Which simultaneous-integrated boost (SIB) intensity-modulated radiotherapy (IMRT) technique is dosimetrically superior in the treatment of breast cancer; volumetric-modulated arc therapy (VMAT) or fixed field (ff) IMRT?

2017 ◽  
Vol 16 (3) ◽  
pp. 272-279
Author(s):  
Steven B. D. Murphy ◽  
Heather Drury-Smith

AbstractBackground and purposeTo determine which concomitant boost technique is dosimetrically superior in the treatment of breast cancer; volumetric-modulated arc therapy (VMAT) or fixed field intensity-modulated radiotherapy (ff-IMRT).Materials and methodsIn total, 30 breast patients were re-planned with both VMAT and fixed field concomitant boost intensity-modulated radiotherapy techniques. A hybrid technique was used delivering 80% of the dose through tangential beams and 20% through an integrated boost. A two-tailed t-test sample for means was used to compare the dosimetric differences between the techniques.ResultsMaximum dose was statistically lower for VMAT; 103·2 versus 103·7% for ff-IMRT along with statistically lower V2 Gy doses to the contralateral lung (0·7 versus 1·6%) and heart for both left- (19·0%/22·6%), and right- (5·5%/8·8%) sided patients, respectively. ff-IMRT boasted significantly lower ipsilateral lung V20, V18 and V10 Gy (7·9/8·6/13·1 versus 8·1/8·8/13·4%) than VMAT, respectively. No differences were found with minimum coverage, mean dose and V5 Gy to all organs at risk (OARs).ConclusionVMAT and ff-IMRT techniques demonstrate excellent target coverage and OAR sparing facilitated by the hybrid planning technique and deep inspiration breath hold. There is no obvious dosimetrically superior option between the two techniques. Reduced treatment times with VMAT make it more desirable to implement clinically.

Author(s):  
Karthikeyan Kalyanasundaram ◽  
Subramani Vellaiyan

Abstract Purpose: The purpose of the study was to evaluate the impact of changes in breathing pattern inside the breath-hold window (BHW) during deep inspiration breath hold treatment for carcinoma left breast patients post-conservative surgery. Methods: Ten patients of carcinoma left breast post-conservative surgery were prospectively selected. Three sets of CT plain images were acquired, one with 5 mm deep inspiration BHW (DIBHR) and the other one with 1 mm BHW matching the lower threshold (DIBHL) and the third one with 1 mm BHW matching the upper threshold (DIBHH) as DIBHR. For all patients, forward intensity-modulated radiotherapy (FIMRT) and volumetric modulated arc therapy (VMAT) plans were generated in the 5 mm BHW CT series and the same plan being copy and pasted in other series. Target volume doses and critical structure doses were tabulated. Results: Planning target volume coverage was adequate and no significant differences were found in any CT series. Significant differences noted in average left lung V5%, V10% and V18% doses between DIBHR versus DIBHH (p values = 0·0461, 0·0283 and 0·0213, respectively) and DIBHL versus DIBHH (p values = 0·0434, 0·0484 and 0·0334, respectively) for FIMRT plans and V18% doses in DIBHR versus DIBHH (p = 0·0067) in VMAT. No differences in heart and apex of heart doses were found. Left anterior descending artery (LAD) mean doses were significant in DIBHL versus DIBHR, DIBHR versus DIBHH and DIBHL versus DIBHH (p = 0·0012, 0·0444 and 0·0048, respectively) series for FIMRT plans and DIBHR versus DIBHH and DIBHL versus DIBHH (p = 0·0341, 0·0001) for VMAT plans. Finding: The changes in the breathing pattern inside DIBH window level cause some variation in LAD doses and no other significant differences in any parameters noted, so care should be taken while treating patients with preexisting cardiac conditions.


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.


Sign in / Sign up

Export Citation Format

Share Document