A vagyonőrök alkalmassági vizsgálatának koncepciója = The concept of the suitability examination of security guards

A vagyonvédelemben élőerős szolgáltatást nyújtó cégeknek évek óta egyre nehezebb feladat a minőségi munkaerő biztosítása. A napjainkban jelentkező képzett munkaerő hiánya – toborzást és képzést tekintve – változásra kényszeríti a vagyonvédelmi cégeket. Ebben a cikkben törekszünk betekintést nyújtani a modern vagyonvédelmi élőerő alkalmassági vizsgálatának technikájába. = Ensuring a quality workforce has been an increasingly difficult task for companies providing live security services for years. The lack of a skilled workforce today is forcing property protection companies to change paradigms in the field of recruitment and training. In this article, our aim is to provide insight into the technique of modern force protection suitability testing

Biological dose summation of intensity-modulated arc therapy and image-guided high-dose-rate interstitial brachytherapy in intermediate- and high-risk prostate cancer

Purpose: To present an alternative method for summing biologically effective doses of intensity-modulated arc therapy (IMAT) as teletherapy (TT), with interstitial high-dose-rate (HDR) brachytherapy (BT) boost in prostate cancer. Total doses using IMAT boost was compared with BT boost using our method. Material and methods: Initially, 25 IMAT TT plus interstitial HDR-BT plans were included, and additional plans using IMAT TT boost were created. The prescribed dose was 2/44 Gy to the whole pelvis, 2/60 Gy to the prostate and seminal vesicles, and 1 x 10 Gy BT or 2/18 Gy IMAT TT to the prostate. Teletherapy computed tomography (CT) was registered with ultrasound (US) of BT, and the most exposed volume of critical organs in BT were identified on these CT images. The minimal dose of these from IMAT TT was summed with their BT dose, and these EQD(2) doses were compared using BT vs. IMAT TT boost. This method was compared with uniform dose conception (UDC). Results: D-90 of the prostate was significantly higher with BT than with IMAT TT boost: 99.3 Gy vs. 77.9 Gy, p = 0.0034. The D-2 to rectum, bladder, and hips were 50.3 Gy vs. 76.8 Gy (p = 0.0117), 64.7 Gy vs. 78.3 Gy (p = 0.0117), and 41.9 Gy vs. 50.6 Gy (p = 0.0044), while D-0.1 to urethra was 96.1 Gy vs. 79.3 Gy (p = 0.0180), respectively. UDC overestimated D-2 (rectum) by 37% (p = 0.0117), D-2 (bladder) by 5% (p = 0.0214), and underestimated D-0.1 (urethra) by 1% (p = 0.0277). Conclusions: Based on our biological dose summation method, the total dose of prostate is higher using BT boost than the IMAT. BT boost yields lower rectum, bladder, and hips doses, but higher dose to urethra. UDC overestimates rectum and bladder dose and underestimates the dose to urethra

Does inverse planning improve plan quality in interstitial high-dose-rate breast brachytherapy?

Purpose: To investigate the effect of input parameters for an inverse optimization algorithm, and dosimetrically evaluate and compare clinical treatment plans made by inverse and forward planning in high-dose-rate interstitial breast implants. Material and methods: By using a representative breast implant, input parameters responsible for target coverage and dose homogeneity were changed step-by-step, and their optimal values were determined. Then, effects of parameters on dosimetry of normal tissue and organs at risk were investigated. The role of dwell time modulation restriction was also studied. With optimal input parameters, treatment plans of forty-two patients were re-calculated using an inverse optimization algorithm (HIPO). Then, a pair-wise comparison between forward and inverse plans was performed using dose-volume parameters. Results: To find a compromise between target coverage and dose homogeneity, we recommend using weight factors in the range of 70-90 for minimum dose, and in the range of 10-30 for maximum dose. Maximum dose value of 120% with a weight factor of 5 is recommended for normal tissue. Dose constraints for organs at risk did not play an important role, and the dwell time gradient restriction had only minor effect on target dosimetry. In clinical treatment plans, at identical target coverage, the inverse planning significantly increased the dose conformality (COIN, 0.75 vs. 0.69, p < 0.0001) and improved the homogeneity (DNR, 0.35 vs. 0.39, p = 0.0027), as compared to forward planning. All dosimetric parameters for non-target breast, ipsilateral lung, ribs, and heart were significantly better with inverse planning. The most exposed small volumes for skin were less in HIPO plans, but without statistical significance. Volume irradiated by 5% was 173.5 cm(3) in forward and 167.7 cm(3) in inverse plans (p = 0.0247). Conclusions: By using appropriate input parameters, inverse planning can provide dosimetrically superior dose distributions over forward planning in interstitial breast implants

Comparative dosimetrical analysis of intensity-modulated arc therapy, CyberKnife therapy and image-guided interstitial HDR and LDR brachytherapy of low risk prostate cancer

Background: The objective of the study was to dosimetrically compare the intensity-modulated-arc-therapy (IMAT), CyberKnife therapy (CK), single fraction interstitial high-dose-rate (HDR) and low-dose-rate (LDR) brachytherapy (BT) in low-risk prostate cancer. Materials and methods: Treatment plans of ten patients treated with CK were selected and additional plans using IMAT, HDR and LDR BT were created on the same CT images. The prescribed dose was 2.5/70 Gy in IMAT, 8/40 Gy in CK, 21 Gy in HDR and 145 Gy in LDR BT to the prostate gland. EQD2 dose-volume parameters were calculated for each technique and compared. Results: EQD2 total dose of the prostate was significantly lower with IMAT and CK than with HDR and LDR BT, D90 was 79.5 Gy, 116.4 Gy, 169.2 Gy and 157.9 Gy (p &lt; 0.001). However, teletherapy plans were more conformal than BT, COIN was 0.84, 0.82, 0.76 and 0.76 (p &lt; 0.001), respectively. The D2 to the rectum and bladder were lower with HDR BT than with IMAT, CK and LDR BT, it was 66.7 Gy, 68.1 Gy, 36.0 Gy and 68.0 Gy (p = 0.0427), and 68.4 Gy, 78.9 Gy, 51.4 Gy and 70.3 Gy (p = 0.0091) in IMAT, CK, HDR and LDR BT plans, while D0.1 to the urethra was lower with both IMAT and CK than with BTs: 79.9 Gy, 88.0 Gy, 132.7 Gy and 170.6 Gy (p &lt; 0.001). D2 to the hips was higher with IMAT and CK, than with BTs: 13.4 Gy, 20.7 Gy, 0.4Gy and 1.5 Gy (p &lt; 0.001), while D2 to the sigmoid, bowel bag, testicles and penile bulb was higher with CK than with the other techniques. Conclusions: HDR monotherapy yields the most advantageous dosimetrical plans, except for the dose to the urethra, where IMAT seems to be the optimal modality in the radiotherapy of low-risk prostate cancer

A magyar sugárterápia jelenlegi helyzetének bemutatása

The purpose of the study is to report the status of Hungarian radiotherapy (RT). In the 13 centers 84 radiation oncologists, 19 residents, 66 physicists and 231 radiotherapy technologists work, and 40 megavoltage units (38 linear accelerators, 2 cobalt units) are in use. HDR afterloader is available in all and CT-simulator in all but one centers. In 2017 33,024 patients received RT, 22,236 were irradiated with MV beams, 1,406 with BT and 9,382 with orthovoltage X-ray. Main indications for BT were gynecological tumors (75%), HDR prostate implants were performed in 3 centers. Due to the recent infrastructural developments the number of patients receiving modern RT increased, but in order to fulfil the international recommendations additional linear accelerators have to be installed along with the replacement of the out of date equipment. From professional point of view further developments are warranted in Budapest