Dosimetric and efficiency comparison of high-dose radiotherapy for esophageal cancer: volumetric modulated arc therapy versus fixed-field intensity-modulated radiotherapy

2013 ◽  
Vol 27 (6) ◽  
pp. 585-590 ◽  
Author(s):  
C.-Y. Lin ◽  
W.-Y. Huang ◽  
Y.-M. Jen ◽  
C.-M. Chen ◽  
Y.-F. Su ◽  
...  
2015 ◽  
Vol 11 (3) ◽  
pp. 3146-3155
Author(s):  
Luhua Wang

Purpose: To evaluate the usefulness of helical tomotherapy (HT) in the treatment of advanced esophageal cancer (EC) and compare target homogeneity, conformity and normal tissue doses between HT and fixed-field intensity-modulated radiotherapy (ff-IMRT).Methods: In all, 23 patients with cT3-4N0-1M0-1a thoracic EC (upper esophagus, 9 patients; middle esophagus, 6; distal esophagus, 6 and esophagogastric junction, 2) who were treated with ff-IMRT (60 Gy in 30 fractions) were re-planned for HT and ff-IMRT with the same clinical require­ments. Comparisons were performed using the Wilcoxon matched-pair signed-rank test.Results: Compared with ff-IMRT, HT significantly reduced the homogeneity index for thoracic, upper, middle and distal ECs by 38%, 31%, 36% and 33%, respectively (P < 0.05). The conformity index was increased by HT for thoracic, upper and middle ECs by 9%, 9% and 18%, respectively (P < 0.05). Target coverage was improved by 1% with HT (P < 0.05). The mean lung dose was significantly reduced by HT for thoracic and upper ECs (P < 0.05). The V20 (volume receiving at least 20 Gy) and higher dose volumes of the lungs were decreased by HT in all cases, but the differences were significant for thoracic, upper and distal ECs (P < 0.05), with reductions of 2.1%, 3.1% and 2.2%, respectively. HT resulted in a larger lung V5 for thoracic, upper, middle and distal ECs, with increases of 3.5%, 1.5%, 7.2% and 3.2%, respectively. Heart sparing was significantly better with HT than with ff-IMRT in terms of the V30 and V40 for thoracic, upper, middle and distal ECs (P < 0.05).Conclusions: Compared to ff-IMRT, HT provides superior target coverage, conformity and homogeneity, with reduced the volume of high doses to the lungs and heart for advanced EC. HT may be a treatment option for advanced EC, especially upper EC.


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.


2020 ◽  
Author(s):  
Deyang Yu ◽  
Shan Lu ◽  
Lei Wang ◽  
Xueyuan Hu ◽  
Xin Li ◽  
...  

Abstract Background: To compare the dosimetric parameters of different radiotherapy plans, helical tomotherapy(HT), volume-modulated arc therapy (VMAT), and fixed-field intensity-modulated radiation therapy (FF-IMRT) for nasopharyngeal carcinoma (NPC) and cervical cancer (CC).Methods: A total of 15 patients with NPC and 15 patients with CC were chosen for retrospective analysis and replanned for HT, VMAT, and FF-IMRT. The prescribed doses of the planning target were 2.12/69.96 Gy, 1.8/59.4 Gy for NPC and 1.8/45 Gy for CC, respectively. The dosimetric parameters of the planning target, organs at risk (OARs), and the efficiency of radiation delivery were assessed and compared using the paired-samples t-test.Results: Compared with VMAT and FF-IMRT, HT plans significantly improved the mean conformity index (CI) and homogeneity index (HI). For the OARs, the HT plans reduced the maximum doses of most organs, such as brainstem, spinal cord, and optic nerves in NPC, and significantly reduced the volume of the high-dose region in NPC and the V30 and V40 of small bowel, rectum, and bladder in CC. However, VMAT evidently reduced the treatment time and improved the efficiency of radiation delivery than HT.Conclusions: For NPC and CC, results showed that HT and VMAT possessed better homogeneity and conformity of the target and better sparing of OARs compared with the conventional FF-IMRT, and HT achieved the best effect. VMAT had the shortest radiation delivery time. The results of this study can provide guidance for the selection of appropriate radiation technologies for patients with NPC and CC who are undergoing concurrent chemoradiotherapy.


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