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ABSTRACT: Previously we described from 20 patients' data with our new "polynomial prediction approach" the volumetrical changes following gliomas 1-125 brachytherapy. The aim of this study is to extend the polynomials for 48 months, and to carry out multivarial analysis of several different aspects.
20 inoperable low-grade gliomas were followed for a 48-month period after 1-125 interstitial irradiation. The delivered dose on the tumor surface was 50-60 Gy. Dose planning and image fusion were done with the BrainLab Target 1.19 software, mathematical and statistical computations were carried out with the Matlab numeric computation and visualization software. Volumes of tumor necrosis, reactive zone and edema referred to as "triple ring" were measured on image fused control MRI and planning CT images. The measured volumes were normalized with respect to the reference volumes. Mean values of volumes were determined, then polynomials were fitted to the mean using the polynomial curve fitting method. The accuracy of our results was verified by correlating the predicted data with the measured ones.
We have found that the edema reaches its maximum two times after irradiation during the 48 months follow up period. We have shown that small tumors react more rapidly and creating greater volumes of the "triple ring" than bigger ones.
The polynomial prediction approach proposed here reveals the dynamics of triple ring for 48 months. The derived polynomials and the multivarial analysis carried out afterwards help to (i) design the best treatment, (ii) follow up the patient's condition and (iii) plan reirradiation if necessary.
Ideggyógyászati szemle 07/2011; 64(7-8):235-8. · 0.49 Impact Factor
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ABSTRACT: The aim of this study is to reveal the long-term effect of Yttrium-90 colloid radioisotope brachytherapy applied for the treatment of cystic craniopharyngiomas. To provide a mathematical expression that can describe the cyst reduction as a function of time in an accurate matter.
Fourteen cystic craniopharyngiomas were selected for intracavital irradiation with stereotactically implanted beta-emitting radioisotope Yttrium-90 silicate colloid. The cumulative dose aimed at the inner surface of the cyst wall was ranging between 180-300 Gy. Volumes of the cysts were measured on image-fused control CT/MRI images for a 28-month period. Dose planning was done with our own software, while stereotactic calculations, volume calculations and image fusion were done with the BrainLab Target 1.19 software. Mathematical and statistical computations were carried out with the Matlab numeric computation and visualization software. To determine the volumes, the control images were fused with the planning images.
Relative volumes normalized with respect to the volume of cysts before irradation were determined from the patients' measured data, the mean values of volumes were calculated, then a polynomial was fitted to the mean values using the polynomial curve fitting method. We have found that the dynamics describing the reduction of cysts can be expressed mathematically by the polynomial V=93.627-18.091t + 1.473t2 - 0.054t3 + 0.0007t4, where "t" denotes the time in months passed after irradiation. The accuracy of our results was verified by correlating the predicted data with the measured ones.
Our long-term results support the view, that intracavitary Yttrium-90 irradiation is a non invasive and very effective method for treatment of craniopharyngioma cysts. The derived polynomial helps to 1. design the best treatment, 2. follow up patients' condition and 3. plan a reirradiation if necessary.
Ideggyógyászati szemle 01/2011; 64(1-2):36-40. · 0.49 Impact Factor
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ABSTRACT: The aim of this study was to reveal the volumetric changes in tumor necrosis, reactive zone, and edema referred to as the "triple ring" appearing after low-dose-rate iodine-125 (I-125) interstitial irradiation of 20 inoperable low-grade gliomas. To enable prediction of these volumetric changes, we provide mathematical expressions that describe the dynamics of the triple ring. Volumes of the three regions on image-fused control CT/MR images were measured for a 24-month period. The delivered dose on the tumor surface was 50-60 Gy. Dose planning and image fusion were performed with Brain-Lab Target 1.19 software; mathematical and statistical computations were carried out with Matlab numeric computation and visualization software. To determine the volumes, control images with the triple rings were fused with the planning images. Relative volumes normalized with respect to the volume of reference dose were calculated and plotted in the time domain. First, the mean values of volumes were determined from the patients' measured data; then, polynomials were fitted to the mean values using the polynomial curve-fitting method. The accuracy of our results was verified by correlating the predicted data with the measured ones. The polynomial prediction approach proposed here reveals the dynamics of the triple ring. These polynomials will assist with (1) designing the best treatment, (2) following the patient's condition, and (3) planning reirradiation if necessary.
Neuro-Oncology 07/2008; 10(4):583-92. · 5.72 Impact Factor
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ABSTRACT: The aim of this study is to reveal the volumetric changes in tumor necrosis, reactive zone and edema following low-dose rate 1-125 interstitial irradiation of 20 inoperable (partially non-resectable, partially inoperable) low-grade gliomas.
The volumes of the three regions on image-fused control CT/MRI images were measured for a 24-month period with 36 occasions. The delivered dose on the tumor surface (GTV) was 50-60 Gy. Dose planning and image fusion were performed with the BrainLab Target 1.19 software, mathematical and statistical computations were carried out with the Matlab Numeric Computation and Visualization software. The control images with the "triple ring" were fused with the planning images, and the isodose curves were adjusted to them.
Relative volumes normalized to volume of the reference dose were calculated and plotted in the time domain. The mean values of volumes were determined from the patients' measured data then a polynom was fitted to the mean values using the polynomial curve fitting method. The accuracy of our results were verified by statistical tools.
The new polynomial prediction approach using image fusion analysis of the volume of tumor necrosis, reactive ring and edema caused by interstitial irradiation as a function of time provides valuable information for 1. selecting the best patient's treatment option, 2. following up patient's condition and 3. planning reirradiation or reoperation if necessary.
Ideggyógyászati szemle 04/2008; 61(3-4):106-13. · 0.49 Impact Factor
