EVALUATION OF DOSE DELIVERY FOR TOTAL MARROW IRRADIATION USING IMAGING DATA OBTAINED WITH TOMOTHERAPY DEVICE

Loginova A.A.1, Tovmasian D.A1.2., Chernyaev A.P.2, Kobyseva D.A.1,

Lisovskaya A.O.1, Nechesnyuk A.V.1

Fractionated total marrow irradiation and lymphoid irradiation (TMLI) is a highly conformal method of radiotherapy, requiring a high degree of dose delivery accuracy. This study presents a quantitative assessment of the delivered dose while taking into account the influence of daily positioning using one patient receiving TMLI as an example.

Material and methods. Before each treatment session on TomoTherapy preliminary visualization is performed by megavoltage computer tomography (MVCT). The resulting images are used to correct the position of the patient and thereby to minimize the error of dose adjustment. In this study dose was recalculated for each treatment fraction, taking into account the current radiation geometry based on the MVCT images of the patient. The planned and delivered total dose distributions were compared.

Results. The difference between the delivered and planned average dose in target comprising bone marrow and lymphoid tissue was less than 0.5%. The volume of the lungs, receiving a dose of 8 Gy did not exceed 39.3% of the total delivered dose, at the same time the coverage of the targets met prescribed requirements.

Discussion. Appropriate immobilization, visualization with subsequent correction of the patient's position prior to each fraction allowed for reliable and accurate dose delivery. The evaluation of the delivered dose provides opportunity for an objective analysis of the therapy.

Conclusion. The analysis of the delivered dose distribution based on MVCT visualization of the patient's body demonstrated the safety of TMLI method in terms of dose to the organs at risk, as well as the acceptable quality of the target coverage.

 

1 - Dmitry Rogachev National Research Center of Pediatric Hematology,

Oncology and

Immunology.

2 - M.V. Lomonosov Moscow State

University.

Moscow, Russia.

Keywords: TMI, TMLI, TomoTherapy, dose delivery, IMRT, MVCT.

 

Corresponding author: Loginova A.A., e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript

 

For citation: Loginova A.A., Tovmasian D.A., Chernyaev A.P., Kobyseva D.A.,

Lisovskaya A.O., Nechesnyuk A.V. Evaluation of dose delivery for total marrow irradiation using imaging data obtained with tomotherapy device. REJR 2021; 11(1):230-237. DOI: 10.21569/2222-7415-2021-11-1-230-237.

 

 

Received:       11.09.20 Accepted: 01.04.21