Predictors of pathologic fracture and local recurrence following stereotactic body radiation therapy to 505 non-spine bone metastases

PURPOSE

Stereotactic Body Radiation Therapy (SBRT) is increasingly applied to treat non-spine bone metastases (NSBM) though data remains limited on this approach. In this retrospective study, we report outcomes and predictors of local failure (LF) and pathological fracture (PF) post-SBRT for NSBM using a mature single-institution database.

METHODS

Patients with NSBM treated with SBRT between 2011 and 2021 were identified. The primary objective was to assess the rates of radiographic LF. Secondary objectives were to assess the rates of in-field PF, overall survival (OS), and late grade ≥ 3 toxicity. Competing risks analysis was used to assess rates of LF and PF. Univariable regression and multivariable regression (MVR) were performed to investigate predictors of LF and PF.

RESULTS

A total of 373 patients with 505 NSBM were included in this study. Median follow-up was 26.5 months. The cumulative incidence of LF at 6, 12, and 24 months were 5.7%, 7.9%, and 12.6%, respectively. The cumulative incidence of PF at 6, 12, and 24 months were 3.8%, 6.1%, and 10.9%, respectively. Lytic NSBM (HR = 2.18; p < 0.01), a lower biologically effective dose (HR = 1.11 per 5 Gy10 decrease; p = 0.04), and a PTV ≥ 54 cc (HR = 4.32; p < 0.01) predicted for a higher risk of LF on MVR. Lytic NSBM (HR = 3.43; p < 0.01), mixed (lytic/sclerotic) lesions (HR = 2.70; p = 0.04), and rib metastases (HR = 2.68; p < 0.01) predicted for a higher risk of PF on MVR.

CONCLUSION

SBRT is an effective modality to treat NSBM with high rates of radiographic local control with an acceptable rate of PF. We identify predictors of both LF and PF that can serve to inform practice and trial design.

The impact of local control on widespread progression and survival in oligometastasis-directed SBRT: Results from a large international database

PURPOSE

We investigated the impact of local control (LC) on widespread progression (WSP) and overall survival (OS) in patients treated to all extracranial oligometastases (OMs) at presentation to SBRT in this retrospective review across 6 international centers.

MATERIALS/METHODS

Relationships between LC status of SBRT-directed OMs and OS and WSP (>5 new active/untreated lesions) were explored using Cox and Fine-Gray regression models, adjusting for radioresistant histology and pre-SBRT systemic therapy receipt. The association between LC and dosimetric predictors was analyzed with competing risk regression using death as a competing risk and across a wide range of simulated α/βratios.

RESULTS

In total, 1700 OMs in 1033 patients were analyzed, with 25.2% NSCLC, 22.7% colorectal, 12.8% prostate, and 8.1% breast histology. Patients who failed locally in any SBRT-directed OM within 6 mo were at 3.6-fold higher risk of death and 2.7-fold higher risk of WSP compared to those who remained locally-controlled (p < 0.001). Similar associations existed for each duration of LC investigated through 3 yrs post-SBRT. There was no significant difference in risk of WSP or death between patients who failed in a subset of SBRT-treated lesions vs. patients who failed in all lesions. Minimum dose (Dmin) to the GTV/ITV was most predictive of LC when compared to prescription dose, PTV Dmin, and PTV Dmax. Sensitivity analysis for achieving 1-yr LC > 95% found thresholds of 41.2 Gy and 55.2 Gy in 5 fractions for smaller (< 27.7 cc) and larger radioresistant lesions, respectively.

CONCLUSION

This large multinational cohort suggests that the duration of LC following OM-directed SBRT strongly correlates with WSP and OS.

A Meta-analysis of the Efficacy and Safety of Stereotactic Arrhythmia Radioablation (STAR) in Patients with Refractory Ventricular Tachycardia

AIMS

Reports of stereotactic arrhythmia radioablation (STAR) in patients with refractory ventricular tachycardia after catheter ablation are limited to small series. Here, we carried out a systematic review and meta-analysis of studies to better determine the efficacy and toxicity of STAR for ventricular tachycardia.

MATERIALS AND METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and the Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines, eligible studies were identified on Medline, Embase, Cochrane Library and the proceedings of annual meetings to 10 February 2023. Efficacy was defined as a ventricular tachycardia burden reduction >70% at 6 months; safety was defined as <10% of any grade ≥3 toxicity.

RESULTS

Seven observational studies with a total of 61 patients treated were included. At 6 months, the ventricular tachycardia burden reduction was 92% (95% confidence interval 85-100%) and use of fewer than two anti-arrhythmic drugs was seen in 85% (95% confidence interval 50-100). Six months after STAR, an 86% reduction (95% confidence interval 80-93) in the number of implantable cardioverter-defibrillator shocks was observed. The rates for improved, unchanged and decreased cardiac ejection fraction were 10%, 84% and 6%, respectively. Overall survival at 6 and 12 months was 89% (95% confidence interval 81-97) and 82% (95% confidence interval 65-98). The cardiac-specific survival at 6 months was 87%. Late grade 3 toxicity occurred in 2% (95% confidence interval 0-5%) with no grade 4-5 toxicity.

CONCLUSION

STAR demonstrated both satisfactory efficacy and safety for the management of refractory ventricular tachycardia and was also associated with a significant decline in anti-arrhythmic drugs consumption. These findings support the continued development of STAR as a treatment option.

Severe kyphosis and stereotactic lung radiation therapy set-up: A case report and lessons learned

INTRODUCTION

Stereotactic body radiation therapy (SBRT) for lung cancers allows for safe ablative radiation doses to be delivered precisely to treat localized stage 1 lung cancers and for the treatment of lung oligometastasis/es. The successful delivery of lung SBRT requires multidisciplinary technical expertise, from radiation oncologists, medical physicists, radiation therapists, and a clinical specialist radiation therapist in SBRT. While the majority of SBRT lung set-ups are routine, we present a challenging situation in the lung SBRT set-up for a patient with severe kyphosis.

CASE AND OUTCOMES

An 80-year-old woman was diagnosed with a right upper lobe non-small cell lung cancer. She declined surgery and was referred for lung SBRT. Her severe kyphosis did present challenges in terms of reproducible lung SBRT set-up. We were successful in immobilizing this patient in a vacuum customized rigid support which was shaped to accommodate this patient's extreme kyphosis and elevated head. The patient tolerated the treatment position and successfully completed her lung SBRT treatments comfortably, without any reproducibility issues. Four months after SBRT, the patient was doing well without any new chest symptoms.

DISCUSSION

This report is the first, in the published medical literature, to describe a lung SBRT set-up for a patient with extreme kyphosis. Her successful set-up and ability to complete her lung SBRT was dependent on creative problem-solving from the multi-disciplinary team and a patient-centred approach to care CONCLUSION: Multidisciplinary collaboration was essential in the successful SBRT treatment for a severely kyphotic patient. The use of a vacuum customized thoracic rigid support was effectively used in a patient with severe kyphosis for lung SBRT. Results from this case report could be useful and guide other clinicians if presented with similarly challenging cases.

The role of thoracic consolidative radiotherapy in the setting of immunotherapy in extensive stage small cell lung cancer

The improvement in treatment strategies and outcomes in small cell lung cancer (SCLC) has lagged behind other cancers. The addition of immune checkpoint inhibitors (ICIs), durvalumab and atezolizumab, to the platinum-based chemotherapy in frontline setting has improved the survival in extensive stage SCLC, (ES-SCLC), albeit modestly, and is now the new standard of care. Prior to advent of immunotherapy into the therapeutic armamentarium in ES-SCLC, consolidative thoracic radiotherapy (TRT) was associated with improved thoracic control and survival outcomes. In the era of ICIs, the role of TRT is not well defined, chiefly because TRT was not incorporated in any immunotherapy trials, secondly due to concerns regarding the increased risks of pneumonitis, and finally uncertain magnitude of benefit with this combined approach. In principle, radiation can increase in the immunogenicity of tumor and hence the activity of immune checkpoint blockade, thereby increasing efficacy both locally and distantly. Such an approach has been promising in non-small cell lung cancer with ICIs improving outcomes after concurrent chemoradiation, but remains unanswered in ES-SCLC. It is, thus, possible that the modest improvement in survival by addition of ICIs to chemotherapy in ES-SCLC can be further improved by the incorporation of consolidative TRT in selected patients. Several early phase trials and retrospective studies have suggested that such an approach may be feasible and safe. Prospective trials are ongoing to answer whether adding radiation therapy to chemoimmunotherapy will improve outcomes in ES-SCLC.

The Effectiveness and Safety of Stereotactic Body Radiation Therapy (SBRT) in the Treatment of Oligoprogressive Breast Cancer: A Systematic Review

Stereotactic body radiotherapy (SBRT) has emerged as a technique to treat oligoprogressive sites among patients with breast cancer who are otherwise doing well on systemic therapy. This study systematically reviewed the efficacy and safety of SBRT in the setting of oligoprogressive breast cancer. A literature search was conducted in the MEDLINE database. Studies regarding SBRT and oligoprogressive breast cancer were included. Key outcomes of interest were toxicity, local control, progression, and overall survival. From 863 references, five retrospective single-center cohort studies were identified. All studies included patients with both oligometastatic and oligoprogressive disease; 112 patients with oligoprogressive breast cancer were identified across these studies. Patient age ranged from 22 to 84, with a median of 55 years of age. Most patients had hormone-receptor-positive and HER2-negative disease. SBRT doses varied from 24 to 60 Gy in 1-10 fractions based on the location/size of the lesion. Forty toxicity events were reported, of which the majority (n = 25, 62.5%) were grade 1-2 events. Among 15 patients who received SBRT concurrently with a CDK4/6 inhibitor, 37.5% of patients experienced grade 3-5 toxicities. Progression-free and overall survival ranged from 17 to 57% and 62 to 91%, respectively. There are limited data on the role of SBRT in oligoprogressive breast cancer, and prospective evaluation of this strategy is awaited to inform its safety and efficacy.

The Judicious Use of Stereotactic Ablative Radiotherapy in the Primary Management of Localized Renal Cell Carcinoma

Localized renal cell carcinoma is primarily managed surgically, but this disease commonly presents in highly comorbid patients who are poor operative candidates. Less invasive techniques, such as cryoablation and radiofrequency ablation, are effective, but require percutaneous or laparoscopic access, while generally being limited to cT1a tumors without proximity to the renal pelvis or ureter. Active surveillance is another management option for small renal masses, but many patients desire treatment or are poor candidates for active surveillance. For poor surgical candidates, a growing body of evidence supports stereotactic ablative radiotherapy (SABR) as a safe and effective non-invasive treatment modality. For example, a recent multi-institution individual patient data meta-analysis of 190 patients managed with SABR estimated a 5.5% five-year cumulative incidence of local failure with one patient experiencing grade 4 toxicity, and no other grade ≥3 toxic events. Here, we discuss the recent developments in SABR for the management of localized renal cell carcinoma, highlighting key concepts of appropriate patient selection, treatment design, treatment delivery, and response assessment.

Radiation and immune checkpoint inhibitors in the treatment of oligometastatic non-small-cell lung cancer: a practical review of rationale, recent data, and research questions

The combined use of stereotactic ablative radiotherapy (SABR) and immune checkpoint inhibitors (ICIs) is an emerging treatment paradigm for oligometastatic non-small-cell lung cancer (NSCLC). Recent phase I and II trial data suggest that SABR to multiple metastases in addition to ICI use is safe and effective with promising progression-free survival and overall survival signals. There is great interest in capitalizing on combined immunomodulation from these two modalities for the treatment of oligometastatic NSCLC. Ongoing trials seek to validate the safety, efficacy, and preferred sequencing of SABR and ICI. This narrative review of the role of SABR when combined with ICI in oligometastatic NSCLC discusses the rationale for this bimodality treatment, summarizes recent clinical trial evidence, and proposes key principles of management based on the available evidence.

Association between COPD and Stage of Lung Cancer Diagnosis: A Population-Based Study

Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of lung cancer; however, the association between COPD and stage of lung cancer diagnosis is unclear. We conducted a population-based cross-sectional analysis of lung cancer patients (2008-2020) in Ontario, Canada. Using estimated propensity scores and inverse probability weighting, logistic regression models were developed to assess the association between COPD and lung cancer stage at diagnosis (early: I/II, advanced: III/IV), accounting for prior chest imaging. We further examined associations in subgroups with previously diagnosed and undiagnosed COPD. Over half (55%) of all lung cancer patients in Ontario had coexisting COPD (previously diagnosed: 45%, undiagnosed at time of cancer diagnosis: 10%). Compared to people without COPD, people with COPD had 30% lower odds of being diagnosed with lung cancer in the advanced stages (OR = 0.70, 95% CI: 0.68 to 0.72). Prior chest imaging only slightly attenuated this association (OR = 0.77, 95% CI: 0.75 to 0.80). The association with lower odds of advanced-stage diagnosis remained, regardless of whether COPD was previously diagnosed (OR = 0.68, 95% CI: 0.66 to 0.70) or undiagnosed (OR = 0.77, 95% CI: 0.73 to 0.82). Although most lung cancers are detected in the advanced stages, underlying COPD was associated with early-stage detection. Lung cancer diagnostics may benefit from enhanced partnership with COPD healthcare providers.

Management of Patients with Cardiovascular Implantable Electronic Devices Undergoing Radiation Therapy: A National Survey of Canadian Multidisciplinary Radiation Oncology Professionals

Purpose

This study aimed to characterize contemporary management of Canadian patients with cardiovascular implantable electronic devices (CIEDs) undergoing radiation therapy (RT) in light of updated American Association of Physicists in Medicine guidelines.

Methods and Materials

A 22-question web-based survey was distributed to members of the Canadian Association of Radiation Oncology, Canadian Organization of Medical Physicists, and Canadian Association of Medical Radiation Technologists from January to February 2020. Respondent demographics, knowledge, and management practices were elicited. Statistical comparisons by respondent demographics were performed using χ² and Fisher exact tests.

Results

In total, 155 surveys were completed by 54 radiation oncologists, 26 medical physicists, and 75 radiation therapists in academic (51%) and community (49%) practices across all provinces. The majority of respondents (77%) had managed >10 patients with CIEDs in their career. Most respondents (70%) reported using risk-stratified institutional management protocols. Respondents used manufacturer recommendations, rather than American Association of Physicists in Medicine or institutionally recommended dose limits, when the manufacturer limit was 0 Gy (44%), 0 to 2 Gy (45%), or >2 Gy (34%). The majority of respondents (86%) reported institutional policies to refer to a cardiologist for CIED evaluation both before and after completion of RT. Cumulative dose to CIED, pacing dependence, and neutron production were considered during risk stratification by 86%, 74%, and 50% of participants, respectively. Dose and energy thresholds for high-risk management were not known by 45% and 52% of respondents, with radiation oncologists and radiation therapists significantly less likely to report thresholds than medical physicists (P < .001). Although 59% of respondents felt comfortable managing patients with CIEDs, community respondents were less likely to feel comfortable than academic respondents (P = .037).

Conclusions

The management of Canadian patients with CIEDs undergoing RT is characterized by variability and uncertainty. National consensus guidelines may have a role in improving provider knowledge and confidence in caring for this growing population.

Stereotactic Body Radiotherapy for Lung Oligo-metastases: Systematic Review and International Stereotactic Radiosurgery Society Practice Guidelines

PURPOSE

A systematic review of treatment characteristics, outcomes, and treatment-related toxicities of stereotactic body radiation therapy (SBRT) for pulmonary oligometastases served as the basis for development of this International Stereotactic Radiosurgery Society (ISRS) practice guideline.

METHODS

In accordance with PRISMA guidelines, a systematic review was performed of retrospective series with ≥50 patients/lung metastases, prospective trials with ≥25 patients/lung metastases, analyses of specific high-risk situations, and all randomized trials published between 2012 and July 2022 in the MEDLINE or Embase database using the key words "lung oligometastases", "lung metastases", "pulmonary metastases", "pulmonary oligometastases", "stereotactic body radiation therapy (SBRT)" and "stereotactic ablative body radiotherapy (SBRT)". Weighted random effects models were used to calculate pooled outcomes estimates.

RESULTS

Of the 1884 articles screened, 35 analyses (27 retrospective-, 5 prospective, and 3 randomized trials) reporting on treatment of >3600 patients and >4650 metastases were included. The median local control was 90 % (Range: 57-100 %) at 1 year and 79 % (R: 70-96 %) at 5 years. Acute toxicity ≥3 was reported for 0.5 % and late toxicity ≥3 for 1.8 % of patients. A total of 21 practice recommendations covering the areas of staging & patient selection (n = 10), SBRT treatment (n = 10), and follow-up (n = 1) were developed, with agreements rates of 100 %, except for recommendation 13 (83 %).

CONCLUSION

SBRT represents an effective definitive local treatment modality combining high local control rates with low risk of radiation-induced toxicities.

Stereotactic body radiotherapy for Ultra-Central lung Tumors: A systematic review and Meta-Analysis and International Stereotactic Radiosurgery Society practice guidelines

BACKGROUND

Stereotactic body radiotherapy (SBRT) is an effective and safe modality for early-stage lung cancer and lung metastases. However, tumors in an ultra-central location pose unique safety considerations. We performed a systematic review and meta-analysis to summarize the current safety and efficacy data and provide practice recommendations on behalf of the International Stereotactic Radiosurgery Society (ISRS).

METHODS

We performed a systematic review using PubMed and EMBASE databases of patients with ultra-central lung tumors treated with SBRT. Studies reporting local control (LC) and/or toxicity were included. Studies with <5 treated lesions, non-English language, re-irradiation, nodal tumors, or mixed outcomes in which ultra-central tumors could not be discerned were excluded. Random-effects meta-analysis was performed for studies reporting relevant endpoints. Meta-regression was conducted to determine the effect of various covariates on the primary outcomes.

RESULTS

602 unique studies were identified of which 27 (one prospective observational, the remainder retrospective) were included, representing 1183 treated targets. All studies defined ultra-central as the planning target volume (PTV) overlapping the proximal bronchial tree (PBT). The most common dose fractionations were 50 Gy/5, 60 Gy/8, and 60 Gy/12 fractions. The pooled 1- and 2-year LC estimates were 92 % and 89 %, respectively. Meta-regression identified biological effective dose (BED10) as a significant predictor of 1-year LC. A total of 109 grade 3-4 toxicity events, with a pooled incidence of 6 %, were reported, most commonly pneumonitis. There were 73 treatment related deaths, with a pooled incidence of 4 %, with the most common being hemoptysis. Anticoagulation, interstitial lung disease, endobronchial tumor, and concomitant targeted therapies were observed risk factors for fatal toxicity events.

CONCLUSION

SBRT for ultra-central lung tumors results in acceptable rates of local control, albeit with risks of severe toxicity. Caution should be taken for appropriate patient selection, consideration of concomitant therapies, and radiotherapy plan design.

Association between the COVID-19 pandemic and first cancer treatment modality: a population-based cohort study

BACKGROUND

Physicians were directed to prioritize using nonsurgical cancer treatment at the beginning of the COVID-19 pandemic. We sought to quantify the impact of this policy on the modality of first cancer treatment (surgery, chemotherapy, radiotherapy or no treatment).

METHODS

In this population-based study using Ontario data from linked administrative databases, we identified adults diagnosed with cancer from January 2016 to November 2020 and their first cancer treatment received within 1 year postdiagnosis. Segmented Poisson regressions were applied to each modality to estimate the change in mean 1-year recipient volume per thousand patients (rate) at the start of the pandemic (the week of Mar. 15, 2020) and change in the weekly trend in rate during the pandemic (Mar. 15, 2020, to Nov. 7, 2020) relative to before the pandemic (Jan. 3, 2016, to Mar. 14, 2020).

RESULTS

We included 321 535 people diagnosed with cancer. During the first week of the COVID-19 pandemic, the mean rate of receiving upfront surgery over the next year declined by 9% (rate ratio 0.91, 95% confidence interval [CI] 0.88-0.95), and chemotherapy and radiotherapy rates rose by 30% (rate ratio 1.30, 95% CI 1.23-1.36) and 13% (rate ratio 1.13, 95% CI 1.07-1.19), respectively. Subsequently, the 1-year rate of upfront surgery increased at 0.4% for each week (rate ratio 1.004, 95% CI 1.002-1.006), and chemotherapy and radiotherapy rates decreased by 0.9% (rate ratio 0.991, 95% CI 0.989-0.994) and 0.4% (rate ratio 0.996, 95% CI 0.994-0.998), respectively, per week. Rates of each modality resumed to prepandemic levels at 24-31 weeks into the pandemic.

INTERPRETATION

An immediate and sustained increase in use of nonsurgical therapy as the first cancer treatment occurred during the first 8 months of the COVID-19 pandemic in Ontario. Further research is needed to understand the consequences.

Ensuring Superior Reporting of Radiation Therapy Noninferiority Trials: A Systematic Review

Purpose

Although the frequency of noninferiority trials is increasing, the consistency of the reporting of these trials can vary. The aim of this systematic review was to assess the reporting quality of radiation therapy noninferiority trials.

Methods and Materials

The PubMed, Embase, and Cochrane databases were queried for randomized controlled radiation therapy trials with noninferiority hypotheses published in English between January 2000 and July 2022, and this was performed by an information scientist. Descriptive statistics were used to summarize data.

Results

Of 423 records screened, 59 (14%) were included after full-text review. All were published after 2003 and open label. The most common primary cancer type was breast (n = 15, 25%). Altered radiation fractionation (n = 26, 45%) and radiation de-escalation (n = 11, 19%) were the most common types of interventions. The most common primary endpoints were locoregional control (n = 17, 29%) and progression-free survival (n = 14, 24%). Fifty-three (90%) reported the noninferiority margin, and only 9 (17%) provided statistical justification for the margin. The median absolute noninferiority margin was 9% (interquartile range, 5%-10%), and the median relative margin was 1.51 (interquartile range, 1.33-2.04). Sample size calculations and confidence intervals were reported in 54 studies (92%). Both intention-to-treat and per-protocol analyses were reported in 27 studies (46%). In 31 trials (53%), noninferiority of the primary endpoint was reached.

Conclusions

There was variability in the reporting of key components of noninferiority trials. We encourage consideration of additional statistical reasoning such as guidelines or previous trials in the selection of the noninferiority margin, reporting both absolute and relative margins, and the avoidance of statistically vague or misleading language in the reporting of future noninferiority trials.

ASTRO Radiation Therapy Summary of the ASCO Guideline on Management of Stage III Non-Small Cell Lung Cancer

PURPOSE

To develop a radiation therapy summary of recommendations on the management of locally advanced non-small cell lung cancer (NSCLC) based on the Management of Stage III Non-Small Cell Lung Cancer: American Society of Clinical Oncology Guideline, which was endorsed by the American Society for Radiation Oncology (ASTRO).

METHODS

The American Society of Clinical Oncology, ASTRO, and the American College of Chest Physicians convened a multidisciplinary panel to develop a guideline based on a systematic review of the literature and a formal consensus process, that has been separately published. A new panel consisting of radiation oncologists from the original guideline as well as additional ASTRO members was formed to provide further guidance to the radiation oncology community. A total of 127 articles met the eligibility criteria to answer 5 clinical questions. This summary focuses on the 3 radiation therapy questions (neoadjuvant, adjuvant, and unresectable settings).

RESULTS

Radiation-specific recommendations are summarized with additional relevant commentary on specific questions regarding the management of preoperative radiation, postoperative radiation, and combined chemoradiation.

CONCLUSIONS

Patients with stage III NSCLC who are planned for surgical resection, should receive either neoadjuvant chemotherapy or chemoradiation. The addition of neoadjuvant treatment is particularly important in patients planned for surgery in the N2 or superior sulcus settings. Postoperatively, patients who did not receive neoadjuvant chemotherapy should be offered adjuvant chemotherapy. The use of postoperative radiation for completely resected N2 disease is not routinely recommended. Unresectable patients with stage III NSCLC should ideally be managed with combined concurrent chemoradiation using a platinum-based doublet with a standard radiation dose of 60 Gy followed by consolidation durvalumab in patients without progression after initial therapy. Patients who cannot tolerate a concurrent chemoradiation approach can be managed either by sequential chemotherapy followed by radiation or by dose-escalated or hypofractionated radiation alone.

Early survival for patients newly diagnosed with cancer during COVID-19 in Ontario, Canada: A population-based cohort study

BACKGROUND

Little is known about the association between the COVID-19 pandemic and early survival among newly diagnosed cancer patients.

METHODS

This retrospective population-based cohort study used linked administrative datasets from Ontario, Canada. Adults (≥18 years) who received a cancer diagnosis between March 15 and December 31, 2020, were included in a pandemic cohort, while those diagnosed during the same dates in 2018/2019 were included in a pre-pandemic cohort. All patients were followed for one full year after the date of diagnosis. Cox proportional hazards regression models were used to assess survival in relation to the pandemic, patient characteristics at diagnosis, and the modality of first cancer treatment as a time-varying covariate. Interaction terms were explored to measure the pandemic association with survival for each cancer type.

RESULTS

Among 179,746 patients, 53,387 (29.7%) were in the pandemic cohort and 37,741 (21.0%) died over the first post-diagnosis year. No association between the pandemic and survival was found when adjusting for patient characteristics at diagnosis (HR 0.99 [95% CI 0.96-1.01]), while marginally better survival was found for the pandemic cohort when the modality of treatment was additionally considered (HR 0.97 [95% CI 0.95-0.99]). When examining each cancer type, only a new melanoma diagnosis was associated with a worse survival in the pandemic cohort (HR 1.25 [95% CI 1.05-1.49]).

CONCLUSIONS

Among patients able to receive a cancer diagnosis during the pandemic, one-year overall survival was not different than those diagnosed in the previous 2 years. This study highlights the complex nature of the COVID-19 pandemic impact on cancer care.

Toxicity and Efficacy of Multitarget Thoracic Stereotactic Body Radiation Therapy

PURPOSE

With the increasing use of stereotactic body radiation therapy (SBRT) for primary and metastatic cancer, use of multitarget thoracic (MTT) SBRT is rising. Given the limited safety and efficacy data, we report the experience of this strategy from a large academic center.

METHODS AND MATERIALS

Between 2012 and 2021, patients who received SBRT for ≥2 thoracic targets separated by ≤1 year were retrospectively reviewed. The primary endpoint was clinically significant radiation pneumonitis (CSRP) requiring steroids, oxygen, or intubation. Secondary endpoints included local failure (LF), initiation or change of systemic therapy (ICST), progression-free survival, and overall survival. Competing risk analysis was used to evaluate the cumulative incidence of CSRP, LF, and ICST. Univariate and multivariable analyses were performed to look for clinical and dosimetric predictive factors of CSRP and LF.

RESULTS

One hundred ninety patients (481 lesions) were treated with MTT SBRT with a median follow-up of 19.7 months. Indications for SBRT were oligometastases (n = 70; 36.8%), oligoprogression (n = 62; 32.6%), curative intent in patients with primary lung cancer (n = 37; 19.5%), and control of dominant areas of metastatic progression (n = 21; 11.0%). The number of irradiated tumors ranged from 2 to 7 and the majority of SBRT courses were delivered simultaneously (88.2%). Overall, 14 patients (7.4%) had CSRP, with 5 cases requiring oxygen. The cumulative incidence of CSRP at 6 and 12 months was 5.3% and 7.6%, respectively. The cumulative incidence of LF at 2 years was 10.5%. The cumulative incidence of ICST at 2 years was 41.1%. Median progression-free survival was 11.8 months and median overall survival was 51.3 months. On multivariable analysis, a higher lung V35_Gy (hazard ratio, 2.59; P = .02) was a statistically significant predictor of CSRP and colorectal histology predicted for higher LF (hazard ratio, 2.12; P = .02).

CONCLUSIONS

In one of the largest institutional series of MTT SBRT, rates of CSRP and LF were low. Optimizing plans to lower the lung V35_Gy may decrease the risk of CSRP.

Use of radiation therapy among patients with Extensive-stage Small-cell lung cancer receiving Immunotherapy: Canadian consensus recommendations

OBJECTIVES

Thoracic radiation therapy (TRT) and prophylactic cranial irradiation (PCI) are commonly used in the management of extensive-stage small-cell lung cancer (ES-SCLC); however, Phase III trials of first-line immunotherapy often excluded these options. Guidance is needed regarding appropriate use of TRT, PCI, and magnetic resonance imaging (MRI) surveillance while new data are awaited.

MATERIALS AND METHODS

In two web-based meetings, a pan-Canadian expert working group of five radiation oncologists and four medical oncologists addressed eight clinical questions regarding use of radiation therapy (RT) and MRI surveillance among patients with ES-SCLC receiving immunotherapy. A targeted literature review was conducted using PubMed and conference proceedings to identify recent (January 2019-April 2022) publications in this setting. Fifteen recommendations were developed; online voting was conducted to gauge agreement with each recommendation.

RESULTS

After considering recently available evidence across lung cancer populations and clinical experience, the experts recommended that all patients with a response to chemo-immunotherapy, good performance status (PS), and limited metastases be considered for consolidation TRT (e.g., 30 Gy in 10 fractions). When considered appropriate after multidisciplinary team discussion, TRT can be initiated during maintenance immunotherapy. All patients who respond to concurrent chemo-immunotherapy should undergo restaging with brain MRI to guide decision-making regarding PCI versus MRI surveillance alone. MRI surveillance should be conducted for two years after response to initial therapy. PCI (e.g., 25 Gy in 10 fractions or 20 Gy in 5 fractions) can be considered for patients without central nervous system involvement who have a response to chemo-immunotherapy and good PS. Concurrent treatment with PCI and immunotherapy or with TRT, PCI, and immunotherapy is appropriate after completion of initial therapy. All recommendations were agreed upon unanimously.

CONCLUSIONS

These consensus recommendations provide practical guidance regarding appropriate use of RT and immunotherapy in ES-SCLC while awaiting new clinical trial data.

Dyspnea in patients with stage IV non-small cell lung cancer: a population-based analysis of disease burden and patterns of care

Background

Patients with metastatic non-small cell lung cancer (NSCLC) experience significant morbidity with dyspnea being a common symptom with a prevalence of 70%. The objective of this study was to determine factors associated with a moderate-to-severe dyspnea score based on the Edmonton Symptom Assessment System (ESAS), as well as resultant patterns of intervention and factors correlated to intervention receipt.

Methods

Using health services administrative data, we conducted a population-based study of all patients diagnosed with metastatic NSCLC treated from January 2007 to September 2018 in the province of Ontario. The primary outcomes of interest are the prevalence of moderate-to-severe dyspnea scores, and the receipt of dyspnea-directed intervention. Differences in baseline characteristic between moderate-to-severe dyspnea and low dyspnea score cohorts were assessed by comparative statistics. Predictors of intervention receipt for patients with moderate-to-severe dyspnea scores were estimated using multivariable modified Poisson regression.

Results

The initial study cohort included 13,159 patients diagnosed with metastatic NSCLC and of these, 9,434 (71.7%) reported a moderate-to-severe dyspnea score. Compared to patients who did not report moderate-to-severe dyspnea scores, those who reported a moderate-to-severe dyspnea score were more likely to complete a greater number of ESAS surveys, be male, have a higher Elixhauser comorbidity index (ECI) score, and receive subsequent systemic therapy after diagnosis. Most patients with a moderate-to-severe dyspnea score received intervention (96%), of which the most common were palliative care management (87%), thoracic radiotherapy (56%) and thoracentesis (37%). Multivariable regression identified older patients to be less likely to undergo pleurodesis. Thoracentesis was less common for patients living in rural and non-major urban areas, lower income areas, and earlier year of diagnosis. Receipt of thoracic radiotherapy was less common for older patients, females, those with ECI ≥4, patients living in major urban areas, and those with later year of diagnosis. Finally, palliative care referrals were less frequent for patients with ECI ≥4, age 60-69, residence outside of major urban areas, earlier year of diagnosis, and lower income areas.

Conclusions

Dyspnea is a prevalent symptom amongst patients with metastatic NSCLC. Subpopulations of patients with moderate-to-severe dyspnea scores were in which inequities may exist in access to care that require further attention and evaluation.

Accelerated Hypofractionated Radiotherapy for Centrally Located Lung Tumours Not Suitable for Stereotactic Body Radiotherapy or Chemoradiotherapy

AIMS

Accelerated hypofractionated radiotherapy is used at our institution for non-small cell lung cancer (NSCLC) patients not eligible for stereotactic body radiotherapy or chemoradiotherapy. The purpose of this study was to report clinical outcomes of delivering 60 Gy in 15 fractions for these patients.

MATERIALS AND METHODS

All NSCLC patients who received 60 Gy in 15 fractions were reviewed. Outcomes of interest were local failure, regional failure, distant progression, overall survival and treatment-associated toxicities.

RESULTS

In total, 111 patients were included. The median age was 78.8 years and most tumours were adenocarcinoma (n = 55, 49.6%). Sixty-five patients (58.6%) were N0. The cumulative incidence of local failure at 12 and 24 months in the N0 cohort was 5.2% and 14.2%, respectively, compared with 11.5% and 14.8% for N+ patients. Tumour size >35 mm predicted for local failure (hazard ratio 2.706, 95% confidence interval 1.002-7.307, P = 0.0494). Distant progression at 12 and 24 months in N0 patients was 13.7% and 24.3% compared with 24.6% and 33.5% in N+ patients. In N0 patients, larger tumour size was associated with increased risk of distant progression. The median overall survival was 38.1 months in N0 patients versus 31.7 months in N+ patients. The most common toxicity was radiation pneumonitis (n = 6, 6.4%). The incidence of any grade 3 toxicity was 10.3% at ≥1 year. There were no deaths or hospitalisations attributed to treatment.

CONCLUSIONS

Accelerated hypofractionated radiotherapy is well tolerated and resulted in favourable clinical outcomes in various stages of NSCLC patients.

Timeliness and Modality of Treatment for New Cancer Diagnoses During the COVID-19 Pandemic in Canada

IMPORTANCE

The impact of COVID-19 on the modality and timeliness of first-line cancer treatment is unclear yet critical to the planning of subsequent care.

OBJECTIVE

To explore the association of the COVID-19 pandemic with modalities of and wait times for first cancer treatment.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective population-based cohort study using administrative data was conducted in Ontario, Canada, among adults newly diagnosed with cancer between January 3, 2016, and November 7, 2020. Participants were followed up from date of diagnosis for 1 year, until death, or until June 26, 2021, whichever occurred first, to ensure a minimum of 6-month follow-up time.

EXPOSURES

Receiving a cancer diagnosis in the pandemic vs prepandemic period, using March 15, 2020, the date when elective hospital procedures were halted.

MAIN OUTCOMES AND MEASURES

The main outcome was a time-to-event variable describing number of days from date of diagnosis to date of receiving first cancer treatment (surgery, chemotherapy, or radiation) or to being censored. For each treatment modality, a multivariable competing-risk regression model was used to assess the association between time to treatment and COVID-19 period. A secondary continuous outcome was defined for patients who were treated 6 months after diagnosis as the waiting time from date of diagnosis to date of treatment.

RESULTS

Among 313 499 patients, the mean (SD) age was 66.4 (14.1) years and 153 679 (49.0%) were male patients. Those who were diagnosed during the pandemic were less likely to receive surgery first (subdistribution hazard ratio [sHR], 0.97; 95% CI, 0.95-0.99) but were more likely to receive chemotherapy (sHR, 1.26; 95% CI, 1.23-1.30) or radiotherapy (sHR, 1.16; 95% CI, 1.13-1.20) first. Among patients who received treatment within 6 months from diagnosis (228 755 [73.0%]), their mean (SD) waiting time decreased from 35.1 (37.2) days to 29.5 (33.6) days for surgery, from 43.7 (34.1) days to 38.4 (30.6) days for chemotherapy, and from 55.8 (41.8) days to 49.0 (40.1) days for radiotherapy.

CONCLUSIONS AND RELEVANCE

In this cohort study, the pandemic was significantly associated with greater use of nonsurgical therapy as initial cancer treatment. Wait times were shorter in the pandemic period for those treated within 6 months of diagnosis. Future work needs to examine how these changes may have affected patient outcomes to inform future pandemic guideline development.

5-year outcomes after stereotactic ablative body radiotherapy for primary renal cell carcinoma: an individual patient data meta-analysis from IROCK (the International Radiosurgery Consortium of the Kidney)

BACKGROUND

Stereotactic ablative body radiotherapy (SABR) is a non-invasive treatment option for primary renal cell carcinoma, for which long-term data are awaited. The primary aim of this study was to report on long-term efficacy and safety of SABR for localised renal cell carcinoma.

METHODS

This study was an individual patient data meta-analysis, for which patients undergoing SABR for primary renal cell carcinoma across 12 institutions in five countries (Australia, Canada, Germany, Japan, and the USA) were eligible. Eligible patients had at least 2 years of follow-up, were aged 18 years or older, had any performance status, and had no previous local therapy. Patients with metastatic renal cell carcinoma or upper-tract urothelial carcinoma were excluded. SABR was delivered as a single or multiple fractions of greater than 5 Gy. The primary endpoint was investigator-assessed local failure per the Response Evaluation Criteria in Solid Tumours version 1.1, and was evaluated using cumulative incidence functions.

FINDINGS

190 patients received SABR between March 23, 2007, and Sept 20, 2018. Single-fraction SABR was delivered in 81 (43%) patients and multifraction SABR was delivered in 109 (57%) patients. Median follow-up was 5·0 years (IQR 3·4-6·8). 139 (73%) patients were men, and 51 (27%) were women. Median age was 73·6 years (IQR 66·2-82·0). Median tumour diameter was 4·0 cm (IQR 2·8-4·9). 96 (75%) of 128 patients with available operability details were deemed inoperable by the referring urologist. 56 (29%) of 190 patients had a solitary kidney. Median baseline estimated glomerular filtration rate (eGFR) was 60·0 mL/min per 1·73 m2 (IQR 42·0-76·0) and decreased by 14·2 mL/min per 1·73 m2 (IQR 5·4-22·5) by 5 years post-SABR. Seven (4%) patients required dialysis post-SABR. The cumulative incidence of local failure at 5 years was 5·5% (95% CI 2·8-9·5) overall, with single-fraction SABR yielding fewer local failures than multifraction (Gray's p=0·020). There were no grade 3 toxic effects or treatment-related deaths. One (1%) patient developed an acute grade 4 duodenal ulcer and late grade 4 gastritis.

INTERPRETATION

SABR is effective and safe in the long term for patients with primary renal cell carcinoma. Single-fraction SABR might yield less local failure than multifraction, but further evidence from randomised trials is needed to elucidate optimal treatment schedules. These mature data lend further support for renal SABR as a treatment option for patients unwilling or unfit to undergo surgery.

FUNDING

None.

Incident Cancer Detection During Multiple Waves of COVID-19: The Tsunami After the Earthquake

No population-based study exists to demonstrate the full-spectrum impact of COVID-19 on hindering incident cancer detection in a large cancer system. Building upon our previous publication in JNCCN, we conducted an updated analysis using 12 months of new data accrued in the pandemic era (extending the study period from September 26, 2020, to October 2, 2021) to demonstrate how multiple COVID-19 waves affected the weekly cancer incidence volume in Ontario, Canada, and if we have fully cleared the backlog at the end of each wave.

Cancer Patients First Treated with Chemotherapy: Are They More Likely to Receive Surgery in the Pandemic?

Due to the ramping down of cancer surgery in early pandemic, many newly diagnosed patients received other treatments first. We aimed to quantify the pandemic-related shift in rate of surgery following chemotherapy. This is a retrospective population-based cohort study involving adults diagnosed with cancer between 3 January 2016 and 7 November 2020 in Ontario, Canada who received chemotherapy as first treatment within 6-months of diagnosis. Competing-risks regression models with interaction effects were used to quantify the association between COVID-19 period (receiving a cancer diagnosis before or on/after 15 March 2020) and receipt of surgical reSection 9-months after first chemotherapy. Among 51,653 patients, 8.5% (n = 19,558) of them ultimately underwent surgery 9-months after chemotherapy initiation. Receipt of surgery was higher during the pandemic than before (sHR 1.07, 95% CI 1.02-1.13). Material deprivation was independently associated with lower receipt of surgery (least vs. most deprived quintile: sHR 1.11, 95% CI 1.04-1.17), but did not change with the pandemic. The surgical rate increase was most pronounced for breast cancer (sHR 1.13, 95% CI 1.06-1.20). These pandemic-related shifts in cancer treatment requires further evaluations to understand the long-term consequences. Persistent material deprivation-related inequity in cancer surgical access needs to be addressed.