Single vs. multiple fraction non-inferiority trial of stereotactic ablative radiotherapy for the comprehensive treatment of oligo-metastases/progression: SIMPLIFY-SABR-COMET.

BACKGROUND: Radiotherapy delivery regimens can vary between a single fraction (SF) and multiple fractions (MF) given daily for up to several weeks depending on the location of the cancer or metastases. With limited evidence comparing fractionation regimens for oligometastases, there is support to explore toxicity levels to nearby organs at risk as a primary outcome while using SF and MF stereotactic ablative radiotherapy (SABR) as well as explore differences in patient-reported quality of life and experience. METHODS: This study will randomize 598 patients in a 1:1 ratio between the standard arm (MF SABR) and the experimental arm (SF SABR). This trial is designed as two randomized controlled trials within one patient population for resource efficiency. The primary objective of the first randomization is to determine if SF SABR is non-inferior to MF SABR, with respect to healthcare provider (HCP)-reported grade 3-5 adverse events (AEs) that are related to SABR. Primary endpoint is toxicity while secondary endpoints include lesional control rate (LCR), and progression-free survival (PFS). The second randomization (BC Cancer sites only) will allocate participants to either complete quality of life (QoL) questionnaires only; or QoL questionnaires and a symptom-specific survey with symptom-guided HCP intervention. The primary objective of the second randomization is to determine if radiation-related symptom questionnaire-guided HCP intervention results in improved reported QoL as measured by the EuroQoL-5-dimensions-5levels (EQ-5D-5L) instrument. The primary endpoint is patient-reported QoL and secondary endpoints include: persistence/resolution of symptom reporting, QoL, intervention cost effectiveness, resource utilization, and overall survival. DISCUSSION: This study will compare SF and MF SABR in the treatment of oligometastases and oligoprogression to determine if there is non-inferior toxicity for SF SABR in selected participants with 1-5 oligometastatic lesions. This study will also compare patient-reported QoL between participants who receive radiation-related symptom-guided HCP intervention and those who complete questionnaires alone. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT05784428. Date of Registration: 23 March 2023.

Defining Minimum Treatment Parameters of Ablative Radiation Therapy in Patients With Hepatocellular Carcinoma: An Expert Consensus.

PURPOSE: External beam radiation therapy (EBRT) is a highly effective treatment in select patients with hepatocellular carcinoma (HCC). However, the Barcelona Clinic Liver Cancer system does not recommend the use of EBRT in HCC due to a lack of sufficient evidence and intends to perform an individual patient level meta-analysis of ablative EBRT in this population. However, there are many types of EBRT described in the literature with no formal definition of what constitutes "ablative." Thus, we convened a group of international experts to provide consensus on the parameters that define ablative EBRT in HCC. METHODS AND MATERIALS: Fundamental parameters related to dose, fractionation, radiobiology, target identification, and delivery technique were identified by a steering committee to generate 7 Key Criteria (KC) that would define ablative EBRT for HCC. Using a modified Delphi (mDelphi) method, experts in the use of EBRT in the treatment of HCC were surveyed. Respondents were given 30 days to respond in round 1 of the mDelphi and 14 days to respond in round 2. A threshold of ≥70% was used to define consensus for answers to each KC. RESULTS: Of 40 invitations extended, 35 (88%) returned responses. In the first round, 3 of 7 KC reached consensus. In the second round, 100% returned responses and consensus was reached in 3 of the remaining 4 KC. The distribution of answers for one KC, which queried the a/b ratio of HCC, was such that consensus was not achieved. Based on this analysis, ablative EBRT for HCC was defined as a BED10 ≥80 Gy with daily imaging and multiphasic contrast used for target delineation. Treatment breaks (eg, for adaptive EBRT) are allowed, but the total treatment time should be ≤6 weeks. Equivalent dose when treating with protons should use a conversion factor of 1.1, but there is no single conversion factor for carbon ions. CONCLUSIONS: Using a mDelphi method assessing expert opinion, we provide the first consensus definition of ablative EBRT for HCC. Empirical data are required to define the a/b of HCC.

Perioperative optimisation in low- and middle-income countries (LMICs): A systematic review and meta-analysis of enhanced recovery after surgery (ERAS).

Background: Enhanced recovery after surgery (ERAS) protocols have largely been incorporated into practice in high-income settings due to proven improvement in perioperative outcomes. We aimed to review the implementation of ERAS protocols and other perioperative optimisation strategies in low- and middle-income countries (LMICs) and their impact on length of hospital stay (LOS). Methods: We searched MEDLINE, PubMed, Global Health (CABI), WHO Global Index Medicus, Index Medicus, and Latin American and Caribbean Health Sciences Literature (LILACS) for studies incorporating ERAS or other prehabilitation approaches in LMICs. We conducted a pooled analysis of LOS using a random-effects model to evaluate the impact of such programs. This systematic review was pre-registered on PROSPERO. Results: We screened 1205 studies and included 70 for a full-text review; six were eligible for inclusion and five for quantitative analysis, two of which were randomised controlled trials. ERAS was compared to routine practice in all included studies, while none implemented prehabilitation or other preoperative optimisation strategies. Pooled analysis of 290 patients showed reduced LOS in the ERAS group with a standardised mean difference of -2.18 (95% confidence interval (CI) = -4.13, -.0.05, P < 0.01). The prediction interval was wide (95% CI = -7.85, 3.48) with substantial heterogeneity (I2 = 94%). Conclusions: Perioperative optimisation is feasible in LMICs and appears to reduce LOS, despite high levels of between-study heterogeneity. There is a need for high-quality data on perioperative practice in LMICs and supplementary qualitative analysis to further understand barriers to perioperative optimisation implementation. Registration: PROSPERO: CRD42021279053.

Clinical Outcomes of Patients with Metastatic Breast Cancer Treated with Hypo-Fractionated Liver Radiotherapy.

PURPOSE: To retrospectively review the clinical outcomes of patients with metastatic breast cancer (MBCa) following liver directed ablative intent radiotherapy (RT). METHODS: Demographics, disease and treatment characteristics of patients with MBCa who received liver metastasis (LM) directed ablative RT between 2004-2020 were analysed. The primary outcome was local control (LC), secondary outcomes included overall survival (OS) and progression-free survival (PFS) analyzed by univariate (UVA) and multi-variable analysis (MVA). RESULTS: Thirty MBCa patients with 50 LM treated with 5-10 fraction RT were identified. Median follow-up was 14.6 (range 0.9-156.2) months. Class of metastatic disease was described as induced (12 patients, 40%), repeat (15 patients, 50%) and de novo (three patients, 10%). Median size of treated LM was 3.1 cm (range 1-8.8 cm) and median biologically effective dose delivered was 122 (Q1-Q3; 98-174) Gy3. One-year LC rate was 100%. One year and two-year survival was 89% and 63%, respectively, with size of treated LM predictive of OS (HR 1.35, p = 0.023) on UVA. Patients with induced OMD had a significantly higher rate of progression (HR 4.77, p = 0.01) on UVA, trending to significance on MVA (HR 3.23, p = 0.051). CONCLUSIONS: Hypo-fractionated ablative liver RT in patients with MBCa provides safe, tolerable treatment with excellent LC.

Climate toxicity: An increasingly relevant clinical issue in Cancer Care.

In recent years the terms time and financial toxicities have entered the vocabulary of cancer care. We would like to introduce another toxicity: climate toxicity. Climate toxicity is a double-edge sword in cancer care. Increasing cancer risk by exposure to carcinogens, and consequently increasing treatment requirements leads to ever growing damage to our environment. This article assesses the impact of climate change on patients, the climate toxicity caused by both healthcare workers and healthcare facilities, and suggests actions that may be taken mitigate them.

Impact of endorectal filling on interobserver variability of MRI based rectal primary tumor delineation.

Background: Online adaptive MR-guided radiotherapy allows for the reduction of safety margins in dose escalated treatment of rectal tumors. With the use of smaller margins, precise tumor delineation becomes more critical. In the present study we investigated the impact of rectal ultrasound gel filling on interobserver variability in delineation of primary rectal tumor volumes. Methods: Six patients with locally advanced rectal cancer were scanned on a 1.5 T MRI-Linac without (MRI_e) and with application of 100 cc of ultrasound gel transanally (MRI_f). Eight international radiation oncologists expert in the treatment of gastrointestinal cancers delineated the gross tumor volume (GTV) on both MRI scans. MRI_f scans were provided to the participating centers after MRI_e scans had been returned. Interobserver variability was analyzed by either comparing the observers' delineations with a reference delineation (approach 1) and by building all possible pairs between observers (approach 2). Dice Similarity Index (DICE) and 95 % Hausdorff-Distance (95 %HD) were calculated. Results: Rectal ultrasound gel filling was well tolerated by all patients. Overall, interobserver agreement was superior in MRI_f scans based on median DICE (0.81 vs 0.74, p < 0.005 for approach 1 and 0.76 vs 0.64, p < 0.0001 for approach 2) and 95 %HD (6.9 mm vs 4.2 mm for approach 1, p = 0.04 and 8.9 mm vs 6.1 mm, p = 0.04 for approach 2). Delineated median tumor volumes and inter-quartile ranges were 26.99 cc [18.01-50.34 cc] in MRI_e and 44.20 [19.72-61.59 cc] in MRI_f scans respectively, p = 0.012. Conclusions: Although limited by the small number of patients, in this study the application of rectal ultrasound gel resulted in higher interobserver agreement in rectal GTV delineation. The endorectal gel filling might be a useful tool for future dose escalation strategies.

The Impact of Parent and Family Caregiver Roles Among Canadian Radiation Oncologists.

PURPOSE: Working parents, and a rising number of adults delivering care for aging relatives, experience numerous challenges in their personal, family, professional, and financial lives owing to multiple responsibilities. This study describes the experiences of Canadian radiation oncologist (RO) parents and family caregivers, reporting challenges that may exist in providing family care with clinical and academic work commitments. METHODS AND MATERIALS: Canadian ROs, via RO heads of departments in cancer centers across Canada, and physician members of the Canadian Association of Radiation Oncology were invited to participate in an anonymous online survey between November 2021 and January 2022. The survey focused on demographics, experiences of pregnancy and leave, parenting and adult caregiving responsibilities, and self-care. RESULTS: A total of 103 staff ROs (38%) completed the survey and 78 (75.7%) identified as having a parental (76 [89.7%]) and/or other family caregiver (8 [10.3%]) role; 41% were female and 59% were male, with no difference between genders in the number of children (median, 2; interquartile range, 1-3; P = .17). More female respondents took parental leave for their first child compared with male respondents (mean, 29 vs 6 weeks; P < .001). Of male respondents who started caring for their first child during residency, 27% took parental leave, compared with 77% who started caring for their first child as a staff member (P = .003). The majority of respondents described "always/usually" having collegial support for each pregnancy and parental leave. Both genders described parental responsibilities as negatively affecting attendance at conferences (male, 65%; female, 77%; P = .31) and early or late work-related meetings (male, 76%; female, 79%; P = 1.0). More female respondents described parental responsibilities as negatively affecting their career (50% vs 29%; P = .085). Of female respondents, 52% (vs 26% of male respondents; P = .044) identified a physician mentor or positive role model around parenting issues. CONCLUSIONS: Parental and other family caregiving responsibilities are not gender unique in Canadian ROs, but competing work and family roles may affect genders differently.

Evaluation of dosimetric predictors of toxicity after IMRT with concurrent chemotherapy for anal cancer.

BACKGROUND: This study investigates the impact of dosimetric parameters on acute and late toxicity for patients with anal squamous cell carcinoma (SCC) treated with image-guided intensity modulated radiation therapy (IG-IMRT) and concurrent chemotherapy. MATERIALS AND METHODS: Patients were enrolled in an observational cohort study between 2008 and 2013 (median follow-up 3.4 years). They were treated with standardized target and organ-at-risk (OAR) contouring, planning, and IG-IMRT. Radiotherapy dose, based on clinicopathologic features, ranged from 45 Gy to 63 Gy to gross targets and 27 Gy to 36 Gy to elective targets. Chemotherapy was concurrent 5-fluorouracil and mitomycin C (weeks 1&5). Toxicity was prospectively graded using NCI CTCAE v.3 and RTOG scales. Logistic regression was used to assess the association between dose/volume parameters (e.g small bowel V5) and corresponding grade 2 + and 3+ (G2+/3 + ) toxicities (e.g. diarrhea). RESULTS: In total, 87 and 79 patients were included in the acute and late toxicity analyses, respectively. The most common acute G2 + toxicities were skin (dermatitis in 87 % [inguino-genital skin], 91 % [perianal skin]) and hematologic in 58 %. G2 + late anal toxicity (sphincter dysfunction), gastrointestinal toxicity, and skin toxicity were respectively experienced by 49 %, 38 %, and 44 % of patients. Statistically significant associations were observed between: G2 + acute diarrhea and small bowel V35; G2 + acute genitourinary toxicity and bladder D0.5cc; G2 + inguino-genital skin toxicity and anterior skin V35; G2 + perianal skin toxicity and posterior skin V15; G2 + anemia and lower pelvis bone V45. D0.5 cc was significantly predictive of late toxicity (G2 + anal dysfunction, intestinal toxicity, and inguino-genital/perianal dermatitis). Maximum skin toxicity grade was significantly correlated with the requirement for a treatment break. CONCLUSION: Statistically significant dose-volume parameters were identified and may be used to offer individualized risk prediction and to inform treatment planning. Additional validation of the results is required.

Safety and Tolerability of Metastasis-Directed Radiation Therapy in the Era of Evolving Systemic, Immune, and Targeted Therapies.

AbstractPurpose: Systemic, immune, and target therapies are growing in use in the management of metastatic cancers. The aim of this review was to describe up-to-date published data on the safety and tolerability of metastasis-directed hypofractionated radiation therapy (RT) when combined with newer systemic, immune, and targeted therapies and to provide suggested strategies to mitigate potential toxicities in the clinical setting. Methods and Materials: A comprehensive search was performed for the time period between 1946 and August 2021 using predetermined keywords describing the use of noncentral nervous system palliative RT with commonly used targeted systemic therapies on PubMed and Medline databases. A total of 1022 articles were screened, and 130 met prespecified criteria to be included in this review. Results: BRAF and MEK inhibitors are reported to be toxic when given concurrently with RT; suspension 3 days and 1 to 2 days, respectively, prior and post-RT is suggested. Cetuximab, erlotinib/gefitinib, and osimertinib were generally safe to use concomitantly with conventional radiation. But in a palliative/hypofractionated RT setting, suspending cetuximab during radiation week, erlotinib/gefitinib 1 to 2 days, and osimertinib ≥2 days pre- and post-RT is suggested. Vascular endothelial growth factor inhibitors such as bevacizumab reported substantial toxicities, and the suggestion is to suspend 4 weeks before and after radiation. Less data exist on sorafenib and sunitinib; 5 to 10 days suspension before and after RT should be considered. As a precaution, until further data are available, for cyclin-dependent kinase 4-6 inhibitors, consideration of suspending treatment 1 to 2 days before and after RT should be given. Ipilimumab should be suspended 2 days before and after RT, and insufficient data exist for other immunotherapy agents. Trastuzumab and pertuzumab are generally safe to use in combination with RT, but insufficient data exist for other HER2 target therapy. Conclusions: Suggested approaches are described, using up-to-date literature, to aid clinicians in navigating the integration of newer targeted agents with hypofractionated palliative and/or ablative metastatic RT. Further prospective studies are required.

Patient-Reported and Clinical Outcomes From 5-Fraction SBRT for Oligometastases: A Prospective Single-Institution Study.

PURPOSE: To describe the long-term outcomes of a 5-fraction normal tissue tolerance adapted strategy for the management of oligometastases (OM). METHODS AND MATERIALS: Patients with histologically confirmed solid tumors, ≤5 extracranial metastases, suitable for a definitive approach for all metastatic lesions, at least one lesion suitable for Stereotactic Body Radiotherapy (SBRT), Eastern Coooperative Oncology Group Performance Status ≤2 were eligible. Treatment intervention was a 5-fraction (25-55 Gy) normal tissue adapted dosing strategy. The primary outcome was cumulative local progression rate at 12 months. RESULTS: Between March 2013 and January 2018, 137 patients started SBRT. Median follow-up was 35.7 months. In addition, 107 (78%) patients had a solitary OM. The mean planning target volume D95 was 39.6 (standard deviation, 8.8; biological effective dose using an alpha/beta ratio of 10, 70.8) Gy. Mean planning target volume D95 was highest for lung lesions (48.7 [standard deviation, 4.7]; biological effective dose using an alpha/beta ratio of 10, 96.1) Gy but was <40 Gy for all other anatomic sites. Two grade 3 toxicities (gastrointestinal bleed) were observed with stomach D0.05 30.3 Gy and 30.4 Gy. The cumulative local progression rate at 12 of 36 months was 16.1% (95% CI, 10-22) and 38.3% (95% CI 30-46.7); overall survival was 90% and 37%, and progression free survival was 58% and 19%, respectively. Mean symptom burden (Edmonton Symptom Assessment Total Score) worsened in patients with progressive disease (+8.8) at 12 months and was paralleled by changes in mean European Organization for Research and Treatment Quality of Life Core Questionnaire Summary Score and Global Health Quality of Life Score. Systemic therapy was initiated in 55% of patients at an average of 12.7 (standard deviation 12.4) months. CONCLUSIONS: If long-term progression free survival is the primary goal of therapy, SBRT for OM achieved this in <20% of patients attributable to a high risk of distant failure. Favorable local progression free survival is accompanied by preservation of quality of life, avoidance of symptom progression and reduced need of antineoplastic therapies at 12 months. Information on symptom burden, quality of life, as well as pattern of antineoplastic therapy use after progressive disease is useful to support conversations between patients, families, and health care providers. Strategies to improve patient selection and reduce distant progression rate remain a priority for further study.

The Impact of Disease Progression on Health-Related Quality of Life Outcomes in Patients With Oligometastatic Disease at 12 Months Post Stereotactic Body Radiation Therapy.

PURPOSE: There is a paucity of published health-related quality of life (HRQOL) outcomes in patients with oligometastatic disease (OMD) who receive stereotactic body radiation therapy (SBRT) and no available data assessing the effect of disease progression post-SBRT on HRQOL in this patient population. METHODS AND MATERIALS: Patients with OMD who received SBRT in a phase II single-arm research ethics board approved study were included. HRQOL was a secondary outcome. This study hypothesized that there is a different pattern of change from baseline HRQOL in patients with OMD treated with SBRT that have disease progression by 12 months (progressors) compared with those that do not progress by 12 months (nonprogressors), as measured by the European Organisation of Research and Treatment in Cancer Quality of Life Questionnaire Core 30. RESULTS: A total of 107 patients were included in this analysis, 41 without progression and 66 with progression by 12 months; median time to progression was 7.7 (0.3-57) months. A statistically significant decline in the mean global health/quality of life (GHQOL) score (73 [SD, 21.8] to 67.2 [SD, 27.1]; P = .04) from baseline in the entire population at the 12-month follow-up was found. Mean GHQOL change score in nonprogressors was -0.8 and in progressors was -8.8 (P = .07). However, only progressors demonstrated a difference between baseline and 12-month mean GHQOL scores (71.2 vs 62.4; P = .01), which was both statistically and clinically significant (-8.8) in the range of small minimal clinically important difference. There was a higher proportion of patients who experienced a minimal clinically important difference deterioration in progressors compared with nonprogressors (37.4% vs 24.4%; P = .14). CONCLUSIONS: Patients who progressed by 12 months did not have a statistical or clinically significant difference in mean GHQOL change score compared with nonprogressors. However, there were signals to suggest that patients who progressed by 12 months post-SBRT experienced a different pattern of change compared with nonprogressors, which was worse compared with baseline.

Stereotactic body radiation therapy for hepatocellular carcinoma: From infancy to ongoing maturity.

Hepatocellular carcinoma (HCC) accounts for 90% of liver tumours and is one of the leading causes of mortality. Cirrhosis due to viral hepatitis, alcohol or steatohepatitis is the major risk factor, while liver dysfunction due to cirrhosis is a deciding factor in its treatment. The treatment modalities for HCC include liver transplant, hepatectomy, radiofrequency ablation, transarterial chemoembolisation, transarterial radioembolisation, targeted therapy, immunotherapy, and radiation therapy. The role of radiation therapy has been refined with the increasing use of stereotactic body radiation therapy (SBRT). Trials over the past two decades have shown the efficacy and safety of SBRT in recurrent and definitive HCC, leading to its acceptance and adoption in some more recent guidelines. However, high quality level I evidence supporting its use is currently lacking. Smaller randomised trials of external beam radiation therapy suggest high efficacy of radiation therapy compared to other treatments for patients with unresectable HCC, and phase III trials comparing SBRT with other modalities are ongoing. In this review, we discuss the rationale for SBRT in HCC and present evidence on its efficacy, associated toxicity, and technological advances.

Applying the intervention Complexity Assessment Tool to brief interventions targeting long-term benzodiazepine receptor agonist use in primary care: Lessons learned.

BACKGROUND: Benzodiazepine receptor agonists (BZRAs) are often prescribed for long-term use. However, guidelines recommend limiting prescriptions to short-term use (< 4 weeks) to reduce the risk of adverse effects and dependence. A recent systematic review reported that brief interventions targeting long-term BZRA use in primary care (e.g., short consultations, written letters to patients) were effective in helping patients to discontinue BZRA medication. However, the complexity of these interventions has not been examined in detail. This study aimed to apply the intervention Complexity Assessment Tool for Systematic Reviews (iCAT_SR) to brief interventions targeting long-term BZRA use.  METHODS: Two reviewers independently assessed the interventions using the six core iCAT_SR dimensions: organisational level/ category targeted, behaviour targeted, number of intervention components, degree of tailoring, skill level required by those delivering and receiving the intervention. The four optional iCAT_SR dimensions were applied where possible. A scoring system was using to calculate a complexity score for each intervention. Pearson's correlations were used to assess the relationship between intervention complexity and effect size, as well as the relationship between intervention complexity and number of component behaviour change techniques (BCTs). Inter-rater reliability was calculated using Cohen's Kappa coefficient. RESULTS: Four of the six core iCAT_SR dimensions were applied to the interventions with high inter-rater reliability (Cohen's Kappa = 0.916). Application of the four optional dimensions was prevented by a lack of detail in study reports. Intervention complexity scores ranged from 8 to 11 (median: 11). There was no relationship detected between intervention complexity and either intervention effect size or number of component BCTs. CONCLUSIONS: This study adds to the literature on worked examples of the practical application of the iCAT_SR. The findings highlight how more detailed reporting of interventions is needed in order to optimise the application of iCAT_SR and its potential to differentiate between interventions across the full range of complexity dimensions. Further work is needed to establish the validity of applying a scoring system to iCAT_SR assessments.

Health related quality of life outcomes following stereotactic body radiotherapy in patients with oligo-metastatic disease: A systematic review and individual patient data meta-analysis.

INTRODUCTION: Published health-related quality of life (HRQOL) outcomes are lacking in patients treated for oligo-metastatic disease (OMD). The aim of this systematic review and individual patient data meta-analysis is to determine the effect of stereotactic body radiotherapy (SBRT) on HRQOL outcomes of patients with OMD. METHODS: Studies screened included adults with extra-cranial OMD, defined as ≤ 5 metastases, SBRT intended as definitive treatment, and HRQOL as primary or secondary outcome. Primary outcome was change in HRQOL at 12-months from baseline in patients with OMD who received SBRT (versus not), reported as standardized mean difference (SMD). RESULTS: A total of 7556 publications were identified, four studies met inclusion criteria (2 single arm interventional studies and 2 randomised controlled trials [RCTs]), and individual patient data was available from 3 studies (175 patients). In the two RCTs, there was no SS difference in the SMD between patients who received SBRT and those that did not (0.09 [95 % CI -0.32, 0.5], P = 0.66). On meta-analysis of patients (N = 107) who received SBRT the SMDwas -0.23 (95 % CI [-0.42, -0.04], versus -0.25 (95 % CI [-0.57, 0.07]) in those who did not (N = 37) receive SBRT, demonstrating a small deterioration from baseline. CONCLUSION: In patients with OMD, there is no difference in HRQOL at 12-months from baseline between patients who received SBRT and those that did not. However, a small HRQOL deterioration was found in both groups of patients. More in-depth analysis of relevant HRQOL domains, in the setting of OMD, is required to better understand the potential impact of SBRT.

First multicentre experience of SABR for lymph node and liver oligometastatic disease on the unity MR-Linac.

The treatment of oligometastatic disease using MR guidance is an evolving field. Since August 2018 patients are treated on a 1.5 Tesla MR-Linac (MRL). We present current workflows and practice standards from seven institutions for the initial patients treated for lymph node and liver metastases.

Stereotactic body radiation therapy for colorectal liver metastases.

Multidisciplinary case discussion of patients with colorectal liver metastases (CRLM) has led to improved selection of more complex patients with the oligometastatic disease for treatment with surgical resection, locally ablative therapy or a combination of local modalities to improve the therapeutic ratio in patients with CRLM. Stereotactic body radiation therapy (SBRT) is a noninvasive local therapy with a potential role in the management of oligometastatic CRLM and may be considered as an alternate choice to other locally ablative therapies like radiofrequency ablation, radioembolization, chemoembolization or surgery or after the failure of other local treatment or in combination with surgery. Existing evidence reports for highly selected patients with CRLM, one to five fractions SBRT can be delivered safely, with satisfactory long-term local control, overall survival and quality of life. This review article will present the evidence of SBRT in this setting.

Coeliac plexus radiosurgery for pain management in patients with advanced cancer : study protocol for a phase II clinical trial.

INTRODUCTION: Pancreatic cancer is characterised by severe mid-back and epigastric pain caused by tumour invasion of the coeliac nerve plexus. This pain is often poorly managed with standard treatments. This clinical trial investigates a novel approach in which high-dose radiation (radiosurgery) is targeted to the retroperitoneal coeliac plexus nerve bundle. Preliminary results from a single institution pilot trial are promising: pain relief is substantial and side effects minimal. The goals of this study are to validate these findings in an international multisetting, and investigate the impact on quality of life and functional status among patients with terminal cancer. METHODS AND ANALYSIS: A single-arm prospective phase II clinical trial. Eligible patients are required to have severe coeliac pain of at least five on the 11-point BPI average pain scale and Eastern Cooperative Oncology Group performance status of two or better. Non-pancreatic cancers invading the coeliac plexus are also eligible. The intervention involves irradiating the coeliac plexus using a single fraction of 25 Gy. The primary endpoint is the complete or partial pain response at 3 weeks. Secondary endpoints include pain at 6 weeks, analgesic use, hope, qualitative of life, caregiver burden and functional outcomes, all measured using validated instruments. The protocol is expected to open at a number of cancer centres across the globe, and a quality assurance programme is included. The protocol requires that 90 evaluable patients" be accrued, based upon the assumption that a third of patients are non-evaluable (e.g. due to death prior to 3-weeks post-treatment assessment, or spontaneous improvement of pain pre-treatment), it is estimated that a total of 120 patients will need to be accrued. Supported by Gateway for Cancer Research and the Israel Cancer Association. ETHICS AND DISSEMINATION: Ethic approval for this study has been obtained at eight academic medical centres located across the Middle East, North America and Europe. Results will be disseminated through conference presentations and peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT03323489.

MRI-Guided Online Adaptive Stereotactic Body Radiation Therapy of Liver and Pancreas Tumors on an MR-Linac System.

PURPOSE: To describe a comprehensive workflow for MRI-guided online adaptive stereotactic body radiation therapy (SBRT) specific to upper gastrointestinal cancer patients with abdominal compression on a 1.5T MR-Linac system. Additionally, we discuss the workflow's clinical feasibility and early experience in the case of 16 liver and pancreas patients. METHODS: Eleven patients with liver cancer and five patients with pancreas cancer were treated with online adaptive MRI-guidance under abdominal compression. Two liver patients received single-fraction treatments; the remainder plus all pancreas cancer patients received five fractions. A total of 65 treatment sessions were investigated to provide analytics relevant to the online adaptive processes. The quantification of target and organ motion as well as definition and validation of internal target volume (ITV) margins were performed via multi-contrast imaging provided by three different 2D cine sequences. The plan generation was driven by full re-optimization strategies and using T2-weighted 3D image series acquired by means of a respiratory-triggered exhale phase or a time-averaged imaging protocol. As a pre-requisite for the clinical development of the procedure, the image quality was thoroughly investigated via phantom measurements and numerical simulations specific to upper abdominal sites. The delivery of the online adaptive treatments was facilitated by real-time monitoring with 2D cine imaging. RESULTS: Liver 1-fraction and 5-fraction online adaptive session time were on average 80 and 67.5 min, respectively. The total session length varied between 70-90 min for a single fraction and 55-90 min for five fractions. The pancreas sessions were 54-85 min long with an average session time of 68.2 min. Target visualization on the 2D cine image data varied per patient, with at least one of the 2D cine sequences providing sufficient contrast to confidently identify its location and confirm reproducibility of ITV margins. The mean/range of absolute and relative dose values for all treatment sessions evaluated with ArcCheck were 90.6/80.9-96.1% and 99/95.4-100%, respectively. CONCLUSION: MR-guidance is feasible for liver and pancreas tumors when abdominal compression is used to reduce organ motion, improve imaging quality, and achieve a robust intra- and inter-fraction patient setup. However, the treatment length is significantly longer than for the conventional linac, and patient compliance is paramount for the successful completion of the treatment. Opportunities for reducing the online adaptive session time should be explored. As the next steps, dose-of-the-day and dose accumulation analysis and tools are needed to enhance the workflow and to help further refine the online re-planning processes.