Janaki Hadjiev

Integrating Functional MRI Information into Radiotherapy Planning of CNS Tumors-Early Experiences

The purpose of our study was to examine the integration of functional MRI (fMRI) information into 3D based planning process of the central nervous system (CNS) malignancies. Between 01.01.2008 and 01.12.2008 four patients with astrocytoma were enrolled to this study. Before the planning process conventional planning CT, postoperative MR and individual functional MRI examinations were delivered. For the functional MRI examination the following four types of stimulus were applied: acoustic, visual, somatosensory and numeral. Three different theoretical planning situations were applied and compared: 3D conformal plan without fMRI information, 3D conformal plan with fMRI information and IMRT plan with fMRI information. For plan comparison DVH analysis, and NTCP model were used. fMRI based OR definition resulted in 4 additional OR’s in the contouring process. As these cases demonstrate, an average of 50% dose reduction was achieved in OR, OR2 and OR3 with IMRT and fMRI based 3D planning, especially in case of midline localization and big tumor extent. IMRT provides additional sparing effect in the optic tract and brainstem, especially for localizations close to the midline. Our results demonstrated that using fMRI information in conventional 3D based treatment planning potentially benefits significant dose reduction in critical organs, with no compromise in PTV coverage. fMRI can be widely used even in low grade cases (long life expectancies, lower acute and late toxicity in radiotherapy) and in cases with high grade astrocytomas or metastases (higher dose to PTV with better risk organ sparing in radiotherapy).

Thermoplastic Patient Fixation

Background and Purpose:Several methods have been developed to reduce tumor motions and patient movements during radiotherapy of lung cancer. In this study, a multislice CT-based analysis was performed to examine the effect of a thermoplastic patient immobilization system on the chest wall and tumor motions.Patients and Methods:Ten patients with stage II–IV lung cancer were enrolled into the study. According to tumor localization, five patients had peripheral, and five patients central lung cancer (T2–T4). In total, six series of measurements were made with a multislice CT scanner, both with and without mask fixation, in normal breathing, at maximal tidal volume inhalation, and at maximal tidal volume exhalation.Results:Movements of chest wall, diaphragm and tumor, with and without mask, under different breathing conditions were registered. With the use of the immobilization system, no significant difference was found in diaphragmatic movements (mean deviation of diaphragm: 41.7–40.5 mm to the right, and 40.5–36.8 mm to the left side) and in tumor motions (mean deviation of tumor: 15.3–12.4 mm in craniocaudal, and 11.5–8.8 mm in posterolateral direction, mean medial deviation: 4.6–4.1 mm, mean lateral deviation: 7.2–5 mm). Significant differences were observed concerning tumor motions in anteroposterior direction (mean: 8.9–6.3 mm) and transverse chest movements in anteroposterior direction.Conclusion:Besides the advantage of optimal patient positioning, the movements of the bony chest wall can be considerably reduced by using the immobilization system. However, this fixation system has limitations concerning its suitability for minimizing tumor motions.Hintergrund und Ziel:Zahlreiche Methoden wurden entwickelt, um die Tumor- und Patientenbewegungen während der Strahlentherapie von Lungenkarzinomen zu reduzieren. In dieser Studie wurde eine Mehrschicht-CT-basierte Analyse zur Untersuchung der Auswirkungen eines thermoplastischen Patientenimmobilisierungssystems auf die Thoraxwand- und Tumorbewegungen durchgeführt.Patienten und Methodik:Zehn Patienten mit Lungenkrebs Stadium II–IV wurden in die Studie eingeschlossen. Gemäß der Tumorlokalisation wiesen fünf Patienten ein peripheres und fünf Patienten ein zentrales Lungenkarzinom auf (T2–T4). Insgesamt wurden sechs Messserien mit einem Mehrschicht-CT-Scanner durchgeführt: mit und ohne Maskenfixierung, bei normaler Atmung sowie mit maximalem Atemvolumen bei Ein- und Ausatmung.Ergebnisse:Die Brustwand-, Zwerchfell- und Tumorbewegungen wurden mit und ohne Maske bei unterschiedlichen Atmungszuständen registriert. Bei Verwendung des Immobilisierungssystems wurden keine signifikanten Unterschiede in den Zwerchfellbewegungen (durchschnittliche Abweichung des Diaphragmas: 41,7–40,5 mm nach links und 40,5–36,8 mm nach rechts) und den Tumorbewegungen (durchschnittliche Abweichung des Tumors: 15,3–12,4 mm in kraniokaudaler und 11,5–8,8 mm in posteroanteriorer Richtung, durchschnittliche mediale Abweichung: 4,6–4,1 mm, durchschnittliche laterale Abweichung 7,2–5 mm) festgestellt. Signifikante Unterschiede waren bezüglich der Tumorbewegungen in anteroposteriorer Richtung (durchschnittlich 8,9–6,3 mm) und der transversalen Brustkorbbewegungen in anteroposteriorer Richtung zu beobachten.Schlussfolgerung:Neben dem Vorteil einer optimalen Patientenpositionierung können die Bewegungen der Thoraxwand mit Hilfe des Immobilisierungssystems erheblich reduziert werden. Dieses Fixierungssystem hat jedoch auch Grenzen hinsichtlich seiner Eignung zur Minimierung der Tumorbewegungen.

Thermoplastic patient fixation: influence on chest wall and target motion during radiotherapy of lung cancer.

Background and Purpose:Several methods have been developed to reduce tumor motions and patient movements during radiotherapy of lung cancer. In this study, a multislice CT-based analysis was performed to examine the effect of a thermoplastic patient immobilization system on the chest wall and tumor motions.Patients and Methods:Ten patients with stage II–IV lung cancer were enrolled into the study. According to tumor localization, five patients had peripheral, and five patients central lung cancer (T2–T4). In total, six series of measurements were made with a multislice CT scanner, both with and without mask fixation, in normal breathing, at maximal tidal volume inhalation, and at maximal tidal volume exhalation.Results:Movements of chest wall, diaphragm and tumor, with and without mask, under different breathing conditions were registered. With the use of the immobilization system, no significant difference was found in diaphragmatic movements (mean deviation of diaphragm: 41.7–40.5 mm to the right, and 40.5–36.8 mm to the left side) and in tumor motions (mean deviation of tumor: 15.3–12.4 mm in craniocaudal, and 11.5–8.8 mm in posterolateral direction, mean medial deviation: 4.6–4.1 mm, mean lateral deviation: 7.2–5 mm). Significant differences were observed concerning tumor motions in anteroposterior direction (mean: 8.9–6.3 mm) and transverse chest movements in anteroposterior direction.Conclusion:Besides the advantage of optimal patient positioning, the movements of the bony chest wall can be considerably reduced by using the immobilization system. However, this fixation system has limitations concerning its suitability for minimizing tumor motions.Hintergrund und Ziel:Zahlreiche Methoden wurden entwickelt, um die Tumor- und Patientenbewegungen während der Strahlentherapie von Lungenkarzinomen zu reduzieren. In dieser Studie wurde eine Mehrschicht-CT-basierte Analyse zur Untersuchung der Auswirkungen eines thermoplastischen Patientenimmobilisierungssystems auf die Thoraxwand- und Tumorbewegungen durchgeführt.Patienten und Methodik:Zehn Patienten mit Lungenkrebs Stadium II–IV wurden in die Studie eingeschlossen. Gemäß der Tumorlokalisation wiesen fünf Patienten ein peripheres und fünf Patienten ein zentrales Lungenkarzinom auf (T2–T4). Insgesamt wurden sechs Messserien mit einem Mehrschicht-CT-Scanner durchgeführt: mit und ohne Maskenfixierung, bei normaler Atmung sowie mit maximalem Atemvolumen bei Ein- und Ausatmung.Ergebnisse:Die Brustwand-, Zwerchfell- und Tumorbewegungen wurden mit und ohne Maske bei unterschiedlichen Atmungszuständen registriert. Bei Verwendung des Immobilisierungssystems wurden keine signifikanten Unterschiede in den Zwerchfellbewegungen (durchschnittliche Abweichung des Diaphragmas: 41,7–40,5 mm nach links und 40,5–36,8 mm nach rechts) und den Tumorbewegungen (durchschnittliche Abweichung des Tumors: 15,3–12,4 mm in kraniokaudaler und 11,5–8,8 mm in posteroanteriorer Richtung, durchschnittliche mediale Abweichung: 4,6–4,1 mm, durchschnittliche laterale Abweichung 7,2–5 mm) festgestellt. Signifikante Unterschiede waren bezüglich der Tumorbewegungen in anteroposteriorer Richtung (durchschnittlich 8,9–6,3 mm) und der transversalen Brustkorbbewegungen in anteroposteriorer Richtung zu beobachten.Schlussfolgerung:Neben dem Vorteil einer optimalen Patientenpositionierung können die Bewegungen der Thoraxwand mit Hilfe des Immobilisierungssystems erheblich reduziert werden. Dieses Fixierungssystem hat jedoch auch Grenzen hinsichtlich seiner Eignung zur Minimierung der Tumorbewegungen.

Effects of intra- and extracellular space properties on diffusion and T2 relaxation in a tissue model ☆

The purpose of this study was to investigate the effects of biophysical factors on the diffusion and the relaxation time T(2) independently. Certain properties of the extracellular and the intracellular space may change radically in pathological conditions resulting in water diffusion changes. A tissue model consisting of red blood cells was studied. The extra- and intracellular spaces were modified osmotically and by suspending medium concentration. Diffusion measurements were evaluated with regard to the effective medium theory. Neither the nature of the protein in the extracellular space nor an increased level of intracellular hydration caused a significant net water diffusion change in the cell suspension. The relaxation time T(2) exhibited very little dependence on the extracellular volume fraction or the concentration or the nature of the protein in the extracellular space. An increased level of intracellular hydration resulted in systematically larger T(2) values. It seems probable that increases in extracellular protein concentrations or in the extent of intracellular hydration do not play a significant role in the diffusion changes detected in pathological conditions. T(2) appears to depend on the level of hydration or the total water content but is seemingly less dependent of the concentration and the nature of the extracellular protein in our model solutions.

Application of MRI for improved local control in complex radiotherapy of cervical cancer

Background: The aim of this study was to analyze the use of magnetic resonance imaging (MRI) as a modern medical imaging technique in radiotherapy with special emphasis on the integration of MRI and a novel technique in brachytherapy to optimize treatment outcome in cervical cancer. Methods: In addition to the CT based shrinking volume conformal teletherapy in 31 patients with locally advanced cervical cancer, MRI examination with a special adjustable applicator at the treatment site was performed for the brachytherapy planning. To avoid excessive doses to the healthy structures during complex cervical radiotherapy isodose curves were calculated upon the information of the MR image and dose distribution was evaluated. Results: The consecutive application of CT and MRI limited the possibility for overdosage of the critical organs and undertreatment of the advanced tumor spread in all cases. The overall response rate for the complex treatment was 74.2% with complete regression in 25.8% of the cases. Based on the exact information of the three dimensional digital data radiation doses could be optimized without increasing the possibility of acute complications rate. Conclusion: The introduction of 3D treatment planning for teletherapy pelvic and boost irradiation of cervical carcinoma as well as for the brachytherapy part of the complex treatment is to be recommended. .

Serial intravascular ultrasonographic measurements after implantation of biodegradable polymer-coated stents in porcine coronary arteries.

Background Biodegradable stent coatings provide a potential for local drug delivery at the time of vascular injury, while possible tissue toxicity is avoided through constant degradation, leaving behind a bare metal stent. Design Serial three‐dimensional (3D) intravascular ultrasonographic results on bare Megaflex stents and biodegradable polymer‐coated Megaflex stents (Hyper stents) (Eurocor, Bonn, Germany) were compared 1 and 4 weeks after intracoronary implantation in pigs. Methods Under general anaesthesia, the left anterior descending and circumflex coronary arteries of domestic pigs were stented with Megaflex and Hyper stents, using right femoral artery access. Control coronary angiography and intravascular ultrasonography (IVUS) were performed 1 and 4 weeks after stent implantation using left femoral artery access and right carotid artery access. After recording of angiographic and IVUS data, the pigs were allowed to recover. Results The 1‐ and 4‐week IVUS follow‐ups revealed less neointima formation with Hyper stents than with Megaflex stents: 1‐week intimal volume, 11.8± 0.93 compared with 15.02 ± 4.18mm3, P = 0.065; intimal area, 0.81 ± 0.06 compared with 1.1 ± 0.16mm2, P = 0.003; maximal intimal thickness, 0.12 ± 0.01 compared with 0.14± 0.02 mm, P =0.049; 4‐week intimal volume, 12.4 ± 1.77 compared with 27.32 ±12.79mm3, P =0.016; intimal area, 0.82 ±0.12 compared with 1.95 ±0.65mm2, P = 0.003; and maximal intimal thickness, 0.13 ± 0.04 compared with 0.30± 0.10 mm, P = 0.003. Conclusions Implantation of biodegradable polymercoated (Hyper) stents results in significantly less neointima formation 1 and 4 weeks after intracoronary implantation than with bare Megaflex stents. Taking advantage of the good collateralization of femoral and carotid arteries of pigs, the use of different arterial accesses allows serial angiographic and 3D IVUS measurements on neointimal development without sacrificing the animals. Coron Artery Dis 14:409‐412 •

A PET/CT szerepe a sugárkezelésre kerülő betegek N és M klinikai stagingjében, a terápia meghatározásában. Intézeti tapasztalatok

INTRODUCTION AND AIM: The aim of our study was to investigate changes in clinical staging N (lymph node) and M (distant metastasis) in patients who receive PET/CT-based 3D radiotherapy within complex oncological treatment, and compare to conventional cross-sectional imaging staging technique. We also investigated the presence of PET/CT-detected second tumors and the effect of PET/CT on therapeutic decisions. METHOD: From the 1st of January 2015 to the 30th of November 2016, 192 patients (n = 192) were treated with PET/CT-based radiation (109 head, 44 lung, 28 rectum and 11 cervical localization) in the Oncoradiology Institute of the Health Center of the University of Kaposvar. All patients received conventional cross-sectional and PET/CT imaging in accordance with the valid investigation protocol. The average time interval between the two cross-sectional investigations was 5.2 weeks. Clinical N and M staging was performed on the basis of the classification of the American Joint Committee on Cancer (AJCC) and the Union of International Cancer Control (UICC). RESULTS: By analyzing the clinical stages N and M separately, based on the results of the PET/CT studies, the N stage was changed in 77 cases and the M stage changed in 31 cases. Overall, the PET/CT study resulted in higher clinical stages in 68 (35.4%) patients and lower clinical stages in 14 (7.3%) patients. The treatment plan was changed in 9% of the patients (n = 18) (definitive versus palliative treatment) and the extension of radiotherapy treatment target volume (PTV) was indicated in 20% of the patients (n = 39) due to the change in clinical lymph node status. PET/CT also detected secondary tumors in 15 (8%) patients. CONCLUSION: Based on our results, the addition of PET/CT to conventional cross-sectional staging imaging permits a more accurate clinical classification of N and M stages and significantly influences therapeutic decisions. PET/CT imaging also provides a great help in detecting occult second tumors. The results of our Institute harmonize with the international data available in the literature. Orv Hetil. 2018; 159(39): 1593-1601.

A PET/MR képalkotás magyarországi klinikai alkalmazásának lehetőségei, első tapasztalatai

Hungarys first and still only multimodality PET/MR device is operating in the Health Center of Kaposvar University. The aim of our review article is to present the current Hungarian PET/MR imaging application opportunities, our available initial experiences with this novel multimodality imaging technique in malignant and non-malignant diseases and further potential targeted clinical fields of use are also addressed. Orv Hetil. 2018; 159(34): 1375-1384.

Clinical outcome in prostate cancer treated with magnetic resonance imaging-guided high-dose-rate brachytherapy combined with external beam radiotherapy

other LR. Our material was not large enough to perform robust statistical analysis to look deeper into the relationship with time to recurrence and distant metastasis. In conclusion, the current outcome of a more detailed intrinsic subtype analysis does not seem to provide further insight into the reasons for the nature of the excess frequency of in-breast recurrences in younger low-risk patients.