Radiation Oncology最新文献

Background: Radiotherapy as a complement or an alternative to neurosurgery has a central role in the treatment of skull base grade I-II meningiomas. Radiotherapy techniques have improved considerably over the last two decades, becoming more effective and sparing more and more the healthy tissue surrounding the tumour. Currently, hypo-fractionated stereotactic radiotherapy (SRT) for small tumours and normo-fractionated intensity-modulated radiotherapy (IMRT) or proton-therapy (PT) for larger tumours are the most widely used techniques. It is expected a decrease of the risk of cognitive impairment with these modern techniques. However prospective data about cognitive long-term consequences of partial brain irradiation with SRT, PT, or IMRT remain very scarce to date.

Methods: CANCER COG is one of the first multicentric study in the world to prospectively assess the cognitive performances of patients following different modalities of cerebral radiotherapy (stereotactic radiotherapy, proton therapy, intensity modulated radiotherapy) for the treatment of grade I-II skull base meningioma, up to at least 10 years after the end of radiotherapy. This longitudinal study includes the follow-up of 3 cohorts, including: patients treated with PRT, IMRT, and SRT. An additionally control group will be formed. The primary objective is to report long-term cognitive deterioration in each cohort until 10 years after the end of irradiation. The rate of clinical symptomatology improvement over time after irradiation, the evolution of health-related quality-of-life, anxiety/depression, fatigue, over time after irradiation, the tumoral local control after irradiation, the progression-free survival (PFS), the professional reintegration for working-age patients will also be assessed. CANCER COG aims to help clinicians to choose the best irradiation techniques with the best benefit/risk ratio. Inclusions started on september 2023.

Trial registration: The study was registered on clinicaltrials.gov with the following number: NCT06036706.

Background: Medulloblastoma is the most common malignant pediatric brain tumor, typically treated with normofractionated craniospinal irradiation (CSI) with an additional boost over about 6 weeks in children older than 3 years. This study investigates the sensitivity of pediatric medulloblastoma cell lines to different radiation fractionation schedules. While extensively studied in adult tumors, these ratios remain unknown in pediatric cases due to the rarity of the disease.

Materials and methods: Five distinct medulloblastoma cell lines (ONS76, UW228-3, DAOY, D283, D425) were exposed to varying radiation doses and fractionation schemes. In addition, ONS76 and UW228-3 stably overexpressing MYC were analyzed. Alpha/beta values, representing fractionation sensitivity, were quantified using the linear-quadratic model of radiation survival.

Results: The study unveiled elevated alpha/beta ratios across diverse medulloblastoma cell lines, with a weighted mean alpha/beta value of 11.01 Gy (CI: 5.23-16.79 Gy). Neither TP53 status nor the levels of MYC expression influenced fractionated radiosensitivity. Furthermore, differences in alpha/beta values cannot be correlated with molecular subgroups (p = 0.07) or radiosensitivity (SF2).

Conclusion: These in vitro findings strongly recommend normofractionated or hyperfractionated radiotherapy for paediatric medulloblastoma cases due to consistently high alpha/beta values across subgroups. Conversely, hypofractionated radiotherapy is not advisable within a curative approach. This study presents significant potential by enabling the estimation of radiobiological fractionations and dose effects in young, vulnerable patients, highlighting its importance for advancing patient-specific therapeutic strategies.

Background: The impact of radiation-related lymphocyte recovery on prognosis in locally advanced esophageal squamous cell carcinoma (LA-ESCC) remains unclear.

Methods: Patients with stage II-IVa ESCC who received definitive RT were screened. Collect absolute lymphocyte counts (ALCs) before, during, and after RT. The recovery status of lymphocytes was observed at one-month post-RT (P1) and three months post-RT (P3). Patients with relatively lower lymphocyte recovery levels at P1 were divided into Group a and those with higher levels were divided into Group b. Patients with relatively lower lymphocyte recovery levels at P3 were divided into Group A and those higher were divided into Group B. Kaplan-Merier's analysis and Cox analysis were conducted to compare survival outcomes. Binary logistic regression analyses was employed to ascertain factors associated with lymphocyte recovery.

Results: 116 patients were enrolled. During RT, ALCs reached the bottom 5 weeks after RT started and 70.7% of patients experienced G3 lymphopenia. The median OS for Group a and Group b were 38.1 months and 14.4 months, p = 0.097. The median PFS for Group a and Group b were 14.2 months and 10.0 months, p = 0.037. Whereas, the median OS for Group A and Group B was 14.5 months and 22.2 months, p = 0.019. The median PFS for Group A and Group B were 8.4 months and 12.4 months, p = 0.021. Cox multivariable analysis revealed that higher lymphocyte recovery level at P3 was significantly associated with superior OS (p = 0.040, HR0.636) and PFS (p = 0.028, HR0.627). The logistic analysis identified a positive association between G4 lymphopenia during RT (p = 0.012, OR 7.742) and PTV dose < 60 Gy (p = 0.014, OR 2.655) with lymphocyte recovery.

Conclusions: The prognostic value of lymphocyte recovery status at P3 appears to be greater than that of lymphocyte recovery status at P1 for locally advanced ESCC patients. Radiation-related lymphocyte recovery might serve as a valuable prognostic factor in LA-ESCC.

Purpose: Conventional radiotherapy (CRT) has limited local control and poses a high risk of severe toxicity in large lung tumors. This study aimed to develop an integrated treatment plan that combines CRT with lattice boost radiotherapy (LRT) and monitors its dosimetric characteristics.

Methods: This study employed cone-beam computed tomography from 115 lung cancer patients to develop a U-Net +  + deep learning model for generating synthetic CT (sCT). The clinical feasibility of sCT was thoroughly evaluated in terms of image clarity, Hounsfield Unit (HU) consistency, and computational accuracy. For large lung tumors, accumulated doses to the gross tumor volume (GTV) and organs at risk (OARs) during 20 fractions of CRT were precisely monitored using matrices derived from the deformable registration of sCT and planning CT (pCT). Additionally, for patients with minimal tumor shrinkage during CRT, an sCT-based adaptive LRT boost plan was introduced, with its dosimetric properties, treatment safety in high dose regions, and delivery accuracy quantitatively assessed.

Results: The image quality and HU consistency of sCT improved significantly, with dose deviations ranging from 0.15% to 1.25%. These results indicated that sCT is feasible for inter-fraction dose monitoring and adaptive planning. After rigid and hybrid deformable registration of sCT and pCT, the mean distance-to-agreement was 0.80 ± 0.18 mm, and the mean Dice similarity coefficient was 0.97 ± 0.01. Monitoring dose accumulation over 20 CRT fractions showed an increase in high-dose regions of the GTV (P < 0.05) and a reduction in low-dose regions (P < 0.05). Dosimetric parameters of all OARs were significantly higher than those in the original treatment plan (P < 0.01). The sCT based adaptive LRT boost plan, when combined with CRT, significantly reduced the dose to OARs compared to CRT alone (P < 0.05). In LRT plan, high-dose regions for the GTV and D_95% exhibited displacements greater than 5 mm from the tumor boundary in 19 randomly scanned sCT sequences under free breathing conditions. Validation of dose delivery using TLD phantom measurements showed that more than half of the dose points in the sCT based LRT plan had deviations below 2%, with a maximum deviation of 5.89%.

Conclusions: The sCT generated by the U-Net +  + model enhanced the accuracy of monitoring the actual accumulated dose, thereby facilitating the evaluation of therapeutic efficacy and toxicity. Additionally, the sCT-based LRT boost plan, combined with CRT, further minimized the dose delivered to OARs while ensuring safe and precise treatment delivery.

Purpose: To determine the dosimetric effects of set-up errors on boost coverage, and compares skin toxicity of sequential and simultaneous boost techniques for left-sided breast cancer.

Materials and methods: This retrospective study included 23 early-stage breast cancer cases. Single isocenter HFWBI-SIB(s-SIB), single isocenter HFWBI-SB(s-SB) and dual isocenter HFWBI-SB(d-SB) were planing. Rotations of 0.5°, 1°, and 2° coupled with translationals of 0.5 mm, 1.0 mm, and 2.0 mm were applied along three orthogonal axes. The dose to 95% of the PTV (D95) and the volume covered by 95% of the prescribed dose (V95) were evaluated using GEE univariate analysis to determine how PTV coverage was related to 1/CI_RTOG, PTVboost volume, PTVboost separation to isocenter. The relationship between the high-dose regions within the PTVbreast and Ratio_V was evaluated using univariate analysis.

Results: The s-SIB had optimal target coverage and lower high-dose volume, but it increased the risk of compromised coverage to tumor bed. For the s-SB technique, V95 exceeded 95% under all setup errors. At 2.0° coupled with 2.0 mm, s-SIB and d-SB exhibited V95 values below 95% in 34.8% and 8.7% of cases, respectively. At other setup errors, both s-SIB and d-SB demonstrated V95 values greater than 95%. Notably, high-dose regions such as V105%, V107%, and V110% within the PTVbreast across the three techniques displayed a significant correlation with Ratio_V.

Conclusion: Simultaneous-integrated boost for early-stage breast cancer can reduce skin toxicity compared to sequential techniques but with the risk of compromising tumor bed coverage.

Background: Several studies have suggested that lung tissue heterogeneity is associated with overall survival (OS) in lung cancer. However, the quantitative relationship between the two remains unknown. The purpose of this study is to investigate the prognostic value of whole lung-based and tumor-based radiomics for OS in LA-NSCLC treated with definitive radiotherapy.

Methods: A total of 661 patients with LA-NSCLC treated with definitive radiotherapy in combination with chemotherapy were enrolled in this study, with 292 patients in the training set, 57 patients from the same hospital from January to December 2017 as an independent test set (test-set-1), 83 patients from a multi-institutional prospective clinical trial data set (RTOG0617) as test-set-2, and 229 patients from a Dutch radiotherapy center as test-set-3. Tumor-based radiomic features and whole lung-based radiomic features were extracted from primary tumor and whole lungs (excluding the primary tumor) delineations in planning CT images. Feature selection of radiomic features was done by the least absolute shrinkage (LASSO) method embedded with a Cox proportional hazards (CPH) model with 5-fold cross-internal validation, with 1000 bootstrap samples. Radiomics prognostic scores (RS) were calculated by CPH regression based on selected features. Three models based on a tumor RS, and a lung RS separately and their combinations were constructed. The Harrell concordance index (C-index) and calibration curves were used to evaluate the discrimination and calibration performance. Patients were stratified into high and low risk groups based on median RS, and a log-rank test was performed.

Results: The discrimination ability of lung- and tumor-based radiomics model was similar in terms of C-index, 0.69 vs. 0.68 in training set, 0.68 vs. 0.66 in test-set-1, 0.61 vs. 0.62 in test-set-2, 0.65 vs. 0.64 in test-set-3. The combination of tumor- and lung-based radiomics model performed best, with C-index of 0.71 in training set, 0.70 in test-set-1, 0.69 in test-set-2, and 0.68 in test-set-3. The calibration curve showed good agreement between predicted values and actual values. Patients were well stratified in training set, test-set-1 and test-set-3. In test-set-2, it was only whole lung-based RS that could stratify patients well and tumor-based RS performed bad.

Conclusion: Lung- and tumor-based radiomic features have the power to predict OS in LA-NSCLC. The combination of tumor- and lung-based radiomic features can achieve optimal performance.

Background and purpose: Treatment record contains most of information related to treatment plan delivery in radiation therapy. Reviewing treatment record is an important quality assurance (QA) task for safety and quality of patient treatments. This task is usually performed by senior medical physicists. However, it is time-consuming, tedious, and error-prone. To assist this process, a treatment record review system (TRRS) is developed to automatically review items related to treatment delivery record.

Methods: The treatment record is firstly extracted from oncology information system (OIS). Based on the daily patient treatment information, the original plan from the treatment planning system is identified. Then the original plan and the delivered plan are correlated. Eight review categories (parameter consistency, treatment completeness, treatment progression, image guidance, override, treatment couch, documentation, and treatment mode) are created. Tailored rules are designed for various review items to automate the review process. As a result, for each daily treatment record, a reviewed flag (pass, failure, warning, and N/A) is assigned by the TRRS. Finally, this system is evaluated by 6 months patient treatment records collected in our institute and compared to the manual process on the same data.

Results: TRRS processed a total of 76,651 treatment fractions from 4230 patients with an average of 574 treatments per day. The percentage of the detected anomalies among the total records was 0.76%. The average processing time was 3.9 s and 282 s per treatment record for the automatic and manual processes, respectively. Comparing with the manual process, the time efficiency of TRRS is improved by a factor of 72. The average numbers of anomalies detected by the automatic and manual processes are 21 and 13 per day, respectively. TRRS detects 61.5% more anomalies than those of the manual process.

Conclusion: TRRS is not only efficient in processing a large amount of treatment records on a daily basis but also effective in finding more anomalies than those of physics weekly check. The application of the TRRS could significantly reduce the workload of the review physicists and let them focus on more important works related to patient safety.

Background: Proton beam therapy (PBT) has been gradually introduced for treating choroidal melanoma. This study systematically reviewed clinical reports to evaluate the efficacy and safety of PBT in choroidal melanoma patients.

Methods: This systematic review included all the primary studies involving PBT for choroidal melanoma patients through April 2024. Four publicly accessible databases were searched, and the statistical data were analyzed using STATA 15.0. The outcomes of interest included overall survival (OS), metastasis-free survival, local control rate, and adverse reactions.

Results: A total of six case series involving 1059 patients with choroidal melanoma were included. The random effect model meta-analysis showed that the 2-, 3-, 5-, and 10-year OS rates of patients with choroidal melanoma treated with PBT were 97%, 92%, 73%, and 39%, respectively. The metastasis-free survival rates at 2, 3, and 5 years were 92%, 89%, and 76%, respectively, and the local control rates at 1, 3, 5, and 10 years were 98%, 92%, 94%, and 88%, respectively. Four studies reported adverse reactions. The most common adverse reactions after PBT were glaucoma, optic neuropathy, and cataracts, with incidence rates ranging from 17.9 to 27%, 12.8-64%, and 29.6-39.8%, respectively.

Conclusions: This meta-analysis identified PBT as a vital local treatment strategy against choroidal melanoma. Both OS and local control rates showed excellent results. However, more prospective trials can help compare the efficacy of PBT with typical therapy.