Computed Tomography Tumor Volume Research Articles

Multi-Modal Ensemble Deep Learning in Head and Neck Cancer HPV Sub-Typing.

Oropharyngeal Squamous Cell Carcinoma (OPSCC) is one of the common forms of heterogeneity in head and neck cancer. Infection with human papillomavirus (HPV) has been identified as a major risk factor for OPSCC. Therefore, differentiating the HPV-positive and negative cases in OPSCC patients is an essential diagnostic factor influencing future treatment decisions. In this study, we investigated the accuracy of a deep learning-based method for image interpretation and automatically detected the HPV status of OPSCC in routinely acquired Computed Tomography (CT) and Positron Emission Tomography (PET) images. We introduce a 3D CNN-based multi-modal feature fusion architecture for HPV status prediction in primary tumor lesions. The architecture is composed of an ensemble of CNN networks and merges image features in a softmax classification layer. The pipeline separately learns the intensity, contrast variation, shape, texture heterogeneity, and metabolic assessment from CT and PET tumor volume regions and fuses those multi-modal features for final HPV status classification. The precision, recall, and AUC scores of the proposed method are computed, and the results are compared with other existing models. The experimental results demonstrate that the multi-modal ensemble model with soft voting outperformed single-modality PET/CT, with an AUC of 0.76 and F1 score of 0.746 on publicly available TCGA and MAASTRO datasets. In the MAASTRO dataset, our model achieved an AUC score of 0.74 over primary tumor volumes of interest (VOIs). In the future, more extensive cohort validation may suffice for better diagnostic accuracy and provide preliminary assessment before the biopsy.

Tumor Growth Rate After Nadir Is Associated With Survival in Patients With EGFR-Mutant Non-Small-Cell Lung Cancer Treated With Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor.

To investigate the association between tumor volume growth rate after the nadir and survival in patients with EGFR-mutant advanced non-small-cell lung cancer (NSCLC) treated with erlotinib. Seventy-one patients with EGFR-mutant advanced NSCLC treated with erlotinib were studied for computed tomography tumor volume kinetics during therapy. The tumor growth rate after nadir was obtained using a previously published analytic module for longitudinal volume tracking to study its relationship with overall survival (OS). The median tumor volume for the cohort was 19,842 mm3 at baseline and 4,083 mm3 at nadir. The median time to nadir was 6.2 months. The tumor growth rate after nadir for logeV (the natural logarithm of tumor volume measured in mm3) was 0.11/mo on average for the cohort (SE: 0.014), which was very similar to the previously validated reference value of 0.12/mo to define slow and fast tumor growth. The OS of 48 patients with slow tumor growth (≤ 0.12/mo) was significantly longer compared with 23 patients with fast tumor growth (> 0.12/mo; median OS: 37.8 v 25.0 months; P = .0012). In Cox models, tumor growth rate was also associated with survival (regression coefficient: 3.9903; P = .0024; faster rate leads to increased hazards), after adjusting for time to nadir (regression coefficient: -0.0863; P = .0008; longer time to nadir leads to decreased hazards) and smoking history. In patients with EGFR-mutant advanced NSCLC treated with erlotinib, slower tumor growth rates after nadir were associated with longer OS, providing a rationale for using tumor growth rates to guide precision therapy for lung cancer.

Prediction Model for Tumor Volume Nadir in EGFR -mutant NSCLC Patients Treated With EGFR Tyrosine Kinase Inhibitors.

In patients with advanced non-small cell lung cancer (NSCLC) and oncogenic driver mutations treated with effective targeted therapy, a characteristic pattern of tumor volume dynamics with an initial regression, nadir, and subsequent regrowth is observed on serial computed tomography (CT) scans. We developed and validated a linear model to predict the tumor volume nadir in EGFR -mutant advanced NSCLC patients treated with EGFR tyrosine kinase inhibitors (TKI). Patients with EGFR -mutant advanced NSCLC treated with EGFR-TKI as their first EGFR-directed therapy were studied for CT tumor volume kinetics during therapy, using a previously validated CT tumor measurement technique. A linear regression model was built to predict tumor volume nadir in a training cohort of 34 patients, and then was validated in an independent cohort of 84 patients. The linear model for tumor nadir prediction was obtained in the training cohort of 34 patients, which utilizes the baseline tumor volume before initiating therapy (V 0 ) to predict the volume decrease (mm 3 ) when the nadir volume (V p ) was reached: V 0 -V p =0.717×V 0 -1347 ( P =2×10 -16 ; R2 =0.916). The model was tested in the validation cohort, resulting in the R2 value of 0.953, indicating that the prediction model generalizes well to another cohort of EGFR -mutant patients treated with EGFR-TKI. Clinical variables were not significant predictors of tumor volume nadir. The linear model was built to predict the tumor volume nadir in EGFR -mutant advanced NSCLC patients treated with EGFR-TKIs, which provide an important metrics in treatment monitoring and therapeutic decisions at nadir such as additional local abrasive therapy.

Implementing CT tumor volume and CT pleural thickness into future staging systems for malignant pleural mesothelioma

ObjectivesTumor thickness and tumor volume measured by computed tomography (CT) were suggested as valuable prognosticator for patients’ survival diagnosed with malignant pleural mesothelioma (MPM). The purpose was to assess the accuracy of CT scan based preoperatively measured tumor volume and thickness compared to actual tumor weight of resected MPM specimen and pathologically assessed tumor thickness, as well as an analysis of their impact on overall survival (OS).MethodsBetween 09/2013–08/2018, 74 patients were treated with induction chemotherapy followed by (extended) pleurectomy/decortication ((E)PD). In 53 patients, correlations were made between CT-measured volume and -tumor thickness (cTV and cTT) and actual tumor weight (pTW) based on the available values. Further cTV and pT/IMIG stage were correlated using Pearson correlation. Overall survival (OS) was calculated with Kaplan Meier analysis and tested with log rank test. For correlation with OS Kaplan-Meier curves were made and log rank test was performed for all measurements dichotomized at the median.ResultsMedian pathological tumor volume (pTV) and pTW were 530 ml [130 ml – 1000 ml] and 485 mg [95 g – 982 g] respectively. Median (IQR) cTV was 77.2 ml (35.0–238.0), median cTT was 9.0 mm (6.2–13.7). Significant association was found between cTV and pTV (R = 0.47, p < 0.001) and between cTT and IMIG stage (p = 0,001) at univariate analysis. Multivariate regression analysis revealed, that only cTV correlates with pTV. Median follow-up time was 36.3 months with 30 patients dead at the time of the analysis. Median OS was 23.7 months. 1-year and 3-year survival were 90 and 26% respectively and only the cTV remained statistically associated with OS.ConclusionPreoperatively assessed CT tumor volume and actual tumor volume showed a significant correlation. CT tumor volume may predict pathological tumor volume as a reflection of tumor burden, which supports the integration of CT tumor volume into future staging systems.

Parametric Response Mapping of Coregistered Positron Emission Tomography and Dynamic Contrast Enhanced Computed Tomography to Identify Radioresistant Subvolumes in Locally Advanced Cervical Cancer

To identify subvolumes that may predict treatment response to definitive concurrent chemoradiation therapy using parametric response mapping (PRM) of coregistered positron emission tomography (PET) and dynamic contrast-enhanced (DCE) computed tomography (CT) in locally advanced cervical carcinoma. Pre- and midtreatment (after 23 ± 4 days of concurrent chemoradiation therapy) DCE CT and PET imaging were performed on 21 patients with cervical cancer who were enrolled in a pilot study to evaluate the prognostic value of CT perfusion for primary cervical cancer (NCT01805141). Three-dimensional coregistered maps of PET/CT standardized uptake value (SUV) and DCE CT blood flow (BF) were generated. PRM was performed using voxel-wise joint histogram analysis to classify voxels within the tumor as highly metabolic and perfused (SUVhiBFhi), highly metabolic and hypoxic (SUVhiBFlo), low metabolic activity and hypoxic (SUVloBFlo), or low metabolic activity and perfused (SUVloBFhi) tissue based on thresholds determined from population means of pretreatment PET SUV and DCE CT BF. Relationships between baseline pretreatment imaging metrics and relative changes in metabolic tumor volume (ΔMTV), calculated from before treatment and during treatment imaging, were determined using univariable and multivariable linear regression models. The relative volume of three PRM subvolumes significantly changed during treatment (SUVhiBFhi: P = .04; SUVhiBFlo: P = .0008; SUVloBFhi: P = .02), whereas SUVloBFlo did not (P = .9). Pretreatment PET SUVmax (r = -.58, P = .006), PET SUVmean (ρ = -.59, P = .005), DCE CT BFmean (r = -.50, P = .02), tumor volume (ρ = -.65, P = .001) and PRM SUVhiBFhi (ρ = -.59, P = .004) were negatively correlated with ΔMTV, whereas PRM SUVloBFlo was positively related to ΔMTV (r = .77, P < .0001). In a multivariable model that predicted ΔMTV, PRM SUVloBFlo, which combines both PET/CT and DCE CT, was the only significant variable (β = 1.825, P = .03), dominating both imaging modalities independently. PRM was applied in locally advanced cervical carcinoma treated definitively with chemoradiation, and radioresistant subvolumes were identified that correlated with changes in MTV and predicted treatment response. Identification of these subvolumes may assist in clinical decision making to tailor therapies, such as brachytherapy, in an effort to improve patient outcomes.

Usefulness of Hybrid PET/MRI in Clinical Evaluation of Head and Neck Cancer Patients.

(1) Background: The novel hybrid of positron emission tomography/magnetic resonance (PET/MR) examination has been introduced to clinical practice. The aim of our study was to evaluate PET/MR usefulness in preoperative staging of head and neck cancer (HNC) patients (pts); (2) Methods: Thirty eight pts underwent both computed tomography (CT) and PET/MR examination, of whom 21 pts underwent surgical treatment as first-line therapy and were further included in the present study. Postsurgical tissue material was subjected to routine histopathological (HP) examination with additional evaluation of p16, human papillomavirus (HPV), Epstein-Barr virus (EBV) and Ki67 status. Agreement of clinical and pathological T staging, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of CT and PET/MR in metastatic lymph nodes detection were defined. The verification of dependences between standardized uptake value (SUV value), tumor geometrical parameters, number of metastatic lymph nodes in PET/MR and CT, biochemical parameters, Ki67 index, p16, HPV and EBV status was made with statistical analysis of obtained results; (3) Results: PET/MR is characterized by better agreement in T staging, higher specificity, sensitivity, PPV and NPV of lymph nodes evaluation than CT imaging. Significant correlations were observed between SUVmax and maximal tumor diameter from PET/MR, between SUVmean and CT tumor volume, PET/MR tumor volume, maximal tumor diameter assessed in PET/MR. Other correlations were weak and insignificant; (4) Conclusions: Hybrid PET/MR imaging is useful in preoperative staging of HNC. Further studies are needed.

P107 PREDICTION OF A POSITIVE CIRCUMFERENTIAL RESECTION MARGIN IN ADENOCARCINOMA OF THE ESOPHAGUS

Abstract Aim To determine if a positive circumferential resection margin (CRM) can be predicted in patients with esophageal adenocarcinoma undergoing neo-adjuvant chemotherapy prior to surgery Methods 223 patients were included in this study. Multivariable analyses of clinico-pathological and computed tomography (CT) imaging predictors were performed to evaluate the likelihood of a positive CRM at initial staging and following neoadjuvant chemotherapy, with prediction models constructed. Area under curve (AUC) with 95% confidence interval (CI) from 1000 bootstrapping was assessed. Results Advanced clinical T-stage (T3-4) (odds ratio, OR 2.93 95%CI 1.03-9.48) and poor tumor differentiation (OR 2.84, 95%CI 1.39-6.01) were independently associated with an increased risk of a positive CRM. Non response to chemotherapy as estimated by CT independently corresponded with an increased risk of CRM positivity (OR 3.38 95% CI 1.43-8.50). Additional CT evidence of local invasion/pleural thickening and higher CT tumor volume (14cm3) improved the performance of a prediction model, including all above parameters; with AUC (c-index) of 0.76 (0.68-0.83). Conclusion Combining advanced clinical T-stage, poor tumor differentiation, CT non-response to chemotherapy, higher CT tumor volume and local invasion may be helpful in selecting patients for intensification of neo-adjuvant treatment prior to resection.

Texture Analysis on [18F]FDG PET/CT in Non-Small-Cell Lung Cancer: Correlations Between PET Features, CT Features, and Histological Types.

The study aims to investigate the correlations between positron emission tomography (PET) texture features, X-ray computed tomography (CT) texture features, and histological subtypes in non-small-cell lung cancer evaluated with 2-deoxy-2-[18F]fluoro-D-glucose PET/CT. We retrospectively evaluated the baseline PET/CT scans of 81 patients with histologically proven non-small-cell lung cancer. Feature extraction and statistical analysis were carried out on the Matlab platform (MathWorks, Natick, USA). Intra-CT correlation analysis revealed a strong positive correlation between volume of the lesion (CTvol) and maximum density (CTmax), and between kurtosis (CTkrt) and maximum density (CTmax). A moderate positive correlation was found between volume (CTvol) and average density (CTmean), and between kurtosis (CTkrt) and average density (CTmean). Intra-PET analysis identified a strong positive correlation between the radiotracer uptake (SUVmax, SUVmean) and its degree of variability/disorder throughout the lesion (SUVstd, SUVent). Conversely, there was a strong negative correlation between the uptake (SUVmax, SUVmean) and its degree of uniformity (SUVuni). There was a positive moderate correlation between the metabolic tumor volume (MTV) and radiotracer uptake (SUVmax, SUVmean). Inter (PET-CT) correlation analysis identified a very strong positive correlation between the volume of the lesion at CT (CTvol) and the metabolic volume (MTV), a moderate positive correlation between average tissue density (CTmean) and radiotracer uptake (SUVmax, SUVmean), and between kurtosis at CT (CTkrt) and metabolic tumor volume (MTV). Squamous cell carcinomas had larger volume higher uptake, stronger PET variability and lower uniformity than the other subtypes. By contrast, adenocarcinomas exhibited significantly lower uptake, lower variability and higher uniformity than the other subtypes. Significant associations emerged between PET features, CT features, and histological type in NSCLC. Texture analysis on PET/CT shows potential to differentiate between histological types in patients with non-small-cell lung cancer.

Bioluminescence Tomography Guided Small-Animal Radiation Therapy and Tumor Response Assessment

The image guided small animal arc radiation treatment platform has adopted onboard cone beam computed tomography and bioluminescence tomography (BLT). We used BLT to guide irradiation delivery and quantitatively assess irradiation-induced tumor response. BLT was first validated on a tissue-simulating phantom, where the internal chemiluminescent liquid had a constant volume while its luminescence intensity gradually decayed. Then, invivo experiments were performed on BALB/c mice orthotopically inoculated with 4T1 breast carcinoma cells expressing luciferase. Animals either received radiation treatment (radiation therapy [RT] group, n=9) or did not (control group, n=9). BLT was used to guide delivery of a single-fraction 5-Gy radiation dose to the tumor and to evaluate the treatment response. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) staining was used to evaluate irradiation-induced DNA damage and cell apoptosis. Phantom results showed that BLT not only recovered the constant target volume with <2% deviation but also accurately monitored the decay of the chemiluminescent molecules. For the RT group of animals, there was significant reduction in both the BLT-based tumor volume (21%±10%, P=.001) and bioluminescence intensity (48%±17%, P=.0008). For the control group, a significant increase was detected in the BLT tumor volume (35%±12%, P<.0001) but not the BLT bioluminescence intensity (P=.4). There was a significant difference in the BLT tumor volume between the RT and control groups 7days after irradiation (P=.03). Regression analysis suggests a strong correlation between the BLT and cone beam computed tomography tumor volume (R2=0.93). Analysis using terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling staining showed a significant difference in tumor cell apoptosis between the RT and control groups (20.6%±2.9% and 3.2%±1.7%, respectively; P<.05). BLT onboard the image guided small animal arc radiation treatment platformcan be used to accurately guide irradiation delivery and to quantitatively assess treatment response by simultaneously monitoring tumor volume and cancer cell population.

Addition of magnetic resonance imaging to computed tomography-based three-dimensional conformal radiotherapy planning for postoperative treatment of astrocytomas: Changes in tumor volume and isocenter shift.

Introduction:Postoperative radiotherapy is the current gold standard treatment in astrocytomas. Computed tomography (CT)-based radiotherapy planning leads to either missing of the tumor volume or underdosing. The aim of this prospective study was to study the changes in tumor volume on addition of magnetic resonance imaging (MRI) to CT-based three-dimensional radiotherapy treatment planning of astrocytomas.Materials and Methods:Twenty-five consecutive patients of astrocytoma (WHO grades I-IV) for postoperative three-dimensional conformal radiotherapy were included in this prospective study. Postoperative tumor volumes were contoured on CT-based images and recontoured on CT-MRI images after automated MRI co-registration on treatment planning system Eclipse 8.9.15 as per ICRU-50 report. Tumor volumes were compared with each other.Result:The MRI-based mean and median tumor volume was 24.24 cc ± 13.489 and 18.72 cc (range 5.6–46.48 cc), respectively, while for CT it was 19.4 cc ± 11.218 and 16.24 cc (range: 5.1-38.72 cc), respectively. The mean and median isocenter shift between CT and MRI was 4.05 mm and 4.39 mm (range 0.92–6.32 mm), respectively. There is a linear relationship between MRI and CT volume with a good correlation coefficient of R2 = 0.989, and MRI-based tumor volume was 1.208 times as compared to CT volume. Statistical analysis using paired sample t-test for the difference in CT and MRI tumor volume was highly significant (P < 0.001).Conclusion:Addition of MRI to the CT-based three-dimensional radiation treatment planning reduces the chances of geographical miss or tumor under dosing. Thus, MRI should be an integral part of three-dimensional planning of astrocytomas.

State of the Art: Response Assessment in Lung Cancer in the Era of Genomic Medicine

Tumor response assessment has been a foundation for advances in cancer therapy. Recent discoveries of effective targeted therapy for specific genomic abnormalities in lung cancer and their clinical application have brought revolutionary advances in lung cancer therapy and transformed the oncologist's approach to patients with lung cancer. Because imaging is a major method of response assessment in lung cancer both in clinical trials and practice, radiologists must understand the genomic alterations in lung cancer and the rapidly evolving therapeutic approaches to effectively communicate with oncology colleagues and maintain the key role in lung cancer care. This article describes the origin and importance of tumor response assessment, presents the recent genomic discoveries in lung cancer and therapies directed against these genomic changes, and describes how these discoveries affect the radiology community. The authors then summarize the conventional Response Evaluation Criteria in Solid Tumors and World Health Organization guidelines, which continue to be the major determinants of trial endpoints, and describe their limitations particularly in an era of genomic-based therapy. More advanced imaging techniques for lung cancer response assessment are presented, including computed tomography tumor volume and perfusion, dynamic contrast material-enhanced and diffusion-weighted magnetic resonance imaging, and positron emission tomography with fluorine 18 fluorodeoxyglucose and novel tracers. State-of-art knowledge of lung cancer biology, treatment, and imaging will help the radiology community to remain effective contributors to the personalized care of lung cancer patients.

Prognostic value of tumor volumetry data of routine imaging data in a head and neck cancer registry

The purpose of this study was to analyze the impact of tumor volume (TV) measurements as prognosticator for recurrence-free survival (RFS) and overall survival (OS) from data of head and neck cancer (HNC) registries. TV measurements were performed in pre-treatment computed tomography (CT) or magnetic resonance images (MRI) of 392 unselected HNC patients. TV measurements were feasible in 275 patients (70 %). Median CT TV and MRI TV were 11.43 and 10.4 cm(3), respectively. The CT TV was significantly different only between T1 and T4. CT TV was significantly different only between T1 and T4 (p = 0.041). MRI TV was significantly different between T1 and T4 (p = 0.003) as well as between T2 and T4 (p = 0.002). Median follow-up was 26.1 months. Median RFS was 80.7 months. Median OS was 66.5 months. On univariate analysis, significant prognostic factors for decreased RFS were advanced T stage (p = 0.010); M1 (p = 0.001) and an MRI TV > 10.4 cm(3) (p = 0.001). Significant prognostic factors for a decreased OS were advanced T stage (p = 0.001), N+ (p = 0 006), M+ (p < 0.001), tumor recurrence (p < 0.001), CT TV (p = 0.005), and MRI TV (p = 0.012). On multivariate analysis for RFS, MRI TV was the best independent prognosticator (p = 0.003). On multivariate analysis for OS, T stage (p = 0.006) was a better prognosticator than CT or MRI TV. Using CT and MRI data sets of an unselected series of HNC patients in a cancer registry, TV measurements were not feasible in all patients. MRT TV was a powerful prognosticator for RFS.

CT Tumor Volume Measurement in Advanced Non-small-cell Lung Cancer: Performance Characteristics of an Emerging Clinical Tool

Determine inter- and intraobserver variability of computed tomography (CT) tumor volume measurements in advanced non-small-cell lung cancer (NSCLC) patients treated in a Phase II clinical trial using chest CT. Twenty-three advanced NSCLC patients with a total of 53 measurable lung lesions enrolled in a Phase II, multicenter, open-label clinical trial of erlotinib were retrospectively studied with institutional review board approval. Two radiologists independently measured the tumor size, volume, and CT attenuation coefficient using commercially available volume analysis software. Concordance correlation coefficients (CCCs) and Bland-Altman plots were used to assess inter- and intraobserver agreement. High CCCs (0.949-0.990) were observed in all types of measurements for interobserver agreement. The 95% limits of agreements for volume, unidimensional, and bidimensional measurements were (-26.0%, 18.6%), (-23.1%, 24.4%), and (-34.0%, 48.6%), respectively. Volume measurement had slightly higher CCC and narrower 95% limits of agreement compared to uni- and bidimensional measurements. CCCs for intraobserver agreement were high (range, 0.946-0.996) with CCC for volume being slightly higher than CCCs of uni- and bidimensional measurements. The smaller the tumor volume was, the larger the interobserver difference of CT attenuation. Location, morphology, or adjacent atelectasis had no significant impact on inter- or intraobserver variability. CT tumor volume measurement in advanced NSCLC patients using clinical chest CT and commercially available software demonstrated high inter- and intraobserver agreement, indicating that the method may be used routinely in clinical practice.

Definitive Radiotherapy for T1-T2 Squamous Cell Carcinoma of Pyriform Sinus

To report the long-term results after definitive radiotherapy (RT) for T1-T2 pyriform sinus squamous cell carcinoma. The data from 123 patients with T1-T2 pyriform sinus squamous cell carcinoma treated with RT with or without neck dissection between November 1964 and June 2003 were analyzed. The median follow-up for all patients was 3.2 years, and the median follow-up for living patients was 10.7 years. The 5-year local control, locoregional control, freedom from distant metastasis, cause-specific survival, and overall survival rate was 85%, 70%, 75%, 61%, and 35%, respectively. The ultimate local control rate, including successful salvage of RT failure, for T1 and T2 cancer patients was 96% and 94%, respectively. The overall local control rate with a functional larynx was 83%. Pretreatment computed tomography tumor volume data were available for 55 patients. The median computed tomography tumor volume was 4.2 cm(3) (range, 0-22.4). Local control was worse for patients with a tumor volume >6.5 cm(3) compared with those with a smaller tumor volume. Of the 123 patients, 16% developed moderate to severe acute (2%), late (9%), or postoperative (5%) complications. Local control with larynx preservation after definitive RT for T1-T2 pyriform sinus squamous cell carcinoma likely results in local control and survival similar to that after total laryngectomy or larynx-conserving surgery. Two-thirds of our living patients retained a functional larynx.

Comparison of computed tomography and magnetic resonance based target volume in brain tumors

This study was mainly framed to study the difference in tumor volumes as seen on computed tomography (CT) and magnetic resonance (MR) and their significance in planning. Twenty-five patients with brain tumor of different diagnoses who underwent stereotactic radiotherapy were included in this study. CT and MR imaging was done for all the patients with 2.5 mm slice thickness. The CT tumor volume and MR tumor volume were measured and compared with each other. The center of mass (CM) of the tumor volume delineated on CT and MR were computed and the shift between the two CMs was determined. The mean and median volume of the tumor as measured from MR scans was 19.67 cc +/- 13.73 and 16.13 cc (range: 3.25 cc-50.37 cc). Similarly, the mean and median volume of the tumor as measured from CT scans was 15.05 cc +/- 10.13 and 11.63 cc (range: 3.0 cc-36.25 cc) respectively. The mean and median CM shift between CT and MR was 5.47 mm and 5.21 mm respectively. The study demonstrates that MR is an indispensable imaging modality in radiotherapy for planning brain tumors.