Explore the vast range of titles available.

Background Texture analysis extracts many quantitative image features, offering a valuable, cost-effective, and non-invasive approach for individual medicine. Furthermore, multimodal machine learning could have a large impact for precision medicine, as texture biomarkers can underlie tissue microstructure. This study aims to investigate imaging-based biomarkers of radio-induced neurotoxicity in pediatric patients with metastatic medulloblastoma, using radiomic and dosiomic analysis. Methods This single-center study retrospectively enrolled children diagnosed with metastatic medulloblastoma (MB) and treated with hyperfractionated craniospinal irradiation (CSI). Histological confirmation of medulloblastoma and baseline follow-up magnetic resonance imaging (MRI) were mandatory. Treatment involved helical tomotherapy (HT) delivering a dose of 39 Gray (Gy) to brain and spinal axis and a posterior fossa boost up to 60 Gy. Clinical outcomes, such as local and distant brain control and neurotoxicity, were recorded. Radiomic and dosiomic features were extracted from tumor regions on T1, T2, FLAIR (fluid-attenuated inversion recovery) MRI-maps, and radiotherapy dose distribution. Different machine learning feature selection and reduction approaches were performed for supervised and unsupervised clustering. Results Forty-eight metastatic medulloblastoma patients (29 males and 19 females) with a mean age of 12 ± 6 years were enrolled. For each patient, 332 features were extracted. Greater level of abstraction of input data by combining selection of most performing features and dimensionality reduction returns the best performance. The resulting one-component radiomic signature yielded an accuracy of 0.73 with sensitivity, specificity, and precision of 0.83, 0.64, and 0.68, respectively. Conclusions Machine learning radiomic-dosiomic approach effectively stratified pediatric medulloblastoma patients who experienced radio-induced neurotoxicity. Strategy needs further validation in external dataset for its potential clinical use in ab initio management paradigms of medulloblastoma.

Due to its inherent technical challenges, craniospinal irradiation (CSI) entails crucial considerations regarding plan complexity and robustness. The scope of this work was to establish and validate methods suitable for the evaluation of robustness, as well as for dose verification in CSI with VMAT. Five patients previously treated with CSI were retrospectively selected. For each patient, two technically different treatment plans were generated, based on the conventional (static overlap) and staggered (dynamic overlap) configuration. These techniques served as a benchmark to evaluate the potential of a metric proposed in this work, aimed at quantifying robustness, the Overlap Robustness Index ( ORI ). Furthermore, they were utilized to assess the suitability of two experimental methods relying on film dosimetry, as well as on Delta 4 phantom for identifying sources of uncertainties in CSI applications. In accordance with the positional error simulation performed, the staggered approach yielded a statistically significant superior ORI value compared to the conventional one. Additionally, the strong correlation observed between the positional shift induced dose distribution changes and ORI results (Spearman’s r = -0.941, p -value < 0.001) demonstrated the sensitivity of ORI in detecting areas of steep dose gradients within the overlapping regions that could potentially compromise the quality of treatment. Concerning dose verification, analysis in terms of dose profiles revealed a superior dosimetric accuracy for the staggered technique relative to conventional for both film and Delta 4 measurements. Film-based gamma index results showed that staggered technique outperformed the conventional for the majority of passing criteria considered, with differences in passing rates up to 8.1%. The two treatment techniques however, exhibited equivalent dose delivery accuracy for the clinically relevant passing criteria when Delta 4 was employed, with passing rate differences less than 0.6%. Findings of this study revealed that ORI is suitable for quantifying robustness in CSI with VMAT, while radiochromic films appeared to be the best candidate for CSI dose verification in this work.

Objective The delivery quality assurance (DQA) of craniospinal irradiation (CSI) due to the target length results in no ideal verification devices. Delivery Analysis (DA) could calculate the dose distribution based on the measured multi leaf open time in helical tomotherapy (HT). This study aimed to evaluate the efficacy of DA for DQA of CSI in HT. Material and Methods 32 CSI plans were classified into two groups based on γ analysis of the PTV‐cranial and PTV‐spine plans using a 2D ionization chamber matrix (MatriXX). Plans with γ passing rates ≥ 95% at 3%/2 mm were classified as the passed group, while those < 95% were classified as the failed group. Receiver operating characteristic (ROC) curves identified optimal passing rate threshold for DA in HT. Logistic regression analyzed risk factors for DQA failure, and failed plans were reoptimized according to the adjusted parameter. Results For PTV‐cranial plans, 30 passed and two failed; for PTV‐spine plans, 21 passed and 11 failed. ROC analysis revealed areas under the curve of 0.858 (PTV‐cranial, threshold: 89.0%) and 0.714 (PTV‐spine, threshold: 86.0%). Logistic regression identified planned modulation factor (MF‐plan; p = 0.046; p = 0.023) and actual modulation factor (MF‐actual; p = 0.027; p = 0.008) as independent risk factors for DQA failure in both MatriXX and DA. Additionally, beam on time (p = 0.043), gantry period (p = 0.007) and maximum leaf open time (p = 0.007) were identified as independent risk factors for DA. Reoptimization of failed plans with MF‐plan = 2.6 significantly improved passing rates in DA (73.70% ± 13.30% vs. 88.20% ± 12.30%; p = 0.010) and MatriXX (91.20% ± 2.60% vs. 96.10% ± 1.40%; p < 0.001). Conclusion Delivery Analysis could be a feasible tool for DQA of CSI in HT. Increasing the MF‐plan is recommended to enhance the passing rate.

Background Craniospinal irradiation (CSI) is essential for treating pediatric medulloblastoma (MB) but causes significant long‐term toxicities. Existing dose‐reduction or partial‐sparing strategies improve neurocognitive outcomes but may compromise survival or fail to address other late effects. Methods A new functional preservation CSI (FP‐CSI) technique was developed to spare the hippocampus, hypothalamic‐pituitary axis (HPA), cochlea, and scalp while ensuring homogeneous vertebral coverage. Eight pediatric patients with average‐risk MB were retrospectively planned with volumetric modulated arc therapy (VMAT) using both FP‐CSI and standard CSI (S‐CSI). Dosimetric parameters for the planning target volume (PTV) and organs at risk (OARs), radiobiological effects, plan robustness, plan complexity, and plan quality assurance (QA) were compared. Results FP‐CSI significantly reduced mean doses to the hippocampus (12.4 vs. 23.9 Gy), hypothalamus (14.7 vs. 23.9 Gy), and pituitary gland (15.4 vs. 24.1 Gy, all p < 0.01). Vertebral dose gradients were halved (4.7 vs. 8.7 Gy). Moderate dose reductions were also achieved for the cochlea and scalp. Compared with S‐CSI, FP‐CSI exhibited slightly inferior PTV homogeneity (HI: 0.16 vs. 0.07) and conformity (CI: 0.88 vs. 0.93), but coverage remained clinically acceptable. Normal tissue complication probability (NTCP) modeling showed pronounced decreases in predicted neurocognitive and endocrine toxicity risks, with probability of neurocognitive impairment reduced from 84.5% to 24.9% and probability of endocrine dysfunction from 44.7% to 27.3%. FP‐CSI increased modulation complexity and produced slightly lower gamma passing rates for cranial beams, while spinal beam deliverability remained similar to S‐CSI. Robustness analysis indicated greater sensitivity of FP‐CSI to setup and rotational errors. Nevertheless, 3D dose reconstruction confirmed accurate delivery, with volumetric dose deviations generally below 1 Gy. Conclusion FP‐CSI effectively spares critical functional structures while maintaining clinically acceptable target coverage, and offers a promising strategy to reduce long‐term radiotherapy‐induced toxicities in pediatric MB.

Background Leptomeningeal disease (LMD) is a fatal complication of cancer linked to poor survival rates and limited treatment options. While photon involved-field radiotherapy is the standard of care for local palliation and symptom alleviation, it lacks durable disease control. Recent data suggest proton craniospinal irradiation (pCSI) to be a promising treatment option, potentially prolonging progression-free survival (PFS) and overall survival (OS). Herein, we report our initial experience with pCSI for treating LMD from solid malignancies. Methods Adult patients treated with pCSI for LMD were identified, with analysis of patient, tumor, and treatment characteristics as well as clinical outcomes. Results Nine patients were eligible for analysis who were treated between February 2023 and February 2024. The median age at pCSI and Karnofsky performance status (KPS) were 58.6 years and 80%, respectively. The primary disease was breast cancer in 33.3%, and LMD involved both the brain and spine in 55.5%. Approximately half of the patients (55.5%) had a cerebrospinal fluid diversion before treatment, and nearly all patients underwent pCSI with 30 Gy (relative biological effectiveness) in 10 fractions. All patients completed pCSI as planned. The median clinical and central nervous system (CNS) radiographic follow-up periods were both 3.5 months. Six deaths were observed during the available follow-up. The median PFS, CNS PFS, and OS were 2.7, 4.0, and 4.0 months, respectively. Younger age, higher KPS, and concurrent treatment with targeted therapy were associated with longer OS, while cases with LMD involving both the brain and spine had shorter survival. The observed toxicity was manageable, without any occurrence of grade 4 or 5 toxicity. Conclusion pCSI can be an effective and safe treatment option for a highly selected population of patients with LMD. Further data and prospective studies are warranted to clarify its role in the management of LMD.

Craniospinal irradiation (CSI) poses a challenge to treatment planning due to the large target, field junction, and multiple organs at risk (OARs) involved. The aim of this study was to evaluate the performance of knowledge-based planning (KBP) in CSI by comparing original manual plans (MP), KBP RapidPlan initial plans (RP ), and KBP RapidPlan final plans (RP ), which received further re-optimization to meet the dose constraints. Dose distributions in the target were evaluated in terms of coverage, mean dose, conformity index (CI), and homogeneity index (HI). The dosimetric results of OARs, planning time, and monitor unit (MU) were evaluated. All MP and RP plans met the plan goals, and 89.36% of RP plans met the plan goals. The Wilcoxon tests showed comparable target coverage, CI, and HI for the MP and RP groups; however, worst plan quality was demonstrated in the RP plans than in MP and RP . For the OARs, RP and RP groups had better dosimetric results than the MP group ( < 0.05 for optic nerves, eyes, parotid glands, and heart). The planning time was significantly reduced by the KBP from an average of 677.80 min in MP to 227.66 min ( < 0.05) and 307.76 min ( < 0.05) in RP , and RP , respectively. MU was not significantly different between these three groups. The KBP can significantly reduce planning time in CSI. Manual re-optimization after the initial KBP is recommended to enhance the plan quality.

Objective This study evaluates various craniospinal irradiation (CSI) techniques used in Turkish centers to understand their advantages, disadvantages and overall effectiveness, with a focus on enhancing dose distribution. Methods Anonymized CT scans of adult and pediatric patients, alongside target volumes and organ-at-risk (OAR) structures, were shared with 25 local radiotherapy centers. They were tasked to develop optimal treatment plans delivering 36 Gy in 20 fractions with 95% PTV coverage, while minimizing OAR exposure. The same CT data was sent to a US proton therapy center for comparison. Various planning systems and treatment techniques (3D conformal RT, IMRT, VMAT, tomotherapy) were utilized. Elekta Proknow software was used to analyze parameters, assess dose distributions, mean doses, conformity index (CI), and homogeneity index (HI) for both target volumes and OARs. Comparisons were made against proton therapy. Results All techniques consistently achieved excellent PTV coverage (V95 > 98%) for both adult and pediatric patients. Tomotherapy closely approached ideal Dmean doses for all PTVs, while 3D-CRT had higher Dmean for PTV_brain. Tomotherapy excelled in CI and HI for PTVs. IMRT resulted in lower pediatric heart, kidney, parotid, and eye doses, while 3D-CRT achieved the lowest adult lung doses. Tomotherapy approached proton therapy doses for adult kidneys and thyroid, while IMRT excelled for adult heart, kidney, parotid, esophagus, and eyes. Conclusion Modern radiotherapy techniques offer improved target coverage and OAR protection. However, 3D techniques are continued to be used for CSI. Notably, proton therapy stands out as the most efficient approach, closely followed by Tomotherapy in terms of achieving superior target coverage and OAR protection.

Background Craniospinal irradiation (CSI) of childhood tumors with the RapidArc technique is a new method of treatment. Our objective was to compare the acute hematological toxicity pattern during 3D conformal radiotherapy with the application of the novel technique. Methods Data from patients treated between 2007 and 2014 were collected, and seven patients were identified in both treatment groups. After establishing a general linear model, acute blood toxicity results were obtained using SPSS software. Furthermore, the exposure dose of the organs at risk was compared. Patients were followed for a minimum of 5 years, and progression-free survival and overall survival data were assessed. Results After assessment of the laboratory parameters in the two groups, it may be concluded that no significant differences were detected in terms of the mean dose exposures of the normal tissues or the acute hematological side effects during the IMRT/ARC and 3D conformal treatments. Laboratory parameters decreased significantly compared to the baseline values during the treatment weeks. Nevertheless, no significant differences were detected between the two groups. No remarkable differences were confirmed between the two groups regarding the five-year progression-free survival or overall survival, and no signs of serious organ toxicity due to irradiation were observed during the follow-up period in either of the groups. Conclusion The RapidArc technique can be used safely even in the treatment of childhood tumors, as the extent of the exposure dose in normal tissues and the amount of acute hematological side effects are not higher with this technique.

Background To determine the optimal treatment modality for intracranial germinoma (IG). Materials and methods A search of Medline, Embase, Web of Science and Cochrane Library was conducted up to April, 2024. Pooled risk ratio (RR) and 95% confidence interval (CI) were calculated. Subgroup analysis was applied according to radiotherapy (RT) alone or with chemotherapy (CTx). Results Total 37 studies were included in systematic review. Most IG patients were treated with biopsy or resection followed by RT with or without CTx. Prognosis of IG patients with different surgical resection is similar. Meta-analyses demonstrated focal field RT were with higher recurrence rate compared with craniospinal irradiation (CSI) [RR = 7.128, 95% CI (5.083, 9.995)], whole-brain RT (WBRT) [RR = 4.094, 95% CI (2.923, 5.735)] or whole-ventricle RT (WVRT) [RR = 3.361, 95% CI (2.126, 5.312)]; both WBRT and WVRT were also with higher recurrence compared with CSI; but no significant difference in recurrence and mortality between WVRT and WBRT. Total 24 studies reported treatment-related acute and/or late toxicity, combination CTx increased acute toxic, and expanded RT field and/or dose increased late toxicity. Conclusion Based on our findings, focal field RT is not recommended regardless of whether combined with CTx for intracranial pure germinoma. Although CSI is associated with better local control than other reduced-field RT, considering the potential toxicity and pattern of relapse, whole ventricles irradiation is more reasonable for localized or nonmetastatic germinoma. Reduced-dose CSI with or without chemotherapy is effective in metastatic or disseminated IG.