Strahlentherapie und Onkologie最新文献

Purpose: The goal is to investigate the best time point for assessing radiological complete response after exclusive chemoradiation in locally advanced cervical cancer (LACC). This is a retrospective single-center study.

Materials and methods: Seventy-nine patients with LACC, stage IB3-IVA FIGO 2018 treated between January and December 2020 were retrospectively analyzed. All patients received external beam radiotherapy (45 Gy in 25 daily fractions ± simultaneous boost to lymph nodes), and interventional radiotherapy (IRT, 28 Gy/twice/weekly) with concurrent chemotherapy. The radiological complete response evaluation was examined using magnetic resonance imaging (MRI) at three timepoints: (i) before IRT, at the end of external beam radiotherapy, (ii) 3 months following the completion of IRT and (iii) 6 months after IRT. Seventy-nine patients were included.

Results: At the three timepoints, the complete response rate increased with 21, 53, and 59 patients reporting a complete response at MRI scan, respectively. Seven patients with partial response at the second assessment had complete response 6 months after treatment completion, overall resulting in 80% clinical complete response.

Conclusions: Our findings suggest that 6 months following the end of exclusive treatment for LACC patients is the best time to detect complete radiological response (measured by MRI scan) after chemoradiation. Waiting this period of time before conclusively assessing response would allow for the inclusion of patients who have not yet fully responded at 3 months, while avoiding the performance of salvage therapies too early.

Background: Single-fraction stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with non-small cell lung cancer (NSCLC) who are ineligible for surgery. This study investigates long-term clinical outcomes, prognostic factors, and toxicity associated with high-dose single-fraction SBRT.

Materials and methods: We retrospectively analyzed 110 patients with 116 NSCLC lesions treated with single-fraction SBRT between 2000 and 2023. Histologic subtypes included adenocarcinoma, squamous cell carcinoma, large cell carcinoma, and CT-defined suspicious lesions without histological confirmation. Local control (LC), progression-free survival (PFS), and overall survival (OS) were assessed using Kaplan-Meier and Cox regression models. Toxicity was evaluated using CTCAE v4.0.

Results: The most common dose was 30 Gy, prescribed in 76.7% of lesions. Among patients who received ≥ 30 Gy, LC at 2, 3, and 5 years was 78%, 74%, and 68%; PFS was 63%, 49%, and 37%; and OS was 84%, 83%, and 60%, respectively. LC and PFS were significantly higher in patients treated with ≥ 30 Gy (p < 0.05). Acute pneumonitis occurred in 2 patients (1.8%), and 22 patients (20.0%) developed late-onset pneumonitis. Pneumonitis incidence was 26.8% in patients planned with 3D-CT, compared to 12.8% with DIBH or 4D-CT. No grade ≥ 3 toxicity was observed.

Conclusion: High-dose (≥ 30 Gy) single-fraction SBRT provides excellent long-term tumor control with minimal toxicity with NSCLC. Advanced motion management techniques were associated with reduced pulmonary toxicity. A ≥ 30 Gy dose significantly improved LC, PFS, and OS. Higher Charlson Comorbidity Index (CCI) was associated with worse OS. These findings support the use of high-dose SF-SBRT in selected patients and highlight the need for individualized treatment planning. Prospective validation is warranted.

Purpose: There is no uniformity across various guidelines in defining the modality and frequency of the follow-up, particularly regarding radiological imaging. The objective is to assess the diagnostic performance of magnetic resonance imaging (MRI)-based posttreatment surveillance for early-stage (I-II) glottic squamous cell carcinoma of the larynx.

Methods: The follow-up of patients diagnosed with glottic squamous cell carcinoma of the larynx, treated with radiotherapy or surgery in curative intent, was analyzed over a period of 2 years posttreatment. MRI diagnostic performance metrics were calculated using clinical and post-MRI endoscopic examinations as the reference standard. MRI sequences included both anatomical and functional imaging, including diffusion-weighted imaging.

Results: In total, 171 eligible MRIs were analyzed in the follow-up. Recurrences were identified with a sensitivity of 75% and a specificity of 99%. However, the positive predictive value of MRI surveillance reflects considerable uncertainty in the diagnosis of recurrences based solely on MRI findings, dropping as low as 21% in sensitivity analyses. Moreover, a notable proportion of MRIs were inconclusive.

Conclusion: MRI demonstrates high specificity and acceptable sensitivity; however, the limited positive predictive value raises concerns regarding its utility as a stand-alone surveillance tool.

Purpose: With increasing use of human epithelial growth factor receptor two (HER2)-targeted therapies, outcomes for numerous breast cancer patients have improved. Nevertheless, patients with HER2-positive tumours face a comparatively heightened risk for developing brain metastases (BM), which are often treated with stereotactic radiosurgery (SRS). Radionecrosis represents one of the clinically most significant adverse events of SRS. However, a knowledge gap remains regarding the effects of concurrent use of HER2-targeted therapies with SRS on development of radionecrosis, given conflicting findings in existing studies.

Methods: This systematic review was conducted in May 2024 through a search across electronic databases PubMed/MEDLINE and Cochrane library and was supplemented by citation searching and an artificial intelligence (AI) search.

Results: The literature search yielded 194 articles. After applying eligibility criteria, a total of 13 studies with 3219 patients total were included, with approximately 270 patients in the topic-relevant subgroup. Investigated substances vary in different publications and include HER2 antibodies, antibody-drug conjugates (ADCs), such as trastuzumab emtansine (T-DM1), and kinase inhibitors. Four of six studies on ADCs demonstrated a higher risk for radionecrosis with concurrent administration. Two studies on lapatinib found no significant effects, as did as most studies investigating mainly HER2 antibodies. One publication reported an even lower risk for radionecrosis (RN) with concurrent use of HER2/EGFR tyrosine kinase inhibitors (TKIs).

Conclusion: While concurrent use of T‑DM1/ADCs seems associated to elevated radionecrosis risk, an ambiguous situation for other substances persists. Heterogenous study designs with varying substances, definitions of concurrent use, and radionecrosis parameters must be considered. Included studies are partly limited by sample size and retrospective study design. Therefore, clinical implications remain difficult to claim; further research on this topic is needed.

Purpose: Single-isocenter multitarget stereotactic radiosurgery (SIMT SRS) offers enhanced clinical efficiency for treating multiple brain metastases. However, it introduces additional uncertainties, such as off-center dose and beam profile inaccuracies, as well as quality assurance (QA) challenges, complicating its implementation. This study aims to evaluate different SIMT SRS approaches.

Methods: We collected and analyzed SIMT SRS protocol and infrastructure parameters from 23 radiotherapy centers across Germany, Austria, and Switzerland, encompassing immobilization systems, computed tomography (CT) protocols, linear accelerators, treatment planning systems, beam configurations, imaging techniques, and QA practices. Consensus, deviations, and compliance with current guidelines were assessed. Subsequent studies will include on-site measurements, evaluation of treatment plan quality and delivery accuracy, and correlation of these findings with the analyzed protocols to identify potential links between protocol parameters and clinical outcomes.

Results: There is consensus (at least 80% agreement) for a CT slice thickness of ≤ 1 mm, the need for six-degree-of-freedom patient setup correction, and noncoplanar treatment. There is notable variability for intrafraction imaging (used by 70%), minimum accepted planning target volume diameter (ranging from 2-10 mm), SRS QA, and general plan parameters, such as photon energy and number of treatment fields. There is also high variability in employed linear accelerator models and treatment planning systems.

Conclusion: These findings highlight a lack of standardization in SIMT SRS practices. Combined with future measurements correlating protocols to treatment quality, our study will provide a foundation for recommendations to support the safe and standardized implementation of SIMT SRS.

Purpose: Melanoma brain metastases (MBM) pose significant challenges in management due to their propensity for intralesional haemorrhage. This retrospective analysis aims to evaluate the oncological outcomes and incidence of haemorrhage following stereotactic radiosurgery (SRS) in patients with MBM.

Methods: Patients who received SRS for MBM between 10/2020 and 01/2023 were included. The primary objective was to analyse the incidence of post-SRS haemorrhage. Secondary objectives included oncological outcomes and radiation necrosis. Descriptive statistics and Kaplan-Meier curves were used. Uni- and multivariate statistics analysed factors influencing the incidence of haemorrhage and local failure.

Results: A total of 69 patients with 250 MBMs were included; 65 metastases (26.0%) showed signs of haemorrhage at the time of SRS. Post-SRS, new or increased haemorrhage occurred in 13.2% of treated metastases, primarily within the first year. The 1‑ and 2‑year local control rates were 76.6% each. The 1‑ and 2‑year distant brain failure rates were 40.6% and 34.1% and median overall survival was 14.3 months. For the haemorrhage endpoint, the presence of initial haemorrhage, biologically effective prescription dose, lesion diameter and the planning target volume margin were statistically significant in univariate analysis, and initial haemorrhage remained significant in multivariate analysis. For local control, significant factors in uni- and multivariate analysis were the status of extracranial disease, post-SRS haemorrhage and the use of anticoagulation.

Conclusion: Stereotactic radiosurgery is an effective treatment for MBM with good local control. The risk of haemorrhage after SRS is low and strongly associated with the presence of pre-SRS haemorrhage. Patients are at risk of developing haemorrhage in new, formerly untreated metastases.

Purpose: This study aims to assess oncological outcomes in children and young adults with diffuse infiltrative pontine glioma (DIPG) who have progressed after initial radiotherapy (RT), with an emphasis on the role of re-irradiation.

Methods: Data from 33 patients aged 25 years or younger with progressive disease after initial RT were retrospectively analyzed.

Results: The median age at diagnosis was 8 years (range 4-24 years), and the median initial RT dose was 54 Gy (range 39-54 Gy). The median time between initial RT and progression was 8 months (range 3-40 months). In addition to systemic therapy, 15 patients (46%) received re-irradiation due to progression, with a median dose of 23.4 Gy (range 19.8-36 Gy), while 18 patients (54%) were treated with systemic therapy alone. In patients who received re-irradiation after progression, the 1‑year post-progression overall survival (OS) was significantly higher compared to those treated with systemic therapy alone (27% vs. 0%, p = 0.01). Among the 15 re-irradiated patients, 9 out of 12 with available data (75%) showed improvement in neurological symptoms following re-irradiation. No patient exhibited acute or late RT-related ≥ grade 3 toxicity.

Conclusion: Palliative re-irradiation in children and young adults with progressive DIPG after initial RT provides an approximately 3‑month OS benefit and clinical improvement without significant toxicity and should be considered as a standard-of-care approach.

Objective: The precise daily positioning of patients during radiation therapy determines the quality of the entire treatment. To avoid additional radiation exposure from regular cone-beam CT (CBCT) scans, surface-guided radiotherapy systems (SGRT) are increasingly used. The aim of this prospective clinical study was to evaluate the advantages, feasibility, and pitfalls of SGRT using the surface tracking recorder prototype of the camera component of ExacTrac Dynamic (Brainlab AG, Munich, Germany). This system combines both surface-based imaging technology and a thermographic camera that records patients via thermal imaging to accurately measure patient geometry.

Methods: The surfaces of patients with various tumor entities and therefore different regions of interest (ROIs) were recorded with the surface camera during positioning and throughout treatment. Subsequently, these surface camera datasets were analyzed to compare the accuracy of patient positioning with the current treatment standard (X-ray-based IGRT). The camera components were used only as an imaging tool and not to correct any deviations. For evaluation of typical pitfalls, errors > 5 mm for extracranial indications and > 2 mm for cranial indications were analyzed using parameters extracted from the surface recordings and the corresponding CBCT shifts.

Results: In total, 162 displacement vector datasets for 130 patients were generated and evaluated. The smallest deviations were found in the head and neck regions (mean deviation 1.9 mm/0.8°). The largest mean translational deviation (4.8 mm) and mean rotational deviation (1.1°) were found in the pelvic area. In all regions, most datasets showed clinically acceptable deviations; however, large outliers were observed in some measurements, particularly longitudinally. These outliers are of special interest because they may indicate mistakes in the use of SGRT, and they were therefore analyzed separately in detail. Several reasons for the outliers were identified, and potential solutions to avoid these pitfalls are presented.

Conclusion: This observational study demonstrated the advantages and pitfalls of SGRT by using the surface tracking recorder prototype of the camera component of ExacTrac Dynamic. These pitfalls can be avoided through thorough application of SGRT. This study may serve as a practical guide for clinicians already using or introducing SGRT for patient positioning.

Purpose: Facial skin cancer of 42 elderly frail patients was treated with individualised 3D-printed mould applicators for high-dose-rate (HDR) brachytherapy. The dosimetric outcome was compared to conventionally manufactured individual moulds used before.

Methods: Tumour-adapted HDR brachytherapy source paths were pre-planned and dosimetrically optimised in the brachytherapy treatment planning system (TPS) using computed tomography (CT) data and considered in the design of the patient-individual moulds. Dosimetric outcome for the planning target volumes and organs at risk were statistically evaluated and compared for pre-planning, final clinical treatment planning with TG-43 formalism and retrospective tissue, material and CT density related TG-186 calculations.

Results: Pre-planning allows reliable brachytherapy source paths design to achieve intended dosimetric clinical goals. The 3D-printed patient-specific moulds show a clear advantage in the dosimetric coverage of the target volume (improving D₉₀ from 98.3% to 104.3%) and the protection of the relevant organs at risk (reduction up to 30% of maximum Dose). With the 3D-printed moulds only minor deviations were observed for TG-43 and TG-186 dose recalculations of the treated plans.

Conclusion: Customised 3D printed moulds offer a safe and efficient technique to treat facial skin cancer in critical locations and complex clinical situations with HDR brachytherapy. The two-step planning process results in reliable PTV dose coverage and efficient sparing of eye lenses and eyeballs. Dosimetric outcome and interfractional position reproducibility with 3D printed moulds were superior to conventionally manufactured facial moulds with respect to the clinical goals.