Post-treatment Plans Research Articles

Model based on ultrasound and clinicopathological characteristics for early prediction of pathological complete response to neoadjuvant chemotherapy in breast cancer.

Accurate assessment of pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in breast cancer (BC) is crucial for mitigating chemotherapy-related toxicity in patients who do not respond to the treatment. Conventional ultrasound (US) has become a pivotal method for evaluating treatment response due to its cost-effectiveness, convenience, and absence of ionizing radiation. The objective of this study was to develop a model combining US and clinicopathological characteristics at baseline, as well as US features after one cycle of NAC, to predict the pCR to NAC in BC. This retrospective study included 74 patients with invasive BC who underwent NAC from January 2022 to December 2023. Data from US and clinicopathological characteristics before NAC (pre-NAC) and US features after one cycle of NAC were collected from all patients. Univariate and multivariate analyses were used to screen the factors independently associated with pCR and to develop the prediction model. Receiver operating characteristic (ROC) curve analysis was performed, and the area under the curve (AUC), sensitivity, and specificity were calculated to assess the predictive efficiency. Four characteristics, including human epidermal growth factor receptor 2 (HER2)-positive [odds ratio (OR) 9.265; 95% confidence interval (CI): 1.617-53.095, P=0.012] and absence of posterior feature or posterior acoustic enhancement of the breast mass on the US pre-NAC (OR 9.435; 95% CI: 1.585-56.180, P=0.014), the maximum diameter reduction measured with the US (OR 1.081; 95% CI: 1.009-1.157, P=0.026), and the angular or spiculated margin of the breast lesion with the US after one cycle of NAC (OR 9.475; 95% CI: 1.247-71.969, P=0.030), were screened as independent predictors. The AUC, sensitivity, and specificity of the prediction model were 0.912, 90.0%, and 79.6%, respectively. US and clinicopathological characteristics at baseline and the US features after one cycle of NAC helped predict pCR for BC. The prediction model may enable early evaluation of the efficacy of treatment strategies and guide less invasive surgical options or personalized post-treatment plans.

Impact of intrafraction motion in pancreatic cancer treatments with MR-guided adaptive radiation therapy.

The total time of radiation treatment delivery for pancreatic cancer patients with daily online adaptive radiation therapy (ART) on an MR-Linac can range from 50 to 90min. During this period, the target and normal tissues undergo changes due to respiration and physiologic organ motion. We evaluated the dosimetric impact of the intrafraction physiological organ changes. Ten locally advanced pancreatic cancer patients were treated with 50 Gy in five fractions with intensity-modulated respiratory-gated radiation therapy on a 0.35-T MR-Linac. Patients received both pre- and post-treatment volumetric MRIs for each fraction. Gastrointestinal organs at risk (GI-OARs) were delineated on the pre-treatment MRI during the online ART process and retrospectively on the post-treatment MRI. The treated dose distribution for each adaptive plan was assessed on the post-treatment anatomy. Prescribed dose volume histogram metrics for the scheduled plan on the pre-treatment anatomy, the adapted plan on the pre-treatment anatomy, and the adapted plan on post-treatment anatomy were compared to the OAR-defined criteria for adaptation: the volume of the GI-OAR receiving greater than 33 Gy (V33Gy) should be ≤1 cubic centimeter. Across the 50 adapted plans for the 10 patients studied, 70% were adapted to meet the duodenum constraint, 74% for the stomach, 12% for the colon, and 48% for the small bowel. Owing to intrafraction organ motion, at the time of post-treatment imaging, the adaptive criteria were exceeded for the duodenum in 62% of fractions, the stomach in 36%, the colon in 10%, and the small bowel in 48%. Compared to the scheduled plan, the post-treatment plans showed a decrease in the V33Gy, demonstrating the benefit of plan adaptation for 66% of the fractions for the duodenum, 95% for the stomach, 100% for the colon, and 79% for the small bowel. Post-treatment images demonstrated that over the course of the adaptive plan generation and delivery, the GI-OARs moved from their isotoxic low-dose region and nearer to the dose-escalated high-dose region, exceeding dose-volume constraints. Intrafraction motion can have a significant dosimetric impact; therefore, measures to mitigate this motion are needed. Despite consistent intrafraction motion, plan adaptation still provides a dosimetric benefit.

SBRT focal dose intensification using an MR-Linac adaptive planning for intermediate-risk prostate cancer: An analysis of the dosimetric impact of intra-fractional organ changes

IntroductionUsing an magnetic resonance linear accelerator (MR-Linac) may improve the precision of visible tumor boosting with ultra-hypofractionation by accounting for daily positional changes in the target and organs at risk (OAR). Patients and methodsFifteen patients with prostate cancer and an MR-detected dominant lesion were treated on the MR-Linac with stereotactic body radiation (SBRT) to 40 Gy in 5 fractions, boosting the gross tumor volume (GTV) to 45 Gy with daily adaptive planning. Imaging was acquired again after initial planning (verification scan), and immediately after treatment (post-treatment scan). Prior to beam-on, additional adjustments were made on the verification scan. Contours were retrospectively adjusted on verification and post-treatment scans, and the daily plan recalculated on these scans to estimate the true dose delivered. ResultsThe median prostate D95% for plan 1, 2 and 3 was 40.3 Gy, 40.5 Gy and 40.3 Gy and DIL D95% was 45.7 Gy, 45.2 Gy and 44.6 Gy, respectively. Bladder filling was associated with reduced GTV coverage (p = 0.03, plan 1 vs 2) and prostate coverage (p = 0.03, plan 2 vs 3). The D0.035 cc constraint was exceeded on verification and post-treatment plans in 24 % and 33 % of fractions for the urethra, 31 % and 45 % for the bladder, and 35 % and 25 % for the rectum, respectively. ConclusionMR-Linac guided, daily adaptive SBRT with focal boosting of the GTV yields acceptable planned and delivered dosimetry. Adaptive planning with a MR-Linac may reliably deliver the prescribed dose to the intended tumor target.

Building a model to predict the risk of multiple severe neurotoxicities in cancer survivors after cisplatin treatment.

e24066 Background: Cisplatin treatment is used for many cancers, including testicular, ovarian, and head and neck malignancies. Cancer survivors with multiple cisplatin-related toxicities can have poor health-related quality of life (HRQOL). Identification of clinical and genetic factors that predict the risk of these neurotoxicities is critical. Methods: Testicular cancer survivors (TCS) enrolled in the Platinum Study completed surveys, underwent physical examination, extensive audiometric testing, and phlebotomy for genotyping and serum platinum analysis. Cases included TCS with two or more severe toxicities (hearing loss [HL], tinnitus, and peripheral sensory neuropathy [PSN]), defined as follows: hearing threshold > 40dB based on geometric mean of 4-12kHz, responding yes to “Do you have ringing or buzzing in the ears?” and/or EORTC-CIPN20 scores in the severe range for items related to sensory neuropathy. Controls were restricted to TCS without any toxicities. TCS with a single toxicity were excluded from analyses. Penalized logistic regression lasso method was used to create the model to predict the binary outcome. Creatinine clearance and residual serum platinum levels were calculated. Polygenic risk scores (PRS) for traits commonly associated with pharmacokinetics and HL, tinnitus, and PSN were calculated for TCS in the training (n = 284) and validation (n = 157) data sets using PRS publicly available in The Polygenic Score Catalog using PRSice 2.3.3. Models were trained and tested in R 4.1.2. Results: A model to assess the risk of developing multiple severe neurotoxicities that could be used without blood work and additional analysis was developed. Clinical predictors incorporated into the model were age at testicular cancer diagnosis, age at phlebotomy, weight and height. PRS incorporated were age-related sensorineural hearing loss (PGS000762), body fat percentage (PGS002133), creatinine in urine (PGS001944), and peripheral nervous system disease (PGS002039). The accuracy of this model was 77.71%, which was significantly greater than the no information rate (NIR) of 65.61% (p = .00067). The positive and negative predictive values (PPV and NPV) were 72.09% and 79.82%, respectively. The AUC-ROC was 0.804. Adding residual platinum levels and creatinine clearance increased the accuracy of the model to 78.34%, which was significantly greater than the NIR (p = .00035). The PPV was 75.00% and the NPV was 79.49%. The area under the receiver operating characteristic curve (AUC-ROC) was 0.832. Conclusions: TCS are often faced with multiple severe neurotoxicities such as HL, tinnitus, and PSN, which impact HRQOL for many decades. If confirmed, a penalized regression model using clinical and genetic characteristics can predict the risk of developing these phenotypes to guide clinicians in treatment and post-treatment management plans.

Microstructure and properties of an as-deposited and post treated high strength carbide-free bainite steel fabricated via laser powder deposition

A carbide-free bainite steel of 0.29C–2.50Si-1.50Mn-1.0Mo-0.97Cr (wt.%) with no voids and cracks was fabricated via laser powder deposition (LPD). Different post-treatment plans were conducted and then microstructures and properties of the steel were studied through optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffractometry (XRD), transmission electron microscopy (TEM), hardness meter and tensile test machines. Obtained results show that the microstructure of the deposited specimen consisted of granular pearlite and retained austenite (RA). The yield strength, tensile strength and elongation were 662 ± 71 MPa, 1051 ± 65 MPa and 13.03 ± 1.33 %, respectively. After austempering at 578 K, the microstructure of the specimen changed to bainite ferrite (BF) and RA. Moreover, it was found that the yield strength and tensile strength significantly increased to 1156 ± 60 MPa and 1289 ± 110 MPa, respectively. However, it had poor strain hardening capacity and elongation remained unchanged. After hot rolling and austempering, the RA content of the specimen significantly increased and the strain hardening capacity improved. However, when the isothermal temperature was less than the Ms temperature (i.e. 553 K), the corresponding microstructure consisted of martensite, BF and 13.6 vol% of RA. In this case, the yield strength, tensile strength and elongation were 895 ± 74 MPa, 1157 ± 92 MPa and 14.59 ± 1.13 %, respectively, indicating slight improvement. Meanwhile, it was found that when the isothermal temperature exceeded Ms temperature, the mechanical properties improved significantly. The present study demonstrated that specimens with an isothermal temperature of 578 K had the best mechanical properties. In particular, the yield strength, tensile strength and elongation of the optimized alloy were 1177 ± 44 MPa, 1398 ± 57 MPa and 19.80 ± 0.79 %, respectively.

Intrafractional Changes May Necessitate the Development of Real-time Adaptive Radiation Therapy for Abdominal Tumors

MR-Linac enables daily optimization of radiotherapy (RT) via online adaptation to patient daily anatomy. However, intrafractional anatomical changes may occur particularly for targets adjacent to or included in the gastrointestinal (GI) tract. These changes include motions due to respiration, peristalsis and unpredictable air filling of GI organs. In this work, we study the intrafractional variability of abdominal organs and its dosimetric impact for online MR guided adaptive RT (MRgART) and discuss the need for developing real-time ART. Thirteen time-sequenced abdominal MRI dataset pairs (MR1 and MR2), separated by 15-60 minutes (similar to the intrafractional timescale in MRgART), for 9 abdominal cancer patients were analyzed. Eight dataset pairs consisting of T2 and T1 images were collected for 8 patients from a 3T MR simulator, while the remaining 5 pairs were motion averaged MR from 4DMRI acquired on MR-Linac immediately before and after each fraction of a patient five-fraction RT course. For each MR pair, we first created an IMRT plan based on MR1 (mimicking online adaptation plan before the delivery) by optimizing dose to the target (the pancreatic head) and organs-at-risk (OAR) in the presence of a 1.5T magnetic field. We then reconstructed the IMRT dose based on MR2 (i.e., post-treatment plan). The differences of dose volume histogram (DVH) parameters between the two plans were analyzed. The GI air cavities change substantially during fractional planning and delivery (15-60 min duration). Air cavity volumes of the stomach and duodenum were found to vary, on average, by 58.6 and 3.2 cc, respectively. The maximum, minimum and mean differences in selected DVH parameters resulted primarily from the intrafractional air cavity changes and are tabulated below. Here, significant deviations from the planned fractional doses are seen. The change of stomach air volume has a strong correlation to the maximum target dose (|r| = 0.8). Most notably, strong correlations between duodenum air volume and the target maximum, minimum and mean doses (|r| = 0.9, 0.7, and 0.9, respectively) are observed for the longitudinal datasets. Furthermore, maximum dose to OARs is seen to change by up to 50% of the planned limits. GI structures, primarily air cavities, can vary rapidly, causing severe intrafractional anatomical changes during MRgART. Such changes can impact the dose delivery of online ART. These results demonstrate the need to develop real-time adaptation to robustly address the intrafraction variation for abdominal tumors and justify further studies with larger datasets.Abstract 1111; TableDifference between pre- and post-treatment plans: max-min(mean)Max Target Dose (% of Rx)4.8-0.1(1.8)Min Target Dose (% of Rx)51.6-1.0(17.0)Mean Target Dose (% of Rx)6.8-0.2(2.1)Target V (97%) (% of Volume)14.2-0.1(4.3)Max Duodenum Dose (% of Rx)26.7-1.2(6.7)Mean Duodenum Dose (% of Rx)37.6-0.3(8.6) Open table in a new tab

Multiple senses of community and recovery processes. A pilot study for a national evaluation of the experiences of persons with substance use problems receiving help and services from Norwegian municipalities.

AimsThis pilot study uses a multifaceted concept of sense of community (SOC)—multiple senses of community (MPSOC)—to understand how the multiple communities of persons with substance use problems, including those with a positive, negative and neutral SOC, influence processes of substance use recovery.MethodsSemi‐structured interviews were conducted with 16 informants from different Norwegian municipalities and regions. A collaborative research design and thematic analyses with a peer researcher were applied.ResultsThe findings confirm prior findings of key ingredients related to recovery. However, they also illustrate that for communities to promote recovery, they need to fulfil individual needs, provide distance from pretreatment status, identity and roles and harmonise with individual meaning systems of an ideal community.ConclusionExperiences of positive and negative community connections within geographical, relational and ideal communities take part in recovery processes. Community participation is suggested to be included in individual outpatient treatment and posttreatment plans.

Questionnaire and Weighted Scoring Formula for Evaluating Clinically Useful Quality-of-Life Scores of Post-Surgical Gastric Cancer Patients

Background: As survival rates of cancer patients are improving, the quality-of-life (QoL) is becoming the next significant clinical endpoint. However, most oncology QoL questionnaires fall short in providing clinically useful information for guiding post-surgery care. Consideration of pre-existing health issues and a scoring formula that assigns weights to different scales for patient grading may generate clinically useful QoL scores. Methods: The Quality-of-Life Questionnaire for Post Gastrectomy (QoLQ-PG), which considers pre-existing health issues, comprises 30 items across five scales (general symptom, post-gastrectomy syndrome, activity, psychological state, social relation) and an overall scale. A total of 2524 survey responses from 1035 gastric cancer (GC) patients were collected. Validity and reliability analyses were performed using the multitrait-multimethod matrix. Regression analysis was performed to determine the weight of each scale. Analysis of variance was performed using Fisher's least significant difference test. Findings: The QoLQ-PG showed good reliability, convergent validity, and discriminant validity (Cronbach's alpha: 0.704-0.840; validity diagonal: 0.529-0.786). The scoring formula accurately represented the contributions of the five scales to the overall QoL (R2 = 0.445; p < 0.001), which showed significant correlations (r = 0.228, p < 0.001) with changes in body weight, a decisive clinical index in post-gastrectomy patients. Classification of the QoLQ-PG scores into four grades allowed clear distinction among patient grades, which were also highly correlated with body weight changes (F = 23.12, p < 0.001). Interpretation: The QoLQ-PG reliably illustrated the QoL of post-gastrectomy GC patients in terms of weighted total score and scale scores, which respectively may be used to denote the level and type of post-surgery care needed. The concept and scoring formula of the QoLQ-PG may be adapted in other cancers to evaluate clinically relevant QoL and guide post-treatment plans. Funding Statement: Asan Institute for Life Sciences and Corporate Relations, Asan Medical Center, Korea Declaration of Interests: All authors have no conflicts of interest. Ethics Approval Statement: The Ethics Committee of Asan Medical Center reviewed and approved the study protocol (2015-1288).

The effect of catheter displacement and anatomical variations on the dose distribution in MRI-guided focal HDR brachytherapy for prostate cancer

PurposeThe aim of this study was to analyze the effect of catheter displacement and anatomical variations of prostate and organs at risk on dose distribution in MRI-guided 19 Gy single fraction focal high-dose-rate brachytherapy (HDR-BT) of the prostate. Methods and MaterialsSeventeen patients with localized prostate cancer were enrolled in a prospective trial investigating focal HDR-BT in a 1.5 T MRI-HDR-BT facility. The diagnostic MRI delineations were registered with intraoperative MR scan, and a single fraction of 19 Gy was applied to the visible tumor. Self-anchoring umbrella catheters were used for HDR-BT delivery. A 1.5 T MRI was performed directly after ultrasound (US)-guided catheter placement for treatment planning. After treatment and before removal of catheters, a posttreatment 1.5 T MRI was performed. Regions of interest were also delineated on the posttreatment MR images and the catheters of 17 patients were reconstructed. The dose plan was constructed for the posttreatment MRI scan to assess the influence of catheter migration and anatomical variation on the dose delivered to the target and the organs at risk. Also on the posttreatment MRI, the complete catheter reconstruction was reassessed, to correct for, for example, bending of the catheters. The displacement of catheters between the MRI scans was determined by comparing the catheter tip positions on the treatment planning and posttreatment 1.5 T MRI scans. ResultsThe displacements of 241 catheters were investigated. Average (range) displacements of the umbrella catheters are 0.6 (0–2.9) mm in the x-direction, 0.5 (0–2.1) mm in the y-direction, and 0.9 (0–5.5) mm in the z-direction. In 3 patients, the displacement was >4 mm and up to 5.5 mm. This occurred in respectively 1/13, 1/16, and 1/18 catheters in these patients. The dosimetric differences between the intraoperative treatment and the posttreatment plans were in most patients less than 1.5 Gy. In 4 patients, a dose difference in clinical target volume D95 of >2 Gy up to 5.8 Gy was reported. No discrimination can be made between dose differences due to catheter displacement and/or organ movement/anatomy changes. ConclusionsIn general, catheter displacements were in the order of a mm and differences in dose to the clinical target volume and the organs at risk between the treatment and posttreatment plans smaller than 1.5 Gy. In some patients, dose differences up to 5.8 Gy were determined, due to either individual larger catheter displacement and/or anatomy changes. A longer followup is necessary to assess the clinical implications of individual large dose differences.

Transition care clinic: Evidence-based survivorship care.

141 Background: The Odette Cancer Centre (OCC) is the sixth largest comprehensive cancer centre in North America. In 2012/2013 fiscal year it is projected there will be 19,633 new cases and 82,293 follow-up visits, of which 16% of new and 24% of follow-ups will be for gastrointestinal (GI) and hematology disease sites. Current specialty cancer clinics are not well equipped to provide evidence-based survivorship care. Methods: The Transition Care Clinic (TCC) was developed for colorectal cancer and lymphoma patients transitioning from acute care at OCC back to their primary care provider (PCP) for follow-up, assessment, and surveillance after completion of active treatment. Patients are seen by a family medicine physician and advanced practice nurse and receive comprehensive survivorship care, individualized treatment summaries, and post-treatment care plans. An accompanying web resource continues to connect patients to OCC after discharge and provides survivorship specific information. Results: An eight month pilot resulted in 66 visits and 28 discharges, of which 53% of visits and 93% of discharges were for GI patients and 47% and 7% respectively for hematology. The 28 discharges resulted in resource utilization savings of 122 OCC clinic visits and 118 hospital CT scans. Symptom screening results across the domains of anxiety, depression, pain, and tiredness were on par with other cancer patients, dispelling concern that these patients experience different/more symptoms after treatment and during transition. Finally, patient feedback indicated that those that found it difficult to attend OCC appointments appreciated knowing guidelines were available and were comfortable with PCP follow-up, while others whose PCP missed initial presenting symptoms preferred cancer centre “specialists” and were not comfortable. Conclusions: There is need for inter-disciplinary development of survivorship and transition programs with buy-in from disease sites, multimodality consensus, revision of eligibility criteria for lymphoma, and efficiencies to complete comprehensive treatment summaries. Short and long-term outcomes to be measured include recurrences and secondary cancers, adherence to guidelines, patient quality of life, and satisfaction.

Living with a pituitary tumour: A narrative analysis

This study aimed to synthesise the illness narratives of individuals living with a pituitary tumour. Eight adults with a pituitary tumour were recruited from an endocrinology service in the north-west of England. A narrative methodology was adopted which investigated elements of the individual narratives such as metaphor and structure but which also aimed to produce a joint account of experience in this particular illness context by extracting themes across the stories; these are presented as part of a chronological narrative. However, the resulting group story was also analysed in terms of different types of narrative plots. The group narrative started from the recognition of symptoms and then diagnosis though treatment to post-treatment and future plans. In terms of narrative plots, one notable element of the joint narrative was the flow between the culturally dominant restitution narrative, where participants focused on treatment and recovery and the chaos narrative when recovery did not seem possible. The findings contain many elements consistent with previous research; however, the use of a celebrity figure to communicate about the illness experience and a perception that objects or individuals should not be taken at face value emerged as more novel findings.

High-dose-rate interstitial brachytherapy for gynecologic malignancies—dosimetric changes during treatment period

To overcome cranio-caudal needle displacement in pelvic high-dose-rate interstitial brachytherapy (HDRIB), we have been utilizing a fullystretched elastic tape to thrust the template into the perineum. The purpose of the current study was to evaluate dosimetric changes during the treatment period using this thrusting method, and to explore reproducible planning methods based on the results of the dosimetric changes. Twenty-nine patients with gynecologic malignancies were treated with HDRIB at the Cancer Institute Hospital. Pre-treatment and post-treatment computed tomography (CT) scans were acquired and a virtual plan for post-treatment CT was produced by applying the dwell positions/times of the original plan. For the post-treatment plan, D90 for the clinical target volume (CTV) and D2cc for the rectum and bladder were assessed and compared with that for the original plan. Cranio-caudal needle displacement relative to CTV during treatment period was only 0.7 ± 1.9 mm. The mean D90 values for the CTV in the pre- and post-treatment plans were stable (6.8 Gy vs. 6.8 Gy) and the post-treatment/pre-treatment D90 ratio was 1.00 ± 0.08. The post-/pre-treatment D2cc ratio was 1.14 ± 0.22 and the mean D2cc for the rectum increased for the post-treatment plan (5.4 Gy vs. 6.1 Gy), especially when parametrial infiltration was present. The mean D2cc for the bladder was stable (6.3 Gy vs. 6.6 Gy) and the ratio was 1.06 ± 0.20. Our thrusting method achieved a stable D90 for the CTV, in contrast to previous prostate HDRIB reports displaying reductions of 35–40% for D90 during the treatment period.

Predicting Relapse for Catholic Clergy Sex Offenders

The Static-99 is an instrument commonly used to measure the likelihood of recidivism among sex offenders. The current study explores whether the Static-99 is an effective predictor of relapse among Catholic clergy who have had sexual contact with minors. Static-99 scores were compiled for 337 treated clergy who had offended against minors, including 21 who were known to have relapsed after treatment. Clergy were followed up for 5 to 25 years posttreatment (M = 16.05; SD = 5.12) after their completion of treatment. Post release, they were closely supervised, with explicit rules limiting their contacts with minors and church officials monitoring their compliance with posttreatment plans. Descriptive information on the victims of clergy sex offenders is provided. Although all clergy offenders had the same score on 4 of the 10 Static-99 items, Static-99 total scores still significantly predicted relapse with a moderate to large effect size (area under the curve [AUC] = .672; Cohen's d = .808). Predictive accuracy of each item is also reported. Issues concerning the use of the Static-99 with this population are discussed.

Sex differences in the perpetrator-victim relationship among emergency department patients presenting with nonfatal firearm-related injuries

Study objective I examine whether female and male emergency department (ED) patients are equally likely to have been nonfatally shot or struck with a gun by someone they know versus by a stranger. Methods This case-control study examined patient records from US hospital EDs from 1993 to 1999. The records of patients aged 15 years or older who presented with nonfatal firearm-related injuries were accessed from the National Electronic Injury Surveillance System. Patients were classified according to 2 firearm-related injury types (penetrating or nonpenetrating [eg, struck with gun] trauma) and 5 perpetrator types (injury inflicted by spouse or ex-spouse, other relative, friend or acquaintance, self, or stranger). Results Compared with male patients, female patients were 3.6 times (95% confidence interval [CI] 2.5 to 5.3) more likely to have been shot and 3.9 times (95% CI 1.6 to 9.4) more likely to have been struck with a gun wielded by a spouse or ex-spouse than by a stranger. Conversely, women were considerably less likely than men to have been struck with a gun or shot by another relative, to have been struck with a gun by a friend or acquaintance, or to have a gunshot injury that was self-inflicted. Conclusion The cause of firearm-related injuries varies by sex. Before releasing firearm-injury victims from the ED, health care providers should consider 2 important factors: (1) the patient's relationship to the perpetrator, and (2) the availability and previous use of firearms in the victim's home. This information may be helpful in formulating posttreatment plans to enhance the victim's safety.