Radiation Oncology最新文献

Purpose: Leveraging the distinct properties of X-rays and γ-rays, a novel radiation therapy platform integrating both modalities has been implemented in clinical practice (NMPA: 20223050973; FDA: K210921). This study investigates the application of this integrated approach in spatially fractionated radiotherapy, systematically evaluating its feasibility and therapeutic potential.

Methods: In this retrospective study, lattice radiotherapy (LRT) was designed for 10 NSCLC cases with gross tumor volumes (GTV) ranging from 572 to 1367 cm³ (mean 862.9 ± 285.4 cm³), incorporating the number of high-dose vertices per case ranged from 6 to 13, with a median of 8.5, respectively. Each LRT plan consisted of a single 12 Gy dose to the intratumoral vertices, followed by conventional external beam radiotherapy (cEBRT) delivering 25 daily fractions of 1.8 Gy to the Planning Target Volume (PTV). Treatment plans were developed using the Varian Eclipse 13.5 Treatment Planning System (TPS) for Linac plans, while TaiChiB system plans were generated using the RT PRO TPS: a focused gamma plan was created to target the vertices, and a Linac plan was optimized to cover the PTV. A comparative analysis of D0.5 cc, D10/D90, EQD2, and Dmean was performed to evaluate the ability of dual-modality to optimize high-dose vertices while reducing doses to GTV margins and organs at risk (OARs).

Results: The LRT plan involved the placement of a median of 8.5 high-dose vertices (range, 6 to13), each with a diameter of 1.5 cm and spaced 3-3.5 cm apart within the GTV. The average vertices volume was 17.2 ± 4.5 cm³, corresponding to 2.05% ± 0.34% of the GTV. Compared to the Linac plans, the TaiChiB system plans demonstrated significantly increased D0.5 cc, Dmean, and EQD2 within the GTV (P < 0.01), improved peak/valley dose ratio (PVDR, D10/D90, P < 0.01), and reduced marginal GTV dose. Additionally, the TaiChiB system plans significantly reduced doses to OARs, including right lung Dmean (P = 0.031), heart Dmean (P = 0.024), esophagus Dmax (P < 0.01), and spinal cord Dmax (P = 0.042). All plans complied with the OARs dose constraints, thereby ensuring clinical feasibility and patient safety.

Conclusion: By integrating X-ray and γ-ray technologies, this platform enhances the vertex dose within the GTV while reducing doses to the GTV margins and OARs, offering a promising and feasible approach for the treatment of LRT in patients with large-volume lung tumors.

Background: It is not clear how frailty may affect the outcomes of stereotactic radiosurgery (SRS) for brain metastasis. This study aimed to evaluate the impact of frailty on clinical outcomes in patients ≥ 60 years old who underwent SRS for brain metastasis from a population-based perspective.

Materials and methods: Data were extracted from the National Readmission Database (NRD), 2016 to 2020. Inclusion criteria were ≥ 60 years old with brain metastasis who underwent SRS. Frailty was assessed using the modified Frailty Index (mFI), derived from 11 clinical conditions. The primary outcomes were in-hospital mortality, length of hospital stay (LOS), total hospital costs, and 30-day and 90-day readmission rates. Logistic and linear regression models were used to assess the association between frailty and outcomes.

Results: A total of 904 patients (mean age: 71 years, 53% male) were included, of which 17.5% were defined as frail. After adjusting for demographic, clinical, and hospital-related factors, frailty was significantly associated with increased in-hospital mortality (adjusted odds ratio [aOR] = 2.39, 95% confidence interval [CI]: 1.16-4.92), longer LOS (adjusted Beta [aBeta] = 2.61 days, 95% CI: 1.95-3.28), higher total costs (aBeta = $36.04 thousand USD, 95% CI: 28.84-43.23), and higher 30-day readmission rate (aOR = 1.47, 95% CI: 1.02-2.11).

Conclusion: Frailty independently predicts poorer outcomes in older adults undergoing SRS for brain metastasis, including higher mortality, longer hospital stays, increased hospital costs, and increased 30-day readmission rate. These findings highlight the importance of incorporating frailty-informed risk stratification and perioperative care planning to optimize patient outcomes.

Trial registration number: Not applicable.

Background: The aim of this study is to investigate the potential mechanisms underlying the protective effects of high-energy X-ray FLASH radiotherapy (FLASH-RT) on intestine through multi-omics analysis.

Methods: This study utilized syngeneic colon carcinoma mouse models of CT26 and MC38 to evaluate the therapeutic efficacy of FLASH-RT versus conventional dose rate radiotherapy (CONV-RT) by monitoring survival, tumor size, and body weight. Furthermore, healthy C57BL/6 female mice received whole-abdominal irradiation with either FLASH-RT, CONV-RT, or sham irradiation to compare differences in normal tissue protection. 72 h post-irradiation, intestinal contents from mice were collected for metagenomic analysis, and intestinal tissue was harvested for non-targeted metabolic and single-cell sequencing analyses.

Results: In CT26 and MC38 models, both CONV-RT and FLASH-RT have demonstrated similar anti-tumor efficacy. Compared with CONV-RT, whole-abdominal FLASH-RT significantly alleviated acute intestinal injury in mice, as evidenced by better preservation of crypt numbers and villus architecture in the FLASH group. Metagenomic analysis revealed that the relative abundance of the gut-protective bacterium Ligilactobacillus ruminis was significantly higher in the FLASH group than in the CONVgroup. Non-targeted metabolomic profiling identified 34 differential metabolites, of which 29 were upregulated and 5 were downregulated in the FLASH group. Notably, the abundance of 2-hydroxyglutarate, a metabolite associated with the butyrate metabolism pathway, was significantly elevated in the FLASH group compared with the CONV group (p < 0.05). Single-cell sequencing data revealed notable differences in cell distribution and proportions between the groups, with a higher proportion of fibroblasts, proliferative cells, macrophages, and CD4 + T cells in the FLASH group compared to the CONV and control groups. Immunofluorescence analysis revealed a significantly greater number of Lgr5⁺ intestinal stem cells in the FLASH group compared to the CONV group. Conversely, immunohistochemical analysis demonstrated stronger p50/p65 staining intensity in the CONV group relative to the FLASH group.

Conclusions: This study confirms that FLASH-RT, compared to CONV-RT, maintains equivalent antitumor efficacy while mitigating damage to normal intestinal tissues. Moreover, it preliminarily reveals that the protective mechanism of FLASH-RT is multifaceted, involving remodeling of the microbiota-metabolite axis, attenuation of inflammatory responses, and enhanced preservation of stem cells.

Background: The Fred Hutchinson Cancer Center (FHCC) has developed a novel in-house method for ocular proton therapy by adapting a pencil beam scanning (PBS) beamline and using a commercial treatment planning system. This manuscript outlines the workflow from simulation to treatment delivery and presents our experiences with the initial 40 patients.

Methods: Key innovations of our treatment approach include in-house developed treatment chair and gaze localization systems, CT imaging for planning, and a Monte Carlo algorithm for dose calculation. We gathered data on patient characteristics, dose volume statistics, and total treatment time. Additionally, we examined the distances patients traveled to access ocular proton therapy. An example illustrating our treatment technique is also presented.

Results: The average patient age at the time of treatment was 63.9 years. Tumor apical height ranged from 0.7 to 11.9 mm, and the largest basal diameter from 2.8 to 15.5 mm. GTV volumes ranged from 0.02 to 0.89 cc, while PTV volumes ranged from 0.17 to 2.27 cc. The D99% dose to GTV ranged from 5041 to 5242 cGy (RBE). The median mean dose to the lacrimal gland was 1570 cGy (RBE), while the median D2% doses to the optic nerve, macula, and optic disc were 4188 cGy (RBE), 5024 cGy (RBE), and 5133 cGy (RBE), respectively. Out of the 40 patients, 16 successfully met all treatment planning goals. The remaining patients did not meet some goals due to the target either abutting or being close (< 2 mm) laterally or distally to the OARs. The total treatment duration per fraction was approximately 25 min. Nearly one-third of the patients traveled around 900 miles to receive ocular treatment.

Conclusions: The approach at FHCC demonstrates that ocular proton therapy can be effectively delivered using a general-purpose PBS beamline, providing a solution for centers without dedicated ocular beamlines.

Background: Hypothalamic hamartomas (HHs) are congenital, non-neoplastic tumors originating from the hypothalamic region. While surgical resection remains the standard treatment, it is associated with substantial morbidity, leading to the exploration of minimally invasive approaches such as radiofrequency thermocoagulation (RFTC), laser interstitial thermal therapy (LiTT), and stereotactic radiosurgery (SRS). This systematic review and meta-analysis evaluate the efficacy and safety of SRS in managing HHs, with a focus on seizure control, endocrine function, and treatment-related complications.

Methods: A comprehensive literature search was conducted on December 6, 2024, using PubMed, Embase, Scopus, and Web of Science. Studies that evaluated the role of SRS in HH patients were included. The R program was used to calculate the pooled estimates.

Results: Seven studies with 152 HH patients were included. The meta-analysis revealed a pooled post-SRS seizure improvement rate of 77% (95% CI: 61%-91%) and a seizure-free status rate of 48% (95% CI: 19%-78%). In addition, the meta-analysis showed a pooled good outcome, Engel I/II, rate of 67% (95% CI: 48%-84%), and a pooled adverse radiation effect (ARE) rate of 0% (95% CI: 0%-1%).

Conclusion: SRS provides favorable seizure control and a promising safety profile for managing patients with HH.

Clinical trial number: Not applicable.

Background: Financial toxicity, defined as hardship from medical costs, is an emerging concept in healthcare. Here we define financial toxicity in head and neck cancer patients receiving radiation, identify risk factors, and determine associations with HRQoL, treatment morbidity, and survival.

Methods: We conducted a prospective study on consecutive patients referred to a tertiary referral center for radiation therapy for head and neck malignancies (July 2021-June 2023). Patients provided consent and were assessed using validated patient-reported outcome measures for financial toxicity (FACIT-COST), HRQoL (EORTC-QLQ-C30), and symptom burden (PRO-CTCAE) before and after radiation therapy. Primary outcomes included two-year overall survival (OS), treatment morbidity (ER visits, hospitalizations, feeding tube placement, missed radiation days), HRQoL, and symptom burden.

Results: Among 74 patients (median age 69), all completed pre-radiation therapy (pre-RT) measures, and 39 completed post-RT measures. Median pre-RT COST was 29 (range: 0-44), with 41.9% scoring ≤25, indicating worse financial toxicity. Lower pre-RT COST scores correlated with younger age, Black race, Medicaid insurance, single or unemployed status, advanced T-stage, and concurrent chemoradiotherapy (p < 0.05). These patients had worse HRQoL, more severe symptoms, increased feeding tube placements, and more ER visits/hospitalizations (p < 0.05). OS was worse with lower pre- (HR = 0.95; 95% CI = 0.91-0.99; p = 0.015) and post-RT COST scores (HR = 0.92; 95% CI = 0.86-0.98; p = 0.012).

Conclusions: Financial toxicity is common in head and neck radiation patients and linked to worse HRQoL, morbidity, and OS. Affected patients had clear socioeconomic risk factors and advanced disease. Further research should explore interventions to improve cancer outcomes.