Strahlentherapie und Onkologie最新文献

Purpose: Treatment of advanced vulvar cancer is challenging. The aim of the study was to investigate the potential of primary (chemo)radiotherapy ((C)RT) with regard to clinical outcome and associated prognostic parameters.

Methods: A total of 39 patients with squamous cell vulvar cancer receiving primary (C)RT were retrospectively identified through hospital databases. Patient and treatment characteristics as well as outcomes were assessed. Survival statistics were calculated using the Kaplan-Meier method. Univariate analysis was performed using the log-rank test and Spearman's correlation to evaluate associations between patient or treatment characteristics and survival outcomes.

Results: Median age at diagnosis was 74 years (range 38-92 years). Patients had advanced stage disease with 28.2%/38.5% presenting with FIGO stage III/IV, respectively. All patients received external beam radiotherapy (EBRT) with a median dose to the primary tumor of 66 Gy EQD2 (range 49.6 Gy-72.6 Gy) and to lymph nodes of 53.1 Gy EQD2 (range 44.1 Gy-67.1 Gy). 69.2% received concurrent chemotherapy, mostly cisplatin weekly or mitomycin/5-fluorouracil. 10.3%/64.1% showed clinical complete remission (cCR)/partial remission (cPR) at first follow-up; 7.7% had disease progression. After a median follow-up of 25.5 months (range 0.5-132.9 months), 3‑year locoregional progression-free survival (LRPFS) and overall survival (OS) were 60.2% and 69.6%, respectively. Age and concurrent chemotherapy were the main prognostic parameters associated with improved oncological outcome.

Conclusion: Definitive (C)RT plays an important role in the management of advanced vulvar cancer with high response rates and satisfactory oncological outcomes. However, there is still room for improvement and future trials are needed to further assess the potential of definitive CRT, especially with regard to possible combinations with immunotherapy.

Purpose: In definitive radiotherapy/radiochemotherapy (RT/RCT) for localized non-small cell lung cancer (NSCLC), the introduction of positron-emission tomography (PET)-CT-based staging/RT planning and dynamic RT techniques (intensity-modulated radiotherapy, IMRT/volumetric modulated arc therapy, VMAT) were important innovations.

Methods: We performed a retrospective study and compared clinical outcomes (1) in patients with PET-CT-based staging (n = 170) vs. conventional staging (n = 103) and (2) in patients with dynamic RT techniques (IMRT/VMAT; n = 99) vs. three-dimensional conformal radiotherapy (3D-CRT; n = 64).

Results: We found improved survival with PET-CT vs. conventional staging. PET-CT patients vs. conventionally staged patients had higher applied RT doses, higher RT completion rates, and a higher rate of patients who received RCT vs. RT only. Additionally, we found higher rates of leukopenia and lung infections in PET-CT patients. When comparing RT techniques (IMRT/VMAT vs. 3D-CRT), there were no differences in survival. IMRT/VMAT patients had higher RT doses and higher rates of intensified concomitant chemotherapy (cisplatin/vinorelbine vs. low-dose cisplatin). IMRT/VMAT was associated with a reduction in pneumonitis and dermatitis.

Conclusion: In summary, refined RT/RCT strategies with PET-CT and IMRT/VMAT enable the intensification of multimodal treatment. Reduction of toxicities with IMRT/VMAT widens the therapeutic window. The coincidence of intensified treatment, improved outcomes, and higher toxicity rates in PET-CT-staged patients emphasizes the need for a detailed risk-benefit assessment during planning and application of treatment modalities.

Purpose: Radiotherapy is an important pillar of treatment for patients with locally advanced head and neck squamous cell carcinoma (HNSCC) in both adjuvant and definitive treatment. However, radiotherapy in the head and neck region is associated with relevant acute and late side effects. With the advent of modern radiotherapy and imaging techniques, numerous studies are underway to personalize radiotherapy with the aim of reducing toxicity while maintaining good control rates. Since the side effects of radiotherapy are often directly related to the irradiated volume, an important approach to individualizing radiotherapy is the reduction of elective nodal irradiation (ENI). Our aim was to provide an overview of published and ongoing studies investigating the de-escalation of radiotherapy in the elective lymphatic drainage areas of head and neck tumors.

Methods: The literature search in MEDLINE, Web of Science, and clinicaltrials.gov was conducted using the following search terms in various combinations: head and neck cancer, elective nodal irradiation, de-escalation, and radiotherapy. Studies that included nasopharyngeal cancer or carcinomas with non-squamous histology were excluded.

Results: Various approaches to deintensifying ENI have been investigated, ranging from ENI dose reduction, general dose reduction, and volume reduction to complete omission of ENI, with some studies using response-adjusted dose and/or volume reduction after induction chemotherapy or dose reduction depending on hypoxia measured by FMISO-PET scan or sentinel lymph nodes measured by SPECT-CT after 99mTc-nanocolloid injection around the primary tumor. All these phase II trials indicate that the recurrence rate outside the radiation field is low (up to 4%). Most recurrences occur in high-risk regions of the clinical target volume (CTV) and in distant regions. However, results of phase III trials are still pending.

Conclusion: Reducing or even omitting ENI in patients with HNSCC seems to be a promising approach to de-escalation, but results of phase III trials are still pending.

Background: Artificial intelligence (AI)-based autocontouring software has the potential to revolutionize radiotherapy planning. In recent years, several AI-based autocontouring solutions with many advantages have emerged; however, their clinical use raises several challenges related to implementation, quality assurance, validation, and training. The aim of this study was to investigate the current use of AI-based autocontouring software and the associated expectations and hopes of radiation oncologists and medical physicists in German-speaking countries.

Methods: A digital survey consisting of 24 questions including single-choice, multiple-choice, free-response, and five-point Likert scale rankings was conducted using the online tool umfrageonline.com (enuvo GmbH, Pfäffikon SZ, Switzerland).

Results: A total of 163 participants completed the survey, with approximately two thirds reporting use of AI-based autocontouring software in routine clinical practice. Of the users, 92% found the software helpful in clinical practice. More than 90% reported using AI solutions to contour organs at risk (OARs) in the brain, head and neck, thorax, abdomen, and pelvis. The majority (88.8%) reported time savings in OAR delineation, with approximately 41% estimating savings of 11-20 min per case. However, nearly half of the respondents expressed concern about the potential degradation of resident training in sectional anatomy understanding. Of respondents, 60% would welcome guidelines for implementation and use of AI-based contouring aids from their respective radiation oncology societies. Respondents' free-text comments emphasized the need for careful monitoring and postprocessing of AI-delivered autocontours as well as concerns about overreliance on AI and its impact on the development of young physicians' contouring and planning skills.

Conclusion: Artificial intelligence-based autocontouring software shows promise for integration into radiation oncology workflows, with respondents recognizing its potential for time saving and standardization. However, successful implementation will require ongoing education and curriculum adaptation to ensure AI enhances, rather than replaces, clinical expertise.

Background: Lymphocytes are among the most radiosensitive cell types, and low-dose exposure during radiotherapy has been associated with measurable immune suppression. In breast cancer treatment, systemic immune exposure is partly driven by irradiation of highly vascularized organs such as the heart, lungs, and liver. The axillary lymph nodes also play a critical role in initiating antitumor immune responses. Isocentric lateral decubitus (ILD) positioning, by modifying the beam orientation, may reduce incidental exposure to these immune-related structures. This study aimed to evaluate the potential of ILD to spare both circulating immune cells and axillary lymph nodes compared to standard supine positioning during whole-breast irradiation (WBI).

Methods: Eight patients with localized breast cancer treated with breast-conserving surgery and adjuvant WBI (without nodal irradiation) were included in this retrospective dosimetric study. Each patient underwent CT simulation and treatment planning in both supine and ILD positions. The estimated dose to circulating immune cells (EDIC) was calculated using a model based on mean doses to the lungs, heart, liver, and whole body. The level I axillary region was retrospectively contoured, and both the mean dose and D95 were extracted. Dosimetric comparisons between positions were performed using paired Wilcoxon signed-rank tests.

Results: Isocentric lateral decubitus positioning significantly reduced the EDIC compared to the supine position (median 0.56 Gy vs. 1.12 Gy; p < 0.01). Lung, heart, and liver doses were also significantly lower. The axillary dose was reduced, with the mean dose decreasing from 10.2 to 3.8 Gy (p = 0.016) and D95% from 0.82 to 0.35 Gy (p = 0.039).

Conclusion: Isocentric lateral decubitus positioning significantly reduces both systemic and regional immune irradiation during adjuvant WBI. These findings suggest that ILD may help to preserve immune function, particularly in immunogenic subtypes such as triple-negative breast cancer, and support its consideration in treatment planning when nodal irradiation is not indicated.

Background and purpose: Online adaptive radiotherapy has demonstrated dosimetric benefits by accounting for interfractional organ variations. However, this study investigates the dosimetric impact of intra-adaptational anatomical changes that take place during the adaptation process.

Methods: Our retrospective analysis was conducted on 155 fractions from 8 prostate cancer patients treated with adaptive radiotherapy using the Varian Ethos system (Varian, Palo Alto, California, USA). Various dose-volume metrics for the targets and organs at risk were assessed for (1) the non-adapted (an original plan on a pretreatment cone-beam CT [CBCT], acquired at the beginning of a treatment session), (2) the adapted (an adapted plan on a pretreatment CBCT), and (3) the delivered dose distributions (an adapted plan on a pre-irradiation CBCT acquired for patient position verification with recontoured organs).

Results: For the target metrics, we quantitatively proved that the delivered dose distribution was still beneficial in comparison to the non-adapted one, despite the anatomical changes during the adaptation process. The bladder dose-volume metrics strongly depended on the bladder volume variations across the planning CT and both CBCTs, frequently showing improvement during the adaptation process as the bladder continued to fill. In contrast, no clear trend was observed for the rectum or posterior rectum wall metrics. In only a small fraction of sessions (up to 5% for most metrics) were the metric objectives not achieved with the delivered dose while they were achieved with the adapted one. Physiological reasons for these occurrences stemmed from meteorism occurring between pretreatment and pre-irradiation CBCTs.

Conclusion: This study confirms that the dosimetric advantages of online adaptive radiotherapy persist in clinical practice, despite anatomical changes due to the time delay needed for the adaptation process.

Purpose: Recent advancements in imaging, particularly 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET/CT), have improved the detection of involved lymph nodes, thus influencing staging accuracy and potentially treatment outcomes. This study is a post hoc analysis of the GAZAI trial data to evaluate the impact of FDG-PET/CT versus computed tomography (CT) alone on radiation target volumes for involved-site radiotherapy (IS-RT) in early-stage follicular lymphoma (FL).

Methods: All patients in the GAZAI trial underwent pretherapeutic FDG-PET/CT examinations, which were subject to central quality control. Lymph nodes with pathological metabolism were assessed for CT morphology. Differential regional involvement and the impact on radiation target volume for IS-RT were compared between PET/CT-based to solely CT-based staging.

Results: In 54 patients with PET-positive lymph nodes after initial surgery, 170 involved lymph nodes were identified in total. FDG-PET/CT identified additionally involved lymph nodes not detected by CT in 61% of the patients, leading to a significant change in radiation treatment fields for 30% of the cohort. Only 58% of all involved lymph nodes exhibited pathological CT morphology. The findings were robust across different Deauville score thresholds and CT morphological metrics.

Conclusion: The findings confirm the essential role of FDG-PET/CT in accurately defining the radiation volume for treatment of early-stage follicular lymphomas with radiotherapy. These results support the integration of FDG-PET/CT into the standard diagnostic pathway and its inclusion in the service catalogue of statutory health insurance, emphasizing its importance for optimal treatment planning and the potential impact on patient outcomes.