Strahlentherapie und Onkologie最新文献

Background and purpose: This study aimed to predict the treatment outcomes and survival of patients with locally advanced cervical cancer (LACC) receiving chemoradiotherapy (CRT) using an unsupervised clustering machine learning method.

Materials and methods: This retrospective study was based on a cohort of 152 consecutive patients. Treatment consisted of definitive CRT, combining external beam radiotherapy to the pelvis with intracavitary brachytherapy to achieve a total equivalent dose of 85-90 Gy at the tumor site. Patient-related data including age, body mass index, standard blood tests and complete blood count were recorded before CRT. Various inflammatory indices were analyzed, including the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), leukocyte-lymphocyte ratio (LLR), systemic immune inflammation index (SII), and aspartate aminotransferase (AST) to neutrophil ratio index (ANRI). Based on these covariates, an unsupervised clustering method based on the agglomerative hierarchical clustering (AHC) algorithm was used to identify clusters of patients. The groups of patients were compared in terms of local control (LC), disease-free survival (DFS), distant metastases-free survival (DMFS), and overall survival (OS). A Cox proportional hazard regression analysis was performed to evaluate the relationship between the clusters and the clinical outcomes.

Results: Clustering analysis reported an optimal number of clusters equal to two. Analysis of variance indicated that the variables contributing most to the separation of the clusters were SII, LLR, ANRI, PLR, NLR, hemoglobin, and white cells count. Significant differences were found between the two groups of lesions in terms of LC (p < 0.001), DFS (p = 0.019), and OS (p = 0.017). At 2 years, LC, DFS, and OS were 93.5%, 72.0%, and 93.1%, and 92.7%, 72.0%, and 70.8% for clusters 1 and 2, respectively. In the unadjusted Cox model, patients in cluster 1 were significantly more likely to experience higher local control (HR 3.88 [95% CI 1.80-8.37]; p = 0.001), disease-free survival (HR 1.97 [95% CI 1.10-3.51]; p = 0.022), and overall survival (HR 2.16 [95% CI 1.13-4.14]; p = 0.021).

Conclusion: This study highlights the predictive value of blood parameters and inflammatory indexes for risk stratification in LACC. An unsupervised clustering approach is able to stratify the treatment outcomes with significant performance.

Purpose: Computed tomography (CT) scans are vital for radiotherapy planning, providing essential data for dose calculations. This study retrospectively evaluated imaging doses, scan lengths, and protocol adherence to support imaging optimization and reduce patient radiation exposure.

Methods: CT data from patients undergoing external beam radiotherapy and brachytherapy in the period 04/2021 to 12/2024 were retrieved from the institutional picture archiving and communication system (PACS). Imaging doses (volumetric CT dose index [CTDIvol] and dose length product [DLP]) were extracted from dose reports. Automated organ segmentation was used to assess standard operating procedures (SOPs) adherence by estimating anatomical scan length differences. Additional quality assurance checks assessed protocol and imaging consistency.

Results: Brain protocols exhibited the highest CTDIvol (73 ± 12 mGy), while head and neck protocols had higher DLP values (3212 ± 757 mGy·cm). The lung 4D protocol showed a higher effective dose (23 ± 9 mSv) compared to the standard lung protocol. Notable anatomical scan length differences were observed at the lower boundary in the upper abdomen (120 ± 75 mm) and spine (155 ± 159 mm), indicating opportunities for workflow improvement.

Conclusion: Enhancing CT workflows for radiotherapy patients is important and feasible. Dose and scan length analyses suggest that revising institutional SOPs, optimizing X‑ray tube modulation, and refining scan length boundaries should be considered to achieve this goal.

Cone-beam computed tomography (CBCT) is a critical imaging modality in various medical fields, yet its repeated use poses radiation risks to patients. Low-dose CBCT image reconstruction aims to mitigate these risks while preserving image quality, which is crucial for clinical diagnosis and treatment. This review paper provides an in-depth analysis of the latest research progress in low-dose CBCT image reconstruction. We explore analytical reconstruction algorithms, iterative reconstruction algorithms, and deep learning approaches, each with distinct characteristics and applications. The paper comprehensively reviews the methods used for dose reduction in CBCT, the evolution of reconstruction algorithms, and their performance evaluations. We also identify challenges and limitations in current techniques, discussing potential future directions for low-dose CBCT reconstruction. Through a systematic literature search and analysis, this review offers a valuable reference for researchers and clinicians alike, aiming to advance the field of CBCT and enhance patient care through reduced radiation exposure and improved imaging outcomes.

Purpose: A prolonged overall treatment time (OTT) has been demonstrated to adversely affect the primary radiation therapy (RT) outcome in various solid tumors, including non-small cell lung cancer (NSCLC). Retrospective data from our group suggested an advantage of shorter OTT also for postoperative RT (PORT) in patients with NSCLC. The PORTAF trial (ClinicalTrials.gov: NCT02189967) was initiated to prospectively test this hypothesis.

Methods: The multicenter prospective randomized phase II trial in patients with NSCLC investigated whether an accelerated schedule of PORT (7 fractions per week, 2 Gy per fraction, OTT 3.5-4 weeks) improved outcome compared to conventional fractionation (5 fractions per week, 2 Gy per fraction, OTT 5-6 weeks). Target volumes and total radiation doses were stratified in both treatment arms based on individual risk factors. Primary endpoint of the study was locoregional tumor control (LRTC) 36 months after PORT, with 154 patients to be included in each arm.

Results: Due to slow accrual and changed indications for PORT, we prematurely closed the trial in 2019. Between 2014 and 2019, eight recruiting centers included 27 evaluable patients. An interim safety analysis performed for the first 21 patients showed nonsignificant differences regarding grade 3 toxicities between the treatment arms, thus not meeting the termination criteria. LRTC was not significantly different between accelerated (73%) and conventionally fractionated RT (92%; p = 0.535). Noteworthily, in 21 FDG-PET/CT restagings before RT, an unexpectedly high number of locoregional recurrences (n = 4) and distant metastases (n = 2) were seen, resulting in changed treatment intentions for these patients.

Conclusion: The prematurely closed PORTAF trial did not find significant differences in 3‑year LRTC when comparing accelerated versus conventionally fractionated irradiation. The observed additional benefit of FDG-PET/CT restaging prior to PORT should be further investigated in a larger cohort to optimize patient selection and avoid unnecessary side-effects.

Purpose: Financial toxicity (FT) associated with cancer and its treatment has become increasingly important. This study investigated factors associated with the development of FT during radiation therapy (RT). SOCOFIN was the first longitudinal prospective study to systematically evaluate FT in the context of RT.

Methods: Financial toxicity was measured with the Comprehensive Score for Financial Toxicity (COST-12) at RT initiation, completion, and at 3 months afterwards. Secondary endpoints included socioeconomic factors, health-related quality of life (EORTC QLQ-C30), depression (PHQ-9), coping mechanisms, and sense of coherence. The data were collected digitally; missing data were estimated using multiple imputation with chained equations.

Results: Between July 2023 and June 2024, 230 patients were recruited. Analyses were performed on 170 records. During RT, FT did not increase; a slight overall decrease was descriptively observed. Of seven tumor groups, the highest difference in FT at baseline was measured between prostate (median 33) and pelvic cancer patients (median 19), reaching statistical significance (Kruskal-Wallis test, p = 0.01). Nonetheless, tumor entity was not found to be a significant predictor of FT following RT in multivariate linear regression models. While factors associated with FT differed between timepoints, financial difficulties at baseline predicted the occurrence of FT most strongly (p < 10^-13) and persistently.

Conclusion: Predictors of FT were predominantly socioeconomic, such as baseline financial difficulties, net income, employment stability, and sense of coherence, which superseded tumor- or treatment-specific variables. The findings of this study underscore the necessity of multifactorial, early screening before RT to mitigate FT among radiation oncology patients.

Background: Due to demographic shifts, the population is aging, and patients are experiencing more comorbidities. Stereotactic body radiotherapy (SBRT) offers high rates of local control for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC). However, obtaining histopathological confirmation can be challenging due to severe comorbidities, small tumors, or unfavorable anatomical locations.

Methods: Between 2011 and 2022, we retrospectively analyzed a cohort of patients who underwent lung SBRT for presumed early-stage NSCLC at our institution. Out of 486 consecutive patients treated during this period, 56 patients (11.5%) with a total of 61 lesions were identified and included in this retrospective study. All included patients lacked histopathological confirmation prior to treatment and had no evidence of other active malignancies. The primary objective of this analysis was to evaluate pulmonary function tests before and after SBRT, including long-term follow-up.

Results: The median overall survival (OS) after empiric SBRT was 50.7 months (95% confidence interval [CI] 12.8-88.7). Survival rates at 1 year and 2 years were 88.4 and 71.1%, respectively. The 1‑, 2‑ and 3‑year local control rates were 96.6%, 92.3% and 87.1%. Pulmonary function tests indicated a relative increase in the mean forced expiratory volume in 1 s (FEV1) of 0.55% (SD 13.5) and 2.0% (SD: 20.0) at 6 and 12 months, respectively. In contrast, the mean diffusing capacity of the lungs for carbon monoxide (DLCO) showed a relative decline of 7.4% (SD 16.6) and 6.3% (SD 26.1) at 6 and 12 months, respectively. Patients with lower comorbidity scores (CCI ≤ 5) exhibited significantly improved OS (p = 0.011). Long-term oxygen therapy (LTOT) prior to SBRT was associated with shorter OS (p = 0.02) and a relatively high incidence of grade 2-3 pulmonary disorders. Chronic obstructive pulmonary disease (COPD) was identified as a possible risk factor for severe treatment-related toxicity. Notably, all patients who experienced grade 3 pulmonary disorders required LTOT before SBRT.

Conclusion: Empiric SBRT is a safe and effective treatment for presumed early-stage NSCLC in patients without histopathological confirmation. Even in patients requiring oxygen therapy and with severe comorbidities, long-term survival is feasible with acceptable treatment-related toxicity. Optimal dose fractionation and biologically effective dose (BED) levels for frail patients without histological confirmation remain undefined. Prospective trials are warranted to determine the most effective and safe SBRT regimens for this vulnerable patient population.

Background and objective: Thie study aimed to examine the economic implications of different radiotherapy fractionation schemes, specifically normofractionation (NF) and hypofractionation (HF), for breast and prostate cancer in the outpatient setting of the German healthcare system. In times of workforce shortages, limited machine availability, and rising patient numbers, the study aims to identify which fractionation approach offers the highest value in terms of efficiency and economic sustainability, aligning with a value-based healthcare framework.

Methods: Economic models were developed using German reimbursement data (EBM), treatment costs, machine usage, and realistic patient volumes. Three breast cancer fractionation schemes (conventional NF with 30 fractions, i.e., 25 fractions to the whole breast +5 boost fractions), NF with simultaneous integrated boost (SIB) comprising 28 fractions, and HF with 20 fractions (15 fractions to the whole breast +5 boost fractions) as well as two prostate cancer regimens (39 × 2.0 Gy versus 20 × 3.0 Gy) were compared. A standardized clinic setup with two linear accelerators and defined full-time staff was assumed. Analyses included cost, break-even points, contribution margins, and personnel needs in both scenarios (HF and NF).

Results: Despite lower reimbursement per case, HF regimens yielded significantly higher economic efficiency due to increased patient throughput and reduced staff-time per treatment. Over 10 years, the total revenue per linear accelerator for HF breast cancer treatments reached approximately € 56.9 million, compared to € 40.2 million and € 46.6 million for the two NF approaches. A one-time investment of € 50,000 for implementing HF (e.g., for software, training, and workflow optimization) could be amortized within a few days, depending on the scenario. Simulation models further demonstrated substantial efficiency gains under hypofractionation without the need to expand machine capacity-an important strategy amidst staffing shortages and increasing demand.

Conclusion: When supported by efficient clinic organization and sufficient patient volume, HF offers clear economic advantages over traditional fractionation schemes. However, for widespread implementation, structural reform of the current outpatient reimbursement system is desirable.