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See detailUTILISATION DE L’IMAGERIE FONCTIONNELLE EN RADIOTHÉRAPIE
LALLEMAND, François ULg; LAKOSI, Ferenc ULg; HUSTINX, Roland ULg et al

in Revue Médicale de Liège (2014), 69(Supp 1), 20-28

Les progrès technologiques réalisés par l’image- rie médicale l’ont placée au centre de la prise en charge des patients oncologiques, tant au niveau du diagnostic, du pro - nostic et du suivi que dans la ... [more ▼]

Les progrès technologiques réalisés par l’image- rie médicale l’ont placée au centre de la prise en charge des patients oncologiques, tant au niveau du diagnostic, du pro - nostic et du suivi que dans la prise en charge thérapeutique. En effet, l’imagerie représente, à l’heure actuelle, la pierre angulaire des traitements de radiothérapie. Les objectifs du radiothérapeute sont d’irradier le plus précisément possible la tumeur à dose curative, tout en évitant les organes sains. Pour y arriver, le radiothérapeute utilise de façon routinière l’imagerie anatomique (Scanner et IRM). Depuis quelques années, le développement des différentes imageries métabo - liques et fonctionnelles, comme l’imagerie par émission de positons (PET-CT) et la résonnance magnétique fonctionnelle, ouvrent de nouvelles possibilités thérapeutiques grâce aux informations qu’elles apportent sur la biologie des tumeurs. Cet article décrit, de manière non exhaustive, les différentes imageries anatomiques et métaboliques à la disposition du radiothérapeute. [less ▲]

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See detailRADIOTHÉRAPIE MAMMAIRE- pret-à-porter ou sur mesure ?
COUCKE, Philippe ULg; LAKOSI, Ferenc ULg

in Revue Médicale de Liège (2014), 69(Supp 1), 81-86

La radiothérapie mammaire après chirurgie conser - vatrice, pour carcinome canalaire in situ ou pour les formes invasives (carcinome canalaire infiltrant et carcinome lobu - laire infiltrant), semble très ... [more ▼]

La radiothérapie mammaire après chirurgie conser - vatrice, pour carcinome canalaire in situ ou pour les formes invasives (carcinome canalaire infiltrant et carcinome lobu - laire infiltrant), semble très bien codifiée et peut être taxée de «prêt-à-porter». Et pourtant, on est en droit de se poser la question s’il est possible de concevoir des indications de traitement «sur mesure». A ce jour, les données de la littéra - ture nous incitent à la prudence. Dans aucun cas de figure, on n’a été capable de démontrer que la radiothérapie pouvait être éliminée de l’approche thérapeutique sans pour autant risquer une augmentation significative du taux de rechute locale. Même si on considère que la radiothérapie adjuvante est une approche standard après une chirurgie conservatrice, il n’en reste pas moins qu’il persiste un certain nombre de questions ouvertes. Ces traitements actiniques pourraient être modulables en fonction des caractéristiques des patientes et des tumeurs. Idéalement, nous aimerions disposer de mar - queurs pronostiques et prédictifs robustes afin de détermi - ner qui il faut soumettre à ce traitement adjuvant. Peut-être que des signatures géniques vont permettre de sélectionner les patientes. Ces signatures géniques ne font pas l’unanimité quant à leur réelle portée clinique [less ▲]

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See detailOpen MR-guided high-dose-rate (HDR) prostate brachytherapy: feasibility and initial experiences
LAKOSI, Ferenc ULg; Gergely Antal; Csaba Vandulek et al

in Pathology Oncology Research (2011), 17(2), 315-24

The aim of our pilot study was to demonstrate the feasibility and dosimetric quality of MR-guided HDR prostate brachytherapy in a low-field 0.35T open MRI scanner and to present our initial clinical ... [more ▼]

The aim of our pilot study was to demonstrate the feasibility and dosimetric quality of MR-guided HDR prostate brachytherapy in a low-field 0.35T open MRI scanner and to present our initial clinical experiences. 16 patients with intermediate- to high-risk localized prostate cancer were treated with 46-60 Gy of external beam radiotherapy preceded and/or followed by an 8 Gy MR-guided HDR boost. For interventions an MR compatible custom-made system, coaxial needles and plastic catheters were used. Template reconstruction, trajectory planning, image guidance, contouring and treatment planning were exclusively based on MR images. For treatment planning, dose-point- and anatomy-based inverse planning optimization was used. Image quality was found to be good to excellent in almost all cases. The mean catheter placement accuracy modeled by Rayleigh distribution was 2.9 mm with a sigma value of 2.3 mm. The mean and standard deviation (SD) of the dosimetric results for the target volume were the following: V100: 94.2 ± 4.3%, V150: 43.9 ± 6.8%, V200: 18.5 ± 5.9%. The mean D(0.1), D(1) and D1 values for the intraprostatic urethra were 117.6 ± 12.5%, 98.5 ± 19.9% and 122.3 ± 16.4%, respectively. Regarding the rectal wall the mean D(0.1), D(1) and D(2) values were 77.3 ± 7.2%, 64.8 ± 7.5%, and 53.2 ± 9.1%, respectively. The mean maximum dose for the inner rectal surface was 53.5 ± 9.2%. No RTOG Grade 3 or worse acute toxicities were observed. Our method seems to be a promising approach for performing feasible, accurate and high-quality MR-guided HDR prostate brachytherapy. To determine the long term side effects and outcome higher number of patients, additional follow-up is needed. [less ▲]

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See detailIntegrating functional MRI information into radiotherapy planning of CNS tumors-early experiences.
Árpád Kovács; Lilla Tóth; Csaba Glavák et al

in Pathology Oncology Research (2011), 17(2), 207-17

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 ... [more ▼]

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). [less ▲]

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See detail3-D conformal photon boost in the treatment of early stage breast cancer: four year follow up results.
Kovacs; LAKOSI, Ferenc ULg; Liposits et al

in Pathology Oncology Research (2011), 17(1), 17-23

In the treatment of early stage breast cancer, breast conserving surgery (BCS) followed by whole breast irradiation (WBI) is the standard treatment. The impact of the tumor bed boost following WBI is well ... [more ▼]

In the treatment of early stage breast cancer, breast conserving surgery (BCS) followed by whole breast irradiation (WBI) is the standard treatment. The impact of the tumor bed boost following WBI is well-defined, but there are various delivery methods. In this study we demonstrate our 4 year experience with the 3-D conformal boost technique. Between January 2004 and June 2005, 77 early stage (Stage I-II) breast cancer patients were treated in our institute with whole breast irradiation (WBI, 50.4 Gy in 28 fractions) after breast conserving surgery. Following WBI, 3-D conformal photon boost was delivered (10-16 Gy in five to eight fractions) for all patients. The clinical outcome was retrospectively recorded in terms of survival and local control. The side effect profile (fibrosis, fat necrosis and cosmetic outcome) was also recorded and studied. In our patient group the mean follow up time was 46.8 months (median: 52, range: 17-71, SD: 14.4) The 4-year probability of local tumor control was 96% (crude rate: 74/77-96.1%), the 4-year probability of overall survival was 96% (crude rate: 74/77-96.1%) in this patient group. In case of the distant metastasis free survival the probability was 89, 5% (crude rate: 70/77-90, 1%). Probability of disease specific survival was 98% (crude rate: 76/77-98. 7%). Local relapse occurred in three cases (3.9%). In ten cases (12.9%) asymptomatic grade I-II breast fibrosis, in eight cases (10.4%) asymptomatic breast fat necrosis were registered. For 14 patients (18.2%) asymptomatic lung fibrosis was recorded on the control CT scans. In term of the relapse free survival, the close resection margin and the nodal positivity resulted in significant difference in favor of the clear resection margin group and the node negative group. In this study the 3-D conformal photon boost resulted in good local control and side effect profile. The presence of tumor bed clips resulted in significantly lower boost PTV volumes, but no correlation was found between the irradiated boost volume and the breast fibrosis. In the relapse free survival analysis, nodal negativity and clear margin status resulted in significantly better RFS. [less ▲]

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See detailTechnical feasibility of transperineal MR-guided prostate interventions in a low-field open MRI unit: canine study.
LAKOSI, Ferenc ULg

in Pathology Oncology Research (2009), 15(3), 31522

Magnetic resonance imaging (MRI) provides superior visualization of the prostate, its substructure, surrounding tissues, and, most important, focal lesions or cancer. The purpose of our canine study was ... [more ▼]

Magnetic resonance imaging (MRI) provides superior visualization of the prostate, its substructure, surrounding tissues, and, most important, focal lesions or cancer. The purpose of our canine study was to demonstrate the feasibility of a low-field (0.35 T) transperineal system that enables precise MR image guidance of prostate interventions. The canines were placed in the right lateral decubitus position. Template reconstruction, trajectory planning, contouring were based on T2-weighted FSE images. For image guidance and target confirmation, fast gradient spoiled-echo (FSPGR) sequence was used. MR compatible coaxial needles were manually inserted through the perineum to the base of the prostate. After satisfactory position was confirmed, brachytherapy catheters were placed through the coaxial needles. The mean deviation of the needle displacements was 2.9 mm with a median value of 2.7 mm. 97% of the errors were less than 4.0 mm. The needle placement accuracy was modelled by the Rayleigh distribution with a sigma value of 2.3 mm. Visual confirmation of needle placements was demonstrated on pathology tissue slices. The time needed for each step was: anaesthesia - 15 min, setup and positioning - 15 min, initial imaging - 15 min, template registration, projection - 15 min, contouring, trajectory planning, insertion of 12 needles - 60 min Based on our canine experiences our method seems to be a promising approach for performing feasible, accurate, reliable and high-quality prostate MR guidance within a reasonable time span. [less ▲]

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See detailDynamic MR Based Analysis of Tumor Movement in Upper and Mid Lobe Localized Lung Cancer
Kovacs; Hadjiev; LAKOSI, Ferenc ULg et al

in Pathology Oncology Research (2008)

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See detailComparison of photon with electron boost in treatment of early stage breast cancer
Kovacs, A.; Hadjiev Janaki; LAKOSI, Ferenc ULg et al

in Pathology Oncology Research (2008), 14(2), 193-7

In the treatment of early stage breast cancer breast conserving surgery (BCS) followed by whole breast irradiation (WBI) is a standard method. The impact of the tumor bed boost following WBI is well ... [more ▼]

In the treatment of early stage breast cancer breast conserving surgery (BCS) followed by whole breast irradiation (WBI) is a standard method. The impact of the tumor bed boost following WBI is well-defined, but there are various delivery methods. In this study the electron and the photon boost techniques were compared. For 78 early stage breast cancer patients both CT based 3D conformal photon boost and electron boost plans were created. For dosimetric comparison coverage index (CI), external volume index (EI) and conformality index (COIN) were studied. Lung volume receiving a dose of 2 Gy was also reviewed. Seventy-eight patients with 156 plans were compared. The mean tumor bed volume was measured as 61.39 cm3 the mean tumor bed-skin distance was 3.13 cm. In the case of CI and COIN significant differences were found in favor of the photon boost. In the comparison of EI no significant difference was detected between the two techniques. The mean lung volume receiving 2 Gy were 42.3 and 168.35 cm3, for photons and electrons respectively. In the adjuvant treatment of early stage breast cancer WBI followed by conformal photon boost showed to be superior to electron boost in focus of the COIN and CI. [less ▲]

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See detailThermoplastic patient fixation: influence on chest wall and target motion during radiotherapy of lung cancer.
Cselik, Zolt; Horvath, Akos; Repa, Imre et al

in Strahlentherapie und Onkologie (2007), 183(5), 271-8

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 ... [more ▼]

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. 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. 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. 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. [less ▲]

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See detailAz MR-képalkotással vezérelt prostata-brachytherapia metodikai tervezése
LAKOSI, Ferenc ULg; Antal, Gergely; Vandulek, Csaba et al

in Magyar Radiologia (2007), 81(5-6), 224-229

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See detailA tumormozgások jelentôségének sokszeletes-CT-alapú képfúziós vizsgálata tüdôdaganatos betegek sugárkezelésénél
Kovács, Árpád; Hadjiev, Janaki; LAKOSI, Ferenc ULg et al

in Magyar Onkologia (2007), 51(3), 219-223

The aim of our study was to detect the possible uncertainties arising from tumor movements in the daily routine treatment planning, in extreme breathing conditions. Ten patients with lung cancer were ... [more ▼]

The aim of our study was to detect the possible uncertainties arising from tumor movements in the daily routine treatment planning, in extreme breathing conditions. Ten patients with lung cancer were enrolled into the study. According to tumor location, five patients had peripheral and five had central tumor. After the normal planning CT scan, two more scans were made with the same CT parameters in maximal exhalation and in maximal inhalation. For planning, the normal breathing scans were used with the fusion of the maximal inhalation and maximal exhalation scans. After the fusion in all breathing phases the gross tumor volumes were contoured (GTV1, GTV2, GTV3). Around the GTV1 (normal breathing phase GTV) 3 planning target volumes (PTV) were generated with the margin of 0.5 cm, 1.5 cm and 2.5 cm (PTV1, PTV2, PTV3). Individual plans were generated to all PTVs. All GTV volumes were registered. In all cases volume deviations were registered in different breathing phases (min: 1.5%, max: 35.6%). For GTV coverage comparison the coverage index (CI) was used. In case of extreme breathing conditions, using 0.5 cm margin was sufficient to reach good coverage for central tumors. For peripheral tumors 1.5 cm margin had to be used for the acceptable coverage (CI: 0.85-1.00). In our study, extreme breathing conditions were analyzed. According to our results, CT scans used in the daily routine do not exactly represent the tumor midposition and the true tumor volume. Due to breathing synchronous tumor movements, 0.5 cm margin must be used for planning in central location. In peripheral tumors wider margin should be used. [less ▲]

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See detailApplication of MRI for improved local control in complex radiotherapy of cervical cancer
Janaki, Hadjiev; Zsolt, Cselik; Péter Bogner et al

in Archive of Oncology (2006), 14(3-4), 95-100

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 ... [more ▼]

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. [less ▲]

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