BackgroundWhole pelvis intensity modulated radiotherapy (IMRT) is increasingly being used to treat cervical cancer aiming to reduce side effects. Encouraged by this, some groups have proposed the use of simultaneous integrated boost (SIB) to target the tumor, either to get a higher tumoricidal effect or to replace brachytherapy. Nevertheless, physiological organ movement and rapid tumor regression throughout treatment might substantially reduce any benefit of this approach.PurposeTo evaluate the clinical target volume - simultaneous integrated boost (CTV-SIB) regression and motion during chemo-radiotherapy (CRT) for cervical cancer, and to monitor treatment progress dosimetrically and volumetrically to ensure treatment goals are met.Methods and materialsTen patients treated with standard doses of CRT and brachytherapy were retrospectively re-planned using a helical Tomotherapy - SIB technique for the hypothetical scenario of this feasibility study. Target and organs at risk (OAR) were contoured on deformable fused planning-computed tomography and megavoltage computed tomography images. The CTV-SIB volume regression was determined. The center of mass (CM) was used to evaluate the degree of motion. The Dice’s similarity coefficient (DSC) was used to assess the spatial overlap of CTV-SIBs between scans. A cumulative dose-volume histogram modeled estimated delivered doses.ResultsThe CTV-SIB relative reduction was between 31 and 70%. The mean maximum CM change was 12.5, 9, and 3 mm in the superior-inferior, antero-posterior, and right-left dimensions, respectively. The CTV-SIB-DSC approached 1 in the first week of treatment, indicating almost perfect overlap. CTV-SIB-DSC regressed linearly during therapy, and by the end of treatment was 0.5, indicating 50% discordance. Two patients received less than 95% of the prescribed dose. Much higher doses to the OAR were observed. A multiple regression analysis showed a significant interaction between CTV-SIB reduction and OAR dose increase.ConclusionsThe CTV-SIB had important regression and motion during CRT, receiving lower therapeutic doses than expected. The OAR had unpredictable shifts and received higher doses. The use of SIB without frequent adaptation of the treatment plan exposes cervical cancer patients to an unpredictable risk of under-dosing the target and/or overdosing adjacent critical structures. In that scenario, brachytherapy continues to be the gold standard approach.

BackgroundThe ongoing EORTC 22042–26042 trial evaluates the efficacy of high-dose radiotherapy (RT) in atypical/malignant meningioma. The results of the Dummy Run (DR) and prospective Individual Case Review (ICR) were analyzed in this Quality Assurance (QA) study.Material/methodsInstitutions were requested to submit a protocol compliant treatment plan for the DR and ICR, respectively. DR-plans (n=12) and ICR-plans (n=50) were uploaded to the Image-Guided Therapy QA Center of Advanced Technology Consortium server (http://atc.wustl.edu/) and were assessed prospectively.ResultsMajor deviations were observed in 25% (n=3) of DR-plans while no minor deviations were observed. Major and minor deviations were observed in 22% (n=11) and 10% (n=5) of the ICR-plans, respectively. Eighteen% of ICRs could not be analyzed prospectively, as a result of corrupted or late data submission. CTV to PTV margins were respected in all cases. Deviations were negatively associated with the number of submitted cases per institution (p=0.0013), with a cutoff of 5 patients per institutions. No association (p=0.12) was observed between DR and ICR results, suggesting that DR’s results did not predict for an improved QA process in accrued brain tumor patients.ConclusionsA substantial number of protocol deviations were observed in this prospective QA study. The number of cases accrued per institution was a significant determinant for protocol deviation. These data suggest that successful DR is not a guarantee for protocol compliance for accrued patients. Prospective ICRs should be performed to prevent protocol deviations.

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AIM: To retrospectively evaluate the overall survival (OS) of patients with brain metastases (BMs) who had been treated with whole brain radiotherapy (WBRT) and Gamma Knife (GK) according to prognostic factors and prognostic index scores. MATERIAL and METHODS: The study included 91 patients with BMs who had been treated with WBRT and/or GK between 2014 and 2017. The patients with BMs were retrospectively evaluated regarding age, sex, Karnofsky Performance Status (KPS), recursive partitioning analysis (RPA) class, basic score for BM (BS-BM), Graded Prognostic Assessment (DS-GPA) index, primary tumour type, extracranial metastases, primary tumour control, number of BMs, and brain metastasectomy. A univariate analysis of the OS was performed using the Kaplan-Meier method, supplemented by the log-rank test. We also applied a multivariate survival analysis using the Cox regression model. RESULTS: The median OS for all patients with BMs was 6 months. Meanwhile, the median OSs for those with WBRT, GK, and WBRT-GK treatment were 6, 4, and 15 months, respectively (p=0.00). In the multivariate analysis, the female sex (p=0.030), brain metastasectomy (p=0.047), treatment with WBRT-GK (p=0.001), and the controlled primary tumour (p=0.007) significantly correlated with the OS. Furthermore, the BS-BM (p=0.022) was closely related with the OS compared to the RPA and DS-GPA in the multivariate analysis. CONCLUSION: The BS-BM was found to better predict the survival of patients with BMs according to the prognostic index scores in the multivariate analysis. Thus, our data suggest that the BS-BM is the most appropriate prognostic index.