FLASH radiotherapy for the treatment of symptomatic bone metastases in the thorax (FAST-02): protocol for a prospective study of a novel radiotherapy approach

BACKGROUND

FLASH therapy is a treatment technique in which radiation is delivered at ultra-high dose rates (≥ 40 Gy/s). The first-in-human FAST-01 clinical trial demonstrated the clinical feasibility of proton FLASH in the treatment of extremity bone metastases. The objectives of this investigation are to assess the toxicities of treatment and pain relief in study participants with painful thoracic bone metastases treated with FLASH radiotherapy, as well as workflow metrics in a clinical setting.

METHODS

This single-arm clinical trial is being conducted under an FDA investigational device exemption (IDE) approved for 10 patients with 1-3 painful bone metastases in the thorax, excluding bone metastases in the spine. Treatment will be 8 Gy in a single fraction administered at ≥ 40 Gy/s on a FLASH-enabled proton therapy system delivering a single transmission proton beam. Primary study endpoints are efficacy (pain relief) and safety. Patient questionnaires evaluating pain flare at the treatment site will be completed for 10 consecutive days post-RT. Pain response and adverse events (AEs) will be evaluated on the day of treatment and on day 7, day 15, months 1, 2, 3, 6, 9, and 12, and every 6 months thereafter. The outcomes for clinical workflow feasibility are the occurrence of any device issues as well as time on the treatment table.

DISCUSSION

This prospective clinical trial will provide clinical data for evaluating the efficacy and safety of proton FLASH for palliation of bony metastases in the thorax. Positive findings will support the further exploration of FLASH radiation for other clinical indications including patient populations treated with curative intent.

REGISTRATION

ClinicalTrials.gov NCT05524064.

The Association of Incidental Radiation Dose to the Heart Base with Overall Survival and Cardiac Events after Curative-intent Radiotherapy for Non-small Cell Lung Cancer: Results from the NI-HEART Study

AIMS

Cardiac disease is a dose-limiting toxicity in non-small cell lung cancer radiotherapy. The dose to the heart base has been associated with poor survival in multiple institutional and clinical trial datasets using unsupervised, voxel-based analysis. Validation has not been undertaken in a cohort with individual patient delineations of the cardiac base or for the endpoint of cardiac events. The purpose of this study was to assess the association of heart base radiation dose with overall survival and the risk of cardiac events with individual heart base contours.

MATERIALS AND METHODS

Patients treated between 2015 and 2020 were reviewed for baseline patient, tumour and cardiac details and both cancer and cardiac outcomes as part of the NI-HEART study. Three cardiologists verified cardiac events including atrial fibrillation, heart failure and acute coronary syndrome. Cardiac substructure delineations were completed using a validated deep learning-based autosegmentation tool and a composite cardiac base structure was generated. Cox and Fine-Gray regressions were undertaken for the risk of death and cardiac events.

RESULTS

Of 478 eligible patients, most received 55 Gy/20 fractions (96%) without chemotherapy (58%), planned with intensity-modulated radiotherapy (71%). Pre-existing cardiovascular morbidity was common (78% two or more risk factors, 46% one or more established disease). The median follow-up was 21.1 months. Dichotomised at the median, a higher heart base Dmax was associated with poorer survival on Kaplan-Meier analysis (20.2 months versus 28.3 months; hazard ratio 1.40, 95% confidence interval 1.14-1.75, P = 0.0017) and statistical significance was retained in multivariate analyses. Furthermore, heart base Dmax was associated with pooled cardiac events in a multivariate analysis (hazard ratio 1.75, 95% confidence interval 1.03-2.97, P = 0.04).

CONCLUSIONS

Heart base Dmax was associated with the rate of death and cardiac events after adjusting for patient, tumour and cardiovascular factors in the NI-HEART study. This validates the findings from previous unsupervised analytical approaches. The heart base could be considered as a potential sub-organ at risk towards reducing radiation cardiotoxicity.

Locoregional Ablative Radiation Therapy for Patients With Breast Cancer Unsuitable for Surgical Resection

PURPOSE

Patients with breast cancer who are unsuitable for surgical resection are typically managed with palliative systemic therapy alone. We report outcomes of 5-fraction ablative radiation therapy for nonresected breast cancers.

METHODS AND MATERIALS

This is a retrospective analysis of an institutional registry of patients with breast cancer who were unsuitable for resection and underwent 35 to 40 Gy/5 fractions to the primary breast tumor or regional lymph nodes from 2014 to 2021. Primary outcomes were cumulative incidence of local failure and grade ≥3 toxicity (Common Terminology Criteria for Adverse Events, version 5.0).

RESULTS

We reviewed 57 patients who received 61 treatment courses (median age of 81 years; range, 38-99). Unresectable tumor (10%), patient refusal (18%), medical inoperability (35%), and metastatic disease (37%) were the causes of not having surgery. Five patients (8%) had previously undergone adjuvant locoregional radiation therapy. Fifty-four percent (n = 33/61) of treatment courses targeted the breast only, 31% (n = 19/61) both the breast and lymph nodes, and 15% (n = 9/61) the lymph nodes only. Sixty-seven percent (n = 35/52) of the courses that targeted the breast were delivered with partial breast irradiation and 33% (n = 17/52) with whole breast radiation therapy (median dose of 25 Gy in 5 fractions) ± simultaneous integrated boost to the primary tumor. Most primary tumors (65%, n = 34/52) and target lymph nodes (61%, n = 17/28) were treated with a dose of 35 Gy in 5 fractions. Most treatments (52%) were delivered with intensity modulated radiation therapy (IMRT). Radiation therapy was delivered daily (20%), every other day (18%), twice weekly (36%), or weekly (26%). The 2-year cumulative incidence of local failure was 11.4% and grade≥3 toxicity was 15.1%. The grade ≥3 toxicity was 6.5% for IMRT treatments, versus 7.7% for non-IMRT treatments targeting partial breast or lymph nodes (hazard ratio, 1.13, P = .92), versus 38.9% for non-IMRT treatments targeting the entire breast (hazard ratio, 6.91, P = .023). All grade ≥3 toxicity cases were radiation dermatitis. No cases of brachial plexopathy were observed.

CONCLUSIONS

Thirty-five to 40 Gy in 5 fractions is a safe and effective breast stereotactic body radiation therapy (SBRT) regimen and may be an attractive option for patients who are not surgical candidates. Highly conformal techniques (ie, IMRT or partial breast irradiation) were associated with a reduced risk of toxicity and should be the preferred treatment approaches.

ARTIA-Cervix: A Prospective Clinical Trial to Assess Patient Reported Intestinal Toxicity with Adaptive External Beam Radiation Therapy in the Treatment of Cervical Cancer

PURPOSE/OBJECTIVE(S)

Chemoradiation (CRT) remains the standard of care for locally advanced cervical cancer. As recent large phase III trials (OUTBACK, CALLA) reported no difference in primary survival outcomes when novel agents were added to CRT, technological advancements continue to be a focus for improving outcomes. Daily imaging has enabled margin reduction on the cervix, uterus and lymph nodes, which can lower radiation dose to bowel and potentially reduce RT-related symptoms. Daily adaptive RT (ART) combines daily imaging with online dosimetry replanning, allowing for decreased margins on the target. A pre-planning study showed bowel V40Gy and V45Gy reductions of 252 cc to140 cc and 167 cc to 43 cc, respectively. ARTIA-Cervix is a single-arm, prospective, multi-institutional, international clinical trial investigating the potential of ART to decrease patient-reported acute gastrointestinal (GI) toxicity.

MATERIALS/METHODS

Planned enrollment is 125 subjects with up to 8 sites participating. Eligibility criteria include locally advanced node-negative cervical cancer FIGO stages IB2-3B. Treatment will consist of cisplatin-based CRT with daily ART, followed by image-guided brachytherapy. Subjects will receive 25 fractions ART at 1.8 Gy per day for a total of 45 Gy. The primary study objective is reduction of patient-reported GI toxicity as measured by PRO-CTCAE score ≥3 at the conclusion of ART. Secondary objectives include patient-reported GU toxicity and sexual quality of life, the development of radiation dosimetry models predicting toxicity, physician-reported toxicities, 2-year disease free survival, and adaptive workflow metrics. Powering of the study and sample size calculation are based on the hypothesis that ART will decrease patient-reported acute GI toxicity from historical rates of 33% to 20% (13% effect size).

RESULTS

This study opened to enrollment on April 28th, 2022. The total study duration will be approximately 5 years.

CONCLUSION

ARTIA-Cervix is an international, prospective clinical trial designed to evaluate reduction of treatment-related GI toxicity through daily online ART. The results of this clinical study will add to the growing body of evidence supporting clinical decisions about utilization of ART technologies.

Simulation CT Features and Radiation Cardiotoxicity in Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Radiation cardiotoxicity is a significant clinical dilemma in non-small cell lung cancer (NSCLC) radiation therapy (RT). Baseline cardiovascular (CV) status may influence the risk of cardiotoxicity, and may be ascertainable from the appearance of the heart on simulation computed tomography (CT). We examined the association of CT features with incidental heart dose and risk of cardiac events in NSCLC.

MATERIALS/METHODS

Patients treated with curative-intent RT between 2015 and 2020 at a regional center were identified. Clinical notes were interrogated for baseline patient and CV health details, and follow-up CV events. Cardiac events were verified by a cardiologist. A deep learning-based auto-segmentation tool was applied, allowing extraction of a pre-specified list of volume parameters in a programming environment. CAC was graded as none, mild, moderate and severe in patients with a non-contrast scan. The craniocaudal relationship of the PTV and heart (Feng atlas) were annotated.

RESULTS

A total of 478 patients were included, with a median age of 70 and Charlson Index of 5. The median mean heart dose was 6.3 Gy (IQR 2.7-11.4). The median lung V20 was 20.0% (IQR 14.8-27.1). Cardiovascular risk factors were common, with most patients having 2 (39%) or 3 (31%). A history of previous cardiac events was common, including myocardial infarction (14%), arrhythmia (11%) or heart failure (9%). A total of 6.9% and 7.1% patients developed a new atrial arrhythmia (AA) or heart failure (HF) after completing RT. The volume metrics with the highest AUC for AA and HF events were the left atrium (LA) (AUC 0.67, p = 0.0002) and left ventricle:right ventricle (LV:RV) ratio (AUC 0.66, p = 0.0021). Kaplan-Meier analysis for cardiac events dichotomizing at the optimal cut-point for maximum sensitivity and specificity demonstrated significantly different rates for both AA (LA 109cc, HR 3.35, 95% CI 1.64-6.83, p = 0.0009) and HF (LV:RV ratio 1.61, HR 2.37, 95% CI 1.19-4.74, p = 0.0143). Only 2 patients with non-contrast scans developed a myocardial infarction, both had mild CAC. The incidence of pooled cardiac events was not significantly different between patients with no (n = 2/21, 9.5%), mild (n = 10/38, 26.3%), moderate (n = 8/53, 15.1%) and severe (n = 7/24, 29.2%) CAC (p = 0.3916). Where the inferior border of the PTV was above the superior border of the heart, mean heart dose was significantly lower than compared with overlap of levels (1.9 Gy v 9.7 Gy, p<0.0001), and this was true for 3DCRT (n = 139, p<0.001), IMRT (n = 94, p<0.001) and VMAT (n = 145, p<0.001) patients.

CONCLUSION

LA volume and LV:RV volume ratio are predictive for the development of AA and HF respectively. CAC grade did not differentiate patients by risk of cardiac events. Where the craniocaudal level of the PTV doesn't overlap with the level of the heart, the cardiac dose is likely to be very low. Several simulation CT features are associated with cardiac events following treatment for NSCLC and prospective evidence of cardiac risk could enable medical optimization prior to RT.

Daily Adaptive vs. Non-Adaptive External Beam Radiation Therapy with Concurrent Chemotherapy for Locally Advanced Non-Small Cell Lung Cancer (NSCLC): A Prospective Randomized Trial of an Individualized Approach for Toxicity Reduction (ARTIA-Lung)

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) with concurrent chemotherapy is a standard treatment for Stage III NSCLC. However, radiation pneumonitis incidence increases rapidly with volume of lung irradiated, and esophagitis increases with dose to the esophagus. Both conditions can have adverse impacts on patients' quality of life. Daily online adaptive RT (ART) may allow for reduced normal tissue doses due to smaller margins around the target, as well as target size reduction with tumor response. This prospective, randomized controlled trial tests the hypothesis that the proportion of study participants who experience score ≥3 PRO-CTCAE cough, dyspnea, or dysphagia will be at least 20% lower with daily ART than with non-adapted RT.

MATERIALS/METHODS

Enrollment goals are 244 subjects at up to 10 cancer centers worldwide. Eligibility criteria include stage IIIA-IIIC (AJCC v8) NSCLC; baseline grade 0-2 dyspnea, cough, and dysphagia; and no contralateral hilar or supraclavicular/cervical lymph node involvement. Subjects will be randomized (1:1) to CBCT-based daily ART or non-adapted RT using IMRT or VMAT delivering 60-66 Gy in 30-33 fractions with concurrent platinum doublet chemotherapy. Adjuvant immunotherapy with durvalumab is permitted. Follow-up for study participants will be for 1-year post-completion of chemoRT. Study endpoints include: frequency of PRO-CTCAE score ≥3 cough, dyspnea, or dysphagia from randomization to 30 days post-chemoRT; patient-reported quality of life (FACT-L and EQ-5D-5L questionnaires); percentage of lung receiving ≥20 Gy; mean doses to lung, heart, and esophagus; primary tumor response on CT or PET-CT (RECIST v1.1); local disease progression; and incidence of grade ≥2 pneumonitis within 1 year. Stratification factors are the treating institution and the presence of contralateral mediastinal lymph node metastases (associated with increased volume of irradiated lung). Interim analyses for futility and superiority will be performed when the primary endpoint data have been collected for 50% of evaluable participants.

RESULTS

This study opened to enrollment on 20 October 2022 and is expected to be completed in approximately 3 years.

CONCLUSION

This prospective, randomized clinical trial rigorously evaluates the impacts of daily online ART on radiation pneumonitis, esophagitis, and quality of life in patients with advanced NSCLC. It will collect standard tumor response and disease progression metrics to assure that reduced margins do not have an adverse impact on outcomes. Online ART is emerging as an innovative approach enabling increased sparing of normal tissues. The results of this clinical study will support evidence-based clinical decisions around ART technologies.

Patient-Level and Endpoint-Specific Clinico-Dosimetric Analysis of the Cardiac Base as a Mediator of Radiation Cardiotoxicity in Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Cardiac disease is a dose-limiting toxicity in non-small cell lung cancer (NSCLC) radiation therapy. Radiation dose to the cardiac base is associated with poor overall survival in several clinical studies, but has not been validated in a non-dose escalated cohort, or with individual patient delineations. In this study we examined the impact of cardiac base dose on overall survival (OS) and cardiac events (CEs), and interrogated the relationships of the substructures comprising the heart base with OS and CEs.

MATERIALS/METHODS

Patients with stage I-III NSCLC treated with curative-intent radiation therapy between 2015 and 2020 at a regional cancer center were identified. Clinical notes were examined for baseline patient, tumor and cardiac details, and both cancer and cardiac outcomes. Three cardiologists verified CEs. Cardiac delineations were completed using a validated deep learning-based autosegmentation tool. Cox and Fine and Gray regressions were undertaken for the risk of death and CEs respectively, accounting for pre-specified evidence-based dose metrics and clinically relevant cardiac covariates.

RESULTS

Most patients received 55 Gy/20# (n = 461/478, 96%) without chemotherapy (58%), planned with VMAT (51%) or IMRT (20%). Pre-existing cardiovascular morbidity was common, with 78% having ≥2 risk factors, and 46% having >1 established cardiac disease. The median follow-up was 21.1 months. Dichotomized at the median, higher heart base Dmax was associated with poorer survival on Kaplan-Meier analysis (21.6 months (95% CI 19.3-24.9) versus 29.4 months (95% CI 21.6-36.6), p = 0.021), and remained significant when statistically compared in published multivariate models. In a multivariate analysis for pooled acute CEs, heart base Dmax was associated with CEs (HR 1.75, 95% CI 1.01-1.06, p = 0.04), but this was not the case for individual CEs. Using Fine and Gray models to account for the competing risk of death, left main coronary maximum dose was associated with atrial fibrillation (p = 0.024), proximal right coronary artery V15 (p = 0.023) and mean dose (p = 0.032), and the right atrium mean dose (p = 0.029) were associated with heart failure. No dose-volume metrics were significantly associated with acute coronary syndrome. None of the constituent base substructures dose were significantly associated with death.

CONCLUSION

Dose to the heart base was associated with increased mortality and an increased pooled cardiac event rate. Accounting for endpoint-specific clinical covariates, only select constituent substructures of the heart base were associated with CEs and no substructures were independently associated with survival. Together, these findings are suggestive of possible interplay between the constituent base substructures in their mediation of radiation cardiotoxicity.

Genicular Artery Embolisation in Patients with Osteoarthritis of the Knee (GENESIS 2): Protocol for a Double-Blind Randomised Sham-Controlled Trial

Knee osteoarthritis is a leading cause of chronic disability and economic burden. In many patients who are not surgical candidates, existing treatment options are insufficient. Clinical evidence for a new treatment approach, genicular artery embolisation (GAE), is currently limited to single arm cohort, or small population randomised studies. This trial will investigate the use of a permanent embolic agent for embolisation of abnormal genicular arterial vasculature to reduce pain in patients with mild to moderate knee osteoarthritis. Up to 110 participants, 45 years or older, with knee pain for ≥ 3 months resistant to conservative treatment will be randomised (1:1) to GAE or a sham procedure. The treatment group will receive embolisation using 100-micron Embozene™ microspheres (Varian, a Siemens Healthineers Company) (investigational use for this indication in the UK), and the sham group will receive 0.9% saline in an otherwise identical procedure. Patients will be followed for 24 months. At 6 months, sham participants will be offered crossover to GAE. The primary endpoint is change of 4 Knee Injury and OA Outcome Score subscales (KOOS4) at 6 months post-randomisation. The study will also evaluate quality of life, health economics, imaging findings, and psychosocial pain outcomes. The primary manuscript will be submitted for publication after all participants complete 6 months of follow-up. The trial is expected to run for 3.5 years. Trial Registration: ClinicalTrials.gov, Identifier: NCT05423587.

Abstract PD3-04: Locoregional Stereotactic Body Radiotherapy in Breast Cancer Patients Unsuitable for Surgical Resection

Purpose: Breast cancer (BC) patients (pts) who are not surgical candidates or decline surgical resection are usually managed with palliative systemic therapy alone or palliative radiotherapy if clinically appropriate. Stereotactic body radiotherapy (SBRT) has shown excellent results for different primary malignancies, and we hypothesized it could improve outcomes in this context with acceptable toxicity. This study aims to assess the local control (LC) and toxicity rates of breast SBRT in pts unsuitable for surgical resection. Methods and Materials: We performed a retrospective analysis using an institutional registry of all BC pts unsuitable for resection who underwent breast and/or regional lymph node (LN) SBRT to a dose of 35-40 Gy in 5 fractions from 2014 to 2021. Patients were deemed unsuitable for resection if they were medically inoperable, declined surgery, had unresectable tumors, or where surgery was not appropriate, such as due to metastatic disease. The primary endpoint was LC (defined as no evidence of progression of the treated lesion as per RECIST 1.1 criteria) and toxicity grade ≥ 3 (as per CTCAE v5.0). Secondary endpoints included radiological response (RR) of the target tumor at the last follow-up, progression-free survival (PFS), and overall survival (OS). All endpoints were assessed per course of treatment, with death as a competing factor for LC. Results: This study included 61 treatment courses in 57 pts. The median age was 81 years (range 38-99), 74% being older than 70 years of age. Eighteen percent had stage I-II, 44% stage III, and 38% stage IV disease. Unresectable tumor (10%), patient refusal (18%), medically inoperability (34%), and metastatic disease (38%) were the main causes of not having surgery. The molecular subtypes were HER-2 in 3%, basal-like 23%, and luminal disease 74%. Previous systemic treatment consisted of endocrine therapy (ET) alone (49%), chemotherapy (CT) or target therapy (TT) alone (11%), both ET and CT/TT (18%), or none (21%). Seventy-two percent of tumors were progressing on ET (44%) or CT/TT (28%) at the time of SBRT. The median interval from cancer diagnosis to SBRT was 14.6 (range 0.5-180) months (mos). Fifty-four percent had breast SBRT, 15% LN SBRT, and 31% both. For LN treatment, axillary, internal mammary, and supraclavicular nodes were the target in 43%, 3%, and 2% of treatments, respectively. The median clinical and radiological follow-up was 16.8 (range 0.2-87) and 13.4 mos (range 1-81), respectively. The worst acute and late grade ≥ 3 toxicity was 16% and 4%, respectively, and all cases consisted of radiation dermatitis. No patient was unable to complete treatment due to acute toxicity. There was one case of grade 4 skin necrosis 6.3 mos after 35 Gy in 5 fractions to an axillary LN. The LC rate at 1 year was 100% and 2 years 88.6% (95% CI = 79-99%). The median time to local progression among those who progressed was 18.2 mos (95% CI = 12-not reached). At last FU, the RR of treated tumors was: complete response = 8%, partial response = 46%, stable disease = 38%, and progressive disease = 8%. The PFS and OS rates at 1 year was 69.8 % (95% CI = 58-82) and 74.6% (95% IC = 63-86), 2 years 39.1% (95% CI = 26—52) and 50.6% (95% IC = 36-65), 3 years 26.7 % (95% CI =14-39) and 38.7% (95% IC = 24-54), and 4 years 18.5 % (95% CI = 8-29) and 29.2% (95% CI = 14-44), respectively. The median PFS was 21.7 mos (95% CI = 17-28) and OS 31.1 mos (95% CI = 21- 38). Ongoing analysis intends to identify clinical and pathological predictors of LC, PFS, and OS. Conclusion: Our initial data suggest that breast SBRT safely provides excellent LC rates in non-operable BC pts. This approach may be a treatment option in pts who are not good surgical candidates, particularly in elderly pts with multiple comorbidities, which comprised 74% of our cohort. A clinical trial is underway to determine the optimal dose and side effect profile for primary breast SBRT with curative intent in pts not undergoing definitive surgery.

Citation Format: Daniel Palhares, Hanbo Chen, Benazir Khan, Claire McCann, Sandi Bosnic, Ezra Hahn, Hany Soliman, Eileen Rakovitch, Justin Lee, Danny Vesprini. Locoregional Stereotactic Body Radiotherapy in Breast Cancer Patients Unsuitable for Surgical Resection [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD3-04.

FLASH Radiotherapy for the Treatment of Symptomatic Bone Metastases (FAST-01): Protocol for the First Prospective Feasibility Study

BACKGROUND

In preclinical studies, FLASH therapy, in which radiation delivered at ultrahigh dose rates of ≥40 Gy per second, has been shown to cause less injury to normal tissues than radiotherapy delivered at conventional dose rates. This paper describes the protocol for the first-in-human clinical investigation of proton FLASH therapy.

OBJECTIVE

FAST-01 is a prospective, single-center trial designed to assess the workflow feasibility, toxicity, and efficacy of FLASH therapy for the treatment of painful bone metastases in the extremities.

METHODS

Following informed consent, 10 subjects aged ≥18 years with up to 3 painful bone metastases in the extremities (excluding the feet, hands, and wrists) will be enrolled. A treatment field selected from a predefined library of plans with fixed field sizes (from 7.5 cm × 7.5 cm up to 7.5 cm × 20 cm) will be used for treatment. Subjects will receive 8 Gy of radiation in a single fraction-a well-established palliative regimen evaluated in prior investigations using conventional dose rate photon radiotherapy. A FLASH-enabled Varian ProBeam proton therapy unit will be used to deliver treatment to the target volume at a dose rate of ≥40 Gy per second, using the plateau (transmission) portion of the proton beam. After treatment, subjects will be assessed for pain response as well as any adverse effects of FLASH radiation. The primary end points include assessing the workflow feasibility and toxicity of FLASH treatment. The secondary end point is pain response at the treated site(s), as measured by patient-reported pain scores, the use of pain medication, and any flare in bone pain after treatment. The results will be compared to those reported historically for conventional dose rate photon radiotherapy, using the same radiation dose and fractionation.

RESULTS

FAST-01 opened to enrollment on November 3, 2020. Initial results are expected to be published in 2022.

CONCLUSIONS

The results of this investigation will contribute to further developing and optimizing the FLASH-enabled ProBeam proton therapy system workflow. The pain response and toxicity data acquired in our study will provide a greater understanding of FLASH treatment effects on tumor responses and normal tissue toxicities, and they will inform future FLASH trial designs.

TRIAL REGISTRATION

: ClinicalTrials.gov NCT04592887; http://clinicaltrials.gov/ct2/show/NCT04592887.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41812.

Proton FLASH Radiotherapy for the Treatment of Symptomatic Bone Metastases: The FAST-01 Nonrandomized Trial

Importance

To our knowledge, there have been no clinical trials of ultra-high-dose-rate radiotherapy delivered at more than 40 Gy/sec, known as FLASH therapy, nor first-in-human use of proton FLASH.

Objectives

To assess the clinical workflow feasibility and treatment-related toxic effects of FLASH and pain relief at the treatment sites.

Design, Setting, and Participants

In the FAST-01 nonrandomized trial, participants treated at Cincinnati Children's/UC Health Proton Therapy Center underwent palliative FLASH radiotherapy to extremity bone metastases. Patients 18 years and older with 1 to 3 painful extremity bone metastases and life expectancies of 2 months or more were eligible. Patients were excluded if they had foot, hand, and wrist metastases; metastases locally treated in the 2 weeks prior; metal implants in the treatment field; known enhanced tissue radiosensitivity; and implanted devices at risk of malfunction with radiotherapy. One of 11 patients who consented was excluded based on eligibility. The end points were evaluated at 3 months posttreatment, and patients were followed up through death or loss to follow-up for toxic effects and pain assessments. Of the 10 included patients, 2 died after the 2-month follow-up but before the 3-month follow-up; 8 participants completed the 3-month evaluation. Data were collected from November 3, 2020, to January 28, 2022, and analyzed from January 28, 2022, to September 1, 2022.

Interventions

Bone metastases were treated on a FLASH-enabled (≥40 Gy/sec) proton radiotherapy system using a single-transmission proton beam. This is consistent with standard of care using the same prescription (8 Gy in a single fraction) but on a conventional-dose-rate (approximately 0.03 Gy/sec) photon radiotherapy system.

Main Outcome and Measures

Main outcomes included patient time on the treatment couch, device-related treatment delays, adverse events related to FLASH, patient-reported pain scores, and analgesic use.

Results

A total of 10 patients (age range, 27-81 years [median age, 63 years]; 5 [50%] male) underwent FLASH radiotherapy at 12 metastatic sites. There were no FLASH-related technical issues or delays. The average (range) time on the treatment couch was 18.9 (11-33) minutes per patient and 15.8 (11-22) minutes per treatment site. Median (range) follow-up was 4.8 (2.3-13.0) months. Adverse events were mild and consistent with conventional radiotherapy. Transient pain flares occurred in 4 of the 12 treated sites (33%). In 8 of the 12 sites (67%) patients reported pain relief, and in 6 of the 12 sites (50%) patients reported a complete response (no pain).

Conclusions and Relevance

In this nonrandomized trial, clinical workflow metrics, treatment efficacy, and safety data demonstrated that ultra-high-dose-rate proton FLASH radiotherapy was clinically feasible. The treatment efficacy and the profile of adverse events were comparable with those of standard-of-care radiotherapy. These findings support the further exploration of FLASH radiotherapy in patients with cancer.

Trial Registration

ClinicalTrials.gov Identifier: NCT04592887.

Patterns of Care, Tolerability, and Safety of the First Cohort of Patients Treated on a Novel High-Field MR-Linac Within the MOMENTUM Study: Initial Results From a Prospective Multi-Institutional Registry

PURPOSE

High-field magnetic resonance-linear accelerators (MR-Linacs), linear accelerators combined with a diagnostic magnetic resonance imaging (MRI) scanner and online adaptive workflow, potentially give rise to novel online anatomic and response adaptive radiation therapy paradigms. The first high-field (1.5T) MR-Linac received regulatory approval in late 2018, and little is known about clinical use, patient tolerability of daily high-field MRI, and toxicity of treatments. Herein we report the initial experience within the MOMENTUM Study (NCT04075305), a prospective international registry of the MR-Linac Consortium.

METHODS AND MATERIALS

Patients were included between February 2019 and October 2020 at 7 institutions in 4 countries. We used descriptive statistics to describe the patterns of care, tolerability (the percentage of patients discontinuing their course early), and safety (grade 3-5 Common Terminology Criteria for Adverse Events v.5 acute toxicity within 3 months after the end of treatment).

RESULTS

A total 943 patients participated in the MOMENTUM Study, 702 of whom had complete baseline data at the time of this analysis. Patients were primarily male (79%) with a median age of 68 years (range, 22-93) and were treated for 39 different indications. The most frequent indications were prostate (40%), oligometastatic lymph node (17%), brain (12%), and rectal (10%) cancers. The median number of fractions was 5 (range, 1-35). Six patients discontinued MR-Linac treatments, but none due to an inability to tolerate repeated high-field MRI. Of the 415 patients with complete data on acute toxicity at 3-month follow-up, 18 (4%) patients experienced grade 3 acute toxicity related to radiation. No grade 4 or 5 acute toxicity related to radiation was observed.

CONCLUSIONS

In the first 21 months of our study, patterns of care were diverse with respect to clinical utilization, body sites, and radiation prescriptions. No patient discontinued treatment due to inability to tolerate daily high-field MRI scans, and the acute radiation toxicity experience was encouraging.

631 The Time to Therapeutic Serum Levels of Vancomycin in Orthopaedic Patients

Introduction

Vancomycin is a commonly used antibiotic in the treatment of deep-seated infections. However, the current dosing calculator utilized in NHS Lothian may not adequately achieve therapeutic vancomycin serum concentrations (VSC), of 15-20mg/L, in a timely manner. We aimed to reaudit the length of time for vancomycin to reach therapeutic levels in orthopaedic patients using the new Lothian calculator. A previous audit loop looked at the current calculator in 2018.

Method

Inclusion criteria orthopaedic patients who were treated with vancomycin at the Royal Infirmary Edinburgh, data collection to finish mid-September. The duration to reach the therapeutic SVC, initial trough SVC and serial levels were recorded. A life-table analysis will be used to examine the data.

Results

First audit had Twenty-three patients. The mean initial trough VSC was 12.7mg/L. The mean duration to therapeutic VSC was 5.2 (± 1.3) days. Statistics not completed for second cycle, but initial data shows improvement in time to VSC.

Conclusions

A delay in reaching therapeutic concentrations was observed in a significant proportion of patients using the current calculator. A more rapid achievement of therapeutic levels is required to maximize the period of antibiotic delivery and subsequently improve patient outcomes. The new calculator pilot will hopefully show that improvement.

944 ‘A Series of Unfortunate Fractures’: Utilising Opportunities Brought About By COVID-19 To Create A National Online Educational Series

Background

The Covid-19 pandemic has disrupted the training and education of Junior Doctors. Physical restrictions have highlighted the potential use of remote online platforms to deliver teaching. We aimed to create and deliver a free educational series for Junior Doctors, delivered by Orthopaedic Registrars and Consultants through an interactive online platform.

Method

Teaching material, learning aims, and advertisement tools including mailing lists were developed. Advertisement was arranged on national scale via the British Orthopaedic Association (BOA) and the British Orthopaedic Trainees Association (BOTA). Six sessions were delivered via the ‘Blackboard Collaborate’ platform.

Results

Six sessions were held over six weeks with 546 total attendees, averaging 92 per session. Foundation Doctors and Medical Students accounted for 39.7% and 54.0% of attendees respectively. Attendees were primarily from the UK (90.1%). Average attendee rating for ‘enjoyment of session’ and ‘relevance to education’ was 9.11/10 and 8.66/10 respectively. Of those surveyed, 100% of attendees reported they would recommend this series to a colleague.

Discussion:

This lecture series was created in response to the restrictions on physical meetings and reduced teaching opportunities during the Covid-19 pandemic. High attendance and overwhelmingly positive feedback from this series supports the use of online teaching for the future of Post-graduate education.

441 Intravenous Tranexamic Acid Given at Femoral Fragility Fracture Surgery Reduces Blood Transfusion Requirements Four-Fold

Introduction

Tranexamic acid (TXA) is proven to reduce blood loss in several surgical fields, but its use in femoral fragility fracture (FFF) management is ill defined. This study examined the effect of intraoperative TXA on the rate of postoperative blood transfusion following FFF.

Method

A prospective non-randomized case-control study of 361 consecutive patients admitted to the study centre with FFFs over a 4-month period was performed. Intravenous TXA 1g was administered intraoperatively at the discretion of the operating team: 178 patients received TXA and 183 did not.

Results

Patients given TXA required fewer blood transfusions: 15/178 (8.4%) vs controls 58/183 (31.7%), (p &lt; 0.001). Calculated blood loss (mean difference -222ml (-337 to -106, 95%CI), p &lt; 0.001) and percentage drop in Hb (mean difference -4.3% (-6.3 to -2.3, 95%CI), p &lt; 0.001) were significantly lower in the TXA group. The difference in CBL was greatest following intramedullary nail (n = 49: mean difference -394ml, p = 0.030) and DHS (n = 101, mean difference -216ml, p = 0.032). There was no significant difference in complication rates: venous thromboembolism TXA 2/178 vs control 1/182 (p = 0.620); MI/stroke/TIA 2/178 vs 0/182 (p = 0.244)

Conclusions

Intraoperative intravenous TXA significantly reduced calculated blood loss and blood transfusion requirements following femoral fragility fracture surgery without increasing the rate of complications.

989 Improving the Completion of Hospital Anticipatory Care Plans in Orthopaedic Trauma Wards During The COVID-19 Pandemic

Background

The COVID-19 pandemic has highlighted the importance of the Hospital Anticipatory Care Plan (HACP). New guidance recommends all patients admitted acutely to hospital should have a HACP completed within 24 hours. We aimed to assess how many orthopaedic trauma patients admitted to the study centre had HACP completed within 24 hours of admission.

Method

Departmental Quality Improvement Project (QIP) permission was granted, and standard audit protocol was utilised. Data were collected in a retrospective manner using our trauma database and online patient record system. Educational interventions including staff teaching sessions and dissemination of infographic posters were implemented. Cycle two was repeated in similar fashion.

Results

Cycle one (50 patients): 37/50(74%) had HACPs completed. Of those with HACPs, 18/37(49%) were completed within 24 hours. Median time to completion was 45.3 hours (range 0.4-275.1 hours). Cycle two (58 patients): HACP completion significantly improved (56/58, 97%; p &lt; 0.01), with more completed within 24 hours (50/56, 89%; p &lt; 0.01). The median time to completion was decreased to 4.92 hours (range 0.27-60.6; p &lt; 0.01).

Conclusions

Unit compliance was initially poor however significantly improved with educational measures. Failing to identify ceilings of care early can result in difficult decisions having to be made in critical situations, risking suboptimal patient care.

896 Improving Intravenous Fluid Therapy to Reduce the Incidence of Acute Kidney Injury in Hip Fracture Patients

Background

Acute kidney injury (AKI) in hip fracture patients is associated with morbidity, mortality, and increased length of stay. To avoid this our unit policy recommends maintenance crystalloid IV fluids of &gt; 62.5mL/Hr for hip fracture patients.

Method

Three prospective audits, each including 100 consecutive acute hip fracture patients, were completed with interventional measures employed between each cycle. Data collection points included details of IV fluid administration and pre/post-operative presence of AKI. Interventions between cycles included implementation of admission/post-take checklist tools and various educational measures for Emergency Department, nursing and admitting team staff with dissemination of infographic posters, respectively.

Results

In cycle one and two, many patients received inadequate fluids (46/100 and 56/100 respectively). There was no significant difference in the incidence of AKI between patients receiving adequate or inadequate fluid in either cycle (p &lt; 0.05).

In cycle three, more patients received adequate fluids (79/100, p &lt; 0.05). Patients prescribed adequate fluids were less likely to develop post-operative AKI (2/79, 2.5% vs 3/21, 14.3%; p &lt; 0.05).

Discussion

This audit demonstrates the importance of administering appropriate IV fluid in hip fracture patients to avoid AKI. Improving coordination with Emergency Department and ward nursing/medical ward staff was a critical step in improving our unit’s adherence to policy.

113 Improving Intravenous Fluid Therapy to Reduce the Incidence of Acute Kidney Injury in Elderly Hip Fracture Patients

Background

Acute kidney injury (AKI) in hip fracture patients is associated with morbidity, mortality, and increased length of stay. To avoid this our unit policy recommends maintenance crystalloid IV fluids of &gt;62.5 mL/Hr for hip fracture patients. However, audits have shown that many patients still receive inadequate IV fluids.

Methods

Three prospective audits, each including 100 consecutive acute hip fracture patients aged &gt;55, were completed with interventional measures employed between each cycle. Data collection points included details of IV fluid administration and pre/post-operative presence of AKI. Interventions between cycles included a revised checklist for admissions with a structured ward round tool for post-take ward round and various educational measures for Emergency Department, nursing and admitting team staff with dissemination of infographic posters, respectively.

Results

Cycle 1: 64/100 (64%) patients received adequate fluids. No significant difference in developing AKI post operatively was seen in patients given adequate fluids (2/64, 3.1%) compared to inadequate fluids (4/36, 11.1%; p = 0.107). More patients with pre-operative AKI demonstrated resolution of AKI with appropriate fluid prescription (5/6, 83.3%, vs 0/4, 0%, p &lt; 0.05) Cycle 2: Fewer patients were prescribed adequate fluids (54/100, 54%). There was no significant difference in terms of developing AKI post operatively between patients with adequate fluids (4/54, 7.4%) or inadequate fluids (2/46, 4.3%; p = 0.52). Resolution of pre-operative AKI was similar in patients with adequate or inadequate fluid administration (4/6, 67% vs 2/2, 100%). Cycle 3: More patients received adequate fluids (79/100, 79%, p &lt; 0.05). Patients prescribed adequate fluids were less likely to develop post-operative AKI than those receiving inadequate fluids (2/79, 2.5% vs 3/21, 14.3%; p &lt; 0.05).

Discussion

This audit demonstrates the importance of administering appropriate IV fluid in hip fracture patients to avoid AKI. Improving coordination with Emergency Department and ward nursing/medical ward staff was a critical step in improving our unit’s adherence to policy.

The MOMENTUM Study: An International Registry for the Evidence-Based Introduction of MR-Guided Adaptive Therapy

Purpose: MR-guided Radiation Therapy (MRgRT) allows for high-precision radiotherapy under real-time MR visualization. This enables margin reduction and subsequent dose escalation which may lead to higher tumor control and less toxicity. The Unity MR-linac (Elekta AB, Stockholm, Sweden) integrates a linear accelerator with a 1.5T diagnostic quality MRI and an online adaptive workflow. A prospective international registry was established to facilitate the evidence-based implementation of the Unity MR-linac into clinical practice, to systemically evaluate long-term outcomes, and to aid further technical development of MR-linac-based MRgRT. Methods and Results: In February 2019, the Multi-OutcoMe EvaluatioN of radiation Therapy Using the MR-linac study (MOMENTUM) started within the MR-linac Consortium. The MOMENTUM study is an international academic-industrial partnership between several hospitals and industry partner Elekta. All patients treated on the MR-linac are eligible for inclusion in MOMENTUM. For participants, we collect clinical patient data (e.g., patient, tumor, and treatment characteristics) and technical patient data which is defined as information generated on the MR-linac during treatment. The data are captured, pseudonymized, and stored in an international registry at set time intervals up to two years after treatment. Patients can choose to provide patient-reported outcomes and consent to additional MRI scans acquired on the MR-linac. This registry will serve as a data platform that supports multicenter research investigating the MR-linac. Rules and regulations on data sharing, data access, and intellectual property rights are summarized in an academic-industrial collaboration agreement. Data access rules ensure secure data handling and research integrity for investigators and institutions. Separate data access rules exist for academic and industry partners. This study is registered at ClinicalTrials.gov with ID: NCT04075305 (https://clinicaltrials.gov/ct2/show/NCT04075305). Conclusion: The multi-institutional MOMENTUM study has been set up to collect clinical and technical patient data to advance technical development, and facilitate evidenced-based implementation of MR-linac technology with the ultimate purpose to improve tumor control, survival, and quality of life of patients with cancer.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Outcomes of emergency laparotomy in patients on extracorporeal membrane oxygenation for severe respiratory failure: A retrospective, observational cohort study

PURPOSE

There is a paucity of literature to support undertaking emergency laparotomy when indicated in patients supported on ECMO. Our study aims to identify the prevalence, outcomes and complications of this high risk surgery at a large ECMO centre.

MATERIALS AND METHODS

A single centre, retrospective, observational cohort study of 355 patients admitted to a university teaching hospital Severe Respiratory Failure service between December 2011 and January 2017.

RESULTS

The prevalence of emergency laparotomy in patients on ECMO was 3.7%. These patients had significantly higher SOFA and APACHE II scores compared to similar patients not requiring laparotomy. There was no difference in the duration of ECMO or intensive care unit (ICU) stay post decannulation between the two groups. 31% of laparotomy patients survived to hospital discharge. Major haemorrhage was uncommon, however emergency change of ECMO oxygenator was commonly required.

CONCLUSION

Survival to hospital discharge is possible following emergency laparotomy on ECMO, however the mortality is higher than for those patients not requiring laparotomy, this likely reflects the severity of underlying organ failure rather than the surgery itself. Our service's collocation with a general surgical service has made this development in care possible. ECMO service planning should consider general surgical provision.

Patient-reported functional outcomes and health-related quality of life following fractures of the talus

INTRODUCTION

The primary aim of this study was to investigate patient-reported outcomes following talar fractures. Secondary aims were to investigate health-related quality of life and to determine whether it is influenced by functional outcome.

MATERIALS AND METHODS

This retrospective study identified 56 talar fractures over eight years. Patients were contacted by post and the Olerud and Molander score (OMS), Manchester-Oxford Foot and Ankle scores (MOXFQ) and Euroqol-5D-3L collected.

RESULTS

The mean age was 35.2 years (range 13-78 years). There were four cases (7.1%) of avascular necrosis and one (1.8%) non-union occurred. Data from patient-reported outcome measures were available for 42 patients (75.0%) with a median follow-up of 67.1 months (range 23.2-111.8 months). Mean OMS was 60.0 (standard deviation ± 29.51) and median MOXFQ was 30.33 (interquartile range 47.13). Median Euroqol-5D-3L index was 0.74 (interquartile range 0.213) and median Euroqol-5D-3L visual analogue score was 80 (interquartile range 21). Older age, open fractures, multiple injuries and subsequent avascular necrosis were associated with worse patient-reported outcomes (P < 0.05), with older age, avascular necrosis and open fractures found to be independent predictors of poor OMS, and avascular necrosis and open fractures independently predicting MOXFQ score on regression analysis (P < 0.05). Poor self-reported function, measured by OMS and MOXFQ, correlated with worse health-related quality of life as measured by the Euroqol-5D-3L index (OMS: r = 0.764, P < 0.001; MOXFQ: r = 0.824, P < 0.001) and visual analogue score (OMS: r = 0.450, P = 0.003; MOXFQ: r=0.559, P < 0.001).

CONCLUSIONS

Older age, avascular necrosis and open fractures predict poorer functional outcomes following talar fractures. Patients with worse limb-specific functional outcomes are more likely to have a worse perception of health-related quality of life.

Barriers and facilitators to the successful development, implementation and evaluation of care bundles in acute care in hospital: a scoping review

Background

Care bundles are small sets of evidence-based recommendations, designed to support the implementation of evidence-based best clinical practice. However, there is variation in the design and implementation of care bundles, which may impact on the fidelity of delivery and subsequently their clinical effectiveness.

Methods

A scoping review was carried out using the Arksey and O’Malley framework to identify the literature reporting on the design, implementation and evaluation of care bundles. The Embase, CINAHL, Cochrane and Ovid MEDLINE databases were searched for manuscripts published between 2001 and November 2017; hand-searching of references and citations was also undertaken. Data were initially assessed using a quality assessment tool, the Downs and Black checklist, prior to further analysis and narrative synthesis. Implementation strategies were classified using the Expert Recommendations for Implementing Change (ERIC) criteria.

Results

Twenty-eight thousand six hundred ninety-two publications were screened and 348 articles retrieved in full text. Ninety-nine peer-reviewed quantitative publications were included for data extraction. These consisted of one randomised crossover trial, one randomised cluster trial, one case-control study, 20 prospective cohort studies and 76 non-parallel cohort studies. Twenty-three percent of studies were classified as poor based on Downs and Black checklist, and reporting of implementation strategies lacked structure.

Negative associations were found between the number of elements in a bundle and compliance (Spearman’s rho = − 0.47, non-parallel cohort and − 0.65, prospective cohort studies), and between the complexity of elements and compliance (p < 0.001, chi-squared = 23.05). Implementation strategies associated with improved compliance included evaluative and iterative approaches, development of stakeholder relationships and education and training strategies.

Conclusion

Care bundles with a small number of simple elements have better compliance rates. Standardised reporting of implementation strategies may help to implement care bundles into clinical practice with high fidelity.

Trial Registration

This review was registered on the PROSPERO database: CRD 42015029963 in December 2015.

Electronic supplementary material

The online version of this article (10.1186/s13012-019-0894-2) contains supplementary material, which is available to authorized users.

Transcriptional subtyping and CD8 immunohistochemistry identifies poor prognosis stage II/III colorectal cancer patients who benefit from adjuvant chemotherapy

Purpose

Transcriptomic profiling of colorectal cancer (CRC) has led to the identification of four consensus molecular subtypes (CMS1 to 4) that have prognostic value in stage II and III disease. More recently, the Colorectal Cancer Intrinsic Subtypes (CRIS) classification system has helped to define the biology specific to the epithelial component of colorectal tumors; however, the clinical value of these classification systems in the prediction of response to standard-of-care adjuvant chemotherapy remains unknown.

Patients and Methods

Using samples from four European sites, we assembled a novel cohort of patients with stage II and III CRC (n = 156 samples) and performed transcriptomic profiling and targeted sequencing and generated a tissue microarray to enable integrated multiomics analyses. We also accessed data from two published cohorts of patients with stage II and III CRC: GSE39582 and GSE14333 (n = 479 and n = 185 samples, respectively).

Results

The epithelial-rich CMS2 subtype of CRC benefitted significantly from treatment with adjuvant chemotherapy in both stage II and III disease (P = .02 and P < .001, respectively), whereas the CMS3 subtype significantly benefitted in stage III only (P = .001). After CRIS substratification of CMS2, we observed that only the CRIS-C subtype significantly benefitted from treatment with adjuvant chemotherapy in stage II and III disease (P = .0081 and P < .001, respectively), whereas the CRIS-D subtype significantly benefitted in stage III only (P = .0034). We also observed that CRIS-C patients with low levels of CD8⁺ tumor-infiltrating lymphocytes were most at risk for relapse in both stage II and III disease (log-rank P = .0031; hazard ratio, 12.18 [95% CI, 1.51 to 98.58]).

Conclusion

Patient stratification using a combination of transcriptional subtyping and CD8 immunohistochemistry analyses is capable of identifying patients with poor prognostic stage II and III disease who benefit from adjuvant standard-of-care chemotherapy. These findings are particularly relevant for patients with stage II disease, where the overall benefit of adjuvant chemotherapy is marginal.

Radiotherapy for patients with unresected locally advanced breast cancer

BACKGROUND

Management of locally-advanced breast cancer is determined by multiple factors, but in patients without distant metastases often involves neoadjuvant systemic therapy, surgery and radiation. If the primary tumour remains unresectable following systemic therapy, radiotherapy may be used for tumour shrinkage prior to surgery. When metastatic disease is present, locoregional radiotherapy is generally reserved for management of tumour-related symptoms. We reviewed our experience of high-dose radiotherapy for unresected locally-advanced breast cancer.

METHODS

A retrospective chart review was conducted of patients with unresected locally advanced breast cancer (LABC) receiving external beam radiotherapy to the breast, chest wall and/or regional lymph nodes. Patients were stratified based on the presence of metastatic disease at presentation. Patient demographics, disease characteristics, and treatment outcomes were recorded.

RESULTS

Forty-three cases were analyzed between 2004 and 2016. Median follow-up was 25 months from diagnosis and 14 months from completion of radiotherapy. There were 24 cases (56%) with metastatic disease on presentation, and 19 (44%) without. Tumour shrinkage occurred within 3 months of completing radiotherapy in 36 cases (84%). Ulceration and bleeding improved following radiotherapy in 13 (54%) of the 24 applicable cases. Twenty-six patients (60%) developed moist desquamation but none experienced grade 4 or 5 radiation dermatitis. Median locoregional progression-free survival for all patients was 12 months from completion of radiotherapy. Locoregional progression-free survival (P=0.2) and overall survival (OS) (P=0.4) were not significantly different between patients with and without distant metastases at presentation.

CONCLUSIONS

Radiotherapy provided good response and symptom control in most patients in this study; there is a role for palliative radiotherapy in patients with LABC.

A qualitative exploration of techniques used by expert midwives to preserve the perineum intact

BACKGROUND

The perineum stretches during birth to allow passage of the baby, but 85% of women sustain some degree of perineal trauma during childbirth, which is painful post-partum. Episiotomy rates vary significantly, with some countries having rates of >60%. Recent Irish and New Zealand studies showed lower severe perineal trauma and episiotomy rates than other countries.

AIM

To explore expert Irish and New Zealand midwives' views of the skills that they employ in preserving the perineum intact during spontaneous vaginal birth.

METHODS

Following ethical approval a qualitative, descriptive study was undertaken. Semi-structured, recorded, interviews were transcribed and analysed using the constant comparative method. Expert midwives employed in New Zealand and one setting in Ireland, were invited to join the study. "Expert" was defined as achieving, in the preceding 3.5 years, an episiotomy rate for nulliparous women of <11.8%, a 'no suture' rate of 40% or greater, and a severe perineal tear rate of <3.2%. Twenty-one midwives consented to join the study.

RESULTS

Four core themes emerged: 'Calm, controlled birth', 'Position and techniques in early second stage', 'Hands on or off?' and 'Slow, blow and breathe the baby out.' Using the techniques described enabled these midwives to achieve rates, in nulliparous women, of 3.91% for episiotomy, 59.24% for 'no sutures', and 1.08% for serious lacerations.

CONCLUSIONS

This study provides further understanding of the techniques used by expert midwives at birth. These findings, combined with existing quantitative research, increases the evidence on how to preserve the perineum intact during spontaneous birth.

Tram system related cycling injuries

INTRODUCTION

Understanding of tram-system related cycling injuries (TSRCI) is poor. The aim of this study was to report the spectrum of injuries, demographics and social deprivation status of patients. Secondary aims included assessment of accident circumstances, effects of TSRCI on patients' confidence cycling, together with time off work and cycling.

METHODS

A retrospective review of patients presenting to emergency services across all hospitals in Edinburgh and West Lothian with tram related injuries between May 2009 and April 2016 was undertaken. Medical records and imagining were analysed and patients were contacted by telephone.

RESULTS

191 cyclists (119 males, 72 females) were identified. 63 patients sustained one or more fractures or dislocations. Upper limb fractures/dislocations occurred in 55, lower limb fractures in 8 and facial fractures in 2. Most patients demonstrated low levels of socioeconomic deprivation. In 142 cases, the wheel was caught in tram-tracks, while in 32 it slid on tracks. The latter occurred more commonly in wet conditions (p = 0.028). 151 patients answered detailed questionnaires. Ninety-eight were commuting. 112 patients intended to cross tramlines and 65 accidents occurred at a junction. Eighty patients reported traffic pressures contributed to their accident. 120 stated that their confidence was affected and 24 did not resume cycling. Female gender (p < 0.001) and presence of a fracture/dislocation (p = 0.012) were independent predictors of negative effects on confidence. Patients sustaining a fracture/dislocation spent more time off work (median 5 days vs 1, p < 0.001) and cycling (median 57 days vs 21, p < 0.001).

CONCLUSIONS

TSRCI occur predominantly in young to middle-aged adults with low levels of socioeconomic deprivation, most commonly when bicycle wheels get caught in tram-tracks. They result in various injuries, frequently affecting the upper limb. Traffic pressures are commonly implicated. Most patients report negative effects on confidence and a sizeable minority do not resume cycling. TSRCI can result in significant loss of working and cycling days.

The development of a 4D treatment planning methodology to simulate the tracking of central lung tumors in an MRI-linac

PURPOSE

Targeting and tracking of central lung tumors may be feasible on the Elekta MRI-linac (MRL) due to the soft-tissue visualization capabilities of MRI. The purpose of this work is to develop a novel treatment planning methodology to simulate tracking of central lung tumors with the MRL and to quantify the benefits in OAR sparing compared with the ITV approach.

METHODS

Full 4D-CT datasets for five central lung cancer patients were selected to simulate the condition of having 4D-pseudo-CTs derived from 4D-MRI data available on the MRL with real-time tracking capabilities. We used the MRL treatment planning system to generate two plans: (a) with a set of MLC-defined apertures around the target at each phase of the breathing ("4D-MRL" method); (b) with a fixed set of fields encompassing the maximum inhale and exhale of the breathing cycle ("ITV" method). For both plans, dose accumulation was performed onto a reference phase. To further study the potential benefits of a 4D-MRL method, the results were stratified by tumor motion amplitude, OAR-to-tumor proximity, and the relative OAR motion (ROM).

RESULTS

With the 4D-MRL method, the reduction in mean doses was up to 3.0 Gy and 1.9 Gy for the heart and the lung. Moreover, the lung's V12.5 Gy was spared by a maximum of 300 cc. Maximum doses to serial organs were reduced by up to 6.1 Gy, 1.5 Gy, and 9.0 Gy for the esophagus, spinal cord, and the trachea, respectively. OAR dose reduction with our method depended on the tumor motion amplitude and the ROM. Some OARs with large ROMs and in close proximity to the tumor benefited from tracking despite small tumor amplitudes.

CONCLUSIONS

We developed a novel 4D tracking methodology for the MRL for central lung tumors and quantified the potential dosimetric benefits compared with our current ITV approach.

Magnetic field dose effects on different radiation beam geometries for hypofractionated partial breast irradiation

PURPOSE

Hypofractionated partial breast irradiation (HPBI) involves treatment to the breast tumor using high doses per fraction. Recent advances in MRI-Linac solutions have potential in being applied to HPBI due to gains in the soft tissue contrast of MRI; however, there are potentially deleterious effects of the magnetic field on the dose distribution. The purpose of this work is to determine the effects of the magnetic field on the dose distribution for HPBI tumors using a tangential beam arrangement (TAN), 5-beam intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT).

METHODS

Five patients who have received HPBI were selected with two patients having bilateral disease resulting in a total of two tumors in this study. Six planning configurations were created using a treatment planning system capable of modeling magnetic field dose effects: TAN, IMRT and VMAT beam geometries, each of these optimized with and without a transverse magnetic field of 1.5 T.

RESULTS

The heart and lung doses were not statistically significant when comparing plan configurations. The magnetic field had a demonstrated effect on skin dose: for VMAT plans, the skin (defined to a depth of 3 mm) D1cc was elevated by +11% and the V30 by +146%; for IMRT plans, the skin D1cc was increased by +18% and the V30 by +149%. Increasing the number of beam angles (e.g., going from IMRT to VMAT) with the magnetic field on reduced the skin dose.

CONCLUSION

The impact of a magnetic field on HPBI dose distributions was analyzed. The heart and lung doses had clinically negligible effects caused by the magnetic field. The magnetic field increases the skin dose; however, this can be mitigated by increasing the number of beam angles.