scholarly journals Hybrid volumetric modulated arc therapy for hypofractionated radiotherapy of breast cancer: a treatment planning study

Author(s):  
Alexander Venjakob ◽  
Michael Oertel ◽  
Dominik Alexander Hering ◽  
Christos Moustakis ◽  
Uwe Haverkamp ◽  
...  

Abstract Purpose This study aims to evaluate the best possible practice using hybrid volumetric modulated arc therapy (H-VMAT) for hypofractionated radiation therapy of breast cancer. Different combinations of H‑VMAT—a combination of three-dimensional radiotherapy (3D-CRT) and VMAT—were analyzed regarding planning target volume (PTV), dose coverage, and exposure to organs at risk (OAR). Methods Planning computed tomography scans were acquired in deep-inspiration breath-hold. A total of 520 treatment plans were calculated and evaluated for 40 patients, comprising six different H‑VMAT plans and a 3D-CRT plan as reference. H‑VMAT plans consisted of two treatment plans including 3D-CRT and VMAT. During H‑VMAT planning, the use of hard wedge filters (HWF) and beam energies were varied. The reference plans were planned with mixed beam energies and the inclusion/omission of HWF. Results Compared to the reference treatment plans, all H‑VMAT plans showed consistently better PTV dose coverage, conformity, and homogeneity. Additionally, OAR protection was significantly improved with several H‑VMAT combinations (p < 0.05). The comparison of different H‑VMAT combinations showed that inclusion of HWF in the base plan had a negative impact on PTV dose coverage, conformity, and OAR exposure. It also increased the planned monitor units and beam-on time. Advantages of using lower beam energies (6-MV photons) in both the base plan and in the VMAT supplementary dose were observed. Conclusion The H‑VMAT technique is an effective possibility for generating homogenous and conformal dose distributions. With the right choice of H‑VMAT combination, superior OAR protection is achieved compared to 3D-CRT.

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Magdalena Charmacińska ◽  
Sara Styś ◽  
Olga Bąk ◽  
Weronika Kijeska ◽  
Agnieszka Skrobała

Nowotwór piersi jest to nowotwór złośliwy powstający z komórek gruczołu piersiowego, który rozwija się miejscowo w piersi oraz daje przerzuty do węzłów chłonnych i narządów wewnętrznych (płuc, wątroby, kości i mózgu). Ponad 23% zachorowań na nowotwory kobiet w Polsce, jak i na świecie stanowią nowotwory piersi. Na przestrzeni ostatnich lat techniki napromieniania nowotworów piersi ulegają ciągłemu rozwojowi. Celem pracy było poglądowe przedstawienie technik radioterapeutycznych stosowanych w napromienianiu nowotworów piersi, od dwuwymiarowej 2D techniki statycznej poprzez techniki dynamiczne (IMRT technika z modulacją intensywnością dawki (ang. intensity modulated radiation therapy), VMAT technika obrotowa z modulacją intensywności dawki (ang. volumetric modulated arc therapy), aż do techniki DIBH techniki napromieniania na głębokim wstrzymanym wdechu (ang. deep inspiration breath hold). W pracy skupiono się na przedstawieniu realizacji omawianych technik i opisie jak dana technika wpływa na rozkład dawki w planowanej objętości do napromieniania PTV (ang. Planning Target Volume) oraz na dawki w narządach krytycznych w radioterapii nowotworów piersi.


2021 ◽  
Author(s):  
Samsun - ◽  
Muhammad Arif Arif ◽  
Gregorius Septayudha Septayudha

Abstract In terms of breast cancer radiation treatment, it has radiation using the 3D-Conformal Radiotherapy (3D-CRT) technique and the continuation of the 3D-CRT technique, namely the Intensity Modulated Radiation Therapy (IMRT) technique. This study aims to evaluate the dosage aspects of PTV and OAR between the 3D-CRT and IMRT techniques in cases of left breast cancer with hypofractionation using the Deep Inspiration Breath Hold (DIBH) method using the Conformity Index (CI) and Homogeneity Index (H.I.) and H.I. organ at risk uses tolerance limits. This type of research is comparative quantitative with ten samples with primary data conducted at Siloam T.B. Hospital. Simatupang from November 2019 to April 2020. The research was carried out in the form of radiation planning with 3D-CRT techniques and IMRT techniques, and the results of planning both techniques were evaluated between 3D-CRT techniques and IMRT techniques through PTV evaluations using CI and H.I. values. Furthermore, the organs at risk use tolerance limits on each organ. The results showed the assessment between 3D-CRT and IMRT on PTV and organs at risk received different doses. The PTV shows the CI value, which is almost the same as the difference of 0.034, and there is a slight difference in H.I. with an average value in the IMRT technique of 0.07 and 3D-CRT of 0.11, and it can be seen that the IMRT is slightly superior because the excellent H.I. value is the closest to 0. Then at the dose of organ at risk received by the sample, the 3D-CRT technique is slightly superior by obtaining a lower dose that obtains the difference in the heart by 0.53%, lung by 3.46%, spinal cord by 6.51 Gy, esophagus at 4.5 Gy, and larynx at 5.18 Gy.


2016 ◽  
Vol 103 (1) ◽  
pp. 72-75 ◽  
Author(s):  
Luciana Lastrucci ◽  
Simona Borghesi ◽  
Silvia Bertocci ◽  
Chiara Gasperi ◽  
Andrea Rampini ◽  
...  

Purpose To compare 3D-conformal radiotherapy (3D-CRT) treatment plans based on free-breathing (FB) and deep inspiration breath hold (DIBH) and investigated whether DIBH technique enables a decrease of cardiac left anterior descending coronary artery (LADCA) and lungs dose with respect to the FB. Methods Twenty-three left-sided breast cancer patients referred for breast radiotherapy were included. The planning target volume (PTV) encompassed the breast and organs at risk including heart, LADCA, lungs, and contralateral breast, which were contoured in FB and DIBH CT scans. Dose to PTV was 50 Gy in 25 fractions. Two treatment plans were generated for each patient: FB-3D-CRT and DIBH-3D-CRT. Dosimetry parameters were obtained from dose volume histograms. Data were compared using the paired-sample Wilcoxon signed rank test. Results For heart, LADCA, and left lung, a significant dose reduction was found using DIBH technique. By using DIBH, an average reduction of 25% was observed in LADCA for the volume receiving 20 Gy and of 48% considering the mean heart dose. Conclusions The DIBH technique results in a significant decrease of dose to the heart, LADCA, and left lung compared to FB.


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