Strahlentherapie und Onkologie最新文献

This report details the reactivation of immune checkpoint inhibitor (ICI)-related autoimmune hepatitis triggered by stereotactic body radiation therapy (SBRT) in a 55-year-old male with hilar cholangiocellular carcinoma. Initially diagnosed in December 2021, the patient underwent successful resection and subsequent adjuvant therapy. Despite stable disease following chemotherapy augmented with durvalumab, he developed grade 3 acute hepatitis after seven cycles of durvalumab. Following a brief prednisolone regimen and normalization of liver tests, SBRT targeting para-aortic lymph nodes was initiated. Remarkably, severe hepatitis reoccurred 7 days after starting SBRT, 88 days following the last durvalumab infusion, necessitating resumed and escalated prednisolone treatment. Another course of SBRT for a newly diagnosed metastatic liver lesion was administered in September 2023, with ongoing prednisolone adjustment. By February 2024, liver tests normalized, but subsequent radiological assessments indicated tumor progression, leading to the reintroduction of chemotherapy. This case underscores the potential of SBRT for activating severe immune-mediated hepatotoxicity in patients treated with ICIs, highlighting the need for careful monitoring and management of such patients. Further, this report highlights the possible survival benefit of the strategic application of SBRT in addition to systematic treatment in recurrent and metastatic cholangiocellular carcinoma.

Background: Adjuvant radiotherapy is essential for reducing local recurrence and improving survival in breast cancer patients, but it carries a risk of ischemic cardiac toxicity, which increases with heart exposure. The isocentric lateral decubitus position, where the breast rests flat on a support, reduces heart exposure and leads to delivery of a more uniform dose. This position is particularly beneficial for patients with unique anatomies, such as those with pectus excavatum or larger breast sizes. While artificial intelligence (AI) algorithms for autocontouring have shown promise, they have not been tailored to this specific position. This study aimed to develop and evaluate a neural network-based autocontouring algorithm for patients treated in the isocentric lateral decubitus position.

Materials and methods: In this single-center study, 1189 breast cancer patients treated after breast-conserving surgery were included. Their simulation CT scans (1209 scans) were used to train and validate a neural network-based autocontouring algorithm (nnU-Net). Of these, 1087 scans were used for training, and 122 scans were reserved for validation. The algorithm's performance was assessed using the Dice similarity coefficient (DSC) to compare the automatically delineated volumes with manual contours. A clinical evaluation of the algorithm was performed on 30 additional patients, with contours rated by two expert radiation oncologists.

Results: The neural network-based algorithm achieved a segmentation time of approximately 4 min, compared to 20 min for manual segmentation. The DSC values for the validation cohort were 0.88 for the treated breast, 0.90 for the heart, 0.98 for the right lung, and 0.97 for the left lung. In the clinical evaluation, 90% of the automatically contoured breast volumes were rated as acceptable without corrections, while the remaining 10% required minor adjustments. All lung contours were accepted without corrections, and heart contours were rated as acceptable in 93.3% of cases, with minor corrections needed in 6.6% of cases.

Conclusion: This neural network-based autocontouring algorithm offers a practical, time-saving solution for breast cancer radiotherapy planning in the isocentric lateral decubitus position. Its strong geometric performance, clinical acceptability, and significant time efficiency make it a valuable tool for modern radiotherapy practices, particularly in high-volume centers.

Background: Myxoid liposarcoma (MLPS) is a rare subtype of soft tissue sarcoma. This entity has a specific clinical behavior, characterized with a distinct pattern of hematogenous spread, as well as with a unique radiosensitivity and chemosensitivity. Oncologic results, metastatic patterns and treatment response after multimodal therapy were evaluated in a unicentric patient cohort.

Methods: Patients with myxoid liposarcoma were retrospectively analyzed in a single institution analysis (n = 31). Oncologic outcomes were evaluated in 28 patients with localized MLPS treated with multimodal therapy in curative intent. Metastatic pattern was analyzed in additional 3 patients with initially metastatic disease. In patients treated with concomitant MR-guided hyperthermia in the preoperative setting (n = 7), tumor size response was evaluated longitudinally during radio(-chemo)therapy in thermometry MRIs and before surgery (based on preoperative imaging).

Results: The median follow-up was 4.1 ± 1.0 years. The most common anatomic localization was the lower extremity (78.6%). The 5‑year rates for oncologic outcomes in 28 patients treated in curative intent were 91.7% (± 8.0%) for overall survival (OS), 77.4% (± 11.0%) for local control (LC), 60.1% (± 10.6%) for distant metastasis-free survival (DMFS) and 55.4% (± 11.1%) for disease free survival (DFS). Excellent 5‑year LC (94.7 ± 5.1%) was demonstrated for the cohort excluding 5 patients treated for local recurrences. Most patients had good pathologic response (< 10% vital tumor tissue) following neoadjuvant treatment (82.4%, 14/17). However, this did not correlate with oncologic outcomes. A specific pattern of distant metastases has been observed, with predilection for soft tissues as the most common metastatic site. Furthermore, no isolated pulmonary metastases were observed. The MR analysis demonstrated a significant tumor size reduction (≥ 25%) of the initial tumor volume in 85.7% (n = 6/7) patients. No local recurrences and no distant metastases were observed in patients with significant MR size reduction.

Conclusion: Sequential MRIs during preoperative radiotherapy of myxoid liposarcoma show distinct patterns of the known size reduction of this specific subentity. Our analysis of metastatic patterns demonstrate mostly soft tissue metastases, no patient experienced isolated pulmonary metastases.

Background: Hyperthermia treatment planning can be supportive to ensure treatment quality, provided reliable prediction of the heating characteristics (i.e., focus size and effects of phase-amplitude and frequency steering) of the device concerned is possible. This study validates the predictions made by the treatment planning system Plan2Heat for various clinically used phased-array systems.

Methods: The evaluated heating systems were AMC-2, AMC-4/ALBA-4D (Med-Logix srl, Rome, Italy), BSD Sigma-30, and Sigma-60 (Pyrexar Medical, Salt Lake City, UT, USA). Plan2Heat was used for specific absorption rate (SAR) simulations in phantoms representing measurement set-ups reported in the literature. SAR profiles from published measurement data based on E‑field or temperature rise were used to compare the device-specific heating characteristics predicted by Plan2Heat.

Results: Plan2Heat is able to predict the correct location and size of the SAR focus, as determined by phase-amplitude settings and operating frequency. Measured effects of phase-amplitude steering on focus shifts (i.e., local SAR minima or maxima) were also correctly reflected in treatment planning predictions. Deviations between measurements and simulations were typically < 10-20%, which is within the range of experimental uncertainty for such phased-array measurements.

Conclusion: Plan2Heat is capable of adequately predicting the heating characteristics of the AMC‑2, AMC-4/ALBA-4D, BSD Sigma-30, and Sigma-60 phased-array systems routinely used in clinical hyperthermia.

Background: The immune system has been identified as an organ at risk in esophageal and lung cancers. However, the dosimetric impact of radiotherapy on immune system exposure in patients treated for breast cancer has never been studied.

Methods: A monocentric retrospective dosimetric study included 163 patients treated at the Institut Curie (Paris, France) between 2010 and 2016 with locoregional helical tomotherapy after conservative surgery or total mastectomy. The effective dose to the immune system (EDIC) was calculated based on diverse dosimetric parameters. The clinical and volumetric determinants of EDIC in adjuvant radiotherapy of breast cancer were analyzed.

Results: The median EDIC for the population was 4.23 Gy, ranging from 1.82 to 6.19 Gy. Right-sided radiotherapy and regional lymph node irradiation were associated with significantly higher EDIC in univariate (4.38 Gy vs. 3.94 Gy, p < 0.01, and 4.27 Gy vs. 3.44 Gy, p < 0.01, respectively) and multivariate analyses (p < 0.01 and p < 0.01). Liver overexposure was the main contributor to EDIC increase in right-sided breast cancer patients (+0.38 Gy [95%CI: +0.30; +0.46]), while the integral total dose increase was the main contributor to EDIC increase in cases of regional node irradiation (+0.63 Gy [95%CI: +0.42; +0.85]).

Conclusion: The EDIC score during adjuvant radiotherapy after breast cancer was statistically significantly higher in the case of right-sided radiotherapy and regional lymph node irradiation. Liver irradiation is the main contributor to immune system exposure in adjuvant irradiation of right-sided breast cancer. Populations in which an association between EDIC and survival would exist have yet to be identified but could potentially include patients treated for triple-negative breast cancer with a poor response to neoadjuvant chemoimmunotherapy.

Purpose: Abscopal effects have been reported predominantly in metastatic cancers, indicating a radiographic response in a lesion that has not been included in the radiotherapy target volume. The response is interpreted as a humoral immune response to radiotherapy-generated tumour-specific antigens. In this case study, we present the first histologically confirmed multifocal low-grade meningioma with spontaneous regression of all other lesions after conventionally fractionated stereotactic radiotherapy (RT).

Case report: Two localisations, right frontal and right spheno-orbital, were resected at the time of the initial diagnosis in a 66-year-old woman. RT was performed 1 year later to a progressive occipital lesion at the cerebral falx.

Results: Regular magnetic resonance imaging (MRI) showed slightly decreasing tumour volume in untreated lesions 1 year after RT and continued during further follow-up. Up to > 7 years after treatment, MRI demonstrated an almost complete response of all initial lesions. Two prior reports with meningioma were published in one patient with an atypical meningioma after conventionally fractionated RT and another patient with an intracranial meningiomatosis after radiosurgery.

Conclusion: This case study supports the concepts of treating only progressive or symptomatic meningioma lesions locally and careful regular MRI surveillance for further assessment. Potential active interventions to trigger an abscopal effect are currently not known. Further research of this beneficial effect for our patients should be supported.

Background and purpose: Combining chemoradiotherapy (CRT) with deep regional hyperthermia (HT) shows promise for enhancing clinical outcomes in selected rectal cancer patients. This study aimed to integrate the evidence and evaluate the efficacy of this combined treatment approach.

Materials and methods: A systematic search of the PubMed, Scopus, and Mendeley databases was performed. This review was conducted according to the PRISMA guidelines. The quality of studies was evaluated using the Newcastle-Ottawa scale (NOS). Random-effects meta-analyses (DerSimonian and Laird) were performed. The primary outcome was pathological complete response (pCR), and secondary endpoints were overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and toxicity.

Results: In total, 12 studies were included, mostly of moderate quality. Patients with locally advanced rectal cancer (LARC; n = 760) and locally recurrent rectal cancer (LRRC; n = 22) were eligible. The pooled pCR rate was 19% (95% confidence interval [CI]: 16-22%) among all 782 patients and 19% (95%CI:16-23%) among 760 LARC patients. Due to significant study heterogeneity, survival outcomes were pooled by excluding LRRC patients. The pooled 5‑year OS rate among 433 LARC patients was 87% (95%CI: 83-90%). The pooled 5‑year DFS and LRFS in LARC patients were 75% (95%CI: 70-80%) and 95% (95%CI: 92-97%), respectively. There was a lack of consistent reporting of HT treatment parameters and toxicity symptoms among the studies.

Conclusion: The collective clinical evidence showed that neoadjuvant CRT combined with HT in rectal cancer patients is feasible, with a 19% pCR rate and excellent survival outcomes in long term follow-up.