Reassessment of the lung dose limits for radioembolization

PurposeThe purpose of this study is to investigate whether there are predictors and cutoff points that can predict the acceptable lung dose using intensity-modulated radiation therapy (IMRT) and volume-modulated arc therapy (VMAT) in radiotherapy for upper ang middle esophageal cancer.Material and MethodsEighty-two patients with T-shaped upper-middle esophageal cancer (UMEC) were enrolled in this retrospective study. Jaw-tracking IMRT plan (JT-IMRT), full-arc VMAT plan (F-VMAT), and pactial-arc VMAT plan (P-VMAT) were generated for each patient. Dosimetric parameters such as MLD and V20 of total lung were compared among the three plannings. Ten factors such as PCTVinferior length and PCTVinferior length/total lung length were calculated to find the predictors and cutoff points of the predictors. All patients were divided into two groups according to the cutoff points, and the dosimetric differences between the two groups of the three plans were compared. ANOVA, receiver operating characteristic (ROC) analysis, and Mann–Whitney U-test were performed for comparisons between datasets. A p <0.05 was considered statistically significant.ResultThe quality of the targets of the three plannings was comparable. The total lung dose in P-VMAT was significantly lower than that in JT IMRT and F-VMAT. Monitor unit (MU) of F-VMAT and P-VMAT was significantly lower than that of JT IMRT. ROC analysis showed that among JT IMRT, F-VMAT, and P-VMAT, PCTVi-L, and PCTVi-L/TLL had diagnostic power to predict the suitability of RT plans according to lung dose constraints of our department. For JT IMRT, the cutoff points of PCTVi-L and PCTVi-L/TLL were 16.6 and 0.59. For F-VMAT, the cutoff points of PCTVi-L and PCTVi-L/TLL were 16.75 and 0.62. For P-VMAT, the cutoff points of PCTVi-L and PCTVi-L/TLL were 15.15 and 0.59. After Mann–Whitney U-test analysis, it was found that among the three plannings, the group with lower PCTVi-L and PCTVi-L/TLL could significantly reduce the dose of total lung and heart (p <0.05).ConclusionPCTVi-L <16.6 and PCTVi-L/TLL <0.59 for JT IMRT, PCTVi-L <16.75 and PCTVi-L/TLL <0.62 for F-VMAT and PCTVi-L <15.15, and PCTVi-L/TLL <0.59 for P-VMAT can predict whether patients with T-shaped UMEC can meet the lung dose limits of our department.

Download Full-text

EVALUATION OF OCCUPATIONAL RADIATION EXPOSURE IN A RADIO-DIAGNOSTIC FACILITY IN KATSINA- NIGERIA

FUDMA Journal of Sciences ◽

10.33003/fjs-2020-0402-406 ◽

2020 ◽

Vol 4 (2) ◽

pp. 722-729

Author(s):

Usman Sani ◽

Bashir Gide Muhammad ◽

Dimas Skam Joseph ◽

D. Z. Joseph

Keyword(s):

Radiation Dose ◽

Radiation Exposure ◽

Short Exposure ◽

Skin Dose ◽

Continuous Training ◽

Short Exposure Time ◽

Occupational Dose ◽

Dose Limits ◽

Radiation Workers ◽

Occupational Radiation

Poor implementation of quality assurance programs in the radiation industry has been a major setback in our locality. Several studies revealed that occupational workers are exposed to many potential hazards of ionizing radiation during radio-diagnostic procedures, yet radiation workers are often not monitored. This study aims to evaluate the occupational exposure of the radiation workers in Federal Medical Centre Katsina, and to compare the exposure with recommended occupational radiation dose limits. The quarterly readings of 20 thermo-luminescent dosimeters (TLDs') used by the radiation workers from January to December, 2019 were collected from the facility's radiation monitoring archive, and subsequently assessed and analyzed. The results indicate that the average annual equivalent dose per occupational worker range from 0.74 to 1.20 mSv and 1.28 to 2.21 mSv for skin surface and deep skin dose, measured at 10 mm and 0.07 mm tissue depth respectively. The occupational dose was within the recommended national and international limits of 5 mSv per annum or an average of 20 mSv in 5 years. Therefore, there was no significant radiation exposure to all the occupational workers in the study area. Though, the occupational radiation dose is within recommended limit, this does not eliminate stochastic effect of radiation. The study recommended that the occupational workers should adhere and strictly comply with the principles of radiation protection which includes distance, short exposure time, shielding and proper monitoring of dose limits. Furthermore, continuous training of the radiation workers is advised.

Download Full-text

Comparison between different boost dose delivery techniques to the tumor bed of right sided breast cancer patients.

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v13i1.5644 ◽

2017 ◽

Vol 13 (1) ◽

pp. 4605-4617

Author(s):

Aly Mahmoud El-Hdidy

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Target Location ◽

Breast Cancer Patients ◽

Photon Beams ◽

Lung Dose ◽

Dose Volume Histograms ◽

Tumor Bed ◽

Boost Dose ◽

Treatment Plans

Comparisons between three different techniques by which the boost dose was delivered to the tumor bed were carried out , aiming to present the best technique of treatment for right breast cancer patients.In this study, ten right sided breast cancer computed tomography (CT) scans were selected for ten early right breast cancer patients. We made three different treatment plans for each patient CT using three different irradiation techniques to deliver a prescribed boost dose of 10 Gy in 5 fractions to the boost PTV. In the first technique, two tangential photon beams were used, in the second technique we, two oblique photon beams were used and in the third technique, a single electron beam was used. The comparative analyses between the three techniques were performed by comparing the boost PTV- dose volume histograms (DVHs), the ipsilateral breast (right breast) DVHs, the ipsilateral lung (right lung) DVHs and the heart DVHs of the three techniques for each patient. Furthermore the dose that covering 100% , 95% of the volume (D100% , D95%) and the volume covered by 95% of the dose (V95%)ofÂ the boost PTV of all techniques, were calculated for each patient to investigate the dose coverage of the target.Results showed that there were variations of the dose received by tumor bed, right breast and OARs depending on the technique used and the target location and size. A decrease of D100% than 90% of the prescribed dose was observed with the 3rd technique for patients 8, 9 and 10, and was observed with the 2nd technique for patient 5. A reduction of right breast dose was observed when the 3rd technique was use in comparison with the 1st and the 2nd techniques for patients 1, 2, 3, 4, 6 and 8.Â Also reduction of right breast was observed when the 2nd technique used in comparison with 1st technique. An increase of lung dose was observed with the 3rd technique for patients 1, 2, 5 and 6, also was observed with 2nd technique in patient 3, 5 and 7. A decrease of lung dose was observed with the 1st technique for patients 2, 4, 5, 6, 7, 8 and 9An individualized treatment, several plans using different irradiation techniques should be developed for each patient individually to reach the best boost PTV dose coverage with minimal OARsâ€™ dose.Â

Download Full-text

P2.01-47 Ipsilateral Lung Dose Constraints Predict Radiation Pneumonitis Better Than Conventional Ones in NSCLC Patients Treated with RCT

Journal of Thoracic Oncology ◽

10.1016/j.jtho.2019.08.1390 ◽

2019 ◽

Vol 14 (10) ◽

pp. S657

Author(s):

E. Korkmaz Kıraklı ◽

S. Erdem ◽

E. Erim ◽

D. Yalman

Keyword(s):

Radiation Pneumonitis ◽

Lung Dose ◽

Ipsilateral Lung ◽

Dose Constraints ◽

Nsclc Patients ◽

Better Than

Download Full-text

Use of Continuous Positive Airway Pressure (CPAP) to Limit Diaphragm Motion—A Novel Approach for Definitive Radiation Therapy for Inoperable Pleural Mesothelioma: A Pilot Study

Biology ◽

10.3390/biology10080711 ◽

2021 ◽

Vol 10 (8) ◽

pp. 711

Author(s):

Assaf Moore ◽

Marc J. Kindler ◽

Aaron Max Allen

Keyword(s):

Pilot Study ◽

Static Field ◽

Normal Lung ◽

Pleural Mesothelioma ◽

Lung Dose ◽

Lung Inflation ◽

Novel Approach ◽

Recent Developments ◽

Ct Simulation ◽

Dose Constraints

Malignant pleural mesothelioma (MPM) is a deadly disease and radiotherapy (RT) plays an important role in its management. Recent developments in technique have made it is possible to deliver RT to MPM in the intact lung. However, it is imperative to reduce normal lung doses. We present a pilot study examining the use of CPAP and VMAT radiotherapy to reduce toxicity when treating MPM, involving three consecutive patients with MPM, not amenable to surgery, who were treated according to Helsinki committee approval. Patients were simulated using four-dimentional CT simulation with the assistance of CPAP lung inflation, then were treated using both IMRT and VMAT techniques. Radiation lung dose was optimized based on accepted lung dose constraints. Patients were followed for toxicity as well as local control and survival. Results: Three patients were treated with CPAP-based IMRT treatment. These patients tolerated the treatment and DVH constraints were able to be met. The comparison plans among the four VMAT arcs and the IMRT static field treatment were able to accomplish the treatment planning objectives without significant advantages with either technique. The treatment combined with CPAP reduced the normal lung dose in MPM patients with intact lungs. This technique is worthy of further investigation.

Download Full-text

PO-0999 Functional Avoidance planning allows for lung dose reduction in radiotherapy of lung cancer

Radiotherapy and Oncology ◽

10.1016/s0167-8140(19)31419-7 ◽

2019 ◽

Vol 133 ◽

pp. S550-S551

Author(s):

K. Farr ◽

K. West ◽

R. Yeghiaian-Alvandi ◽

D. Farlow ◽

R. Stensmyr ◽

...

Keyword(s):

Lung Cancer ◽

Dose Reduction ◽

Lung Dose

Download Full-text

Clinicians Often Unaware of Colchicine Dose Limits; What is a “Bolus?”; Drug Information Leaflets can Help Prevent Errors

Hospital Pharmacy ◽

10.1177/001857870203700402 ◽

2002 ◽

Vol 37 (4) ◽

pp. 355-356

Author(s):

Michael R. Cohen

Keyword(s):

Health Care ◽

Medication Errors ◽

Training Programs ◽

Drug Information ◽

Health Care Facilities ◽

Inservice Training ◽

Safe Medication ◽

Information Leaflets ◽

Care Facilities ◽

Dose Limits

These medication errors have occurred in health care facilities at least once. They will happen again—perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them in your inservice training programs. Your assistance is required to continue this feature. The reports described here were received through the USP Medication Errors Reporting Program, which is presented in cooperation with the Institute for Safe Medication Practices. If you have encountered medication errors and would like to report them, you may call USP toll-free, 24 hours a day, at 800-233-7767 (800-23-ERROR). Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below.

Download Full-text