scholarly journals Comparative study between Acuros XB algorithm and Anisotropic Analytical Algorithm in the case of heterogeneity for the treatment of lung cancer

2018 ◽  
Vol 24 (3) ◽  
pp. 115-119
Author(s):  
Mohammed El Adnani Krabch ◽  
Abdelouahed Chetaine ◽  
Abdelati Nourreddine ◽  
Fatim Zohra Er-Radi ◽  
Laila Baddouh
Keyword(s):  
Lung Cancer ◽  
At Risk ◽  
Heterogeneous Media ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Target Volume ◽  
Conformity Index ◽  
Acuros Xb ◽  
Significant Difference ◽  
The Impact

Abstract The aim of this study was to investigate the impact of heterogeneity on the dose calculation for two algorithms implemented in the TPS “Analytical Anisotropic Algorithm (AAA) and Acuros XB” and validated the use of Acuros XB algorithm in clinical routine. First, we compare the dose calculated by these algorithms and the dose measured at the given point P, which is found after heterogeneity insert. Second, we extend our work on clinical cases that present a complex heterogeneity. By evaluating the impact of the choice of the algorithm on the dose coverage of the tumor, and the dose received by the organs at risk for 20 patients affected by lung cancer. The result of our phantom study showed a good agreement with several studies that showed the superiority of the Acuros XB over the AAA in predicting dose when it concerns heterogeneous media. The treatment plans for 20 lung cancers were calculated by two algorithms AAA and Acuros XB, the results show a statistical significant difference between algorithms for Homogeneity Index and the maximum dose of planning target volume (HI: 0.11±0.01 vs 0.05±0.01 p = 0.04; Dmax: 69.30±3.12 vs 68.51±2.64 p = 0.02). Instead, no statistically significant difference was observed for conformity index CI and mean dose (CI: 0.98±0.18 vs 0.99±0.14 p = 0.33; Dmean: 66.3±0.65 vs 66.10 ±0.61 p = 0.54). For organs at risk, the maximum dose for spinal cord, mean dose and D37 % of lung minus GTV (dose receiving 37% of lung volume) were found to be lower for AAA plans than Acuros XB and the differences were statistically significant (p<0.05). For the heart D33% and D67% were found to be higher for AAA plans than Acuros XB and the differences were statistically significant (p<0.05), but No difference was observed for D100% of the heart. The use of the AXB algorithm is suitable in the case of presence of heterogeneity, because it allows to have a better accuracy close to the Monte Carlo calculation.

scholarly journals Planning Lung Radiotherapy Incorporating Motion Freeze PET/CT Imaging

2018 ◽  
Vol 8 (9) ◽  
pp. 1583 ◽  
Author(s):  
Shih-Neng Yang ◽  
Wan-Chi Chiang ◽  
Kuei-Ting Chou ◽  
Geoffrey Zhang ◽  
Tzung-Chi Huang
Keyword(s):  
Lung Cancer ◽  
Spinal Cord ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Three Dimensional ◽  
Intensity Modulated Radiotherapy ◽  
Standardized Uptake Value ◽  
Target Volume ◽  
Gated Radiotherapy ◽  
The Impact

Motion Freeze (MF), which integrates 100% of the signal of each respiratory phase in four-dimensional positron emission tomography (4D-PET) images and creates the MF-PET, is capable of eliminate the influences induced by respiratory motion and dispersing from three-dimensional PET (3D-PET) and 4D-PET images. In this study, the effectiveness of respiratory gated radiotherapy applying MF-PET (MF-Plan) in lung cancer patient was investigated and compared with three-dimensional intensity modulated radiotherapy (3D-Plan) and routine respiratory gated radiotherapy (4D-Plan) on the impact of target volume and dosimetry. Thirteen lung cancer patients were enrolled. The internal target volumes were generated with 40% of maximum standardized uptake value. The 3D-Plan, 4D-Plan, and MF-Plan were created for each patient to study the radiation to the targets and organs at risk. MF-Plans were associated with significant reductions in lung, heart, and spinal cord doses. The median reductions in lung V20, lung mean, heart mean doses, and spinal cord maximum dose compared with 3D-Plans were improved. When compared with 4D-Plans, the median reductions in lung V20, lung mean dose, heart mean dose, and spinal cord maximum dose were improved. Our results indicate that the MF-Plan may improve critical organ sparing in the lung, heart, and spinal cord, while maintaining high target coverage.

scholarly journals Transition from conformal to advanced radiotherapy techniques in treatment planning of gynecological cancer patients

2021 ◽  
pp. 77-77
Author(s):  
Borislava Petrovic ◽  
Olivera Ivanov ◽  
Milana Marjanovic ◽  
Jelena Licina ◽  
Ivan Gencel ◽  
...  
Keyword(s):  
At Risk ◽  
Cancer Patients ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Gynecological Cancer ◽  
Conformal Radiation Therapy ◽  
Significant Difference ◽  
Treatment Plans ◽  
Radiation Induced ◽  
Risk Treatment

Background/ Aim. Transition from standard to highly conformal radiation therapy techniques, requires implementation of complex advanced dosimetry. The aim of the work was comparison of dosimetric parameters of 3DCRT and VMAT plan, as well as complications after treatment in relation to dosimetric parameters at gynecological cancer patients. Methods. Forty-nine gynecological cancer patients were included in the study. All patients were planned for 3D CRT, but due to unacceptable doses to organs at risk, treatment plans for IMRT or VMAT were generated for 21 patients. The patients were prescribed 50.4 Gy/28 fractions (4) and 45 Gy/25 fractions (45 patients). The coverage of PTV and doses to organs at risk were recorded. PTV margins were evaluated for both techniques according to the Van Herk formula. Results. ICRU 83 criteria were fulfilled in all 3DCRT /VMAT/IMRT plans providing optimal coverage of PTV. Doses to OARS: in average, the V45Gy in small bowel in IMRT/VMAT plans was four times smaller than the same of 3DCRT plans. The V45Gy of small bowels was in average 49.4cm3 in IMRT/VMAT plans, while in 3DCRT plans it was 211.6 cm3. In case of femoral head, significant reduction in V30Gy (10.8 % vs. 33.1%) and mean dose in case of IMRT/VMAT plans was recorded (30.4 Gy in 3DCRT vs 23.6 Gy). Rectum was planned with significantly lower dose in terms of V30Gy (79.5% vs 95.2%) in IMRT/VMAT plans. Bladder was better spared in VMAT plans in terms of V40Gy (51% vs. 91%), but maximum dose was higher in VMAT plans than in 3DCRT (50.1 Gy to 48.1 Gy in average). For all OARs there is statistically significant difference registered at p>0.05. Toxicities recorded in VMAT and 3DCRT patients include mainly radiation induced cystitis and enteritis. Patients treated with 3DCRT generally have longer recovery time. Homogeneity index was 0.11 for VMAT plans and 0.09 for 3DCRT plans. Conclusions. Analysis of dosimetric parameters revealed significant differences in normal tissue doses for same 3DCRT and VMAT patient, which confirmed necessity for implementation of advanced techniques for as many patients as possible.

scholarly journals A Comparative Study of Auto-contouring Softwares in Delineation of Organs at Risk in Lung Cancer and Rectal Cancer

2021 ◽  
Author(s):  
weijun chen ◽  
Cheng Wang ◽  
Wenming Zhan ◽  
Yongshi Jia ◽  
Fangfang Ruan ◽  
...  
Keyword(s):  
Lung Cancer ◽  
At Risk ◽  
Rectal Cancer ◽  
Organs At Risk ◽  
Similarity Index ◽  
Slight Modification ◽  
Ct Images ◽  
Target Area ◽  
Ct Image ◽  
Significant Difference

Abstract Background:Radiotherapy requires the target area and the organs at risk to be contoured on the CT image of the patient. During the process of organs-at-Risk (OAR) of the chest and abdomen, the doctor needs to contour at each CT image. The delineations of large and varied shapes are time-consuming and laborious.This study aims to evaluate the results of two automatic contouring software on OAR definition of CT images of lung cancer and rectal cancer patients. Methods: The CT images of 15 patients with rectal cancer and 15 patients with lung cancer were selected separately, and the organs at risk were outlined by the same experienced doctor as references, and then the same datasets were automatically contoured based on AiContour®© (Manufactured by Linking MED, China) and Raystation®© (Manufactured by Raysearch, Sweden) respectively. Overlap index (OI), Dice similarity index (DSC) and Volume difference (DV) were evaluated based on the auto-contours, and independent-sample t-test analysis is applied to the results. Results: The results of AiContour®© on OI and DSC were better than that of Raystation®© with statistical difference. There was no significant difference in DV between the results of two software. Conclusions: With AiContour®©, auto-contouring results of most organs in the chest and abdomen are good, and with slight modification, it can meet the clinical requirements for planning. With Raystation®©, auto-contouring results in most OAR is not as good as AiContour®©, and only the auto-contouring results of some organs can be used clinically after modification.

scholarly journals Dosimetric evaluation of three commercial radiotherapy planning systems for lung cancer and nasopharyngeal carcinoma cases

2020 ◽  
Author(s):  
Wan-jia Zheng ◽  
Ming-li Wang ◽  
Jun Zhang ◽  
Yi-mei Liu ◽  
Li Chen ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Spinal Cord ◽  
Nasopharyngeal Carcinoma ◽  
Treatment Time ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Radiotherapy Planning ◽  
Planning Systems ◽  
Significant Difference ◽  
Better Than

Abstract Purpose: To identify planning systems and techniques suitable for different sites tumors by analyzing dosimetric differences using three commercial radiotherapy planning systems: Tomotherapy, Monaco and Eclipse.Methods: We retrospectively analyzed 20 lung cancer and 8 nasopharyngeal carcinoma (NPC), and each patient plans were designed using the three systems. The dose distribution of the target and organs at risk (OARs) were compared, and monitor unit (MU) and treatment time were also evaluated.Results: For lung cancer, mean dose of PGTV, PTV1 and PTV2 in Monaco and Tomo plans were lower than Eclipse plan. PTV2 CI in Monaco and Eclipse plans were better than Tomo plans (p=0.002, p=0.022). Monaco and Tomo plans were better than Eclipse plan regarding to mean dose and V15Gy of lungs; the lowest lungs V20Gy and V30Gy were provided by Tomo plan. The esophagus, heart and SpinalCord_03 dose were lowest in Monaco plan, and the maximum dose and V45Gy of SpinalCord_03 were 592.1cGy and 1.37% lower than Eclipse plan, respectively. For NPC, mean dose of PGTV, PTV1 and PTV2 in Eclipse plan were superior to Tomo plan (p=0.008, p=0.000, p=0.003); PTV2 V95% in Tomo plan was increased by 1.64% than Eclipse plan. There was no significant difference between Monaco and Eclipse plans. Tomo plan showed better spinal cord and brainstem protection, with spinal cord max dose 249.38cGy lower than Eclipse plan and 555cGy lower than Monaco plan, respectively.Conclusion: Although the three plans reflected their respective advantages in different aspects, in general, the Monaco plan (VMAT) was the best choice for lung cancer, and for the more advanced nasopharyngeal carcinoma, the Tomo plan (HT) was superior to the other two plans.

PD-0894 The impact of beam setup on robustness and organs-at-risk dose in IMPT for lung cancer patients

2021 ◽  
Vol 161 ◽  
pp. S733-S734
Author(s):  
S. Visser ◽  
R. Wijsman ◽  
D. Wagenaar ◽  
C.O. Ribeiro ◽  
A. Knopf ◽  
...  
Keyword(s):  
Lung Cancer ◽  
At Risk ◽  
Cancer Patients ◽  
Organs At Risk ◽  
Lung Cancer Patients ◽  
The Impact

scholarly journals Deep inspiration breath-hold intensity modulated radiation therapy in a large clinical series of 239 left-sided breast cancer patients: a dosimetric analysis of organs at risk doses and clinical feasibility from a single center experience

2019 ◽  
Vol 92 (1101) ◽  
pp. 20190150 ◽  
Author(s):  
Alessandro Testolin ◽  
Stefano Ciccarelli ◽  
Giulia Vidano ◽  
Rossella Avitabile ◽  
Francesca Dusi ◽  
...  
Keyword(s):  
At Risk ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Intensity Modulated Radiation Therapy ◽  
Target Volume ◽  
Contralateral Breast ◽  
Breath Hold ◽  
Deep Inspiration ◽  
Breast Cancer Patients ◽  
Deep Inspiration Breath Hold

Objective: To evaluate dose to organs at risk, target coverage and treatment compliance in left-sided breast cancer patients (LSBCP) treated with deep inspiration breath-hold (DIBH) and intensity modulated radiation therapy (IMRT) technique in a contest of daily clinical practice. Methods: A total of 280 consecutive LSBCP referred for adjuvant radiotherapy were systematically screened for suitability of DIBH technique. 239 were able to comply with the requirement for DIBH. Whole breast or chest wall were irradiated in DIBH, monitored by Varian RPM™ Respiratory Gating System, and two tangential inverse-planned beams with dynamic dose delivery. Dose prescription was 42.4 Gy/16 fractions in 205 patients and 50 Gy/25 fractions in 34. 23 patients received local and nodal treatment. Boost to tumor bed, of 10 Gy/5 fractions was used in 135 patients. Relevant dose metrics for heart, left anterior descending (LAD) coronary artery, lungs, contralateral breast and planning target volume were retrospectively analyzed. Results: The average mean heart dose (MHD) for all patients was 0.94 Gy and mean maximum LAD dose was 13.82 Gy. MHD and LAD maximum dose were significantly higher in patients treated with conventional fractionation whether expressed in absolute dose (1.44 vs 0.85 Gy, p < 0.0005 and 20.78 vs 12.45 Gy, p < 0.0005 respectively) or in equivalent doses of 2 Gy fractionation (0.88 vs 0.52 Gy, p =< 0.0005 and 17.68 vs 10.63 Gy, p = 0.0002 respectively). In 57 patients (23.8%) the maximum LAD dose was >20 Gy. Mean V20 ipsilateral lung dose was 8.5%. Mean doses of contralateral breast and lung were 0.13 Gy and 0.09 Gy respectively. Mean planning target volume V95% coverage was 96.1%. Compliance rate of DIBH technique was 84.5% (239/280). Conclusion: DIBH and IMRT in daily clinical practice are feasible in high percentage of unselected patients and allows low levels of irradiation of organs at risk without compromising target coverage. However, despite low MHD a significant proportion of patients receives a maximum LAD dose superior to 20 Gy. Advances in knowledge: The value of MHD used exclusively is not able to describe entirely the risk of late heart toxicity, which can be better evaluated with the joint analysis of the maximum dose to LAD region. The vast majority of LSBCP referred to adjuvant radiotherapy in the setting of routine practice are able to comply with the requirement of DIBH.

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