluated, and only studies that reported 1 year follow up were included. The search results yielded 2193 studies, 1977 of which were in English. Of those, 304 were clinical trials or clinical studies. After abstract review, 23 trials were included in the review evaluating the following treatment modalities: pilocarpine (three); cevimeline (one); amifostine (eleven); submandibular gland transfer (five); acupuncture like transcutaneous electrical nerve stimulation (ALTENS) (one); hyperbaric oxygen (one); and acupuncture (one). Pilocarpine, cevimeline, and amifostine have been shown in some studies to improve xerostomia outcomes, at the cost of toxicity. ALTENS has similar efficacy with fewer side effects. Submandibular gland transfer is effective but requires an elective surgery, and thus may not always be appropriate or practical. The use of intensity-modulated radiation therapy, in addition to dose de-escalation in select patients, may result in fewer patients with late xerostomia, reducing the need for additional interventions.

Three- Versus Five-Fraction Regimens of Stereotactic Body Radiotherapy for Peripheral Early-Stage Non-Small-Cell Lung Cancer: A Two-Institution Propensity Score-Matched Analysis

PURPOSE

To evaluate differences in outcomes of early-stage peripheral non-small-cell lung cancer (NSCLC) treated with either 3- or 5-fraction stereotactic body radiotherapy (SBRT) at 2 institutions.

PATIENTS AND METHODS

Patients diagnosed with peripherally located early-stage NSCLC who received either a median dose of 60 Gy (interquartile range [IQR], 60-60, biologically effective dose, 151-151) in 3 fractions or a median dose of 50 Gy (IQR, 50-50, biologically effective dose, 94-94) in 5 fractions were included in this study. All data were retrospectively collected and reviewed in an institutional review board-approved database.

RESULTS

A total of 192 lesions in 192 patients were identified: 94 received 3-fraction SBRT and 98 received 5-fraction SBRT. Patients in the 5-fraction cohort had significantly smaller tumors (P = .0021). Larger tumor size was associated with worse overall survival (hazard ratio, 1.40, P = .0013) for all patients. A single grade 3 toxicity was reported in each cohort. A propensity score-matched cohort of 94 patients was constructed with a median follow-up of 29.3 months (IQR, 17.3-44.6) for the 3-fraction cohort and 31.0 months (IQR, 17.0-48.5) for the 5-fraction cohort (P = .84). There were no statistically significant differences between these 2 cohorts in overall survival (P = .33), progression-free survival (P = .40), local failure (P = .86), and nodal or distant failure (P = .57) at 2 years.

CONCLUSION

The 3- and 5-fraction SBRT regimens for early-stage peripheral NSCLC had comparable clinical outcomes. Both regimens were well tolerated. A large tumor size was an adverse prognostic factor for worse survival.

Comparison of Single- and Three-fraction Schedules of Stereotactic Body Radiation Therapy for Peripheral Early-stage Non-Small-cell Lung Cancer

BACKGROUND

To compare the clinical outcomes of patients with early-stage non-small-cell lung cancer (NSCLC) who had undergone either single-fraction (SF) or three-fraction (TF) stereotactic body radiation therapy (SBRT) at a single institution during over 8-year period.

PATIENTS AND METHODS

Patients with peripherally located early-stage NSCLC who had undergone SBRT from February 2007 to November 2015 were included in the present study. SBRT was delivered without heterogeneity correction. Data were retrospectively reviewed and collected in an institutional review board-approved database. R software (version 3.3.2) was used for statistical analysis.

RESULTS

Of 159 total lung tumors, 65 lesions received 30 Gy (median, 30 Gy) in 1 fraction, and 94 lesions received 48 to 60 Gy (median, 60 Gy) in 3 fractions. Patients with a Karnofsky performance status < 80 were more common in the SF-SBRT cohort (P = .050). After a median follow-up of 22.2 and 26.2 months for the SF-SBRT and TF-SBRT cohorts, respectively (P = .29), no statistically significant difference was found in overall survival (P = .86), progression-free survival (P = .95), local failure (P = .95), nodal failure (P = .91), and distant failure (P = .49) at 24 months. At 1 and 2 years, the overall survival rates were 86.1% and 63.2% for the SF-SBRT cohort and 80.8% and 61.6% for the TF-SBRT cohort, respectively. At 1 and 2 years, the local control rates were 95.1% and 87.8% for the SF-SBRT cohort and 92.7% and 86.2% for the TF-SBRT cohort, respectively. Both regimens were well tolerated.

CONCLUSION

Despite more patients with poor performance status in the SF-SBRT cohort, the SF- and TF-SBRT regimens showed no differences in clinical outcomes. SF-SBRT is now our standard approach.