Quy trình đặt bệnh xạ trị trục não tủy với kỹ thuật điều biến thể tích theo cung tròn bằng máy Truebeam Bệnh viện Ung bướu Thành phố Hồ Chí Minh

2020 ◽  
Author(s):  
Phuong Le Anh
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Radiation Dose ◽  
Organs At Risk ◽  
Recurrence Risk ◽  
Field Size ◽  
External Beam Radiation ◽  
Beam Radiation ◽  
Field Coupling ◽  
Target Volumes

The purpose of external beam radiation therapy is to precisely deliver a specified dose into target volumes, while minimizing radiation dose to at-risk organs (OARs). Radiation therapy requires precision throughout entire process from simulation to planning and administering radiation therapy. Cranial Spinal Irradiation (CSI) is a complex technique, due to the large target volumes and the limited field-size of the accelerator machine, requiring multiple isocenters and coupling fields. The irradiation field coupling must be highly accurate. Setup errors lead to field-overlaping resulting in OARs overdose and recurrence risk due to underdose to target volumes. New radiation techniques which help highly optimizing radiation dose to the target volumes and better protecting organs at risk, even require more accuracy in setting up process. Here, we introduce the patient setting up procedure using for VMAT- CSI process at the TrueBeam machine in Ho Chi Minh City Cancer Hospital.

scholarly journals Strategies to Mitigate Toxicities From Stereotactic Body Radiation Therapy for Spine Metastases

Neurosurgery ◽  
2019 ◽  
Vol 85 (6) ◽  
pp. 729-740 ◽  
Author(s):  
Stephanie K Schaub ◽  
Yolanda D Tseng ◽  
Eric L Chang ◽  
Arjun Sahgal ◽  
Rajiv Saigal ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Stereotactic Body Radiation Therapy ◽  
De Novo ◽  
Organs At Risk ◽  
Performance Status ◽  
Compression Fracture ◽  
Neurological Dysfunction ◽  
External Beam Radiation ◽  
Beam Radiation ◽  
Stereotactic Body Radiation

Abstract Improvements in systemic therapy are translating into more patients living longer with metastatic disease. Bone is the most common site of metastasis, where spinal lesions can result in significant pain impacting quality of life and possible neurological dysfunction resulting in a decline in performance status. Stereotactic body radiation therapy (SBRT) of the spine has emerged as a promising technique to provide durable local control, palliation of symptoms, control of oligoprogressive sites of disease, and possibly augment the immune response. SBRT achieves this by delivering highly conformal radiation therapy to allow for dose escalation due to a steep dose gradient from the planning target volume to nearby critical organs at risk. In our review, we provide an in-depth review and expert commentary regarding seminal literature that defined clinically meaningful toxicity endpoints with actionable dosimetric limits and/or clinical management strategies to mitigate toxicity potentially attributable to SBRT of the spine. We placed a spotlight on radiation myelopathy (de novo, reirradiation after conventional external beam radiation therapy or salvage after an initial course of spinal SBRT), plexopathy, vertebral compression fracture, pain flare, esophageal toxicity, myositis, and safety regarding combination with concurrent targeted or immune therapies.

scholarly journals Comparative Study of Conventional Planning and MRI Based Volume Optimized Planning of Intracavitary Brachytherapy of Cervical Cancer

2020 ◽  
Vol 7 (50) ◽  
pp. 3061-3066
Author(s):  
Niharika Darasani
Keyword(s):  
Cervical Cancer ◽  
At Risk ◽  
Large Volume ◽  
Organs At Risk ◽  
External Beam Radiation ◽  
Intracavitary Brachytherapy ◽  
Target Coverage ◽  
Cancer Cervix ◽  
Beam Radiation ◽  
The Mean

BACKGROUND Cervical cancer is one of the commonest malignancies among women in India. The main stay of treatment is the combination of External Beam Radiation Therapy (EBRT) and Intracavitary Brachytherapy (ICBT) in these patients. We compared conventional point A based treatment planning and MRI based volume optimized planning in ICBT of cervical carcinoma along with doses to organs at risk in both plans. We also compared the radiation doses to organs at risk in both the plans by International Committee on Radiation Units (ICRU) recommended points and dose volume histograms. METHODS Eighteen Patients with cancer cervix (72.22% with stage IIB) received EBRT on linear accelerator by four field technique using 15 MV energy for a dose of 46 Gray (Gy) – 50 Gy in 23-25 fractions 2.0 Gy per fraction, five days per week, for 5 weeks to whole pelvis. Most of the patients received at least three doses of chemotherapy. A total of 50 high-dose rate intracavitary brachytherapy (HDR-ICBT) applications done in 18 patients were used for analysis in the study. Clinical history, gynaecology examination and punch biopsy were undertaken. The patients were assessed during EBRT after 2 weeks, for ICBT application and suitable patients were selected for the procedure. CT based point A planning and MRI based volume optimised planning were done for each ICBT application before intracavity brachytherapy. Contouring of rectum, bladder, right and left femoral heads, and small bowel were done. RESULTS The median age of patients in this study was 50.4 ± 03.25 years. 72.22% (13/18) of the patients were of stage IIB. The mean dose delivered to 90% high-risk clinical target volume (D90- HR-CTV) for all 50 applications by volume optimized planning was 06.87 ± 0.942 Gy. The mean D90-HR-CTV by point A based conventional planning was 13.69 ± 1.06 GY. The mean D100-HR-CTV by volume optimized planning was 05.30 Gy (± 0.20). The mean D100-HR-CTV by point A based conventional planning was 08.91 ± 0.74 Gy. Maximum doses in the bladder and rectum were significantly lower (p<0.05) for MRI planning than for the conventional approach (06.49 GY Vs. 07.45 GY) for bladder; (04.57 GY vs. 05.06 GY) for rectum respectively. Both bladder (D2cc) and rectum (D2cc) doses could be reduced significantly by volume optimization. CONCLUSIONS D90-HR-CTV adequately covered by MRI based volume optimized planning was superior to conventional point A based planning in terms of both conformity of target coverage and evaluation of Organ at Risk (OARs), including the rectum and bladder. Both bladder and rectum doses in the most irradiated 2cc volume are significantly reduced in volume optimized planning. Hence, volume optimized planning would be more beneficial in large volume diseases to get better target coverage at the same time sparing the organs in small volume diseases. Hence, the use of MRI-based volume optimization brachytherapy for patients with large volume tumours with parametrial invasion is beneficial. KEYWORDS Cancer, Cervix, Woman, Radiotherapy, Brachytherapy, EBRT, ICBT, Prognosis

scholarly journals Advantages of 3D-CT Based Conformal Radiotherapy Treatment Planning Over 2D Conventional Tera Six Planning for Cervical Cancer Treatment at Ocean Road Cancer Institute

2020 ◽  
Vol 8 (1) ◽  
pp. 59-68
Author(s):  
Khamis Amour ◽  
Dr. Khamza Maunda ◽  
Dr. Mohamed Mazunga ◽  
Dr. Peane Maleka ◽  
Professor Peter Msaki
Keyword(s):  
Cervical Cancer ◽  
At Risk ◽  
Radiation Therapy ◽  
Cancer Patients ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Planning System ◽  
External Beam Radiation ◽  
Treatment Planning System ◽  
3D Ct

Although External Beam Radiation Therapy (EBRT) is essential tool for the radiation therapy of cervical cancer; only one cancer institute in Tanzania performs 3-Dimensional Conformal Radiation Therapy (3DCRT) Computed Tomography (CT)-based planning. To identify benefits and advantages of 3D-CRT over 2D- conventional radiation therapy (2D-CRT), dosimetric parameters for tumor targets and organs at risk (OARs) were compared between these modalities for 23 cervical cancer patients. 11 cervical cancer patients were CT scanned after proper positioning and immobilization and transferred to Eclipse Treatment Planning System (TPS) for dose planning. The remaining 12 curative intent patients were planned using 2D-CRT system and treatment times were calculated for each patient. From the CT based planning, the minimum dose (D min), maximum dose (D max) and mean dose (D mean) to Planning Target Volume (PTV) and organs at risk (OAR), were compared for each plan. On average, the optimized maximum doses for bladder, rectum, femoral heads, PTV and Gross Tumor Volume (GTV) were 46.56 Gy, 42.65 Gy, 28.76 Gy, 48.56 Gy and 48.53 Gy. For 2D-concentional planning, the dose rate was 75.75 cGy/min and the average treatment time was 1.6075 minutes. This study confirms that 3D CT-based planning is a good choice in the treatment protocol for carcinoma cervix as it delivered a highly homogeneous and conformal plan with superior dose coverage to PTV and better OARs sparing.

Differential vaginal wall dosing in high-dose rate brachytherapy for endometrial cancer: The potential for superior coverage of at-risk areas while preserving organs at risk—An analysis of simulated data.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e17121-e17121
Author(s):  
Dhiraj Sinha ◽  
Kellie Alleyne-Mike ◽  
Sherisse De_four ◽  
Naveen Ratan ◽  
Shashidhar Ramesh
Keyword(s):  
At Risk ◽  
Endometrial Cancer ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Small Sample ◽  
External Beam Radiation ◽  
High Dose ◽  
Beam Radiation ◽  
Data Set ◽  
Risk Areas

e17121 Background: The treatment of curable endometrial cancer (EC)involves surgery with adjuvant radiotherapy. Histology of EC is a major determining factor for intracavitary brachytherapy (ICRT) treatment volume in early stage EC. Many guidelines recommend ICRT treatment of an extended volume up to the whole length of the vaginal stump (VS) for cases of high risk histologies (HRH) wherein a differential dosing of proximal and distal VS has the potential to achieve targeted therapeutic doses to at risk areas without compromise to critical structures.We present a simulated novel way to treat the VS by ICRT in cases of EC with HRH. Analysis of the simulated and approved plans allow us to compare the doses to organs at risk (OAR’s). Methods: Seventy-five cases from July 2017-August 2018 were reviewed and twenty-five (25) met the criteria for inclusion in this study. All these cases received External Beam Radiation Therapy (EBRT) dose of 50.4Gy/28. The ICRT simulation CT data-set was subsequently used to generate the study plan which was then compared to the actual treatment plan. In order to treat the whole VS but spare OARs a club-shaped design was proposed. This technique involved treating the upper 1/3 with a prescription point at 0.5cm lateral to the applicator surface and the lower 2/3 with a prescription point at the applicator surface. The length of the VS was defined from the tip of the applicator to 2cm superior to the introitus. The D2cc values for the contoured bladder and rectum were extracted from the treatment plan and used along with the D2cc values from the EBRT treatment to calculate OAR EQD2. QUANTEC Constraints used were (ICRU 83): EQD2 bladder: 90Gy; EQD2 rectum: 75Gy. Once calculated, the results were analyzed and the percent deviation between the proposed plan and the constraints as well as the approved plan were determined. Results: Twelve (12) of twenty-five (25) cases were HRH cases. The club-shaped design to treat the whole VS didn't further compromise the OAR (EQD2: 22% below constraints) or the rectum (EQD2: 1% below constraints). There was only a 2% difference between the final constraints in both treatment techniques. Conclusions: This technique to treat the full VS length can be used without adversely affecting OAR toxicities with superior coverage to at risk areas while maintaining dose constraints to OAR. Results, however, are limited by the small sample size.

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