Strahlentherapie und Onkologie最新文献

Purpose: A prototype infrared camera - cone-beam computed tomography (CBCT) system for tracking in brachytherapy has recently been developed. We evaluated for the first time the corresponding tracking accuracy and uncertainties, and implemented a tracking-based prediction of needles on CBCT scans.

Methods: A marker tool rigidly attached to needles was 3D printed. The precision and accuracy of tool tracking was then evaluated for both static and dynamic scenarios. Euclidean distances between the tracked and CBCT-derived markers were assessed as well. To implement needle tracking, ground truth models of the tool attached to 200 mm and 160 mm needles were matched to the tracked positions in order to project the needles into CBCT scans. Deviations between projected and actual needle tips were measured. Finally, we put our results into perspective with simulations of the system's tracking uncertainties.

Results: For the stationary scenario and dynamic movements, we achieved tool-tracking precision and accuracy of 0.04 ± 0.06 mm and 0.16 ± 0.18 mm, respectively. The tracked marker positions differed by 0.52 ± 0.18 mm from the positions determined via CBCT. In addition, the predicted needle tips in air deviated from the actual tip positions by only 1.62 ± 0.68 mm (200 mm needle) and 1.49 ± 0.62 mm (160 mm needle). The simulated tracking uncertainties resulted in tip variations of 1.58 ± 0.91 mm and 1.31 ± 0.69 mm for the 200 mm and 160 mm needles, respectively.

Conclusion: With the innovative system it was possible to achieve a high tracking and prediction accuracy of marker tool and needles. The system shows high potential for applicator tracking in brachytherapy.

Objective: In the era of image-guided adaptive radiotherapy, definition of the clinical target volume (CTV) is a challenge in various solid tumors, including esophageal cancer (EC). Many tumor microenvironmental factors, e.g., tumor cell proliferation or cancer stem cells, are hypothesized to be involved in microscopic tumor extension (MTE). Therefore, this study assessed the expression of FAK, ILK, CD44, HIF-1α, and Ki67 in EC patients after neoadjuvant radiochemotherapy followed by tumor resection (NRCHT+R) and correlated these markers with the MTE.

Methods: Formalin-fixed paraffin-embedded tumor resection specimens of ten EC patients were analyzed using multiplex immunofluorescence staining. Since gold fiducial markers had been endoscopically implanted at the proximal and distal tumor borders prior to NRCHT+R, correlation of the markers with the MTE was feasible.

Results: In tumor resection specimens of EC patients, the overall percentages of FAK⁺, CD44⁺, HIF-1α⁺, and Ki67⁺ cells were higher in tumor nests than in the tumor stroma, with the outcome for Ki67⁺ cells reaching statistical significance (p < 0.001). Conversely, expression of ILK⁺ cells was higher in tumor stroma, albeit not statistically significantly. In three patients, MTE beyond the fiducial markers was found, reaching up to 31 mm.

Conclusion: Our findings indicate that the overall expression of FAK, HIF-1α, Ki67, and CD44 was higher in tumor nests, whereas that of ILK was higher in tumor stroma. Differences in the TME between patients with residual tumor cells in the original CTV compared to those without were not found. Thus, there is insufficient evidence that the TME influences the required CTV margin on an individual patient basis.

Trial registration number and date: BO-EK-148042017 and BO-EK-177042022 on 20.06.2022, DRKS00011886, https://drks.de/search/de/trial/DRKS00011886 .

Purpose: Multiple myeloma is associated with osteolytic bone lesions, often requiring surgery of the spine and postoperative radiotherapy (RT). Although common, data for clinical and informed decision-making are sparse. In this monocentric retrospective study, we aim to report the outcome of patients who underwent spinal surgery and postoperative RT due to multiple myeloma.

Methods: A total of 54 patients with multiple myeloma who underwent prior spinal surgery and postoperative RT at our institution between 2009 and 2020 were analyzed. Spinal instability neoplastic score (SINS) and Bilsky score, posttherapeutic adverse events, clinical data, and outcomes were collected and analyzed. The primary endpoint of this study was overall survival (OS), secondary endpoints were progression-free survival (PFS), pain response, local control, and skeletal-related events (SRE).

Results: The 3‑ and 5‑year overall survival (OS) was 74.9% (95% confidence interval [CI]: 63.5-88.4%) and 58% (95% CI: 44.5-75.6%), respectively. Median survival was not reached and 75% survival was 34.3 months (95% CI: 28.7-95.4 months). Median follow-up was 63 months (95% CI: 49-94 months). The number of patients with good to adequate performance status (Karnofsky performance score [KPS] ≥ 70) significantly increased after surgery (p < 0.01). We observed no grade 3/4 toxicity and only 13 (24%) grade 1/2 adverse events. Two patients (4%) experienced SRE. Overall, 92% of patients reported reduced pain after radiotherapy, with 66% reporting complete pain response. There was no difference in pain response between patients with different Bilsky scores. Bisphosphonate therapy and lower Bilsky score at the start of RT were associated with improved OS in univariate analysis (all p < 0.05). Multivariate Cox regression confirmed a Bilsky score of 2 or 3 as an independent negative prognostic factor (HR 3.89; 95 CI 1.4-10.7; p < 0.01). We observed no in-field recurrences.

Conclusion: In this study, we were able to show that the current standard of RT after spinal surgery of osteolytic lesions is safe. In addition, we observed a very low rate of SRE (4%) and no in-field recurrences, demonstrating the local efficacy of RT in multiple myeloma patients. Higher Bilsky scores were associated with worse OS in multivariate analysis, but had no effect on pain response.

Background: Radiotherapy is one of the main treatment options for patients with esophageal cancer; however, it has been linked with an increased risk of cardiac toxicities. In the current study, we evaluated the effect of planning the radiation in deep-inspiration breath hold (DIBH) on the dose sparing of cardiac substructures and lung.

Materials and methods: In this study, we analyzed 30 radiation therapy plans from 15 patients diagnosed with esophageal cancer planned for neoadjuvant radiotherapy. Radiation plans were generated for 41.4 Gy and delivered in 1.8 Gy per fraction for free-breathing (FB) and DIBH techniques. We then conducted a comparative dosimetric analysis, evaluating target volume coverage, the impact on cardiac substructures, and lung doses across the two planning techniques for each patient.

Results: There was no significant disparity in target volume dose coverage between DIBH and FB plans. However, the D_mean, D2%, and V30% of the heart experienced substantial reductions in DIBH relative to FB, with values of 6.21 versus 7.02 Gy (p = 0.011), 35.28 versus 35.84 Gy (p = 0.047), and 5% versus 5.8% (p = 0.048), respectively. The D_mean of the left ventricle was notably lower in DIBH compared to FB (4.27 vs. 5.12 Gy, p = 0.0018), accompanied by significant improvements in V10. Additionally, the D_mean and D2% of the left coronary artery, as well as the D2% of the right coronary artery, were significantly lower in DIBH. The dosimetric impact of DIBH on cardiac substructures proved more advantageous for middle esophageal (ME) than distal esophageal (DE) tumors.

Conclusion: Radiotherapy in DIBH could provide a method to reduce the radiation dose to the left ventricle and coronaries, which could reduce the cardiac toxicity of the modality.

Purpose: To assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery.

Methods: Consecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As a secondary endpoint, reported toxicity was assessed.

Results: A total of 34 localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31 patients. Grade 3 side effects were experienced by 26.7% of patients and there were no grade 4 or 5 events observed. Median PFS was 19 months. Median OS was 20 months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008).

Conclusion: IMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as a component of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.