[Historical overview and the current practice of intracavitary treatment of cervical and endometrial cancer in the Oncoradiology Center of Budapest]. / A méhtest- és méhnyakrák intrakavitális kezelésének történeti áttekintése és jelen gyakorlata a Fõvárosi Onkoradiológiai Központban.

The aims of our study were to describe the history and development of intracavitary brachytherapy in the treatment of gynecological tumors, to introduce our current practice for intracavitary brachytherapy treatments based on CT planning. Gynecological intracavitary brachytherapy has been applied in our department since the early 1930s. After a long development it has been completely renewed by 2014. In our center definitive and/or preoperative gynecological HDR-AL brachytherapy treatments were given to 25 patients (13 corpus uterine cancer patients and 12 cervical cancer patients) during the period of 01. 01. 2014-31. 01. 2015. In each case, target volumes were planned by CT images, DVH (dose volume histogram) analysis was performed in order to calculate the radiation tolerance dose of rectum and urinary bladder. Evaluation was performed by the EclipseTM 11.0.47. brachytherapy treatment planning system. During the definitive treatments of the 13 uterine cancer patients the D2cc value related to rectum tolerance was 66.3 GyEQD2 (46-91 Gy). The average D2cc value of urinary bladder tolerance was 76.5 GyEQD2 (30-112 Gy). CI was 0.72 (0.6-0.95). Average value of COIN was 0.57 (0.35-0.78). Compared to the prescribed dose D100 and D90 values were given in ratios. Compared to the volume which receives 100% of reference dose V150 and V200 values were also given in ratios. D100 and D90 were calculated to be 0.66 (0.47-0.97) and 0.91 (0.8-1.25). V150 and V200 volumes were 0.11 (0.04-0.18) and 0.06 (0.02-0.1). During the definitive treatments of 12 cervical cancer patients the D2cc value related to rectum tolerance calculated by DVH was 75.2 GyEQD2 (60-82 Gy). The average D2cc value of urinary bladder tolerance was 85 GyEQD2 based on DVH. CI was 0.66 (0.42-0.76). Average value of COIN was 0.52 (0.32-0.78). Mean value of DHI was 0.46 (0.27-0.54). D100 and D90 were calculated to be 0.72 (0.57-0.89) and 0.91 (0.84-1.11). V150 and V200 volumes were 0.057 (0.02-0.13) and 0.02 (0.002-0.06). During treatments no severe side effects were found. During gynecological intracavitary HDR therapies the calculated dose of the target volume can be given safely using the EclipseTM 11.0.47. brachytherapy planning system and CT-based planning. CT-based treatment planning provides optimal safety for organs at risk, acceptable doses for rectum and urinary bladder while the target volume receives the proper prescribed dose.

Verification of quality parameters for portal images in radiotherapy.

BACKGROUND: The purpose of the study was to verify different values of quality parameters of portal images in radiotherapy. MATERIALS AND METHODS: We investigated image qualities of different field verification systems. Four EPIDs (Siemens OptiVue500aSi(®), Siemens BeamView Plus(®), Elekta iView(®) and Varian PortalVision™) were investigated with the PTW EPID QC PHANTOM(®) and compared with two portal film systems (Kodak X-OMAT(®) cassette with Kodak X-OMAT V(®) film and Kodak EC-L Lightweight(®) cassette with Kodak Portal Localisation ReadyPack(®) film). RESULTS: A comparison of the f50 and f25 values of the modulation transfer functions (MTFs) belonging to each of the systems revealed that the amorphous silicon EPIDs provided a slightly better high contrast resolution than the Kodak Portal Localisation ReadyPack(®) film with the EC-L Lightweight(®) cassette. The Kodak X-OMAT V(®) film gave a poor low contrast resolution: from the existing 27 holes only 9 were detectable. CONCLUSIONS: On the base of physical characteristics, measured in this work, the authors suggest the use of amorphous-silicon EPIDs producing the best image quality. Parameters of the EPIDs with scanning liquid ionisation chamber (SLIC) were very stable. The disadvantage of older versions of EPIDs like SLIC and VEPID is a poor DICOM implementation, and the modulation transfer function (MTF) values (f50 and f25) are less than that of aSi detectors.

[Quality control of computed tomography scanners from the viewpoint of radiotherapy planning in Hungary]. / Computertomográfiás készülékek minôségellenôrzése a besugárzástervezés szempontjai alapján (Magyarországi helyzetelemzés).

The aim of this publication is to review the requirements necessary for using computed tomography (CT) for radiotherapy treatment planning. The equipments were tested with different CT phantoms. The authors made several measurements for checking the CT number, the quality and the mechanical parameters of CT tables. The CT numbers measured on the equipments of different manufacturers were in quite good agreement with the IAEA requirements. The geometric distortions of CT images are negligible, while the mechanical parameters of CT tables show considerable variety. A quality assurance - quality control protocol is recommended to implement in a safe workflow.

[PET/CT based radiotherapy treatment planning in head and neck cancers]. / PET/CT alapú besugárzástervezéssel szerzett tapasztalatok fej-nyaki tumorokban.

The purpose of this study was to evaluate the experiences of PET/CT based radiation planning in patients suffering from head and neck cancer. PET/CT based 3D-conformal irradiation was used in eleven patients between March 2008 and February 2009. In six of the eleven cases the therapeutic plan was modified after PET/CT examination, as the previously determined lymph node negative state proved to be lymph node positive. For that reason, the treatment needed to be completed by chemotherapy and in some cases clinical target volume and planning target volume have been also modified. PET/CT examination has a decisive influence on therapeutic planning and on the planning process in patients with head and neck cancer.