Stereotactic Body Radiation Research Articles

Patient, tumour, and dosimetric factors influencing survival in non-small cell lung cancer patients treated with stereotactic ablative body radiotherapy.

We aimed to analyse clinical outcomes of peripheral, early-stage non-small cell lung cancer (NSCLC) patients treated with stereotactic ablative body radiotherapy (SABR), and evaluate potential patient, tumour, and dosimetric variables influencing survival. Data were collected retrospectively from patients treated between September 2012 and December 2016 and followed up until January 2021. Patient demographics, tumour characteristics, SABR dosimetric parameters, and survival data were collected from electronic patient medical records. Descriptive statistics were performed, and SPSS software was used for survival analysis. Eighty-nine patients were included of whom 49.5% were male and 50.5% female. Median age was 74 years. 98.8% of patients had T1-2 tumours and 89.9% underwent 55 Gy in 5 fractions. Median overall survival time was 58.7 months. On uni- and multi-variate analysis, neither patient nor tumour variables showed association with overall survival. However, planning target volume (PTV) and minimum dose to PTV correlated with overall survival. There was a signal for association between mean lung dose and overall survival on multivariate analysis. Our long-term results show SABR is an effective treatment for peripheral, early-stage NSCLC with excellent overall survival, comparable to other series. Our study found only the PTV and minimum dose to PTV had an impact on overall survival, which demonstrates the importance of generating optimal SABR plans. Our work identified lung SABR dosimetric parameters that correlate with survival, which illustrates the importance of producing optimal lung SABR plans.

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 ≤ 5cm 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.

Oligometastatic Urothelial Cancer and Stereotactic Body Radiotherapy: A Systematic Review and an Updated Insight of Current Evidence and Future Directions.

Stereotactic body radiation therapy (SBRT) is the most commonly used metastasis-directed therapy (MDT) for oligometastatic urothelial carcinoma (omUC). Despite efforts in defining this disease entity, open questions remain concerning the role of MDT and the use of biomarkers, imaging, and its combination with systemic therapies. The aim of the present systematic review is to provide an updated overview of the current clinical evidence on SBRT for omUC in terms of survival and local control benefits. We also aim to provide updates on controversial areas and future directions in this emerging field. With a systematic approach, following PRISMA recommendations, we searched two databases to identify and select articles published up until March 2024 reporting the use of SBRT for omUC with or without concomitant systemic therapies. Prospective randomized or non-randomized studies as well as retrospective studies were included. Eight studies were selected for data extraction and 293 omUC patients treated with SBRT were collectively analyzed. In metachronous omUC patients, SBRT delivered with ablative doses (BED10 ≥ 78 Gy) was associated with a 2-year overall survival (OS) rate of 50.7% (95% CI 35.1-64.4%). The use of sub-ablative SBRT doses (BED10 = 43.2 Gy) in combination with immunotherapy did not demonstrate significant clinical outcome improvement in two prospective studies. The overall tolerance was good, with only one study reporting toxicity of grade 3 in up to 18% of the patients treated with SBRT in combination with immunotherapy. SBRT is an effective and widely available MDT option in omUC, although this is based on a limited number of studies. Despite the attempt to use SBRT as an immune response trigger in combination with immunotherapy, no significant improvement in survival outcomes has been observed. The integration of new systemic agents with MDT will likely define a new scenario for the treatment of omUC. The review protocol was registered in PROSPERO, ID: CRD42024522381.

Stereotactic Body Radiotherapy for Medically Inoperable Early-Stage Non–Small Cell Lung Cancer

Stereotactic Body Radiotherapy for Medically Inoperable Early-Stage Non–Small Cell Lung Cancer

Five-Year Prostate-Specific Membrane Antigen Positron Emission Tomography-Based Outcomes of Spot-Scanning Proton Radiation Therapy for Localized Prostate Cancer: A Single Institution Experience

PURPOSE: We report 5-year oncologic outcomes of a prospective series of patients with prostate cancer treated with spot-scanning proton therapy (SSPT).METHODS AND MATERIALS: A prospective registry identified patients with prostate cancer treated with SSPT between January 2016 and December 2018. Five-year overall survival (OS), local control (LC), biochemical failure (BF), regional and distant failures, and adverse events (AEs) were assessed. Biochemical failure was defined as rise in PSA ≥ 2.0 ng/mL above nadir PSA. Baseline-adjusted toxicities were assigned using CTCAE v5.0.RESULTS: With a median follow up of 4.4 years, 284 prostate cancer patients were treated with SSPT. Median total radiation dose was 79.2 Gy over 44 fractions, 70 Gy over 28 fractions, and 38 Gy over 5 fractions for conventional fractionation (CF), hypofractionation (HF), and stereotactic body radiation therapy (SBRT), respectively. Biochemical failure rate for all patients was 6.7%. Five-year LC rates for CF, HF, and SBRT were 100%, 100%, and 97.3%, respectively (p = 0.07). Regional recurrences occurred in 12 (4.2%) patients: 8 treated with CF, 2 with HF, and 2 with SBRT (p = 0.62). Distant failures occurred in 12 patients (4.2%): 5 treated with CF, 7 with HF, and none with SBRT (p = 0.05). Five-year OS for patients treated with CF, HF, and SBRT SSPT were 88.1%, 86.1%, and 97.2%, respectively (p = 0.1). Acute and chronic grade 2+ GI AEs occurred in 8 (2.8%) and 51 (18.0%) patients, respectively. Acute and chronic grade 3+ GI AEs occurred in 3 (1.1%) and 4 (1.4%) patients, respectively. Acute and chronic grade 2+ GU-related AEs were observed in 71 (25%) and 63 (22.2%) patients, respectively. Acute and chronic grade 3+ GU toxicity were observed in 3 (1.1%) and 6 (2.1%) patients, respectively.CONCLUSIONS: SSPT provides high local control rates and excellent oncologic outcomes across different fractionation schedules with low long-term AE rates.

Stereotactic Body Radiation Therapy For Medically Inoperable Stage I Non-small Cell Lung Cancer

Stereotactic Body Radiation Therapy For Medically Inoperable Stage I Non-small Cell Lung Cancer

Safety and Efficacy of Balloon-Assisted Kyphoplasty Followed by Stereotactic Body Radiation Therapy for Pathological Fractures.

In patients experiencing pain secondary to pathological compression fractures, balloon-assisted kyphoplasty and subsequent stereotactic body radiation therapy (SBRT) may allow for restoration of vertebral height and irradiation of the underlying malignancy to control local disease progression. The aim of this study was to evaluate the safety and efficacy of kyphoplasty treatment before SBRT in patients with spinal metastases and benign tumors. An analysis of a prospectively collected database of 70 patients and 75 metastatic and benign spinal lesions that underwent kyphoplasty before SBRT at a single institution (2002-2023) was conducted. Patient characteristics were recorded, including treatment history, dosimetry and fractionation schedule, pain outcomes, local control (LC), and overall survival. The Bilsky score and Spinal Instability Neoplastic Score were calculated to assess epidural involvement and spinal stability, respectively. The median time from kyphoplasty to SBRT was 29 days (range: 2-159). Seventy-two lesions (96%) were managed with single-fraction SBRT and 3 lesions (4%) with a multifraction regimen. The median single-fraction prescription dose was 20 Gy (range: 12-25) delivered to a median tumor volume of 35.1 cc (range: 2.2-160). After a median follow-up period of 9 months (range: 1-201), 6 lesions (8%) locally progressed. Pain was reported to improve or remain stable for most patients (88%). The LC rate was 88% at 6 months, 1 year, and 2 years. No prognostic factors were significantly associated with LC. The median overall survival was 11 months (range: 1-201) after radiosurgery. There were no reports of cement extravasation or radiation-induced neurological deficit. Two acute pain flares (3%) were reported 1 and 3 months after radiosurgery. The combined kyphoplasty and SBRT treatment paradigm can be used to treat patients with painful pathological compression fractures. Long-term LC and patient-reported improvement in pain were observed without the morbidity associated with open surgery.

Implementing stereotactic arrhythmia radioablation with STOPSTORM.eu consortium support: intermediate results of aprospective Israeli single-institutional trial.

Ventricular tachycardia (VT) is alife-threatening arrhythmia originating from the heart's ventricles. Traditional treatments include antiarrhythmic medications, implantable cardioverter-defibrillators (ICDs), and catheter ablation. Stereotactic body radiation therapy (SBRT) targeting the arrhythmogenic focus in the left ventricle-stereotactic arrhythmia radioablation (STAR)-is an emerging treatment and may offer apotential solution for patients with refractory VT. We designed an interventional prospective clinical trial in Israel aligned with the STOPSTORM.eu consortium's benchmarks, recommendations, and directives to assess the safety and efficacy of STAR in patients with refractory VT. Our phaseI/II single-institutional trial was approved by the Ministry of Health of Israel for 10patients, initially assessing safety in the first 3patients. We included patients with ICDs experiencing symptomatic monomorphic VT after an inadequate response to previous therapies. The primary endpoints were treatment-related serious adverse events and areduction in VT burden as assessed by ICD interrogation. Secondary outcomes included areduction in antiarrhythmic medications and changes in quality of life. From August 2023 to August 2024, 3patients underwent STAR treatment. The prescription dose was asingle fraction of 25 Gy. Planning target volumes were 47.8, 49.7, and 91.8 cc, and treatment was successfully delivered with no grade3 or higher adverse events reported. Over afollow-up period of 12months for the first patient and 8months for the second one, no VT events were recorded after treatment. The third patient died from progressive heart failure 3months after treatment. Left ventricular ejection fraction remained stable, and no significant radiation-induced inflammatory changes were noted. The initial results of this trial suggest that STAR can reduce VT episodes in patients with refractory VT without severe adverse effects. The study highlights the importance of international collaboration and standardization in pioneering new treatments. Further follow-up and additional patient data will be necessary to confirm these findings and evaluate long-term outcomes, including potential adjustments to antiarrhythmic medication regimens.

Abstract B078: A comprehensive spatial atlas of neoadjuvant chemoradiation therapy in resected pancreatic cancer identifies cellular & microenvironmental determinants of persister populations

Abstract Background The molecular pathways involved in the response to radiation therapy (RT) in pancreatic ductal adenocarcinoma (PDAC) remain poorly understood. Despite extensive molecular stratification efforts, improvements in molecularly informed RT-based therapeutic strategies in the neoadjuvant setting have been limited. This study aims to elucidate the adaptive mechanisms and interactions within PDAC to identify new combinatorial therapeutic targets with RT. MethodsWe constructed a high-resolution molecular landscape of the cellular subtypes and spatial communities that constitute PDAC. Single-cell RNA sequencing (scRNA- seq) was performed on 16 PDAC biopsies of matched pre- and post-treatment samples from a Phase I/II dose-escalation clinical trial of pancreatic stereotactic body radiation therapy (SBRT). Additionally, Visium spatial transcriptomics (ST) was conducted on biopsies from primary PDAC patients collected at the time of surgery. These patients received either no neoadjuvant therapy (n = 8) or neoadjuvant chemoradiation (chemoRT) (n = 20). Cell type profiles were determined from scRNA-seq to compare changes in cell type proportions and signatures before and after RT. From these profiles, we employed robust cell type decomposition to analyze cell type signatures in our ST dataset. ResultsChemoRT induced several significant effects compared to controls within the tumor microenvironment, including an increase in the proportion of myofibroblasts, specifically senescent cancer-associated fibroblasts (CAFs), with signatures consistent with immune cell dysfunction. We observed an increase in CD8 and CD4 effector memory cells with RT; however, this occurred alongside a rise in immunosuppressive alternatively activated tumor-associated macrophages. Additionally, RT upregulated pathways related to HIF, cytokine production, B cell proliferation, and negative regulation of lymphocytes. Patients with increased infiltration of NK, memory B, and CD8 effector memory cells demonstrated improved overall survival outcomes. Inference of copy number variations enabled us to identify cancer subclones as either responsive or resistant in matched pre and post RT biopsies. Resistance was characterized by augmented hypoxia, KRAS activation, epithelial- mesenchymal transition, and interferon-gamma response signaling. Conversely, responders exhibited increased oxidative phosphorylation signaling and pathway enrichment associated with cell proliferation and cell cycle progression. Interestingly, RT induced a decrease in cancer cells characterized as harboring a chemoresistant basal-like molecular subtype. ConclusionThrough both longitudinal and therapy stratified tumor biopsies, we were able to observe significant selection pressures on stromal and cancer cells following RT. This includes upregulation of innate and adaptive immune pathways with a compensatory immunosuppressive response driven by myeloid cells and CAFs. This may provide opportunities for development of clinical trials to therapeutically target specific cellular phenotypes and their interactions. Citation Format: Vincent Bernard, Galia Jacobson, Kimal Rajapakshe, Jimin Min, Guangsheng Pei, Daniel Lin, Ayush Suresh, Dadi Jiang, Ching-Wei Tzeng, Manoop S Bhutani, Linghua Wang, Paola A Guerrero, Ethan B Ludmir, Albert C Koong, Anirban Maitra, Cullen M Taniguchi, Eugene J Koay. A comprehensive spatial atlas of neoadjuvant chemoradiation therapy in resected pancreatic cancer identifies cellular & microenvironmental determinants of persister populations [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B078.

Systematic review and recommendations for re-irradiation for intraprostatic radiorecurrent prostate cancer after definitive radiation therapy.

Intraprostatic recurrence (IRR) of prostate cancer after radiation therapy is increasingly identified. Our objective was to review the literature to determine the optimal workup for identifying IRR, the management options, and practical considerations for the delivery of re-irradiation as salvage local therapy. We performed a systematic review of available publications and ongoing studies on the topics of IRR, with a focus on salvage re-irradiation. Work up of biochemically recurrent prostate cancer includes PSMA PET/CT and multiparametric MRI, followed by biopsy to confirm IRR. Management options include continued surveillance, palliative hormonal therapy, and salvage local therapy. Salvage local therapy can be delivered using re-irradiation with low dose rate brachytherapy, high dose rate (HDR) brachytherapy, and stereotactic body radiotherapy (SBRT), as well as non-radiation modalities, such as cryotherapy, high-intensity focused ultrasound, irreversible electroporation and radical prostatectomy. Data demonstrate that HDR brachytherapy and SBRT have similar efficacy compared to the other salvage local therapy modalities, while having more favorable side effect profiles. Recommendations for radiation therapy planning and delivery using HDR and SBRT based on the available literature are discussed. Salvage re-irradiation is safe and effective and should be considered in patients with IRR.

Executive Summary of the American Radium Society Appropriate Use Criteria for NSCLC in a Central/Ultracentral Location: Systematic Review and Guidelines

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

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

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. 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. 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). 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.

Biology-guided radiotherapy in metastatic prostate cancer: time to push the envelope?

The therapeutic landscape of metastatic prostate cancer has undergone a profound revolution in recent years. In addition to the introduction of novel molecules in the clinics, the field has witnessed a tremendous development of functional imaging modalities adding new biological insights which can ultimately inform tailored treatment strategies, including local therapies. The evolution and rise of Stereotactic Body Radiotherapy (SBRT) have been particularly notable in patients with oligometastatic disease, where it has been demonstrated to be a safe and effective treatment strategy yielding favorable results in terms of disease control and improved oncological outcomes. The possibility of debulking all sites of disease, matched with the ambition of potentially extending this treatment paradigm to polymetastatic patients in the not-too-distant future, makes Biology-guided Radiotherapy (BgRT) an attractive paradigm which can be used in conjunction with systemic therapy in the management of patients with metastatic prostate cancer.

Brachial plexopathy following stereotactic body radiation therapy in apical lung malignancies: A dosimetric pooled analysis of individual patient data

Background and objectivesThe aim of this study is to establish dosimetric constraints for the brachial plexus at risk of developing grade ≥ 2 brachial plexopathy in the context of stereotactic body radiation therapy (SBRT). Patients and MethodsIndividual patient data from 349 patients with 356 apical lung malignancies who underwent SBRT were extracted from 5 articles. The anatomical brachial plexus was delineated following the guidelines provided in the atlases developed by Hall, et al. and Kong, et al.. Patient characteristics, pertinent SBRT dosimetric parameters, and brachial plexopathy grades (according to CTCAE 4.0 or 5.0) were obtained. Normal tissue complication probability (NTCP) models were used to estimate the risk of developing grade ≥ 2 brachial plexopathy through maximum likelihood parameter fitting. ResultsThe prescription dose/fractionation schedules for SBRT ranged from 27 to 60 Gy in 1 to 8 fractions. During a follow-up period spanning from 6 to 113 months, 22 patients (6.3 %) developed grade ≥2 brachial plexopathy (4.3 % grade 2, 2.0 % grade 3); the median time to symptoms onset after SBRT was 8 months (ranged, 3–54 months). NTCP models estimated a 10 % risk of grade ≥2 brachial plexopathy with an anatomic brachial plexus maximum dose (Dmax) of 20.7 Gy, 34.2 Gy, and 42.7 Gy in one, three, and five fractions, respectively. Similarly, the NTCP model estimates the risks of grade ≥2 brachial plexopathy as 10 % for BED Dmax at 192.3 Gy and EQD2 Dmax at 115.4 Gy with an α/β ratio of 3, respectively. Symptom persisted after treatment in nearly half of patients diagnosed with grade ≥2 brachial plexopathy (11/22, 50 %). ConclusionsThis study establishes dosimetric constraints ranging from 20.7 to 42.7 Gy across 1–5 fractions, aimed at mitigating the risk of developing grade ≥2 brachial plexopathy following SBRT. These findings provide valuable guidance for future ablative SBRT in apical lung malignancies.

Oncologic outcomes and rates of hepatotoxicity following stereotactic body radiotherapy for hepatocellular carcinoma

Aim: Hepatocellular carcinoma (HCC) localized to the liver has various treatment options, including external beam radiotherapy (EBRT). Despite many prospective and retrospective reports showing excellent local control (LC) and favorable toxicity, EBRT has not been widely adopted in the first-line setting and this may be due to a perceived lack of evidence. This study aims to share a decade of experience with Stereotactic Body Radiotherapy (SBRT) for HCC, leveraging a homogenous treatment technique. Methods: This retrospective study at a single institution included patients with HCC treated with SBRT, with a standardized treatment protocol. Freedom from local progression (FFLP), overall survival (OS), and rates of hepatotoxicity post-treatment using child-pugh (CP) and albumin-bilirubin (ALBI) scores were analyzed. A mixed-effects multivariable analysis (MVA) was also performed to assess various factors’ impact on outcomes. Results: A total of 138 lesions in 106 patients were treated between 2009 and 2020. FFLP was 91% at one year and 86% at three years. OS was 80% and 46% at 1 and 3 years, respectively. Baseline liver function was a significant predictor of FFLP and OS on MVA. CP scores and ALBI grades were stable 3 months after treatment in ≥ 70% of patients. Conclusion: SBRT provides excellent LC and low toxicity for HCC patients. While long-term survival remains challenging, treatment decisions should consider overall clinical status. Multidisciplinary review and forthcoming prospective trial results will further clarify radiotherapy’s role in HCC management.

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

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. 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. 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). 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.

Stereotactic body radiotherapy using CyberKnife versus interstitial brachytherapy in accelerated partial breast irradiation on left-sided breast: A comparison of dosimetric characteristics and preliminary clinical results

IntroductionWe compared the dosimetric characteristics of the target and organs at risk (OARs) as well as the preliminary clinical outcomes between two accelerated partial breast irradiation (APBI) techniques. MethodsForty-four patients diagnosed with left-sided early breast cancer who underwent APBI using either interstitial brachytherapy (IB) or stereotactic body radiation therapy (SBRT) with CyberKnife (CK) were retrospectively reviewed. The dosimetric parameters of the target and OARs were compared. Preliminary clinical outcomes, including tumor control and acute toxicity, were analyzed. ResultsTreatment plans with CK demonstrated a better cardiac dose-sparing effect. Radiation doses to the heart at V150cGy for the CK and IB groups were 24.4 % and 60.4 %, respectively (p < 0.001), while the mean heart doses for the CK and IB groups were 107.4 cGy and 204 cGy, respectively (p < 0.001). The heart D1c.c. and the ipsilateral lung received a lower dose in the IB group, without any significant differences. The median follow-up time in the CK and IB groups was 28.6 and 61.3 months, respectively. No patients died from either breast cancer or cardiac events during follow-up. A locoregional recurrence event at the neck occurred in one patient within the IB group. ConclusionsAPBI planned by CK was shown to have a better dose-sparing effect on the heart, as well as better conformity and homogeneity to the target. CK is a non-invasive treatment which showed minimal acute toxicity and promising tumor control.

Cost-Utility Analysis of Stereotactic Body Radiation Therapy Versus Surgery for Patients With Stage I Non-small Cell Lung Cancer in Japan.

Stereotactic body radiation therapy (SBRT) for patients with operable stage I non-small cell lung cancer (NSCLC) is less invasive than surgery. However, differences in lifetime costs and patient outcomes remain unclear. In this study, a cost-utility analysis of SBRT compared with surgery for Japanese patients with operable stage I NSCLC was conducted. A partitioned survival model was constructed using each treatment arm's overall survival (OS) and progression-free survival (PFS) data. The data for the SBRT arm were extracted from the Japanese multicenter cohort study, which enrolled 678 medically operable patients with stage I NSCLC, and patient registry data were used for the surgery arm. The 5-year OS rate was 78.2% for SBRT and 74.8% for surgery from both studies. The 5-year PFS rate was 57.0% for SBRT and 63.4% for surgery. The quality of life values of PFS and progressive disease were obtained from domestic and overseas literature (PFS: 0.74, progressive disease: 0.65). The time horizon was set to 10 years. The expected costs and quality-adjusted life years for each treatment group were calculated. All costs are expressed in Japanese yen converted to US dollars (USD). SBRT was the dominant strategy, reducing treatment costs by 4,443.8 USD and increasing quality-adjusted life years by 0.131 compared with surgery. According to probabilistic sensitivity analysis, the probability of SBRT being dominant and cost-effective was 50.6% and 72.4%, respectively. Under the budget impact analysis, the total savings for the patients with stage I NSCLC in Japan was 6,252,870.0 USD (n = 1,407). SBRT is a more cost-effective option than surgery in patients with medically operable stage I NSCLC in Japan. Large-scale epidemiologic studies that reflect the latest clinical realities, such as OS/PFS, will be needed to validate this study's robustness.

Stereotactic Body Radiation Therapy for Oligoprogressive Ovarian Cancer Patients Treated During Poly(ADP‐Ribose)‐Polymerase Inhibitor Maintenance: Efficacy and Adverse Events From the Epimetheo Retrospective Study

The aim of this observational, retrospective, multicenter study (Epimetheo) was to analyze the activity and the safety of stereotactic body radiation therapy (SBRT) during poly(ADP-ribose)-polymerase inhibitor (PARPi) maintenance in a series of oligometastatic ovarian cancer (OC) patients. Patients treated with PARPi in maintenance setting received SBRT if oligometastatic progression occurred. Maintenance treatment was continued until the extensive progression of the disease. The primary endpoints of the study were as follows: next systemic treatment change-free survival (NEST-FS) and acute and late toxicity; the secondary endpoints were as follows: the rate of clinical complete response (CR), the 2-year actuarial local control (LC, progression of disease inside SBRT field) rate on "per lesion" basis, the 2-year actuarial progression-free survival, and 2-year overall survival (OS). From April 2018 to September 2023, SBRT was used to treat 74 OC patients with a total of 158 lesions (98 lymph nodes and 60 parenchymal lesions) under PARPi maintenance. Olaparib, niraparib, and rucaparib were administered to 41.9%, 48.6%, and 9.5% of patients, respectively. CR, partial response, stable disease, and progressive disease were observed in 115 (72.8%), 32 (20.3%), 9 (5.7%), and 2 lesions (1.3%), respectively. Severe toxicities were reported in less than 3% of patients. The actuarial median NEST-FS was 10 months, with a range of 6.7-13.3 months. The 12- and 24-month actuarial NEST-FS rates were 44.9% and 31.4%, respectively. The 2-year actuarial LC, progression-free survival, and OS were 68.1%, 22.5%, and 77%, respectively with differences in figures between complete and incomplete responders. The achievement of CR was found to be correlated with an improvement in LC and OS. This study reports the activity and the low toxicity profile of SBRT in association with PARPi in oligometastatic OC patients. A rapid, minimally invasive, and cost-effective treatment such as SBRT may be proposed as a means of prolonging NEST-FS and maintaining an effective treatment regimen involving PARPi.

Comparison of Metastasectomy and Stereotactic Body Radiation Therapy for Pulmonary Oligometastasis From Hepatocellular Carcinoma: A Propensity Score-Weighted Analysis

Although there is a growing role for local therapy in patients with hepatocellular carcinoma (HCC) and pulmonary oligometastasis, it remains unclear whether metastatectomy or stereotactic body radiation therapy (SBRT) is the more effective treatment for these patients. We aimed to compare the oncologic outcomes of metastasectomy and SBRT for HCC with pulmonary oligometastasis. We retrospectively analyzed 209 patients with HCC with 322 metastatic lung lesions who underwent either metastasectomy (150 patients with 241 lesions) or SBRT (59 patients with 81 lesions) between January 2008 and December 2018. Propensity score-based inverse probability of treatment weighting was used to minimize potential bias between the 2 groups. The median follow-up duration was 39.8 months (range, 2.3-166.9 months). The 2-year rate of freedom from local progression was 98.2% in the metastasectomy group and 97.0% in the SBRT group (P = .197). The 2-year rates of overt systemic progression-free survival (PFS) (51.0% vs 46.1%; P = .274), PFS (26.3% vs 9.1%; P = .074), and overall survival (OS, 74.0% vs 57.6%; P = .006) were higher in the metastasectomy group. After the probability of treatment weighting adjustment, the 2-year rates of overt systemic PFS (50.8% vs 52.7%; P = .396), PFS (23.0% vs 24.7%; P = .478), and OS (72.6% vs 83.0%, P = .428) were not significantly different between the 2 groups. In multivariate analysis, viable intrahepatic lesions and the number of prior liver-directed therapies were found to be significant prognostic factors for OS and PFS. The time interval between HCC diagnosis and the development of pulmonary metastases was also significantly associated with OS. Both metastasectomy and SBRT demonstrated excellent local control and comparable oncologic outcomes in patients with pulmonary oligometastasis from HCC. The treatment modality for these patients could be determined based on the individual patient's condition and intrahepatic disease status.