scholarly journals Head and neck radiotherapy on the MR linac: a multicenter planning challenge amongst MRIdian platform users

2021 ◽  
Author(s):  
Madalyne Chamberlain ◽  
Jerome Krayenbuehl ◽  
Janita E. van Timmeren ◽  
Lotte Wilke ◽  
Nicolaus Andratschke ◽  
...  
Keyword(s):  
Head And Neck ◽  
Treatment Time ◽  
Organs At Risk ◽  
Wilcoxon Test ◽  
Planning System ◽  
Oropharyngeal Carcinoma ◽  
Delivery Time ◽  
Plan Quality ◽  
Overall Treatment Time ◽  
Number Of Segments

Abstract Purpose Purpose of this study is to evaluate plan quality on the MRIdian (Viewray Inc., Oakwood Village, OH, USA) system for head and neck cancer (HNC) through comparison of planning approaches of several centers. Methods A total of 14 planners using the MRIdian planning system participated in this treatment challenge, centrally organized by ViewRay, for one contoured case of oropharyngeal carcinoma with standard constraints for organs at risk (OAR). Homogeneity, conformity, sparing of OARs, and other parameters were evaluated according to The International Commission on Radiation Units and Measurements (ICRU) recommendations anonymously, and then compared between centers. Differences amongst centers were assessed by means of Wilcoxon test. Each plan had to fulfil hard constraints based on dose–volume histogram (DVH) parameters and delivery time. A plan quality metric (PQM) was evaluated. The PQM was defined as the sum of 16 submetrics characterizing different DVH goals. Results For most dose parameters the median score of all centers was higher than the threshold that results in an ideal score. Six participants achieved the maximum number of points for the OAR dose parameters, and none had an unacceptable performance on any of the metrics. Each planner was able to achieve all the requirements except for one which exceeded delivery time. The number of segments correlated to improved PQM and inversely correlated to brainstem D0.1cc and to Planning Target Volume1 (PTV) D0.1cc. Total planning experience inversely correlated to spinal canal dose. Conclusion Magnetic Resonance Image (MRI) linac-based planning for HNC is already feasible with good quality. Generally, an increased number of segments and increasing planning experience are able to provide better results regarding planning quality without significantly prolonging overall treatment time.

Evaluation on dosimetric plan quality and treatment delivery time of dynamic jaw mode in TomoTherapy® for left-side breast cancer patients

2021 ◽  
pp. 1-8
Author(s):  
Sin Ting Chiu ◽  
Po Man Wu ◽  
Ka Fai Cheng ◽  
Pui Hei Fok ◽  
George Chiu
Keyword(s):  
Breast Cancer ◽  
Treatment Time ◽  
Organs At Risk ◽  
Statistical Significance ◽  
Left Lung ◽  
Delivery Time ◽  
Plan Quality ◽  
Nodal Involvement ◽  
Treatment Delivery ◽  
Supraclavicular Fossa

Abstract Background: Few studies claimed that dynamic jaw (DJ) mode in Helical TomoTherapy® (HT) could improve the cranio-caudal dose distribution without prolonging the treatment time in treating different types of cancer. Also, studies suggested that DJ with a wider 5 cm field width (FW) could replace fixed jaws (FJ) with 2.5 cm FW to reduce the delivery time with the sustainable plan quality. Yet, the study on breast cancer with supraclavicular fossa (SCF) nodal involvement using DJ mode in HT is limited. This study aims to evaluate the DJ mode retrospectively by comparing their dosimetric quality with normal tissue complication probability (NTCP) of organs at risk and treatment delivery time with FJ mode on treating left-side breast with SCF nodal involvement. Materials and methods: All post-mastectomy patients, who had been irradiated for left-side breast with SCF nodal involvement were selected retrospectively in this study. With the same dose constraint and prescription as the treated DJ2.5 plan, two extra plans using DJ mode with 5 cm FW(DJ5.0) and FJ mode with 2.5 cm FW (FJ2.5) were computed for plan comparison. Results: No statistical significance was found in all the parameters of PTV and OARs, except for V20 of whole lung. DJ5.0 received V20 in ipsilateral left lung than FJ2.5 and DJ2.5. However, the average delivery time of DJ5.0 was significantly lower than that of DJ2.5 and FJ2.5 by almost 40%. Conclusions: No statistical significance was found in those dosimetric and radiobiological parameters among three modes while the delivery time has greatly reduced by using DJ5.0. A shorter treatment time can minimise intra-fractional error and better the patient’s experience during treatment.

Altered Fractionation Schedules in Radiotherapy of Head and Neck Cancer. A Review

1992 ◽  
Vol 78 (5) ◽  
pp. 311-325 ◽  
Author(s):  
Carlo Fallai ◽  
Patrizia Olmi
Keyword(s):  
Total Dose ◽  
Head And Neck ◽  
Local Control ◽  
Randomized Trials ◽  
Treatment Time ◽  
Dose Intensity ◽  
Field Size ◽  
Overall Treatment Time ◽  
Altered Fractionation ◽  
Improvement In Survival

The authors review the main contributions of international literature to show the current status in clinical trials on unconventional fractionations of the dose in radiotherapy of head and neck cancers. Several clinical (but only a few randomized) trials have been conducted over the last 15 years using hyperfractionated (HF), accelerated (AF) or mixed (HF-AF) schedules. HF schedules have obtained promising results in terms of local control in comparison with conventional fractionation (CF) of the dose. Improvement in survival was also obtained by the random trials of Pinto and Sanchiz, whereas in EORTC trial no. 22791, the improvement in survival rate was only marginal. A significant increase in local control and, less frequently, in survival has been claimed in several studies using HF-AF. Such data still need to be confirmed by a random study, since EORTC trial 22811 showed superimposable results in comparison with CF. Selection of the most suitable cases for altered fractionation schemes is also being studied in ongoing trials of the EORTC (22851) and RTOG (90-03). As regards acute reactions during and after altered fractionation, they are more severe than after CF. Only pure HF with a dose intensity approximately comparable to CF seems to produce similar acute reactions. Several factors have been found to influence the severity of acute mucosal reactions: interfraction interval, overall treatment time, total dose, and field size. As regards late damage, genuine HF schemes seem to cause roughly equivalent late damage in comparison to CF, whereas high-dose intensity schedules have a higher rate of complications. Interfraction interval, overall treatment time, total dose, fraction size and field size can influence the risk of late sequelae. Before altered fractionations can be considered standard therapy, more data are needed, which should be provided by multicentric randomized trials, some of which are already in progress.

scholarly journals Comparison of Plan Quality and Delivery Time Between Volumetric Arc Therapy (RapidArc) and Gamma Knife Radiosurgery for Multiple Cranial Metastases

Neurosurgery ◽  
2014 ◽  
Vol 75 (4) ◽  
pp. 409-418 ◽  
Author(s):  
Evan M. Thomas ◽  
Richard A. Popple ◽  
Xingen Wu ◽  
Grant M. Clark ◽  
James M. Markert ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Treatment Time ◽  
Radiation Therapy Oncology Group ◽  
Gamma Knife Radiosurgery ◽  
Delivery Time ◽  
Plan Quality ◽  
Volumetric Arc Therapy ◽  
Significant Difference ◽  
Arc Therapy ◽  
Single Isocenter

Abstract BACKGROUND: Volumetric modulated arc therapy (VMAT) has been shown to be feasible for radiosurgical treatment of multiple cranial lesions with a single isocenter. OBJECTIVE: To investigate whether equivalent radiosurgical plan quality and reduced delivery time could be achieved in VMAT for patients with multiple intracranial targets previously treated with Gamma Knife (GK) radiosurgery. METHODS: We identified 28 GK treatments of multiple metastases. These were replanned for multiarc and single-arc, single-isocenter VMAT (RapidArc) in Eclipse. The prescription for all targets was standardized to 18 Gy. Each plan was normalized for 100% prescription dose to 99% to 100% of target volume. Plan quality was analyzed by target conformity (Radiation Therapy Oncology Group and Paddick conformity indices [CIs]), dose falloff (area under the dose-volume histogram curve), as well as the V4.5, V9, V12, and V18 isodose volumes. Other end points included beam-on and treatment time. RESULTS: Compared with GK, multiarc VMAT improved median plan conformity (CIVMAT = 1.14, CIGK = 1.65; P < .001) with no significant difference in median dose falloff (P = .269), 12 Gy isodose volume (P = .500), or low isodose spill (P = .49). Multiarc VMAT plans were associated with markedly reduced treatment time. A predictive model of the 12 Gy isodose volume as a function of tumor number and volume was also developed. CONCLUSION: For multiple target stereotactic radiosurgery, 4-arc VMAT produced clinically equivalent conformity, dose falloff, 12 Gy isodose volume, and low isodose spill, and reduced treatment time compared with GK. Because of its similar plan quality and increased delivery efficiency, single-isocenter VMAT radiosurgery may constitute an attractive alternative to multi-isocenter radiosurgery for some patients.

Higher dose per fraction and shorter overall treatment time using intensity-modulated radiation therapy versus conventional radiation therapy with concurrent carboplatin and 5-fluorouracil for locally advanced oropharyngeal carcinoma: A comparison of toxicity and efficacy

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 6038-6038 ◽  
Author(s):  
S. Clavel ◽  
D. Nguyen ◽  
P. Després ◽  
B. Fortin ◽  
G. Coulombe ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Retrospective Study ◽  
Treatment Time ◽  
Locally Advanced ◽  
Intensity Modulated Radiation Therapy ◽  
Disease Free Survival ◽  
Oropharyngeal Carcinoma ◽  
Overall Treatment Time ◽  
Intensity Modulated ◽  
Dose Per Fraction

6038 Background: The aim of this retrospective study was to compare toxicity and efficacy of two different radiotherapy regimens, the first one using intensity-modulated radiation therapy (IMRT) to that of conventional radiotherapy (CRT) in patients treated with concomitant chemotherapy for locally advanced oropharyngeal cancer. Methods: Between January 2000 and December 2007, 249 patients with stage III-IV squamous cell oropharyngeal carcinoma were treated at our institution with definitive concurrent chemoradiation using carboplatin 70 mg/m2/day for four days and 5-fluorouracil 600 mg/m2/day as a continuous infusion every 3 weeks. One hundred patients had 70 Gy in 33 fractions using IMRT (2.12 Gy per day) and 149 received CRT at 70 gy in 35 fractions (2 Gy per day), both administered five times a week. Toxicities were compared using Fisher's exact test. Overall survival (OS), disease-free survival (DFS), and locoregional control (LRC) were estimated using the Kaplan-Meier method and compared with the log-rank test. Results: Median follow-up was 33 months. Three year actuarial rates for OS, DFS, and LRC were 95.4 vs. 75.8% (p < 0.001), 89.3 vs. 71.6% (p < 0.001), and 92.4 vs. 85.3% (p = 0.050) for IMRT and CRT respectively. To minimize the effect of changes in treatment paradigm over time, analyses were performed for patients treated after January 2004 and still showed OS, DFS, and LRC differences. Comparison of toxicities demonstrated that IMRT was associated with fewer dermatitis than CRT (p < 0.01), but caused the same rates of mucositis, weight loss, enteral feeding, hospitalization and death during treatment. There was significantly less xerostomia at 24 and 36 months (p < 0.001) following the end of treatment with IMRT. Conclusions: In this retrospective study, higher dose per fraction and shorter overall treatment time using IMRT given concurrently with chemotherapy when compared to CRT is a safe regimen with better OS, DFS, LRC, and less long term xerostomia. Altered fractionation RT with chemotherapy seems to result in better outcome and future prospective trials are needed to confirm this hypothesis. No significant financial relationships to disclose.

Volumetric modulated arc therapy: a dosimetric comparison with dynamic IMRT and step-and-shoot IMRT

2019 ◽  
Vol 19 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Payal Raina ◽  
Sudha Singh ◽  
Rajanigandha Tudu ◽  
Rashmi Singh ◽  
Anup Kumar
Keyword(s):  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Delivery Time ◽  
Arc Therapy ◽  
Step And Shoot

AbstractAim:The aim of this study was to compare volumetric modulated arc therapy (VMAT) with dynamic intensity-modulated radiation therapy (dIMRT) and step-and-shoot IMRT (ssIMRT) for different treatment sites.Materials and methods:Twelve patients were selected for the planning comparison study. This included three head and neck, three brain, three rectal and three cervical cancer patients. Total dose of 50 Gy was given for all the plans. Plans were done for Elekta synergy with Monaco treatment planning system. All plans were generated with 6 MV photons beam. Plan evaluation was based on the ability to meet the dose volume histogram, dose homogeneity index, conformity index and radiation delivery time, and monitor unit needs to deliver the prescribed dose.Results:The VMAT and dIMRT plans achieved the better conformity (CI98% = 0·965 ± 0·023) and (CI98% = 0·939 ± 0·01), respectively, while ssIMRT plans were slightly inferior (CI98% = 0·901 ± 0·038). The inhomogeneity in the planning target volume (PTV) was highest with ssIMRT with HI equal to 0·097 ± 0·015 when compared to VMAT with HI equal to 0·092 ± 0·0369 and 0·095 ± 0·023 with dIMRT. The integral dose is found to be inferior with VMAT 105·31 ± 53·6 (Gy L) when compared with dIMRT 110·75 ± 52·9 (Gy L) and ssIMRT 115 38 ± 55·1(Gy L). All the techniques respected the planning objective for all organs at risk. The delivery time per fraction for VMAT was much lower than dIMRT and ssIMRT.Findings:Our results indicate that dIMRT and VMAT provide better sparing of normal tissue, homogeneity and conformity than ssIMRT with reduced treatment delivery time.

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