Stereotactic body radiation therapy for inoperable early stage lung cancer

Radiographic Manifestations of Lung Cancer

Chest radiography is one of the most frequently utilized imaging procedures, offering advantages like accessibility, speed, affordability, and relatively low radiation exposure. Lung cancer is the third most prevalent cancer in the United States and results in the highest number of cancer-related deaths. Understanding the role of chest radiography in evaluating patients with lung cancer is crucial. This article explores the radiographic manifestations of lung cancer, the role of chest radiography in the management of lung cancer, its limitations, and when the use of computed tomography is indicated.

Stereotactic body radiation therapy in the management of lung neoplasms: is it ready for prime time?

PURPOSE OF REVIEW

Advances in radiation delivery have expanded the scope of stereotactic body radiation therapy (SBRT) in lung cancer treatment, as it offers better local control, shorter treatments, and enhanced immunostimulation. This review summarizes recent literature regarding SBRT's role in nonoperable and operable early-stage, locally advanced, central, and oligometastatic nonsmall cell lung cancer (NSCLC), and its mixed results with immunotherapy.

RECENT FINDINGS

Recent studies demonstrate SBRT achieves excellent local control in inoperable early-stage NSCLC and is being explored as an alternative to surgery for operable cases. Additionally, SBRT can be done safely in central tumors if strict dose limits to normal structures are observed. SBRT shows promise in locally advanced disease, as consolidative local therapy for oligoprogressive and oligometastatic disease and in combination with immune checkpoint inhibitors. Advances in adaptive radiation therapy and novel fractionation schedules, including ultra-hypofractionation and personalized approaches, further refine SBRT's role in lung cancer management, with more practice changing clinical trials on the horizon.

SUMMARY

SBRT provides durable and well tolerated treatment for patients with localized and metastatic lung cancer. With ongoing trials exploring its synergy with immunotherapy and its applicability in operable patients and large tumors, SBRT is poised to play an even greater role in personalized lung cancer treatment.

Induction Immunochemotherapy Followed by Hypo-Fractionated Radiotherapy in Unresectable Stage III Non-Small Cell Lung Cancer

PURPOSE

To evaluate the efficacy and safety of induction immunochemotherapy followed by hypo-fractionated radiotherapy (Hypo-RT) for locally advanced unresectable non-small cell lung cancer (LA-NSCLC).

METHODS

This retrospective analysis involved the data of 35 patients with unresectable stage III LA-NSCLC receiving immunotherapy plus Hypo-RT from January 1, 2019, to December 31, 2023. At least 2 cycles of induction immunochemotherapy were initially administered, followed by a definitive Hypo-RT at 4 Gy per fraction. The primary endpoint was overall survival (OS) and the secondary endpoints were progression-free survival (PFS) and grade ≥ 3 nonhematologic toxicities. Time-to-event outcomes for the entire cohort were calculated using the Kaplan-Meier method.

RESULTS

At a median follow-up of 31.5 months (95% confidence interval, 26.1 to 36.9 months), median OS did not reach, with 1, 2, and 3-year OS rates of 100.0%, 82.5%, and 77.3%, respectively. Disease progression or death was recorded in 18 (51.4%) patients, with a median PFS of 28.0 months (95% CI, 9.4 to 46.6 months). The 1, 2, and 3-year PFS rates were 74.3%, 55.7%, and 47.6%, respectively.

CONCLUSION

Induction immunochemotherapy followed by Hypo-RT demonstrated promising efficacy and acceptable toxicity in patients with LA-NSCLC. Studies on Hypo-RT combined with induction and consolidation immunotherapies are warranted in the future.

Immunotherapy-Boosted Stereotactic Ablative Radiotherapy in Inoperable Early-Stage Non-Small Cell Lung Cancer

OPINION STATEMENT

The combination of stereotactic ablative radiotherapy (SABR) with immune checkpoint inhibitors, known as iSABR, marks a significant evolution in treating early-stage, inoperable non-small cell lung cancer (NSCLC). Managing these cases requires a multidisciplinary approach involving radiation and medical oncologists. Clinical evidence from a meta-analysis of seven studies, including 462 patients, indicates that iSABR may offer better outcomes than SABR alone. The analysis showed significantly improved progression-free survival (PFS) rates at 1-, 2-, and 3-year follow-ups for iSABR compared to SABR. There was also a trend toward better overall survival (OS) with iSABR. Subgroup analyses highlighted enhanced 3-year PFS with programmed death-1 (PD-1) inhibitors and doses per fraction ≥ 12.5 Gy. While iSABR slightly increased the risk of grade ≥ 3 adverse events like pneumonitis, fatigue, and skin reactions, these risks are generally manageable within a multidisciplinary treatment framework. In conclusion, iSABR demonstrates potential benefits and manageable risks in phase I/II trials for early-stage, inoperable NSCLC, with improved PFS and acceptable toxicity. These findings warrant further investigation in a larger phase III prospective randomized controlled trial to validate efficacy, optimize protocols, and establish long-term safety.

Clinical outcomes of proton beam therapy for inoperable stage I-IIA non-small cell lung cancer: Japanese nationwide registry study

PURPOSE

Radiotherapy is the standard treatment for unresectable stage I-IIA non-small cell lung cancer (NSCLC). One treatment option within radiotherapy is proton beam therapy (PBT). Currently, a prospective observational study is being conducted at all proton therapy centers in Japan as part of a proton beam all-case registry. This study aimed to evaluate the outcomes of PBT for inoperable stage I-IIA NSCLC.

METHODS

We included patients with stage I-IIA (UICC 8th) NSCLC who had started PBT between May 2016 and June 2020. Overall survival (OS), progression-free survival (PFS), cumulative incidence of local failure (LF), and adverse events were evaluated. Prognostic factors were compared using log-rank test and Cox proportional hazards model. The cumulative incidence curves were compared using Gray's test.

RESULTS

A total of 309 patients were evaluated. The median follow-up period was 47 months, calculated using the reverse Kaplan-Meier method. The 3/5-year OS was 62.7 %/47.7 %, PFS was 52.9 %/40.0 %, and LF was 14.4 %/22.1 %. According to the stage, 3-year OS, PFS, and LF were 69.6 %, 58.7 %, 13.3 %, respectively, for stage IA; 55.3 %, 41.6 %, 15.6 %, respectively, for stage IB; 33.9 %, 41.5 %, 25.6 %, respectively, for stage IIA. Female sex and good performance status, absence of interstitial pneumonia, absence of double cancer, and T1 stage were favorable prognostic factors for OS in a multivariate analysis. Grade ≥ 4 adverse events were not observed.

CONCLUSION

This study provided real-world treatment outcomes of PBT for inoperable stage I-IIA NSCLC in Japan.

Inhalable biomimetic polyunsaturated fatty acid-based nanoreactors for peroxynitrite-augmented ferroptosis potentiate radiotherapy in lung cancer

The limited efficacy and poor tumor accumulation remain crucial challenges for radiotherapy against lung cancer. To address these limitations, we rationally developed a polyunsaturated fatty acid (PUFA)-based nanoreactor (DHA-N@M) camouflaged with macrophage cell membrane to improve tumoral distribution and achieve peroxynitrite-augment ferroptosis for enhanced radiotherapy against lung cancer. After nebulization, the nanoreactors exhibited superior pulmonary accumulation in orthotopic lung cancer-bearing mice, with 70-fold higher than intravenously injected nanoreactors at 12 h post-administration, and distributed deeply in the tumors. DHA-N@M selectively released nitric oxide (NO) in glutathione (GSH)-enriched tumor cells, with consumption of GSH and subsequent inactivation of glutathione peroxidase 4 (GPX4). Under radiation, NO reacted with radiotherapy-induced reactive oxygen species (ROS) to generate peroxynitrite (ONOO-), resulting in redox homeostasis disruption. Combined with docosahexaenoic acid (DHA)-induced lipid metabolism disruption, overwhelming ferroptosis was induced both in vitro and in vivo. Notably, DHA-N@M mediated ferroptosis-radiotherapy significantly suppressed tumor growth with a 93.91% inhibition in orthotopic lung cancer models. Therefore, this design provides a nebulized ferroptosis-radiotherapy strategy for lung cancer.

Stereotactic body radiation therapy (SBRT) of centrally located medically inoperable early-stage non-small cell lung cancer (T1-T3N0M0) - A subgroup analysis of the expanded HILUS study

INTRODUCTION

Centrally located early-stage non-small cell lung cancer (ES NSCLC) with tumors close to the bronchi is potentially curable with stereotactic body radiation therapy (SBRT). To evaluate the clinical benefit of the treatment, both the risk of high-grade toxicity as well as the treatment efficacy need to be assessed.

MATERIAL AND METHODS

From the expanded HILUS cohorts, 72 patients with T1-T3N0M0 NSCLC were included in the current analysis. All patients had been treated with SBRT in 8 fractions to 56 Gy for a tumor located within 2 cm from the tracheobronchial tree. Primary endpoint was progression free survival (PFS) and secondary endpoints included pattern of failure, local control (LC), lung cancer-specific survival (LCSS), overall survival (OS) and toxicity. The Kaplan-Meier method and Cox regression analysis were used.

RESULTS

The median age of the cohort was 73 years and all patients suffered from comorbidities prior to SBRT. T2-T3 tumors were seen in 65 % of the patients. Seventeen patients relapsed after SBRT and distant recurrence was the most common form of relapse. Three-year PFS was 31 % (95 % CI 22-44) and largely explained by the short overall survival (38 % (95 % CI 22-44) at 3 years). Three-year rates of LC and LCSS were 97 % (95 % CI 92-100) and 76 % (95 % CI 65-89), respectively. Twelve patients (17 %) suffered from grade 5 toxicity, of which 9 were bronchopulmonary bleedings.

CONCLUSION

The severe toxic profile limits the clinical benefit using SBRT with the investigated approach for patients with centrally located ES NSCLC.

Dose Planning and Radiation Optimization for Thoracic Conventional, Twice Daily, and Stereotactic Radiation Therapy: A Delphi Consensus From a National Survey of Practitioners

PURPOSE

We sent surveys to a large number of radiation oncologists with active thoracic cancer practices and applied the Delphi method over 3 rounds to generate consensus dose-volume histogram metrics. We used these results to create consensus-based organs-at-risk dose constraints and target goal templates for practical implementation.

METHODS AND MATERIALS

In this institutional review board-approved study, data were collected using REDCap electronic data capture on a secure server. Radiation oncologists identified from the Accreditation Council for Graduate Medical Education-accredited departments' websites were asked to confirm their self-identification as thoracic radiation oncologists and nominate other respondents. All invitees were asked to complete 3 rounds of questions related to normal tissue constraints, target coverage metrics, prescribing practices, and other planning considerations. Preliminary consensus statements were presented in the second round of surveys for voting on a 5-point Likert scale. The third and last round of surveys presented the iterated consensus statements and target coverage metric statements for final voting. The high consensus was predefined as ≥ 75% agreement.

RESULTS

Eighty-three (42.8%) of 194 invitees completed at least 1 round of surveys. The group included a diversity of gender, geography, and clinical settings. Response rates were 83%, 57%, and 55%, respectively, for the 3 rounds. By the end of the process, 48 of 96 (50%) originally proposed normal tissue dose constraint statements were iterated to consensus, and 5 of 7 (71%) proposed target coverage metric statements achieved consensus. These were used to create crowdsourced treatment planning templates.

CONCLUSION

This study achieved broad-based consensus-building on ideal and acceptable dose constraints for conventional, twice-daily, and stereotactic thoracic radiation therapy. Future directions could include extending this approach to other disease sites, studying the influence of widespread implementation on treatment planning, or facilitating the development of community consensus around emergent or controversial questions.

Immunotherapy for Early-Stage Non-Small Cell Lung Cancer: A Practical Guide of Current Controversies

The role of immunotherapy as systemic therapy for nonmetastatic non-small cell lung cancer (NSCLC) has evolved rapidly over the last decade. There are several well-conducted phase 3 clinical trials evaluating immunotherapy in the neoadjuvant, perioperative, adjuvant and nonoperative setting. In this narrative review, we summarize the data from these studies and discuss ongoing controversies in applying these data to clinical practice. These controversies relate to the value of the adjuvant component of perioperative immunotherapy, treatment of patients with PDL1 negative tumors, defining resectability, optimal use of operative versus nonoperative management, the role of stereotactic radiation therapy for very early lung cancers, and management of tumors with an oncogenic driver.

Stereotactic Body Radiation Therapy for Primary Lung Cancer and Metastases: A Case-Based Discussion on Challenging Cases

PURPOSE

Data informing the safety, efficacy, treatment logistics, and dosimetry of stereotactic body radiation therapy (SBRT) for lung tumors has primarily been derived from patients with favorably located solitary tumors. SBRT is now considered a standard-of-care treatment for inoperable early-stage non-small cell lung cancer and lung metastases, and therefore extrapolation beyond this limited foundational patient population remains an active source of interest.

METHODS AND MATERIALS

This case-based discussion provides a practical framework for delivering SBRT to challenging, yet frequently encountered, cases in radiation oncology. The cases highlighted herein include the use of SBRT for ultracentral tumors, multiple tumors, and reirradiation. Patient characteristics, fractionation, prescription dose, treatment technique, and dose constraints are discussed. Relevant literature to these cases is summarized to provide a framework for the treatment of similar patients.

RESULTS

Treatment of challenging cases with lung SBRT requires many considerations, including treatment intent, fractionation selection, tumor localization, and plan optimization. In such scenarios, patient selection is critical to understanding the risk-benefit profile of an SBRT approach despite significant advances in delivery techniques and safety.

CONCLUSIONS

A case-based discussion was developed by the Radiosurgery Society to provide a practical guide to the common challenging scenarios noted above affecting patients with lung tumors. A multidisciplinary approach should guide the treatment of such cases to maximize the therapeutic window.

Patient Positional Uncertainty and Margin Reduction in Lung Stereotactic Ablative Radiation Therapy Using Pneumatic Abdominal Compression

PURPOSE

Motion management presents a significant challenge in thoracic stereotactic ablative radiation therapy (SABR). Currently, a 5.0-mm standard planning target volume (PTV) margin is widely used to ensure adequate dose to the tumor. Considering recent advancements in tumor localization and motion management, there is merit to reassessing the necessary PTV margins for modern techniques. This work presents a large-scale analysis of intrafraction repositioning for lung SABR under forced shallow breathing to determine the margin requirements for modern delivery techniques.

METHODS AND MATERIALS

Treatment data for 124 lung SABR patients treated in 607 fractions on a linear accelerator were retrospectively collected for analysis. All patients were treated using pneumatic abdominal compression and intrafraction 4-dimensional (4D) cone beam computed tomography (4D CBCT)-guided repositioning halfway through treatment. Executed repositioning shifts were collected and used to calculate margin requirements using the 2-SD method and an analytical model which accounts for systematic and random errors in treatment.

RESULTS

A total of 85.7% of treated fractions had 3-dimensional repositioning shifts under 5.0 mm. Fifty-three fractions (8.7%) had shifts ≥ 5.0 mm in at least 1 direction. Margins in the right-left, inferior-superior, and posterior-anterior directions were 3.62 mm, 4.34 mm, and 3.50 mm, respectively, calculated using the 2-SD method. The analytical approach estimated that 4.01 mm, 4.37 mm, and 3.95 mm margins were appropriate for our workflow. Executing intrafraction repositioning reduced margin requirements by 0.73 ± 0.07 mm.

CONCLUSIONS

Clinical data suggest that the uniform 5.0-mm margin is conservative for our workflow. Using modern techniques such as 4D CT, 4D CBCT, and effective motion management can significantly reduce required margins, and therefore necessary healthy tissue dose. However, the limitations of margin calculation models must be considered, and margin reduction must be approached with caution. Users should conduct a formal risk assessment prior to adopting new standard PTV margins.

Comparison of Survival Outcomes of Early-Stage Non-Small-Cell Lung Cancer in Elderly Patients (≥ 70 years) Treated With Stereotactic Body Radiotherapy Versus Surgical Resection

OBJECTIVE

To evaluate the survival outcomes of stereotactic body radiotherapy (SBRT) versus surgical resection in elderly patients (≥ 70 years old) with early-stage non-small-cell lung cancer (NSCLC).

METHODS

A systematic search was conducted across databases such as PubMed, Web of Science, EMBASE, Cochrane Library, CNKI, VIP, and Wanfang to collect comparative studies on the survival outcomes of SBRT versus surgery for early-stage NSCLC in elderly patients, with searches up to December 2023 and statistical analysis performed using Stata software. This meta-analysis included 10 comparative studies, encompassing 9410 elderly patients with early-stage NSCLC.

RESULTS

The results indicated that the SBRT group had worse outcomes compared to the surgery group in terms of 3-year overall survival (OS) [HR = 1.31, 95% CI (1.02-1.70), p < 0.05], 5-year OS [HR = 1.37, 95% CI (1.06-1.77), p < 0.05], 1-year cancer-specific survival (CSS) [HR = 1.32, 95% CI (1.03-1.68), p < 0.05], 3-year CSS [HR = 1.89, 95% CI (1.70-2.11), p < 0.01], and 5-year CSS [HR = 1.92, 95% CI (1.75-2.10), p < 0.01]. There were no statistically significant differences between the two groups in terms of 1-year OS, 1-year, 3-year, and 5-year progression-free survival (PFS), and locoregional control (LC) rates (p > 0.05).

CONCLUSION

For elderly early-stage NSCLC patients with acceptable risk, surgery remains the more appropriate treatment method. For patients unable to undergo surgery or who refuse it, SBRT serves as a viable alternative treatment option.

A Propensity-Matched Comparison Between Minimally Invasive Surgery and Stereotactic Radiotherapy in the Treatment of Clinical Stage IA Non-Small-Cell Lung Cancer (NSCLC)

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death globally, with stage IA NSCLC presenting a unique opportunity for curative interventions. The efficacy of minimally invasive surgery (MIS) vs. stereotactic ablative radiotherapy (SABR) remains debated due to limited direct comparative data.

METHODS

This multicenter observational study analyzed data from 1014 patients diagnosed with clinical stage IA NSCLC (2015-2021) and treated with MIS (including VATS and RATS) or SABR. After propensity score matching, 234 patients (117 per group) were included. Matching balanced age, ECOG performance status, Charlson Comorbidity Index, lung function, and histological subtype to compare overall survival (OS), freedom from recurrence (FFR), and recurrence rates.

RESULTS

The mean follow-up was 35 months for MIS and 33 months for SABR. The matched cohort (n = 234) showed superior 5-year locoregional control (LRC) rates for MIS (93%) vs. SABR (88%). FFS at 2 and 5 years was higher for MIS (93.5% and 90.3%) than SABR (82.1% and 77.9%; P = .010). OS was significantly higher in MIS, with a hazard ratio of 1.60 (95% CI: 1.11-2.31). Early mortality rates were 2.6% for MIS at 30 and 90 days. SABR exhibited no 30-day mortality and a 90-day rate of 1.7%.

CONCLUSION

MIS is associated with higher OS, LRC and FFR, but higher treatment-related mortality compared to SABR for stage IA NSCLC. This study supports the preference for surgical interventions where feasible. While future randomized controlled trials may provide more insights, this observational study contributes valuable evidence to guide clinical decision-making.

Stereotactic reirradiation for in-field lung cancer recurrence after stereotactic ablative radiotherapy: A systematic review and meta-analysis

PURPOSE

There is paucity of data for thoracic in-field reirradiation with two courses of stereotactic ablative radiotherapy (SABR). This meta-analysis evaluates the safety and efficacy of repeat SABR as salvage therapy for in-field failures after definitive SABR.

MATERIALS AND METHODS

A systematic search of PubMed, Cochrane Library, MEDLINE, and EMBASE databases was conducted in accordance with PRISMA guidelines. Studies were included if they involved adult patients treated with salvage SABR for in-field recurrences of lung cancer following prior SABR. To address varying definitions of local failure, studies were included if recurrence occurred within the original planning target volume (PTV). Studies with out-of-field failures (>1 cm from PTV) or those using non-SABR techniques were excluded. Pooled 1- and 2-year local control (LC) rates, overall survival (OS), and toxicities were calculated using a random-effects model. Population-weighted linear regression was employed to assess the relationship between dosimetric and clinico-pathologic variables and patient outcomes.

RESULTS

Twelve studies involving 197 patients were included in the quantitative analysis. All patients received two courses of SABR, with a median total dose of 50 Gy in 5 fractions. Pooled 1- and 2-year LC rates were 78.2 % (95 % CI: 66-87 %) and 68.0 % (95 % CI: 55-79 %), respectively. Patients receiving a cumulative biologically effective dose (BED) ≥ 200 Gy had significantly higher LC rates (84.9 %, 95 % CI: 70-93 %) vs (64.9 %, 95 % CI: 54-75 %, p = 0.02). Median OS did not significantly differ between low and high BED groups, though there was a trend toward improved survival with higher BED (21.4 vs 32.6 months). The pooled median OS across all studies was 26.3 months (95 % CI: 25.4-27.1). Improved LC rates were associated with smaller tumours (<2 cm), higher BED from the initial treatment and longer interval (>12 months) between initial and repeat SABR (p < 0.01). Toxicities were minimal, with a pooled incidence of ≥ grade 2 pneumonitis at 6.4 % and only 0.10 % reporting ≥ grade 3 toxicity.

CONCLUSIONS

Salvage in-field reirradiation with SABR achieves high local control and low toxicity, particularly in patients receiving higher cumulative BED (≥200 Gy) and with longer intervals (≥12 months) between treatments. These results suggest that repeat SABR is a viable salvage option for selected patients. Further prospective studies are needed to optimise dosing and patient selection for safe and effective reirradiation.

Realistic closed-form TCP model including cell sensitivity dependence

Objective.To develop a mechanistic extension of the Poisonnian linear quadratic (LQ) tumor control probability (TCP) formulation by incorporating tumor volume and cell sensitivity inter-patient variations which can be applied to a cohort of patients.Approach.A novel closed-form expression for TCP was derived from first principles, incorporating inter-individual variations in tumor volume and cell sensitivity within the LQ model of tumor control. Furthermore, an exponential time dependence of local control (LC) in terms of TCP was introduced. The proposed model was fitted to 22 datasets of early-stage non-small cell lung cancer (NSCLC), encompassing various dose regimes, tumor volumes, treatment duration and outcome values over different follow-up periods. A log-likelihood algorithm was employed for the fitting process.Main results.The fit of the population TCP model, which adopts tumor volume and cell radiosensitivities uniformly distributed, resulted in a cell sensitivity value ofα¯U=0.37 [0.13-0.47]Gy-1, its corresponding bandwidthΔα= 0.37 [0.04-0.42] Gy-1,β =0. 015 [0.009-0.039] Gy-2, the characteristic time at which LC reaches TCP,t1/2= 19.6 [7.3-90.8] months, and the cell population doubling timeTd= 2.0 [0.2 4.9] days. The parametersα¯U,Δα andβwere found to be significant (p< 0.05), whilet1/2andTdproved non-statistically significant for the model under Wald test. This model describes data from 1675 lesions and offers a better fit compared to alternative approaches incorporating Gaussian or log-normal radiosensitivity distributions.Significance.A closed form of TCP population model was derived by including cell sensitivity and tumor size heterogeneities. A relation between TCP and LC was established by modeling LC as an exponential function of follow-up time. The derived TCP population model facilitates direct application to clinical datasets and was tested against NSCLC clinical data. Individual TCP can be estimated from the radiobiological parameters of the population.

Chronic progressive pulmonary aspergillosis within the irradiated field after stereotactic body radiotherapy: two case reports

Stereotactic body radiation therapy (SBRT) is the standard treatment for patients who are medically inoperable or who refuse surgery with stage I non-small cell lung cancer (NSCLC). While acute lymphopenia following SBRT is documented, the long-term effects on the immune system and infectious disease remain unclear. In this report, we present two cases of chronic progressive pulmonary aspergillosis (CPPA) occurring within the irradiated field following SBRT for inoperable stage I NSCLC. Case 1 was a man in his 70 s with a history of smoking and a previous pulmonary resection and SBRT for metachronous primary lung cancer. He received SBRT for T1aN0M0 NSCLC in the right lower lobe as his third primary lung cancer. After 20 months, the patient developed a cough and sputum, and a computed tomography (CT) scan revealed a cavity shadow in the irradiated field, which led to the diagnosis of CPPA. Intravenous voriconazole was immediately started, and after 3 week's administration, the symptoms improved, and the cavity disappeared. After 34 months, the patient died with no recurrence of CPPA and lung cancer. Case 2 was a man in his 80 s with a history of smoking and previous pulmonary resection for lung cancer. He received SBRT for T1cN0M0 NSCLC in the right lower lobe as his second primary lung cancer. After 19 months, the patient developed a fever, and a CT scan revealed a cavity shadow in the irradiated field, which led to the diagnosis of CPPA. Oral itraconazole was administered, followed by diarrhea and anorexia. After 22 days, the patient died. During the follow-up period, there was no recurrence of lung cancer. Risk factors for CPPA include a history of smoking and lung resection, common among candidates for pulmonary SBRT. When a cavity shadow develops following SBRT, differentiating consolidation as radiation pneumonitis, local recurrence, or infection can be challenging. When a cavity is identified on a follow-up CT scan after SBRT, it is crucial to include CPPA in the differential diagnosis.

Risk-adapted stereotactic body radiation therapy for the treatment of large (>3 cm) primary lung cancer with or without histologic confirmation: A propensity score matched and weighted analysis

PURPOSE

Stereotactic body radiation therapy (SBRT) is a promising therapeutic approach for inoperable, small (≤3 cm) primary lung cancer. However, the efficacy and safety of risk-adapted SBRT for treating large (>3 cm) primary lung cancer remains inadequately characterized.

PATIENTS AND METHODS

Patients with large (>3 cm) primary lung cancer, diagnosed either clinically or histologically, were recruited between November 1, 2010 and December 31, 2022. Risk-adapted SBRT was administered in fractions (median, 5) for a total dose of 60 Gy (range, 45-63 Gy). The primary endpoint was overall survival (OS), and secondary endpoints included progression-free survival (PFS), local failure (LF), regional failure (RF), distant metastasis (DM), cancer-specific mortality (CSM), and toxicity. Differences in baseline characteristics were balanced via propensity score matching (PSM) with the logistic regression model, as well as 1:1 ratio matching and inverse probability of treatment weighting (IPTW). The Cox proportional hazards model was used for univariate and multivariate analyses aimed at identifying prognostic factors influencing OS and PFS.

RESULTS

The 126 enrolled patients included 61 cases (48.4 %) diagnosed clinically and 65 cases (51.6 %) diagnosed pathologically. Following PSM and IPTW, no differences were found between patients diagnosed clinically versus pathologically in OS, PFS, tumor failure, and CSM. Univariate and multivariate analyses identified a Charlson comorbidity index ≥5 as an adverse prognostic factor for OS and PFS. One patient (0.8 %) in the pathologically diagnosed group developed grade 5 pneumonitis 2 months after undergoing SBRT.

CONCLUSIONS

Risk-adapted SBRT may be an optimal treatment for appropriately selected patients with a large (>3 cm) primary lung cancer lacking histologic confirmation.

Stereotactic Magnetic Resonance Guided Adaptive Radiation Therapy in One Fraction: A Multicenter, Single-Arm, Phase 2 Trial

PURPOSE

Stereotactic body radiation therapy (SBRT) is an advanced technique that enables precise delivery of radiation directly to a tumor, typically in ≤5 fractions. Single-fraction SBRT for visceral tumors is uncommon, likely related to concerns about risks of geographic tumor miss because of suboptimal cone beam computed tomography scan quality on conventional linear accelerators (linacs). Magnetic resonance (MR) guided linacs are a novel technology offering superior imaging that might facilitate the safe delivery of single-fraction SBRT.

METHODS AND MATERIALS

We conducted a multicenter phase 2 trial of single-fraction SBRT delivered on a 0.35 Tesla MR-linac for primary or metastatic lesions of the lung (30-34 Gy; biologically effective dose [BED10] = 120-149.6 Gy10), liver (35-40 Gy; BED10 = 157.5-200 Gy10), pancreas (25 Gy; BED10 = 87.5 Gy10), adrenal gland (25 Gy10), kidney (25 Gy10), and abdominal/pelvic lymph nodes (25 Gy10). Primary objectives included feasibility and safety. The trial is registered with ClinicalTrials.gov, NCT04939246.

RESULTS

The study accrued 30 patients with 32 lesions at 2 centers in the United States between June 2021 and June 2023. All patients had 1 lesion except for 2 with 2 lesions each. Target locations included lung (34.4%), adrenal gland (28.1%), lymph node (18.8%), liver (15.6%), and pancreas (3.1%). The primary objectives were met; total in-room time was <90 minutes for 87.1% of delivered plans and 1 acute grade 3 adverse event was possibly related to single-fraction SBRT. No late grade 3-to-5 adverse events were observed. One-year local control and overall survival were 96.2% (95% CI, 88.8%-100%) and 86.3% (95% CI, 73.8%-98.8%), respectively.

CONCLUSIONS

This is the first prospective study to demonstrate that MR guided single-fraction SBRT is feasible, safe, and effective for not only tumors in the peripheral lung, but also the abdomen and pelvis. Future studies should clarify patient selection for single- versus multifraction SBRT.

A Systematic Review of SBRT Boost for Cervical Cancer Patients Who Cannot Benefit from Brachytherapy

Stereotactic body radiation therapy has emerged as a promising alternative to brachytherapy, delivering high doses to tumors with precision while sparing surrounding organs. This systematic review evaluates the role of SBRT as a boost for patients who are ineligible for brachytherapy. A total of 17 studies, involving 288 patients, were analyzed, focusing on dosimetric parameters and toxicity. The radiation regimens varied in dose and fractionation schedules, with external beam doses ranging from 44 to 61.6 Gy, and SBRT boost doses ranging from 5 to 30 Gy. The total EQD2 doses were between 50.5 and 92.4 Gy. The results indicate adequate tumor control with SBRT, with local control rates ranging from 57% to 95.5%. The acute genitourinary and gastrointestinal toxicities were mostly grade 1 or 2, while late toxicities were less common. The overall survival rates varied between 34% and 96%. These results suggest that SBRT boost offers a viable option for cervical cancer patients ineligible for brachytherapy, with acceptable toxicity and promising survival outcomes. Nevertheless, the scarcity of data, which mainly originate from small studies with patients having varied stages of disease, as well as the lack of long-term follow up with SBRT, should encourage clinicians to utilize brachytherapy whenever suitable as a boost in these patient cohorts.

Survival benefit of surgery vs radiotherapy alone to patients with stage IA lung adenocarcinoma: a propensity score-matched analysis

OBJECTIVES

We compared the overall survival (OS) and cancer-specific survival (CSS) of patients who received radiotherapy and surgery, respectively, in a large population.

METHODS

In this study, we counted the patients diagnosed with stage IA lung adenocarcinoma in the SEER database from 2015 to 2019. We compared the overall survival (OS) and cancer-specific survival (CSS) through Kaplan Meier analysis, balanced the differences of primary data through propensity score matching (PSM), screened independent prognostic factors through Cox regression analysis, and then compared the survival differences of different treatment methods through hierarchical analysis.

RESULTS

Among 11,159 patients with stage IA lung adenocarcinoma, 4254 patients chose radiotherapy alone (38.1%), and 6688 patients were finally included through the propensity score matching. The median survival time for patients with radiotherapy alone was 53 months, while the patients with surgery alone did not reach the median survival time (p < 0.001). Multivariate analysis showed that age, sex, tumor size, and household income affected the prognosis of patients. The results of the stratified analysis showed that, except in the subgroup of age ≤ 50 years, almost all subgroup analyses showed that surgical treatment achieved better results.

CONCLUSIONS

Radiotherapy alone can be used as an option for patients with stage IA lung adenocarcinoma who cannot tolerate surgery, but the benefit to patients is limited, and surgical treatment may still be the best choice.

Clinical practice in stereotactic radiotherapy delivery at treatment unit: a practitioner survey and consensus-based recommendations for multidisciplinary professional development

PURPOSE

Stereotactic radiation therapy (SRT) is on the rise around the world. We aimed to provide recommendations to streamline and assess medical practices in SRT delivery at treatment unit, while complying with legal obligations concerning safety.

MATERIALS AND METHODS

We conducted an online closed practice survey for heads of radiotherapy departments both nationally in comprehensive cancer centers and university hospitals throughout France, and internationally. The aim was to obtain a better understanding of how the delivery of SRT at treatment unit was managed across different centers according to experience, and to the machines and repositioning techniques used. Radiation oncologists (ROs) were also asked to assess the difficulties of technical implementation in the department, and whether residents were involved in the validation and delivery of SRT. Differences among countries regarding legislation governing the validation of SRT sessions at treatment unit were also collected. A videoconference was then held to draw up proposals for regulatory changes based on the results obtained. Finally, recommendations were drawn up by the steering committee and approved by heads of radiotherapy departments in comprehensive cancer centers and university hospitals throughout France.

RESULTS

Thirty-five French centers and 15 centers from 14 foreign countries responded to the questionnaire. The most common stereotactic machines were Varian Truebeam STX® (45%) and Cyberknife® (39.2%). The departments had been performing SRT for more than 10 years in 60.5% of cases, and for less than 5 years in 10.1% of cases. A RO validated the SRT fractions at each session in 62.9% of French departments, while in countries outside France RO validation concerned the first fraction only for 35.3% or was performed only in the event of an issue for 23.5%. RO patient positioning validation of SRT fractions were considered as: time-consuming / task-interrupting (80%); having no added value with regards its systematic use (41.8%); and leading to a loss of machine time (33.1%). Most heads of departments would like to see an evolution towards systematic RO validation for the first session, then validation by a radiation therapist (RTT) for all subsequent sessions, leaving open the possibility of RO intervention when required in case of difficulty. We drew up a task delegation procedure to meet these requirements.

CONCLUSION

Comparing the French practice to international ones confirmed the need to develop and harmonize recommendations in terms of patient positioning validation at treatment unit. Regulatory changes incorporating a competence transfer to RTTs, particularly after the empowerment process, is key. However, these changes need to be adapted to the experience of each Center and to that of each RTT, as assessed with clearly established criteria and learning curve.

Stereotactic body radiotherapy for treating lung cancer with a leadless pacemaker: A case report

RATIONALE

Stereotactic body radiotherapy (SBRT) is a precise treatment modality for lung cancer, delivering high-dose radiation to tumors while sparing surrounding organs. However, because of their intracardiac placement and proximity to the chest radiation field, leadless pacemakers (LLPMs) pose unique challenges that are not fully addressed by the existing protocols for conventional pacemakers.

PATIENT CONCERNS

In this case study, we aimed to emphasize the importance of identifying LLPMs before initiating SBRT for lung cancer and to discuss the necessary adjustments in treatment planning needed to accommodate these devices.

DIAGNOSES

An 81-year-old female with stage IA adenocarcinoma in the left lower lobe of the lung underwent SBRT.

INTERVENTIONS

During initial planning, the presence of an LLPM implanted in the right ventricle of the heart was overlooked. According to the original rotational arc therapy plan, 5 Gy of radiation would have been delivered to the pacemaker; therefore, a revised treatment plan using a fixed-beam multiport approach was adopted to avoid exposing the device to radiation.

OUTCOMES

Pacemaker functionality was unaffected post-treatment, and the therapy was concluded without complications.

LESSONS

This case emphasizes the critical need for identifying LLPMs prior to treatment and the importance of tailored radiotherapy plans to prevent device malfunction. The increasing use of these devices necessitates adherence to guidelines which recommend cumulative radiation doses of <5 Gy. Consequently, a thorough patient history and meticulous imaging review are required since identifying LLPMs on computed tomography can be challenging. Furthermore, effective SBRT in patients with lung cancer and LLPMs requires careful planning to ensure safety and therapeutic success. This case provides valuable insights for radiation oncologists, advocating for diligent pretreatment evaluation and customized radiation strategies in the context of evolving cardiac implant technologies.

Effect of Treatment Delivery Schedule for Patients With Early-Stage Non-Small Cell Lung Cancer Treated With Stereotactic Ablative Radiation Therapy: A Population-Based Analysis

PURPOSE

The optimal SABR treatment delivery schedule in stage I non-small cell lung cancer (NSCLC) remains unclear. This population-based study investigated grade ≥2 toxicity rates, local failure (LF), and overall survival (OS) in patients treated with 48 Gy in 4 fractions scheduled every other day versus daily with weekends and consecutive daily without weekends.

METHODS AND MATERIALS

Between January 2019 and June 2022, treatment records using 48 Gy in 4 fractions were extracted from a provincial cancer registry and grouped by delivery as every other day, daily with weekends, or consecutive daily without weekends. Toxicity events were recorded using National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0. The Kaplan-Meier method was used to compute OS and LF was calculated using cumulative incidence methods with death as a competing risk. Cox regression analyses and Fine-Gray modeling was used to assess for variables associated with OS and LF, respectively.

RESULTS

Of 404 patients meeting study criteria, 190, 111, and 103 received SABR every other day, daily with weekends, and consecutive daily without weekends, respectively. More patients receiving SABR daily with weekends were medically inoperable and more patients receiving SABR consecutive daily without weekends had tumors abutting the chest wall. Median follow-up time was 29.5 months (IQR, 19.2-38.4 months). Overall toxicity was low, with crude rates of acute and late grade ≥2 toxicity not being statistically different among the groups. No grade 4 or 5 toxicities were recorded. LF rates at 24 months were not different at 7.5% (95% CI, 3.7-11.3), 9.5% (95% CI, 3.9-15.1), and 11.0% (95% CI, 4.9-17.2) for the every other day, daily with weekends, and consecutive daily without weekends groups, respectively (P = .60). Schedules of daily with weekends and consecutive daily without weekends were not associated with LF. Similarly, no significant differences in median OS were found among the every other day, daily with weekends, and consecutive daily without weekends groups at 47.5 months (95% CI, 39.26-55.74), 52.7 months (95% CI, 34.7-70.7), and 49.0 months (95% CI, 31.6-66.4), respectively. Schedules of daily with weekends and consecutive daily without weekends were not associated with OS.

CONCLUSIONS

This population-based study demonstrated no statistically significant differences in grade ≥2 toxicity rates, LF, and OS for patients with stage I NSCLC treated with lung SABR using 48 Gy in 4 fractions delivered every other day, daily with weekends, and consecutive daily without weekends. Patient convenience and optimization of resources may be considered when choosing a lung SABR treatment delivery schedule.

Radiomics and dosiomics approaches to estimate lung function after stereotactic body radiation therapy in patients with lung tumors

Lung function assessment is essential for determining the optimal treatment strategy for radiation therapy in patients with lung tumors. This study aimed to develop radiomics and dosiomics approaches to estimate pulmonary function test (PFT) results in post-stereotactic body radiation therapy (SBRT). Sixty-four patients with lung tumors who underwent SBRT were included. Models were created to estimate the PFT results at 0-6 months (Cohort 1) and 6-24 months (Cohort 2) after SBRT. Radiomics and dosiomics features were extracted from the computed tomography (CT) images and dose distributions, respectively. To estimate the PFT results, Models A (dose-volume histogram [DVH] + radiomics features) and B (DVH + radiomics + dosiomics features) were created. In the PFT results, the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were estimated using each model, and the ratio of FEV1 to FVC (FEV1/FVC) was calculated. The Pearson's correlation coefficient (Pearson r) and area under the curve (AUC) for FEV1/FVC (< 70%) were calculated. The models were evaluated by comparing them with the conventional calculation formulae (Conventional). The Pearson r (FEV1/FVC) values were 0.30, 0.64, and 0.69 for Conventional and Models A and B (Cohort 2), respectively, and the AUC (FEV1/FVC < 70%) values were 0.63, 0.80, and 0.78, respectively. This study demonstrates the possibility of estimating lung function after SBRT using radiomics and dosiomics features based on planning CT images and dose distributions.

[Stereotactic radiotherapy for lung cancer]

The treatment of early stage T1-T2N0M0 non-small cell lung cancers (NSCLC) was previously based on surgery. However, 20 to 25% of patients are inoperable due to their age, comorbidities or refuse surgery. Since 2018, stereotactic body radiation therapy (SBRT) has become the standard treatment for these patients. For operable patients, the comparison surgery - SBRT is difficult without a clear conclusion, the different phase III trials have not yet permitted to provide a formal answer in terms of local control and survival by default of inclusion. Dose and fractionation need to be selected according to tumor location. Tolerance is usually good, with few grade ≥3 toxicities; however, caution is advised for ultra-central tumors and in case of interstitial pneumonia. Post-therapeutic imaging monitoring is complex, sometimes with uncertainties between radiation-induced pneumonitis and relapse. This complexity may increase in ongoing trials combining SBRT and immunotherapy.

Comparison of surgical and radiotherapy outcomes in octogenarians with early-stage non-small cell lung cancer: a SEER database retrospective cohort study

BACKGROUND

Lung cancer remains the leading cause of death worldwide, yet optimal treatment strategies for octogenarians with early-stage non-small cell lung cancer (NSCLC) remain unclear.

AIMS

To investigate treatment patterns and survival outcomes in octogenarians and older with early-stage NSCLC.

METHODS

A retrospective cohort study was conducted using Surveillance, Epidemiology, and End Results database. Patients aged ≥ 80 years with stage I-IIA NSCLC diagnosed between 2011 and 2020 were included. Primary treatments included surgery, radiation, and no treatment. Kaplan-Meier curves were used to evaluate overall survival (OS) and cancer-specific survival (CSS) stratified by treatment and year. Propensity score matching balanced clinical characteristics between surgery and radiation groups, followed by Cox regression analysis. Survival outcomes were further compared within matched subgroups stratified by tumor size.

RESULTS

Among 7,372 patients, median survival was 67 months for surgery and 33 months for radiotherapy. Radiotherapy use increased from 31.2% in 2011 to 49.4% in 2020, while surgery rates declined. Multivariate analysis (N = 2,434) showed radiotherapy was associated with worse OS (hazard ratio = 1.96, 95% CI = 1.78-2.15, P < 0.001) compared to surgery.

DISCUSSION

Radiotherapy is increasingly used to treat early-stage NSCLC in octogenarians, yet surgery provides superior long-term survival. Limitations of lack of detailed comorbidity data and differentiation between conventional radiotherapy and stereotactic ablative radiotherapy (SABR) may have expanded the advantages of surgery. Meanwhile, patient performance status and preferences must be considered in treatment decisions.

CONCLUSIONS

Surgery remains the preferred treatment option for eligible octogenarians with early-stage NSCLC.

Surgery Versus Stereotactic Radiotherapy in Patients over 75 Years Treated for Stage IA-IIA NSCLC

INTRODUCTION

Lobectomy with lymph node dissection is the gold standard treatment for stage IA-IIA Non-Small Cell Lung Cancer (NSCLC). Surgery is responsible for higher early mortality but offers better overall long-term survival. The patient population concerned is often elderly and combines the comorbidities of smoking and age. Several trials have shown good results of stereotactic radiotherapy (SABR) in terms of local control and tolerance in elderly subjects. Our objective is to study the survival and regional control of patients over 75 years treated by surgery or SABR for localized NSCLC.

MATERIALS AND METHOD

We conducted a single-center retrospective study between January 2012 and December 2022 including elderly patients who received surgery or SABR for NSCLC less than 5 cm in size, N0, M0. A cumulative comorbidity index was calculated for each patient, considering severity and impact of treatment. We performed subgroup analyses using CART method to identify factors impacting survival and early death.

RESULTS

After propensity score matching, 127 operated patients were matched to 85 patients treated with SABR. Overall survival at 1 and 5 years for the operated patients was 83.87% and 47.30% compared with 88.8% and 31.5% in the radiotherapy group (p = 0.068). We have identified four factors influencing the incidence of early mortality: gender, World Health Organization Performance status (WHO status), Forced Expiratory Volume in 1 s (FEV1), and treatment group.

CONCLUSIONS

Surgery seems to remain the standard of treatment in terms of overall survival and locoregional recurrence, in a context where SABR nevertheless provides excellent local control and tolerance in the short and long term. In order to improve patient selection, we are proposing for the first time a tool to aid therapeutic decision-making.

Case report: Long-term survival in synchronous double primary malignancies of lung adenocarcinomas and esophageal squamous cell carcinoma treated with definitive chemoradiotherapy and SBRT combined with anti-PD-1

Background

The occurrence of multiple primary cancers has become common, and the treatment of such patients is very complex, so it is necessary to combine a variety of individualized treatment methods to achieve better treatment results.

Case description

This report describes a patient with double primary tumors of lung and esophageal cancer had more than 36 months survival with non-operation treatment. The patient diagnosed as lung adenocarcinomas (LADC) and esophageal squamous cell carcinoma (ESCC), was treated with albumin-bound paclitaxel, nedaplatin, and anti-programmed death 1 (anti-PD-1). The esophageal lesions achieved complete response (CR) after finishing two courses of induction chemotherapy combined with anti-PD-1 followed by definitive chemoradiotherapy (CRT). Radiation pneumonitis (RP) occurred one month after the completion of CRT. The pneumonia was relieved after dexamethasone and moxifloxacin treatment. Then, the lung lesion was treated with oral chemotherapy followed by stereotactic body radiation therapy (SBRT). As of July 2024, the patient has survived for more than 3 years after the above treatments, and the current efficacy evaluation is CR of esophageal lesions, PR of pulmonary lesions.

Conclusion

The multi-modality approach of systemic therapy combined with localized radiotherapy is an effective treatment in the patients of the double primary malignant tumors of LADC and ESCC. The safety and toxicity of radiotherapy for the thoracic double primary tumors demonstrate acceptability.

Pulse-by-pulse treatment planning and its application to generic observations of ultra-high dose rate (FLASH) radiotherapy with photons and protons

Objective.The exact temporal characteristics of beam delivery affect the efficacy and outcome of ultra-high dose rate (UHDR or 'FLASH') radiotherapy, mainly due to the influence of the beam pulse structure on mean dose rate. Single beams may also be delivered in separate treatment sessions to elevate mean dose rate. This paper therefore describes a model for pulse-by-pulse treatment planning and demonstrates its application by making some generic observations of the characteristics of FLASH radiotherapy with photons and protons.Approach.A beam delivery model was implemented into the AutoBeam (v6.3) inverse treatment planning system, so that the individual pulses of the delivery system could be explicitly described during optimisation. The delivery model was used to calculate distributions of time-averaged and dose-averaged mean dose rate and the dose modifying factor for FLASH was then determined and applied to dose calculated by a discrete ordinates Boltzmann solver. The method was applied to intensity-modulated radiation therapy with photons as well as to passive scattering and pencil beam scanning with protons for the case of a simple phantom geometry with a prescribed dose of 36 Gy in 3 fractions.Main results.Dose and dose rate are highest in the target region, so FLASH sparing is most pronounced around the planning target volume (PTV). When using a treatment session per beam, OAR sparing is possible more peripherally. The sparing with photons is higher than with protons because the dose to OAR is higher with photons.Significance.The framework provides an efficient method to determine the optimal technique for delivering clinical dose distributions using FLASH. The most sparing occurs close to the PTV for hypofractionated treatments.

Recent developments in the field of radiotherapy for the management of lung cancer

Lung cancer has a poor prognosis, and further improvements in outcomes are needed. Radiotherapy plays an important role in the treatment of unresectable lung cancer, and there have been recent developments in the field of radiotherapy for the management of lung cancer. However, to date, there have been few reviews on the improvement in treatment outcomes associated with high precision radiotherapy for lung cancer. Thus, this review aimed to summarize the recent developments in radiotherapy techniques and indicate the future directions in the use of radiotherapy for lung cancer. Stereotactic body radiotherapy (SBRT) for unresectable stage I lung cancer has been reported to improve local control rates without severe adverse events, such as radiation pneumonitis. For locally advanced lung cancer, a combination of chemoradiotherapy and adjuvant immune checkpoint inhibitors dramatically improves treatment outcomes, and intensity-modulated radiotherapy (IMRT) enables safer radiation therapy with less frequent pneumonitis. Particle beam therapy, such as carbon-ion radiotherapy and proton beam therapy, has been administered as advanced medical care for patients with lung cancer. Since 2024, it has been covered under insurance for early stage lung cancer with tumors ≤ 5 cm in size in Japan. In addition to chemotherapy, local ablative radiotherapy improves treatment outcomes in patients with oligometastatic stage IV lung cancer. A particular problem with radiotherapy for lung cancer is that the target location changes with respiratory motion, and various physical methods have been used to control respiratory motion. Recently, coronavirus disease has had a major impact on lung cancer treatment, and cancer treatment during situations, such as the coronavirus pandemic, must be performed carefully. To improve treatment outcomes for lung cancer, it is necessary to fully utilize evolving radiotherapy modalities, and the role of radiotherapy in lung cancer treatment is expected to increase.

Pre-immunotherapy alters stereotactic ablative radiotherapy-induced systemic T cell responses in early-stage NSCLC

BACKGROUND

Stereotactic ablative radiotherapy (SABR) is thought to activate T cell responses in patients with cancer, leading to its combination with immunotherapy and chemotherapy for treatment of non-small-cell lung cancer (NSCLC). Here, we aimed to provide a high-resolution transcriptomic profiling of the systemic T cell response following SABR, with or without preceding immunotherapy/chemotherapy.

METHODS

We conducted single-cell RNA and T cell receptor (TCR) sequencing of T cells from peripheral blood of seven patients with early-stage NSCLC taken pre- and post-SABR without or with prior immunotherapy and chemotherapy (icSABR). Other flow cytometry, single-cell RNA-seq data and bulk RNA-seq data were used to validate the results.

RESULTS

We uncovered distinct T cell response patterns induced by these treatments: while terminal effector CD8+ T cells showed increased cytotoxic and inhibitory scores, and upregulated immune-activated pathways post-SABR, the reverse responses occurred post-icSABR. Furthermore, the proportion of large T cell clones increased and single clone decreased post-SABR, while the opposite was seen post-icSABR. Of note, both SABR and icSABR largely changed TCR clonotypes, which were mainly large clones post-SABR but single clone post-icSABR, and predominantly from terminal effector CD8+ T cells and T helper cells, respectively.

CONCLUSIONS

These findings reveal a complex interplay between SABR and immunotherapy, with potentially valuable implications for treatment strategies involving SABR and immunotherapy to induce systemic T cell responses for tumor eradication in patients with NSCLC.

Patients With Surgically Resectable Lung Cancer Who Opt for Radiation Have Worse Outcomes

BACKGROUND

Surgery has been the standard procedure for resectable primary LC. Survival after stereotactic body radiation therapy, another treatment, is significantly biased due to preponderance of data from patients deemed unsuitable for surgery. We examined survival of patients refusing surgery in favor of radiation therapy.

METHODS

We used the Surveillance, Epidemiology, and End Results database to identify patients with primary Stage I NSCLC diagnosed between 2007 and 2016. Patients were excluded if it was unknown if they were recommended for surgery or if surgery was contraindicated. Multiple predictors were assessed: radiation versus surgery, age at diagnosis, sex, race/ethnicity, health insurance status, marital status, tumor size, and histology. A multivariate analysis was performed to estimate hazard ratios and generate Kaplan-Meier survival curves.

RESULTS

When adjusted for confounding variables, survival was greater for patients undergoing surgical resection than those refusing surgery in favor of radiation (HRadj 2.66; 95% CI: 2.27-3.11, p < 0.001) or for those receiving no standardized treatment (HRadj 4.43; 95% CI: 3.57-5.50, p < 0.001).

CONCLUSIONS

SBRT is an effective treatment for inoperable early LC but there is limited data comparing outcomes against surgical resection. When eligible for both, patients refusing surgery and choosing radiation had worse survival when adjusting for variables including age, tumor size, and histology, and suggests that surgical resection is a superior treatment modality.

Establishing a prognostic scoring system and exploring prognostic value of examined lymph node numbers for stage I non-small cell lung cancer: a retrospective study of Surveillance, Epidemiology, and End Results (SEER) database and a Chinese cohort

Background

There is currently no recognized assessment system to predict disease outcomes for stage I non-small cell lung cancer (NSCLC). This research aimed to develop a prognostic scoring system for predicting 5-year overall survival (OS) of individuals with stage I NSCLC following definitive therapeutic intervention. Additionally, the optimal number of examined lymph nodes (ELNs) count for tumors no larger than 30 mm was determined.

Methods

Patients (n=22,617) diagnosed with stage I NSCLC from 2007 to 2015 who underwent definitive treatment (pulmonary lobectomy, pulmonary sublobectomy, or radiotherapy) were identified from the Surveillance, Epidemiology, and End Results (SEER) database. There were 400 Chinese patients with stage I NSCLC diagnosed in 2017 enrolled for external validation. The nomogram was constructed based on gradient boosting machine. The optimal ELNs in patients with tumors ≤30 mm and node-negative undergoing pulmonary lobectomy or pulmonary sublobectomy were determined using log-rank test and validated by multivariable analysis.

Results

Age at diagnosis, histology, differentiated grade, tumor staging, number of ELNs, and definitive treatment pattern were recognized as important factors for 5-year OS. The prognostic scoring system exhibited superior discrimination accuracy, calibration ability, and net clinical benefit compared to the tumor, node, metastasis (TNM) staging system. For patients with tumors ≤30 mm, more than 10 and 20 ELNs demonstrated the maximum OS difference during lobectomy and sublobectomy, respectively.

Conclusions

This prognostic scoring system will anticipate the prognosis of stage I NSCLC patients after radical treatment, thereby offering individualized treatment recommendations for both clinicians and patients. A minimum of 10 ELNs during lobectomy and 20 ELNs during sublobectomy are necessary for small-sized NSCLC.

Outcomes After Surgical Management of Early-Stage Lung Cancer in Octogenarians: An In-Depth Analysis of a Nationally Representative Cohort

INTRODUCTION

As the United States population ages more octogenarians are undergoing surgical resection for lung cancer. We aimed to provide an updated and expanded assessment of age-related risks associated with surgical resections for early-stage NSCLC.

METHODS

The Surveillance, Epidemiology, and End Results and Medicare databases were queried for stage IA NSCLC cases treated by surgery between 2006 and 2018. Analyses included generalized linear models for one-year mortality and Cox proportional hazards models for five-year survival.

RESULTS

One-year all-cause mortality among 4061 octogenarians was more than double that of the youngest group (age: 65-69 y): 15.2% versus 7.3%, p value less than 0.001. Octogenarians were discharged to extended skilled nursing facility stays more than three times as often as the youngest group (19.9% versus 6.3%, p < 0.001). For those with skilled nursing facility duration greater than 30 days, there was a 36% greater one-year mortality risk compared with those discharged to home or home-health. In adjusted analyses, octogenarians had 62% greater one-year mortality risk compared with those aged below 80 years (risk ratio = 1.62, 95% confidence interval: 1.48-1.78). The risk of death within five years was 52% higher (hazard ratio = 1.52, 95% confidence interval: 1.42-1.62). Additional factors associated with one-year mortality included male sex, higher comorbidity burden, lower county median income, open approach, and sub-lobar resection.

CONCLUSIONS

This analysis provides an updated and expanded characterization of age-related outcomes on the basis of a large national cohort representative of elderly patients treated outside of clinical trials. Substantial gaps in survival and discharge disposition motivate further research and the development of interventions to help improve outcomes in older patients.

Pulmonary Rehabilitation in Patients with Operable Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related death worldwide, and patients with operable early-stage NSCLC are typically managed surgically. While effective, surgical resection can significantly impact pulmonary function and quality of life. Pulmonary rehabilitation (PR) is a comprehensive, multimodal approach that is an established cornerstone in the treatment of COPD. It has similarly demonstrated multiple benefits in patients with lung cancer who have undergone lobectomy or resection by improving pulmonary function, increasing exercise tolerance, improving nutritional status, providing psychological support, and enhancing quality of life. Despite this, PR for early-stage operable NSCLC is oftentimes not standardized, and challenges to adherence remain. In this review, we examine the components of PR, the role of PR in pre- and postoperative settings in patients with early-stage NSCLC, implementation strategies for PR, and future directions and challenges of PR in operable NSCLC.

Comparative Dosimetry and Biological Risk Assessment of Lung Oligometastasis SBRT: VMAT, Helical Tomotherapy, and CyberKnife

PurposeTo compare the dosimetry and biological risk of volumetric modulated arc therapy (VMAT), helical tomotherapy (HT) and cyberKnife (CK) in the treatment of lung oligometastases.Methods and materialsThis retrospective study included a cohort of 21 lung oligometastasis patients, each with 2 or 3 lesions, who had previously undergone stereotactic body radiation therapy (SBRT). VMAT, HT and CK plans were made for each patient. The dose distribution of planning target volume (PTV) and organs at risk (OARs) were evaluated. Three biological risks were evaluated, namely radiation pneumonitis (RP), coronary artery disease (CAD) and congestive heart failure (CHF). Monitor Units (MUs) and beam-on-time were also recorded.ResultsAll techniques were able to produce clinically deliverable plans. The expected biological risks for VMAT plans, CK plans, and HT plans were 6.69%, 5.05%, 5.88% for RP, 1.20%, 1.15%, and 1.17% for CAD, 1.26%, 1.19%, and 1.22% for CHF. The expected risks of RP were slightly lower in CK plans compared to VMAT and HT plans (p < 0.001), with VMAT plans showing the highest expected risks. For central lung cancer, the expected CAD risks of CK and HT plans were lower than those of VMAT plans (p < 0.05). The delivery efficiency of VMAT plans was significantly higher than that of CK plans and HT plans.ConclusionsAll three techniques, VMAT, HT, and CK, meet the therapeutic requirements for target coverage and dose constraints for OARs. Although there are statistical differences, the difference between the expected risk values of RP and CAD is very small, so the clinical manifestations may not show differences.

Primary lung tumour stereotactic body radiotherapy followed by concurrent mediastinal chemoradiotherapy and adjuvant immunotherapy for locally advanced non-small-cell lung cancer: a multicentre, single-arm, phase 2 trial

BACKGROUND

Patients with locally advanced non-small-cell lung cancer (NSCLC) who undergo concurrent chemotherapy and radiotherapy often experience synergistic toxicity, and local regional control rates remain poor. We assessed the activity and safety outcomes of primary tumour stereotactic body radiotherapy (SBRT) followed by conventional chemoradiotherapy to the lymph nodes and consolidation immunotherapy in patients with unresectable locally advanced NSCLC.

METHODS

In this multicentre, single-arm, phase 2 trial, patients aged 18 years and older were enrolled at eight regional cancer centres in North Carolina and South Carolina, USA. Patients were eligible if they had stage II-III, unresectable, locally advanced NSCLC (any histology), with peripheral or central primary tumours that were 7 cm or smaller, excluding central tumours within 2 cm of involved nodal disease, and an Eastern Cooperative Oncology Group performance status of 0-2. Patients who had previously received systemic therapy or radiotherapy were excluded. Participants received SBRT to the primary tumour (50-54 Gy in three to five fractions) followed by standard radiotherapy (planned up to 60 Gy in 30 2 Gy fractions) to the involved lymph nodes with concurrent platinum doublet chemotherapy (either paclitaxel 50 mg/m2 intravenously plus carboplatin area under the curve 2 mg/mL per min every 7 days for a total of six 1-week cycles or etoposide 50 mg/m2 intravenously on days 1-5 and days 29-33 plus cisplatin 50 mg/m2 intravenously on days 1, 8, 29, and 36 for two cycles of 4 weeks). An amendment to the protocol (Dec 11, 2017) permitted the administration of consolidation durvalumab at the discretion of the treating investigator. An additional protocol amendment on Jan 13, 2021, directed patients without disease progression after chemoradiotherapy to receive consolidation durvalumab (10 mg/kg intravenously on day 1 and day 15 of a 4-week cycle for up to 12 cycles or 1500 mg intravenously on day 1 of a 4-week cycle for up to 12 cycles). The primary endpoint was 1-year progression-free survival (per Response Evaluation Criteria in Solid Tumours version 1.1), assessed in all participants who received at least one fraction of SBRT and had radiological follow-up data up to 1 year. A 1-year progression-free survival rate of greater than 60% was required to reject the null hypothesis and show significant improvement in 1-year progression-free survival. One-sided exact binomial tests were used to compare the primary endpoint versus the historical control 1-year progression-free survival rate used to determine the sample size. Safety was assessed in all patients who received at least one fraction of SBRT. This study is registered with ClinicalTrials.gov, NCT03141359, and is closed to accrual.

FINDINGS

Between May 11, 2017, and June 27, 2022, 61 patients were enrolled and received at least one dose of fractionated SBRT, of whom 59 were evaluable for the primary endpoint. Median age was 67 years (IQR 61-72), 28 (46%) of 61 were female, 33 (54%) were male, 51 (84%) were White, seven (11%) were Black, and three (5%) were of other or unknown race. Of the 61 patients enrolled, 47 received at least one dose of consolidation durvalumab. As of data cutoff (July 12, 2023), median follow-up was 29·5 months (IQR 14·9-47·1). 1-year progression-free survival was 62·7% (90% CI 51·2-73·2; one-sided p=0·39, compared with the historical control rate), with 37 of 59 evaluable participants progression free and alive 1 year after enrolment (n=14 progressed, n=8 died). The most common grade 3-4 treatment-related adverse events were decreased neutrophil count (nine [15%] of 61 patients), decreased white blood cell count (five [8%]), and anaemia (four [7%]). Treatment-related serious adverse events occurred in 11 (18%) of 61 patients, which included lung infection (three [5%]), pneumonitis (two [3%]), decreased neutrophil count (two [3%]), febrile neutropenia (two [3%]), and dyspnoea, hypoxia, respiratory failure, sinus tachycardia, bronchial infection, and acute kidney injury (each in one [2%] patient). Treatment-related deaths occurred in four (7%) of 61 patients (one each of respiratory failure, respiratory failure and dyspnoea, lung infection, and pneumonitis).

INTERPRETATION

Although this study did not meet the primary endpoint, activity and safety profiles of primary lung tumour SBRT followed by concurrent mediastinal chemoradiotherapy were favourable compared with other modern trials treating locally advanced NSCLC with chemoradiotherapy. These findings serve as the basis for the ongoing randomised phase 3 study NRG Oncology LU008 (NCT05624996).

FUNDING

AstraZeneca and Atrium Health Levine Cancer Institute.

High barriers to treatment are associated with stereotactic radiation instead of surgery for patients with operable stage I non-small cell lung cancer†

OBJECTIVES

Although surgery is considered the standard of care for early-stage lung cancer, there has been increased use of stereotactic radiotherapy for operable patients in recent years. Given that this modality may be perceived as a more practical treatment, we hypothesized that it might be more often delivered to patients who experience barriers to care.

METHODS

The National Cancer Database (2018-2020) was queried for patients with clinical stage IA non-small cell lung cancer treated with surgery or stereotactic radiotherapy (48-60 Gy, 3-5 fractions), excluding patients with contraindications to surgery. Patients who had all the following characteristics were categorized as experiencing 'high barriers' to treatment: income below median national levels, lack of private insurance, treatment at a community facility and residence in non-metropolitan areas. Using multivariable logistic regression, the association between high barriers to treatment and stereotactic radiotherapy use was estimated.

RESULTS

A total of 60 829 patients were included, of whom 3382 (5.6%) experienced high barriers to treatment. Among them, 13 535 (22.3%) underwent stereotactic radiotherapy and 47 294 (77.7%) underwent surgery. Overall, more patients undergoing stereotactic radiotherapy faced high barriers to treatment compared to those who received surgery (8.6% vs 4.7%, P < 0.001). Geographic region was associated with the delivery of stereotactic radiotherapy (P < 0.001). The magnitude of such association was stronger among those who faced high barriers. In multivariable analysis, experiencing high barriers to treatment remained associated with receiving stereotactic radiotherapy (OR: 1.46, 95% CI 1.35-1.58).

CONCLUSIONS

The use of stereotactic radiotherapy is more prevalent among patients facing barriers to care. Further research is needed to clarify the role of this treatment modality in early-stage lung cancer.

The Treatment of Patients with Early-Stage Non-Small Cell Lung Cancer Who Are Not Candidates or Decline Surgical Resection: The Role of Radiation and Image-Guided Thermal Ablation

The standard of care for early-stage NSCLC has historically been surgical resection. Given the association of lung cancer with smoking, a large number of early-stage patients also have active smoking-related medical comorbidities such as COPD precluding surgery. The current approach for treating such inoperable patients is frequently considered to be stereotactic body radiation therapy (SBRT). SBRT (also known as stereotactic ablative radiation therapy or SABR) is a curative modality that precisely delivers very high dose radiation in few (typically <5) sessions. That said, because of their minimal invasiveness and repeatable nature, image-guided thermal ablation therapies such as radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) have also been used to treat early-stage lung tumors. For those patients deemed to have "high operative risk" (i.e., those who cannot tolerate lobectomy, but are candidates for sublobar resection), the appropriateness of potential alternatives [e.g., SBRT; ablation] to surgery is an active area of investigation. In the absence of completed randomized phase III trials, the approach to comparing outcomes between surgery, SBRT, or ablative therapies by their efficacy or equivalence is complex. An overview of the role of SBRT and other non-surgical modalities in the management of early-stage lung cancer is the subject of the present review.

Systematic Review of Stereotactic Ablative Radiotherapy (SABR)/Stereotactic Body Radiation Therapy (SBRT) for Treatment of High-Risk Patients with Stage I Non-Small Cell Lung Cancer

Stereotactic ablative radiotherapy (SABR) has emerged as an alternative, non-surgical treatment for high-risk patients with stage I non-small cell lung cancer (NSCLC) with increased use over time. The American Association for Thoracic Surgery (AATS) Clinical Practice Standards Committee (CPSC) assembled an expert panel and conducted a systematic review of the literature evaluating the results of SABR, which is also referred to as stereotactic body radiation therapy (SBRT) or stereotactic radiosurgery (SRS), prior to developing treatment recommendations for high-risk patients with stage I NSCLC based on expert consensus. Publications detailing the findings of 16 prospective studies of SABR and 14 retrospective studies of SABR for the management of early-stage lung cancer in 54,697 patients were identified by systematic review of the literature with further review by members of our expert panel. Medical inoperability (93-95%) was the primary reason for utilizing SABR. The median rate of histologically confirmed cancer in treated patients was 67% (range 57-86%). In retrospective studies and prospective studies, the most common dosing regimens were 48-54Gy in 3-5 fractions and 44-66Gy in 3-5 fractions respectively. The median follow-up after SABR was 30 months (range 15-50). The complications, oncological results and quality of life after SABR in high-risk patients with early-stage NSCLC are summarized in this Expert Review article. Further prospective randomized trials are needed and are currently underway to compare outcomes after SABR with outcomes after sublobar resection to fully evaluate treatment options applicable this high-risk group of patients.

Recent Advances and Current Challenges in Stereotactic Body Radiotherapy for Ultra-Central Lung Tumors

Stereotactic body radiotherapy has been established as a viable treatment option for inoperable early-stage non-small cell lung cancer or secondary lesions mainly in oligoprogressive/oligometastatic scenarios. Treating lesions in the so-called "no flight zone" has always been challenging and conflicting data never cleared how to safely treat these lesions. This is truer considering ultra-central lesions, i.e., directly abutting or whose PTV is overlapping critical mediastinal organs. While historical retrospective data are abundant but mostly heterogenous in terms of the definition of ultra-central lesions, dosing regimens and outcomes, prospective data remain scarce, even though recently published studies have given new encouraging results for such delicate treatment scenarios. For this reason, we aimed to review and summarize current knowledge on stereotactic radiation treatment for ultra-central thoracic lesions, highlighting the most recent advances and the messages that can be taken from them. Lastly, we propose a workflow of the necessary steps to identify and treat such patients, therefore helping in elucidating the advantages and caveats of such treatment options.

Long-term survival and failure patterns in inoperable early-stage non-small cell lung cancer following stereotactic body radiotherapy: a single-institution retrospective study

This study is to analyse the failure patterns and long-term survival after stereotactic body radiotherapy (SBRT) in patients with T1-3N0M0 inoperable non-small cell lung cancer (NSCLC). Early-stage NSCLC patitents who received SBRT at Zhejiang Cancer Hospital from January 2012 to September 2018 were retrospectively analyzed. The primary endpoint were the patterns of disease progression, which were divided into local recurrence, regional failure, and distant metastasis. Kaplan-Meier method survival analysis was used to calculate overall survival (OS), progression-free survival (PFS). Cox model was used for univariate analysis and multivariate analysis. A total of 215 patients with 224 lesions were enrolled. After the median follow-up time of 50.8 months (1.0-117.9 months), 76 (35.3%) patients progressed, with regional progression occurring in 4 cases (1.8%), local and local-regional progression in 17 cases (7.9%), various distant metastases developing in 55 cases (25.6%). The OS rates at 1, 3, and 5 years were 97.1%, 80.9%, and 63.8%, respectively, with a median OS of 92.2 months (95%CI, 61.5-122.9 months). The PFS rates at 1, 3, and 5 years were 87.5%, 65.9%, and 50.8%, respectively, with a median PFS of 62.2 months (95% CI, 45.0-59.4 months). There was no significant difference in OS (P = 0.832) and PFS (P = 0.672) between the two groups with or without pathology. Multivariate analysis showed that BED and patient age were independent prognostic factors affecting early-stage lung cancer survival (all P < 0.05). Distant metastasis was the main failure pattern of inoperable early-stage NSCLC after SBRT, and the high-risk population should be selected for further systemic treatment.

Consecutive Daily Versus Every Other Day Stereotactic Body Radiation Therapy Scheduling for Stage I Non-small Cell Lung Cancer

Purpose

The optimal delivery schedule for stereotactic body radiation therapy (SBRT) in treating stage I non-small cell lung cancer (NSCLC) is unknown. This study used the National Cancer Database to examine daily versus every other day (QOD) SBRT scheduling, including trends over time and association with survival.

Methods and Materials

The National Cancer Database was used to retrospectively identify patients with stage I NSCLC treated with 3-, 4-, or 5-fraction of SBRT between 2004 and 2016. Survival analysis was performed using the Kaplan-Meier method and Cox regression modeling.

Results

Of 15,269 patients, 3927 (25.7%) received SBRT daily, and 11,342 (74.3%) received treatment QOD. The use of QOD treatment increased from 63.2% in 2007 to 78.3% in 2016, and 5-fraction SBRT increased from 3.7% in 2004 to 51.4% in 2016 (both P < .0001). QOD 5-fraction became the most prevalent scheduling from 2012 to 2016 (28.5% in 2012 to 41.6% in 2016). Factors significantly associated with daily SBRT scheduling included number of fractions, race, lower income, lower comorbidities, and treatment at academic/research programs (all P ≤ .01).Median survival for daily SBRT was 37.9 months versus 38.4 months for QOD (P = .4). On multivariable analysis, no difference was found in overall survival between daily versus QOD scheduling (adjusted hazard ratio [aHR], 0.99; 95% confidence interval [CI], 0.94-1.04; P = .55). Five-fraction SBRT was associated with worse survival versus 3 fractions (aHR, 1.09; 95% CI, 1.03-1.15; P = .002). With 3-fraction SBRT, QOD treatment was associated with improved survival versus daily treatment (aHR, 0.91; 95% CI, 0.84-0.98; P = .02). With 5-fraction SBRT, QOD treatment was associated with worse survival versus daily treatment (aHR, 1.11; 95% CI, 1.02-1.22; P = .02).

Conclusions

QOD SBRT schedules were more frequently used to treat stage I NSCLC than daily regimens by a factor of 3:1, and QOD 5-fraction SBRT became the most common dose schedule after 2012. Three-fraction QOD SBRT was associated with improved survival versus daily, whereas 5-fraction QOD SBRT was associated with worse survival versus daily.

The Role of Chest Radiography in Lung Cancer

Chest radiography is one of the most commonly performed imaging tests, and benefits include accessibility, speed, cost, and relatively low radiation exposure. Lung cancer is the third most common cancer in the United States and is responsible for the most cancer deaths. Knowledge of the role of chest radiography in assessing patients with lung cancer is important. This article discusses radiographic manifestations of lung cancer, the utility of chest radiography in lung cancer management, as well as the limitations of chest radiography and when computed tomography (CT) is indicated.

Appropriate Use Criteria (AUC) for the Management of Non-Small Cell Lung Cancer in a Central/Ultra-Central Location: Guidelines from the American Radium Society

INTRODUCTION

Definitive radiation therapy is considered standard therapy for medically inoperable early-stage NSCLC. Nevertheless, for patients with tumors located near structures such as the proximal tracheobronchial tree, esophagus, heart, spinal cord, and brachial plexus, the optimal management regimen is controversial. The objective was to develop expert multidisciplinary consensus guidelines on managing medically inoperable NSCLC located in a central or ultracentral location relative to critical organs at risk.

METHODS

Case variants regarding centrally and ultracentrally located lung tumors were developed by the 15-member multidisciplinary American Radium Society (ARS) Thoracic Appropriate Use Criteria (AUC) expert panel. A comprehensive review of the English medical literature was performed from January 1 1946 to December 31 2023 to inform consensus guidelines. Modified Delphi methods were used by the panel to evaluate the variants and procedures, with at least three rating points from median defining agreement/consensus. The guideline was then approved by the ARS Executive Committee and released for public comment per established ARS procedures.

RESULTS

The Thoracic ARS AUC Panel identified 90 relevant references and obtained consensus in all variants. Radiotherapy alone was considered appropriate, with additional immunotherapy to be considered primarily in the clinical trial setting. Hypofractionated radiotherapy in eight to 18 fractions was considered appropriate for ultracentral lesions near the proximal tracheobronchial tree, upper trachea, and esophagus. For other ultracentral lesions near the heart, great vessels, brachial plexus, and spine, or for non-ultracentral but still central lesions, five-fraction stereotactic body radiation therapy was also considered an appropriate option. Intensity-modulated radiotherapy was considered appropriate and three-dimensional-conformal radiotherapy inappropriate for all variants. Other treatment planning techniques to decrease the risk of overdosing critical organs at risk were also considered.

CONCLUSIONS

The ARS Thoracic AUC panel has developed multidisciplinary consensus guidelines for various presentations of stage I NSCLC in a central or ultracentral location.

Stereotactic ablative radiotherapy (SABR) for patients with lung tumor and severe pulmonary function impairment

PURPOSE

To evaluate clinical outcomes after SABR in a cohort of early-stage non-small cell lung cancer (NSCLC) or pulmonary metastases in chronic obstructive pulmonary disease (COPD) patients with forced expiratory volume in the first second predicted (FEV1) ≤ 50%.

METHODS

Retrospective single-center study was performed to analyze clinical outcomes and toxicities in COPD patients with severe lung dysfunction treated with SABR from 1st June 2015 to 31st October 2022.

RESULTS

Thirty four patients (forty locations) were enrolled for analysis. Median follow-up was 2.9 years. Median age was 73.5 years (range, 65.6-80.1). FEV1 was 38% (range, 28.2-50.0) prior to radiotherapy. Median overall survival (OS) was 41.1 months (95% CI 38.9-not reached). OS rates at 2-, 3-, and 5- years were 79%, 71%, and 36%, respectively. Cancer-specific survival rates at 2-, 3-, and 5- years were 96%, 96%, and 68%, respectively. Local control rates at 2-, 3-, and 5- years were 88%, 83%, and 83%, respectively. No grade 4 or 5 toxicity was observed. The most common acute toxicity was pneumonitis (38.2%), of which only 1 patient (2.9%) reported grade 3 acute toxicity.

CONCLUSIONS

Lung SABR in patients with poor pulmonary function may be effective with acceptable toxicity.

Models and Biomarkers for Local Response Prediction in Early-Stage and Oligometastatic Non-small Cell Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy Using Machine Learning

Background A minority of patients receiving stereotactic body radiation therapy (SBRT) for non-small cell lung cancer (NSCLC) are not good responders. Radiomic features can be used to generate predictive algorithms and biomarkers that can determine treatment outcomes and stratify patients to their therapeutic options. This study investigated and attempted to validate the radiomic and clinical features obtained from early-stage and oligometastatic NSCLC patients who underwent SBRT, to predict local response. Methodology A single-institution, Institutional Review Board (IRB)-approved retrospective review was conducted on adult patients with early-stage and oligometastatic SBRT-treated NSCLC at the Jewish General Hospital. The study included 98 patients (82 with early-stage NSCLC and 16 with oligometastatic disease), with a median age of 76 years and a male-to-female ratio of 46:52. A total of 116 lesions were treated with SBRT between 2009 and 2022. Radiomics features (n = 107) were extracted from CT planning scans using PyRadiomics, and clinical data were collected for all 98 patients. Local response was assessed according to Response Evaluation Criteria In Solid Tumors (RECIST 1.1) criteria. Classification models, including support vector machines, random forests, adaptive boosting, and multi-layer perceptrons (MLPs), were used. Models were trained using a fivefold cross-validation scheme. Their performances were measured with receiver operating characteristic plots on the validation folds. Using the importance of the permutation feature, predictive biomarkers were identified. Results The most predictive model, incorporating all patients and using an MLP classifier with Adaptive Synthetic (ADASYN) sampling, a combined-input approach, and a radiomic filter, achieved an area under the curve (AUC) of 0.94 ± 0.05. When oligometastatic patients were omitted, the best model (AUC 0.95 ± 0.06) was also predictive, using a support vector classification (SVC) radial basis function (RBF) classifier, ADASYN sampling, and a clinical-based input. Treatment site and performance status, along with radiomic features such as first-order root-mean-squared-intensity, first-order skewness, and gray-level nonuniformity, were found to be predictive biomarkers. Conclusions The predictive models generated and the biomarkers identified could be used in clinical decision support systems for SBRT-treated NSCLC patients. Additionally, treatment site, performance status, and radiomic features were the most predictive variables.