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Showing 3 results for Helical Tomotherapy.
Ph.d., M. Okutan, A. Franko, C. Köksal, E.o. Göksel, Ş. Karaman, Y. Emre Akpınar, N. Dağoğlu, B. Demir,
Volume 18, Issue 4 (10-2020)
Abstract
Background: Radiation Pneumonia (RP) is one of the most extensive side effects in Stereotactic Body Radiotherapy (SBRT) of lung cancer. SBRT are performed by means of Intensity Modulated Radiotherapy (IMRT), Intensity Modulated Arc Therapy (IMAT), CyberKnife (CK) or Helical Tomotherapy (HT) treatment methods. In this study, we performed a plan study to determine the plan parameter such as the Mean Lung Dose (MLD), V20Gy Lung Volume and V5Gy Lung Volume in the evaluation of RP risk in the treatment of lung with SBRT. Materials and Methods: Fifteen patients with Lung Cancer who had a tumor diameter of less than 5 cm and peripheral located were included to this study. Intensity Modulated Radiotherapy, Intensity Modulated Arc Therapy, CyberKnife and Helical Tomotherapy plans were separately created for each patients. For each plan, a total of 54 Gy dose were given to Planning Target Volume (PTV) in 3 fractions using a dose of 18 Gy per fraction. Results: In each technique for all parameters of PTV and critical organ doses (OAR) meet the required criteria. Total Lung MLD were found as 3.21 Gy and Total Lung V20Gy Volume were found as 4.05 cc, Total Lung V5Gy Volume were found as 14.06 cc as the lowest value in IMRT-SBRT plan. Conclusion: When treatment plans are evaluated in terms of RP risk, Total Lung MLD, Total Lung V20Gy Volume and Contralateral Lung V5Gy Volume are found the lower in IMRT- SBRT plan than other SBRT techniques. We suggest that IMRT-SBRT irradiation should be preferred in lung radiotherapy in case of high RP risk.
A. Watcharawipha, M.d., I. Chitapanarux, B. Jia-Mahasap,
Volume 20, Issue 3 (7-2022)
Abstract
Background: The Helical Tomotherapy (HT) technique has been introduced for use in Stereotactic Radiosurgery (SRS). Previously, the smallest field width (FW) has been recommended for optimum results, which would require a long beam-on time (BoT). The uncertainty of the intrafraction could be maximized during the delivery by this BoT. This study then investigated the plan qualities and dosimetric parameters among different FWs and treatment modes. Materials and Methods: Fifteen patients previously treated by the HT technique with fixed-FW 10 mm (FW10f) were selected. The treatment planning systems of TomoTherapy involved other plans that employed fixed-FW 25 mm (FW25f) and dynamic-FW 25 mm (FW25d). The plan quality indexes and the dosimetric parameters of the large FWs (FW 25 mm) were compared according to the FW10f benchmark and then analyzed by relevant statistics. Results: The plan quality indexes and the dosimetric parameters revealed no significant differences between FW10f and FW25d. Accordingly, FW25f revealed a significant difference in the FW10f values in some indexed parameters. The maximum dose on the right optic nerves and the value of the integral dose revealed a significant difference between FW10f and FW25f. The BoT of the FW10f presented the longest treatment time when compared with the other FWs. Conclusion: The outcomes of this investigation clearly ensure that the performance of FW25d is comparable with that of FW10f in terms of the plan qualities and the dosimetric parameters. Notably, the short BoT of this FW might benefit the minimization that is associated with intrafraction uncertainty.
N. Monadi, Ph.d., D. Shahbazi-Gahrouei, S. Monadi, L. Mahani, A. Shams, A. Akhavan, R. Mohammadi,
Volume 21, Issue 3 (7-2023)
Abstract
Background: This study aims to evaluate and compare Three-Dimensional Conformal Radiotherapy (3D-CRT) versus Helical Tomotherapy (HT) based on treatment planning and selection of the most appropriate method to reduce side effects. Materials and Methods: Treatment planning was performed on images of 20 patients with head and neck cancer with lymph node involvement by HT and 3D-CRT techniques in Seyed Al-Shohada hospital, Isfahan, Iran. The quality of target coverage, the exposure of normal tissue, and radiation delivery efficiency in two studied methods were compared. Results: Tomotherapy showed significant improvement over 3D-CRT in terms of D2%, D50% Dmean, V95%, CI (conformity index), and HI (homogeneity index) for PTV (planning target volume) and in terms of D2%, D98%, Dmean, V95%, CI and HI for PTV Nodal. The mean dose received by 98% of PTV (D98%) increased in HT compared to 3D-CRT. Whereas, higher doses received in organs at risk (OARs) in 3D-CRT compared to HT. Conclusion: Results showed improvements in target quality for HT over 3D-CRT, including dosimetric coverage of target volumes, homogeneity and conformity indices, and reduction of the volume of cold and hot spots. Tomotherapy also performed better than that of 3D-CRT in OARs. Overall, with the satisfactory results obtained here, HT technique has considerable promise for treating head and neck cancers with the involvement of regional lymph nodes.
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