Esophageal Delineation: In regard to Kong et al “Consideration of Dose Limits for Organs at Risk of Thoracic Radiotherapy: Atlas for Lung, Proximal Bronchial Tree, Esophagus, Spinal Cord, Ribs, and Brachial Plexus” (Int J Radiat Oncol Biol Phys 2011;81:1442–1457)

2012 ◽  
Vol 83 (2) ◽  
pp. 484-485 ◽  
Author(s):  
Timothy Zagar ◽  
Lawrence Marks
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Brachial Plexus ◽  
Radiat Oncol Biol Phys ◽  
Organs At Risk ◽  
Bronchial Tree ◽  
Thoracic Radiotherapy ◽  
Dose Limits

scholarly journals Impact of cervicothoracic region stereotactic spine radiosurgery on adjacent organs at risk

2017 ◽  
Vol 42 (1) ◽  
pp. E14 ◽  
Author(s):  
Mayur Sharma ◽  
Elizabeth E. Bennett ◽  
Gazanfar Rahmathulla ◽  
Samuel T. Chao ◽  
Hilary K. Koech ◽  
...  
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Radiation Dose ◽  
Brachial Plexus ◽  
Organs At Risk ◽  
Cleveland Clinic ◽  
Compression Fracture ◽  
Target Volume ◽  
Tumor Control ◽  
Radiation Toxicity

OBJECTIVE Stereotactic radiosurgery (SRS) of the spine is a conformal method of delivering a high radiation dose to a target in a single or few (usually ≤ 5) fractions with a sharp fall-off outside the target volume. Although efforts have been focused on evaluating spinal cord tolerance when treating spinal column metastases, no study has formally evaluated toxicity to the surrounding organs at risk (OAR), such as the brachial plexus or the oropharynx, when performing SRS in the cervicothoracic region. The aim of this study was to evaluate the radiation dosimetry and the acute and delayed toxicities of SRS on OAR in such patients. METHODS Fifty-six consecutive patients (60 procedures) with a cervicothoracic spine tumor involving segments within C5–T1 who were treated using single-fraction SRS between February 2006 and July 2014 were included in the study. Each patient underwent CT simulation and high-definition MRI before treatment. The clinical target volume and OAR were contoured on BrainScan and iPlan software after image fusion. Radiation toxicity was evaluated using the common toxicity criteria for adverse events and correlated to the radiation doses delivered to these regions. The incidence of vertebral body compression fracture (VCF) before and after SRS was evaluated also. RESULTS Metastatic lesions constituted the majority (n = 52 [93%]) of tumors treated with SRS. Each patient was treated with a median single prescription dose of 16 Gy to the target. The median percentage of tumor covered by SRS was 93% (maximum target dose 18.21 Gy). The brachial plexus received the highest mean maximum dose of 17 Gy, followed by the esophagus (13.8 Gy) and spinal cord (13 Gy). A total of 14 toxicities were encountered in 56 patients (25%) during the study period. Overall, 14% (n = 8) of the patients had Grade 1 toxicity, 9% (n = 5) had Grade 2 toxicity, 2% (n = 1) had Grade 3 toxicity, and none of the patients had Grade 4 or 5 toxicity. The most common (12%) toxicity was dysphagia/odynophagia, followed by axial spine pain flare or painful radiculopathy (9%). The maximum radiation dose to the brachial plexus showed a trend toward significance (p = 0.066) in patients with worsening post-SRS pain. De novo and progressive VCFs after SRS were noted in 3% (3 of 98) and 4% (4 of 98) of vertebral segments, respectively. CONCLUSIONS From the analysis, the current SRS doses used at the Cleveland Clinic seem safe and well tolerated at the cervicothoracic junction. These preliminary data provide tolerance benchmarks for OAR in this region. Because the effect of dose-escalation SRS strategies aimed at improving local tumor control needs to be balanced carefully with associated treatment-related toxicity on adjacent OAR, larger prospective studies using such approaches are needed.

Normal-tissue toxicities of thoracic radiation therapy: esophagus, lung, and spinal cord as organs at risk

2004 ◽  
Vol 18 (1) ◽  
pp. 131-160 ◽  
Author(s):  
Maria Werner-Wasik ◽  
Xiaoli Yu ◽  
Lawrence B Marks ◽  
Timothy E Schultheiss
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Radiation Therapy ◽  
Normal Tissue ◽  
Organs At Risk ◽  
Thoracic Radiation

scholarly journals Deep inspiration breath hold versus free breathing technique in mediastinal radiotherapy for lymphoma

BJR|Open ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 20200067
Author(s):  
Orla Anne Houlihan ◽  
Guhan Rangaswamy ◽  
Mary Dunne ◽  
Christine Rohan ◽  
Louise O'Neill ◽  
...  
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Clinical Practice ◽  
Organs At Risk ◽  
Free Breathing ◽  
Breath Hold ◽  
Deep Inspiration ◽  
Deep Inspiration Breath Hold ◽  
The Impact

Objective: Radiotherapy plays an important role in the management of lymphoma and many patients with lymphoma are cured with treatment. Risk of secondary malignancy and long-term cardiac and pulmonary toxicity from mediastinal radiotherapy exists. Delivery of radiotherapy using a deep inspiration breath-hold (DIBH) technique increases lung volume and has the potential to reduce dose to heart and lungs. We undertook a prospective study to assess the dosimetric differences in DIBH and free breathing (FB) plans in patients requiring mediastinal radiotherapy in clinical practice. Methods: We performed both FB and DIBH planning scans on 35 consecutive patients with mediastinal lymphoma needing radiotherapy. Contours and plans were generated for both data sets and dosimetric data were compared. All patients were planned using volumetric modulated arc therapy (VMAT). Data were compared for FB and DIBH plans with each patient acting as their own control using the related-samples Wilcoxon signed rank test. Results: DIBH significantly reduced lung doses (mean 10.6 vs 11.4Gy, p < 0.0005; V20 16.8 vs 18.3%, p = 0.001) and spinal cord maximum dose (20.6 vs 22.8Gy, p = 0.001). DIBH increased breast V4 (38.5% vs 31.8%, p = 0.006) and mean right breast dose (4.2 vs 3.6Gy, p = 0.010). There was no significant difference in heart doses when the entire study cohort was considered, however, mean heart dose tended to be lower with DIBH for upper mediastinal (UM) tumours (4.3 vs 4.9Gy, p = 0.05). Conclusion: Our study describes the potential benefit of DIBH in a population reflective of clinical practice. DIBH can decrease radiation dose to lungs, heart and spinal cord, however, may increase dose to breasts. DIBH is not always superior to FB, and the clinical significance of differences in dose to organs at risk in addition to the time required to treat patients with DIBH must be considered when deciding the most appropriate radiotherapy technique for each patient. Advances in knowledge: To our knowledge, this is the largest study comparing DIBH and FB planning for patients with lymphoma receiving mediastinal radiotherapy in clinical practice. It demonstrates the impact of an increasingly common radiotherapy technique on dose to organs at risk and the subsequent potential for long-term radiotherapy side-effects.

scholarly journals Application of dose-volume histogram prediction in biologically related models for nasopharyngeal carcinomas treatment planning

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Wufei Cao ◽  
Yongdong Zhuang ◽  
Lixin Chen ◽  
Xiaowei Liu
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Planning System ◽  
Treatment Planning System ◽  
Dose Volume Histogram ◽  
Parotid Glands ◽  
Dose Volume ◽  
Dose Sparing

Abstract Purpose In this study, we employed a gated recurrent unit (GRU)-based recurrent neural network (RNN) using dosimetric information induced by individual beam to predict the dose-volume histogram (DVH) and investigated the feasibility and usefulness of this method in biologically related models for nasopharyngeal carcinomas (NPC) treatment planning. Methods and materials One hundred patients with NPC undergoing volumetric modulated arc therapy (VMAT) between 2018 and 2019 were randomly selected for this study. All the VMAT plans were created using the Monaco treatment planning system (Elekta, Sweden) and clinically approved: > 98% of PGTVnx received the prescribed doses of 70 Gy, > 98% of PGTVnd received the prescribed doses of 66 Gy and > 98% of PCTV received 60 Gy. Of these, the data from 80 patients were used to train the GRU-RNN, and the data from the other 20 patients were used for testing. For each NPC patient, the DVHs of different organs at risk were predicted by a trained GRU-based RNN using the information given by individual conformal beams. Based on the predicted DVHs, the equivalent uniform doses (EUD) were calculated and applied as dose constraints during treatment planning optimization. The regenerated VMAT experimental plans (EPs) were evaluated by comparing them with the clinical plans (CPs). Results For the 20 test patients, the regenerated EPs guided by the GRU-RNN predictive model achieved good consistency relative to the CPs. The EPs showed better consistency in PTV dose distribution and better dose sparing for many organs at risk, and significant differences were found in the maximum/mean doses to the brainstem, brainstem PRV, spinal cord, lenses, temporal lobes, parotid glands and larynx with P-values < 0.05. On average, compared with the CPs, the maximum/mean doses to these OARs were altered by − 3.44 Gy, − 1.94 Gy, − 1.88 Gy, 0.44 Gy, 1.98 Gy, − 1.82 Gy and 2.27 Gy, respectively. In addition, significant differences were also found in brainstem and spinal cord for the dose received by 1 cc volume with 4.11 and 1.67 Gy dose reduction in EPs on average. Conclusion The GRU-RNN-based DVH prediction method was capable of accurate DVH prediction. The regenerated plans guided by the predicted EUDs were not inferior to the manual plans, had better consistency in PTVs and better dose sparing in critical OARs, indicating the usefulness and effectiveness of biologically related model in knowledge-based planning.

scholarly journals Fully convolutional network-based multi-output model for automatic segmentation of organs at risk in thorax

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110201
Author(s):  
Jie Zhang ◽  
Yiwei Yang ◽  
Kainan Shao ◽  
Xue Bai ◽  
Min Fang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Organs At Risk ◽  
Automatic Segmentation ◽  
Ground Truth ◽  
Convolutional Network ◽  
Fully Convolutional Network ◽  
Bilateral Lung ◽  
The Impact ◽  
Ct Slices

Purpose: To propose a multi-output fully convolutional network (MOFCN) to segment bilateral lung, heart and spinal cord in the planning thoracic computed tomography (CT) slices automatically and simultaneously. Methods: The MOFCN includes two components: one main backbone and three branches. The main backbone extracts the features about lung, heart and spinal cord. The extracted features are transferred to three branches which correspond to three organs respectively. The longest branch to segment spinal cord is nine layers, including input and output layers. The MOFCN was evaluated on 19,277 CT slices from 966 patients with cancer in the thorax. In these slices, the organs at risk (OARs) were delineated and validated by experienced radiation oncologists, and served as ground truth for training and evaluation. The data from 61 randomly chosen patients were used for training and validation. The remaining 905 patients’ slices were used for testing. The metric used to evaluate the similarity between the auto-segmented organs and their ground truth was Dice. Besides, we compared the MOFCN with other published models. To assess the distinct output design and the impact of layer number and dilated convolution, we compared MOFCN with a multi-label learning model and its variants. By analyzing the not good performances, we suggested possible solutions. Results: MOFCN achieved Dice of 0.95  ±  0.02 for lung, 0.91  ±  0.03 for heart and 0.87  ±  0.06 for spinal cord. Compared to other models, MOFCN could achieve a comparable accuracy with the least time cost. Conclusion: The results demonstrated the MOFCN’s effectiveness. It uses less parameters to delineate three OARs simultaneously and automatically, and thus shows a relatively low requirement for hardware and has potential for broad application.

scholarly journals Comparison Between Thermo Luminescence Dosimeter and Planning System Dose Calculation in The Brain and Spinal Cord Tumour

2019 ◽  
Vol 16 (1) ◽  
pp. 272-279
Author(s):  
Ehab A Hegazy
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Direct Measurement ◽  
Organs At Risk ◽  
Dose Calculation ◽  
High Sensitivity ◽  
Target Volume ◽  
Planning System ◽  
Planning Systems ◽  
The Brain

Radiotherapy of Spinal cord and brain tumor requires High care due to considerable changes in the white matter of the brain, which consequently lead to a reduction of patient learning and mental skills. It is considered a very critical tumor due to high sensitivity of gross volume location and normal tissues surrounding it, including eye, heart, plate thyroid, and testis. XiO planning systems, TLD dosimeter found in Mansoura university oncology department, CMS XIO USA TPS were compared using electron and photon beams with different energies at a different site in target volume and organs at risk. We conclude that regular calibration of planning systems and direct measurement of the dose delivered to main target and organs at risk should be done to avoid the difference between XiO planning systems and direct measurement by TLd.

scholarly journals Radiation-related Adverse Effects of CT-guided Implantation of 125I Seeds for Thoracic Recurrent and/or Metastatic Malignancy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhe Ji ◽  
Yuliang Jiang ◽  
Fuxin Guo ◽  
Ran Peng ◽  
Haitao Sun ◽  
...  
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Adverse Effects ◽  
Confidence Interval ◽  
Organs At Risk ◽  
Radiation Dermatitis ◽  
Ct Guided ◽  
Upper Limit ◽  
Iodine 125

Abstract During radioactive Iodine-125 seed implantation (RISI), Iodine-125 radionuclide is implanted directly into a lesion and kills tumor cells by steadily emitting radiation. In our study, we analyzed the adverse effects of RISI for thoracic malignancy, and investigated the safety, dosage, and adverse effects of RISI for these cases. Between June 2007 and January 2018, 77 patients with thoracic recurrent and/or metastatic tumors who underwent CT-guided RISI were enrolled. Radiation-related adverse effects were analyzed, including pneumonia, esophagitis, hemorrhage, fistula, skin injury, heart injury, and spinal cord injury. We used the Common Terminology Criteria for Adverse Events (CTCAE) v4.03 to evaluate adverse effects and analyzed the relationship between adverse effects and dosimetric parameters of organs at risk (OAR), including D0.1cc, D2cc, Dmean, and V20. The results of the study were as follows: The median follow-up period was 11 months. The median postoperative dose (D90) was 122 Gy (45.7–241.8 Gy). Three patients (3.9%) showed radiation pneumonitis of grade ≥2. Two patients (2.6%) showed radiation-induced esophagitis of grade ≥2. One patient (1.3%) showed an esophageal fistula. Two patients (2.6%) had a tracheal fistula. Five patients (6.5%) had radiation-related skin reactions. One patient (1.3%) reported chest wall pain, while three (3.9%) showed hemoptysis. No patients showed radiation myelitis or cardiotoxicity. The mean D2cc of organs at risk were 165.7 Gy (lung), 10.61 Gy (esophagus), 10.25 Gy (trachea), 18.07 Gy (blood vessel), 12.64 Gy (heart), 14.77 Gy (spinal cord), 17.47 Gy (skin). Dosimetric parameters, such as D0.1cc, D2cc and Dmean, were higher in patients with toxic reactions (above the upper limit of 95% confidence interval among the overall data). Chi-square test showed that skin D0.1cc > 600 Gy, D2cc > 500 Gy, and Dmean >90 Gy were associated with grade ≥2 radiation dermatitis (p < 0.05), but no clear dose-toxicity correlation was found in other OARs. So, we concluded that the overall incidence of toxicity and adverse effects from RISI for the treatment of thoracic tumors is low. The dose-toxicity characteristics have not been fully defined. Doses within the upper limit of the 95% confidence interval may be considered safe. This was a retrospective analysis, and follow-up period was minimal, indicating possible limitations of this study.

scholarly journals Comparison of dosimetry in head and neck cancer patients treated with intensity modulated radiation therapy and helical tomotherapy

2021 ◽  
Vol 9 (11) ◽  
pp. 3374
Author(s):  
Yashaswini B. R. ◽  
Kumara Swamy
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Radiation Therapy ◽  
Head And Neck ◽  
Helical Tomotherapy ◽  
Organs At Risk ◽  
Intensity Modulated Radiation Therapy ◽  
Conformity Index ◽  
Homogeneity Index ◽  
Intensity Modulated

Background: This study was conducted to compare dosimetric parameters and dose to specific organs at risk (spinal cord and parotids) between intensity modulated radiation therapy (IMRT) and helical tomotherapy (HT) in head and neck squamous cell carcinomas (HNSCC).Methods: Thirty patients with histologically proven HNSCC were treated with chemo radiotherapy, to a dose of 60-70 Gray in 30-35 fractions. This study consists of two arms; IMRT arm and tomotherapy arm. Fifteen consecutive patients treated under IMRT and 15 patients were treated under helical tomotherapy, along with concurrent chemotherapy. PTV1 encompasses low risk planning target volume (PTV) which receives 50 Gy; PTV2 encompasses intermediate risk PTV which receives 54-60 Gy and PTV3 encompasses high risk PTV which receives 66-70 Gy. After completion of planning, dose to the organs at risk (OARs) and targets, homogeneity index and conformity index were evaluated, and tabulated.Results: On evaluation of plans we found that V95% in PTV1, PTV2 and PTV3 were 91.82%, 96.85% and 90.67% respectively for IMRT and 99.25%, 99.68% and 99.73% respectively for tomotherapy. For PTV3, V110% was 0.11% for IMRT and 0.01% for tomotherapy. Homogeneity index in IMRT arm was 0.285 and it was 0.206 in tomotherapy arm. Conformity index was found to be 1.04 for IMRT plans and 1.06 for tomotherapy plans. When mean dose to contra lateral parotids was evaluated, it was 26.91 Gy in IMRT arm and 25.97 Gy in tomotherapy arm. Max dose to spinal cord was better in tomotherapy (43.07 Gy in IMRT and 34.41 Gy in tomotherapy).Conclusions: There was statistically significant reduction in spinal cord maximum dose and point doses in tomotherapy plans compared to IMRT plans. The decrease in spinal cord dose can increase the tolerance reserve which can be useful in dose escalation or re-irradiation if required. There was also decrease in contra lateral parotid doses (not statistically significant). There was significant improvement in V95% in tomotherapy arm compared to IMRT arm, indicating the significantly superior coverage of target volumes in helical tomotherapy plans compared to IMRT plans. V110% (hot spots) inside the target was very minimal in tomotherapy arm compared to IMRT arm. Conformity index, homogeneity index between two arms were comparable.

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