Strahlentherapie und Onkologie最新文献

Background and purpose: Stereotactic body radiotherapy (SBRT) is associated with good local control and symptom relief in the management of spinal metastases. Delivery of ablative doses and re-irradiation is challenged by spinal cord toxicity. We hypothesized that lower spinal cord doses as well as better target coverage could be yielded with stereotactic magnetic resonance-guided adaptive radiotherapy (SMART).

Materials and methods: Institutional records were reviewed to retrieve patients who received online MR-guided SBRT for spinal metastases. Each fraction was reviewed to determine the necessity of adaptive planning, to identify reasons for violations that required adaptive planning, and to assess the spinal cord dose. The study also evaluated how adaptive planning contributed to reducing spinal cord doses.

Results: A total of 34 patients with 61 lesions were included. The treatment intent was definitive for 47 (77.1%), palliative for 12 (19.7%), and postoperative for two (3.3%) lesions. The median prescribed Biological Equivalent Dose (BED)₁₀ was 51.3 Gy. Treatment plans often required adaptive adjustments (81.8%). Adaptive planning significantly improved target coverage (median PTV coverage 92.75% vs. 95%; p < 0.001) and reduced spinal cord D_max (median spinal cord D_max constraint: 7.3 Gy, median predicted spinal cord D_max: 7.76, and median adaptive spinal cord D_max 6.18; p < 0.001). Lesion-based median follow-up from irradiation was 7.5 months (range: 1-46 months). One-year LPFS was 94.3%. Six lesions progressed and none of the progressed lesions received a dose above the median BED₁₀ of 51.3 Gy.

Conclusion: Herein we present our institutional experience with SMART for spinal bone metastases. According to our results, adaptive planning yields better target coverage as well as lower spinal cord doses compared to the predicted plan, which translates into a feasible method for delivering SBRT. Future prospective studies evaluating spinal SMART are awaited.

Background: Palliative radiotherapy (PRT) is crucial for improving quality of life in patients with advanced-staged cancer. This large data analysis investigates the travel distances and potential disparities in PRT access especially focusing on the burden of excess travel for palliative cancer patients in Victoria, Australia.

Methods: Using a state-wide linked dataset from the PRedicting the health economic IMPact of new and current Cancer Treatments (PRIMCAT) research program, we analysed the estimated road travel distance (ERTD) and potential excess travel distance (PETD) as well as received radiotherapy fractions for 29,807 PRT patients being treated from 2010-2019. We examined disparities by socioeconomic status (SEIFA) and remoteness (RA) of the residential area of PRT patients, and receiving treatment at a public or private centre.

Results: The average one-way ERTD for all PRT patients was 43 km, with variations based on SEIFA and RA. Patients in the lowest SEIFA quintile and those living in outer regional areas had the longest ERTD. Approximately 50% did not receive treatment at the closest facility, with a mean PETD of 27.9 km for private and 24.3 km for public facility patients. Fractionation patterns showed no significant reduction in the number of fractions with increased travel distance. Patients at private facilities received more fractions on average (8.49) compared to those at public facilities (5.91).

Conclusion: This study highlights potential disparities in PRT access in Victoria, with patients living in socioeconomically disadvantaged and remote regions facing longer travel distances and excess travel. These findings underscore the need for strategic referral practices and further research to optimise equitable access to PRT.

Purpose: Proton beam therapy (PBT) has a promising local control rate, but clinical data supporting its use for intermediate-stage hepatocellular carcinoma (HCC) remains insufficient, and its survival benefit over transarterial chemoembolization (TACE) has yet to be established. This study aimed to compare the two modalities by evaluating real-world survival outcomes.

Methods: The propensity score-matched (PSM) cohort study used data from a multi-institutional medical research database. Treatment-naïve patients with Barcelona Clinic Liver Cancer (BCLC) stage B HCC who underwent PBT or TACE as monotherapy were enrolled. Baseline patient and tumor characteristics were used for matching. Overall survival (OS) and post-treatment albumin-bilirubin (ALBI) grade were assessed, and stratified analyses were performed to evaluate the heterogeneity.

Results: Between January 2007 and December 2022, 4349 patients with BCLC‑B HCC were identified, 1172 of whom met the inclusion criteria (PBT: 68; TACE: 1104). The PSM cohort matched 340 patients (PBT: 68; TACE: 272). Cox regression analysis revealed a significant survival benefit in the PBT group (p = 0.032, hazard ratio (HR) 0.64, 95% CI 0.42-0.97). Liver function was assessed in terms of ALBI grade every 3 months for 12 months after treatment, and the proportion of patients who maintained better liver function was greater in the PBT group than in the TACE group (p = 0.006).

Conclusion: For patients with BCLC‑B HCC who are suitable candidates for PBT, PBT preserves better liver function than TACE and provides superior OS.

Purpose: The aim is to evaluate treatment outcomes and prognostic factors in patients with thymic epithelial tumor (TET) treated with radiotherapy (RT).

Methods: Sixty-four patients were treated between 2000 and 2023. The median age was 52 years (20-83), and 81% of underwent R0 resection. The stage (s) distribution for I, II, III, and IV were 5%, 61%, 26%, and 8% by Masaoka-Koga and 63%, 11%, 17%, and 9% by TNM, respectively. WHO types A/AB/B/C and thymic neuroendocrine tumors were seen in 5%, 22%, 64%, 6%, and 3% of patients, respectively. The median RT dose was 5040 cGy (1620-6596). Survival was calculated from the beginning of RT.

Results: The median follow-up was 70 months (1.5-268). The median time to recurrence was 30 months (6.5-106), seen in 23% of patients. Mean overall (OS), progression-free survival (PFS) and 5‑year local control were 141, 138 months, and 82.4%, respectively. In univariate analysis, the presence of organ invasion and TNM stage were significant as new prognostic factors for survival (p < 0.05). In multivariate analysis, the high-risk group (B2/B3/C) and another surgical center (p < 0.05) for OS, and KPS ≤ 80, thymic carcinoma, and Masaoka-Koga sIII-IV (p < 0.05) for PFS were identified as unfavorable prognostic factors.

Conclusion: Recurrence in TET can occur over a longer period. In this study, 5‑year local control of 82.4% was achieved. The prognostic importance of KPS, histology, Masaoka-Koga stage, risk group, and surgical center was demonstrated. Advances in the diagnosis, staging, and treatment of TET will enable more personalized treatment.

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: Radiotherapy-induced head and neck cancer harms the structural and biochemical integrity of dentin and causes mineral loss, breakdown of collagen, and increased sensitivity to radiation-induced caries and restorative failure.

Objective: To evaluate the therapeutic effectiveness of nanohydroxyapatite (nHAp) and vitamin E-individually and in combination-for remineralization and collagen matrix preservation of irradiated dentin.

Methods: Forty human third molars (n = 8 per group) were allocated into five groups randomly: non-irradiated control, irradiation-only (60 Gy linear accelerator, LINAC), irradiation + nHAp treatment, irradiation + vitamin E treatment, and irradiation + combination treatment (nHAp + vitamin E). Dentin samples were analyzed using Fourier transform infrared spectroscopy (FTIR), X‑ray diffraction (XRD), scanning electron microscopy with energy-dispersive X‑ray spectroscopy (SEM-EDX), and Vickers microhardness testing.

Results: Radiotherapy caused widespread microstructural loss and amide I and II band intensity decreases (mean of 41.3% and 47.7%, respectively) as well as a 33% loss in crystallinity. The nHAp treatment recovered phosphate peak intensity to 82.1% of the control mean, and vitamin E retained amide I and II bands at 91.3% and 88.9% of the control means, respectively. The combined treatment achieved the best recovery, with the crystallinity returning to 89.5% of the control, near full recovery of the intensities of amide and phosphate bands, normalization of the Ca/P ratio, and microhardness values that were not significantly different from the non-irradiated control (p > 0.05).

Conclusion: Nanohydroxyapatite and vitamin E have synergistic actions, promoting organic as well as mineral phases of irradiated dentin. Their combined application significantly increases microhardness, chemical composition, and ultrastructure, promoting a double-therapy strategy for the restorative rehabilitation of head and neck cancer patients after radiotherapy.