Stereotactic body radiotherapy for T1 glottic cancer: dosimetric data in 27 consecutive patients

2021 ◽  
pp. 030089162110004
Author(s):  
Giuseppe Sanguineti ◽  
Raul Pellini ◽  
Antonello Vidiri ◽  
Simona Marzi ◽  
Pasqualina D’Urso ◽  
...  
Keyword(s):  
Stereotactic Body Radiotherapy ◽  
Organs At Risk ◽  
Glottic Cancer ◽  
True Vocal Cord ◽  
Dosimetric Data ◽  
Planning Treatment ◽  
Target Volumes ◽  
Treatment Volume ◽  
Planning Treatment Volume ◽  
Prospective Phase

Aim: Because the clinical feasibility of stereotactic body radiotherapy (SBRT) for early glottic cancer (T1) is controversial, we report dosimetric results in 27 consecutive patients from a prospective phase I and II study that started in 2017. Methods: In our approach, only the parts of the true vocal cord containing cancer and those immediately adjacent are planned to be treated to 36 Gy and 30 Gy, respectively, in 3 fractions. Several dosimetric metrics for both target volumes and organs at risk were extracted from individual plans and results were compared to those achieved by other authors in a similar setting. Results: Proper coverage was reached at planning in 2/3 of planning treatment volume 30 Gy, but only 4 planning treatment volume 36 Gy; conversely, the maximum dose objective was met for most of the patients on either arytenoid cartilage, but this was not the case for 51.9% and 96.3% of cricoid and thyroid cartilages, respectively. Our dosimetric results are similar to if not better than those achieved by others. Conclusion: SBRT in 3 fractions for T1 glottic lesions is dosimetrically challenging. Clinical validation is awaited.

Prostate Planning Treatment Volume Margin Calculation Based on the ExacTrac X-Ray 6D Image-Guided System: Margins for Various Clinical Implementations

2007 ◽  
Vol 69 (3) ◽  
pp. 936-943 ◽  
Author(s):  
Sara Alonso-Arrizabalaga ◽  
Luis Brualla González ◽  
Juan V. Roselló Ferrando ◽  
Jorge Pastor Peidro ◽  
José López Torrecilla ◽  
...  
Keyword(s):  
X Ray ◽  
Image Guided ◽  
Planning Treatment ◽  
Treatment Volume ◽  
Planning Treatment Volume

scholarly journals Setup Accuracy in Craniospinal Irradiation: Implications for Planning Treatment Volume Margins

2021 ◽  
pp. 100747
Author(s):  
Jennifer Novak ◽  
Dongsu Du ◽  
Ashwin Shinde ◽  
Richard Li ◽  
Arya Amini ◽  
...  
Keyword(s):  
Craniospinal Irradiation ◽  
Setup Accuracy ◽  
Planning Treatment ◽  
Treatment Volume ◽  
Planning Treatment Volume

scholarly journals Reduction of inter-observer differences in the delineation of the target in spinal metastases SBRT using an automatic contouring dedicated system

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Niccolò Giaj-Levra ◽  
Vanessa Figlia ◽  
Francesco Cuccia ◽  
Rosario Mazzola ◽  
Luca Nicosia ◽  
...  
Keyword(s):  
Organs At Risk ◽  
Performance Status ◽  
Spinal Metastases ◽  
Dice Similarity Coefficient ◽  
Normal Tissues ◽  
Correct Definition ◽  
Target Definition ◽  
Target Volumes ◽  
Treatment Volume ◽  
Automatic Contouring

Abstract Background Approximately one third of cancer patients will develop spinal metastases, that can be associated with back pain, neurological symptoms and deterioration in performance status. Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) have been offered in clinical practice mainly for the management of oligometastatic and oligoprogressive patients, allowing the prescription of high total dose delivered in one or few sessions to small target volumes, minimizing the dose exposure of normal tissues. Due to the high delivered doses and the proximity of critical organs at risk (OAR) such as the spinal cord, the correct definition of the treatment volume becomes even more important in SBRT treatment, thus making it necessary to standardize the method of target definition and contouring, through the adoption of specific guidelines and specific automatic contouring tools. An automatic target contouring system for spine SBRT is useful to reduce inter-observer differences in target definition. In this study, an automatic contouring tool was evaluated. Methods Simulation CT scans and MRI data of 20 patients with spinal metastases were evaluated. To evaluate the advantage of the automatic target contouring tool (Elements SmartBrush Spine), which uses the identification of different densities within the target vertebra, we evaluated the agreement of the contours of 20 spinal target (2 cervical, 9 dorsal and 9 lumbar column), outlined by three independent observers using the automatic tool compared to the contours obtained manually, and measured by DICE similarity coefficient. Results The agreement of GTV contours outlined by independent operators was superior with the use of the automatic contour tool compared to manually outlined contours (mean DICE coefficient 0.75 vs 0.57, p = 0.048). Conclusions The dedicated contouring tool allows greater precision and reduction of inter-observer differences in the delineation of the target in SBRT spines. Thus, the evaluated system could be useful in the setting of spinal SBRT to reduce uncertainties of contouring increasing the level of precision on target delivered doses.

scholarly journals Optimal planning strategy among various arc arrangements for prostate stereotactic body radiotherapy with volumetric modulated arc therapy technique

2017 ◽  
Vol 51 (1) ◽  
pp. 112-120 ◽  
Author(s):  
Sang Won Kang ◽  
Jin Beom Chung ◽  
Jae Sung Kim ◽  
In Ah Kim ◽  
Keun Yong Eom ◽  
...  
Keyword(s):  
Stereotactic Body Radiotherapy ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Tumor Control ◽  
Tumor Control Probability ◽  
Biological Metrics ◽  
Significant Difference ◽  
Arc Therapy ◽  
Femoral Heads ◽  
Target Volumes

Abstract Background The aim of this study was to determine the optimal strategy among various arc arrangements in prostate plans of stereotactic body radiotherapy with volumetric modulated arc therapy (SBRT-VMAT). Patients and methods To investigate how arc arrangements affect dosimetric and biological metrics, SBRT-VMAT plans for eighteen patients were generated with arrangements of single-full arc (1FA), single-partial arc (1PA), double-full arc (2FA), and double-partial arc (2PA). All plans were calculated by the Acuros XB calculation algorithm. Dosimetric and radiobiological metrics for target volumes and organs at risk (OARs) were evaluated from dosevolume histograms. Results All plans were highly conformal (CI<1.05, CN=0.91) and homogeneous (HI=0.09-0.12) for target volumes. For OARs, there was no difference in the bladder dose, while there was a significant difference in the rectum and both femoral head doses. Plans using 1PA and 2PA showed a strong reduction to the mean rectum dose compared to plans using 1FA and 2FA. Contrastively, the D2% and mean dose in both femoral heads were always lower in plans using 1FA and 2FA. The average tumor control probability and normal tissue complication probability were comparable in plans using all arc arrangements. Conclusions The use of 1PA had a more effective delivery time and produced equivalent target coverage with better rectal sparing, although all plans using four arc arrangements showed generally similar for dosimetric and biological metrics. However, the D2% and mean dose in femoral heads increased slightly and remained within the tolerance. Therefore, this study suggests that the use of 1PA is an attractive choice for delivering prostate SBRT-VMAT.

scholarly journals 455 Proton Beam Therapy in Rectal Cancer: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
M Fok ◽  
S Toh ◽  
J E Maducolil ◽  
H Fowler ◽  
R Clifford ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Proton Beam ◽  
Organs At Risk ◽  
Meta Analysis ◽  
Locally Advanced ◽  
Significant Risk ◽  
Proton Beam Therapy ◽  
Recurrent Rectal Cancer ◽  
Pelvic Bone ◽  
Dosimetric Data

Abstract Introduction Radiotherapy for locally advanced rectal cancer is conventionally performed using photon-based radiotherapy (PBR), carrying significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) potentially delivers equivalent dosimetric radiation to the targeted tissue with improved sparing of OAR. We aimed to compare dosimetric irradiation of OAR for PBT versus PBR in patients with rectal cancer and assess any oncological outcomes. Method An extensive electronic literature search was performed from inception till April 2020 and subsequent meta-analysis performed. Results Six articles met the inclusion criteria. Dosimetric data of irradiation delivered to OAR for PBT and PBR were calculated for the same patients. PBT had significantly less irradiated small bowel compared to 3DCRT and IMRT, (MD -16.95, 95% CI [-24.03, -9.88], p &lt; 0.00001) and (MD -6.96, 95% CI [-12.99, -0.94], p = 0.02) respectively. Similar results were observed for bladder and pelvic bone marrow. Two studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43% and 68%. Conclusions Dosimetric treatment plans have less irradiation of OAR for rectal cancer with PBT compared to PBR. There is a need for further research in PBT and rectal cancer, as promising results have been shown in recurrent rectal cancer.

scholarly journals Investigation of whether in-room CT-based adaptive intracavitary brachytherapy for uterine cervical cancer is robust against interfractional location variations of organs and/or applicators

2016 ◽  
Vol 57 (6) ◽  
pp. 677-683 ◽  
Author(s):  
Yoshifumi Oku ◽  
Hidetaka Arimura ◽  
Tran Thi Thao Nguyen ◽  
Yoshiyuki Hiraki ◽  
Masahiko Toyota ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Radiation Treatment ◽  
Organs At Risk ◽  
Normal Tissue Complication Probability ◽  
Uterine Cervical Cancer ◽  
Intracavitary Brachytherapy ◽  
Conformity Index ◽  
Tumor Control ◽  
Tumor Control Probability ◽  
Target Volumes

Abstract This study investigates whether in-room computed tomography (CT)-based adaptive treatment planning (ATP) is robust against interfractional location variations, namely, interfractional organ motions and/or applicator displacements, in 3D intracavitary brachytherapy (ICBT) for uterine cervical cancer. In ATP, the radiation treatment plans, which have been designed based on planning CT images (and/or MR images) acquired just before the treatments, are adaptively applied for each fraction, taking into account the interfractional location variations. 2D and 3D plans with ATP for 14 patients were simulated for 56 fractions at a prescribed dose of 600 cGy per fraction. The standard deviations (SDs) of location displacements (interfractional location variations) of the target and organs at risk (OARs) with 3D ATP were significantly smaller than those with 2D ATP (P &lt; 0.05). The homogeneity index (HI), conformity index (CI) and tumor control probability (TCP) in 3D ATP were significantly higher for high-risk clinical target volumes than those in 2D ATP. The SDs of the HI, CI, TCP, bladder and rectum D2cc, and the bladder and rectum normal tissue complication probability (NTCP) in 3D ATP were significantly smaller than those in 2D ATP. The results of this study suggest that the interfractional location variations give smaller impacts on the planning evaluation indices in 3D ATP than in 2D ATP. Therefore, the 3D plans with ATP are expected to be robust against interfractional location variations in each treatment fraction.

scholarly journals Hybrid volumetric-modulated arc therapy for postoperative breast cancer including regional lymph nodes: the advantage of dosimetric data and safety of toxicities

2020 ◽  
Vol 61 (5) ◽  
pp. 747-754
Author(s):  
Yoshiko Doi ◽  
Minoru Nakao ◽  
Hideharu Miura ◽  
Shuichi Ozawa ◽  
Masahiro Kenjo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Lymph Nodes ◽  
Irradiation Dose ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Conformity Index ◽  
Regional Lymph Nodes ◽  
Dosimetric Data ◽  
Arc Therapy

ABSTRACT To improve the homogeneity and conformity of the irradiation dose for postoperative breast cancer including regional lymph nodes, we planned Hybrid volumetric-modulated arc therapy (VMAT), which combines conventional tangential field mainly for the chest area and VMAT mainly for the supraclavicular area and marginal zone. In this study, we compared the dosimetric impact between traditional 3D conformal radiotherapy (3DCRT) and Hybrid VMAT and observed toxicities following Hybrid VMAT. A total of 70 patients indicated between October 2016 and December 2017 were included. The prescribed dose was 50 Gy/25 fractions. For the dosimetric impact, 3DCRT and Hybrid VMAT plans were compared in each patient with respect to the dosimetric parameters. Toxicities were followed using the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up duration was 319 days. For the dosimetric impact, the homogeneity index (HI) and conformity index (CI) of PTV were significantly improved in the Hybrid VMAT plan compared with that in the 3DCRT plan (HI, 0.15 ± 0.07 in Hybrid VMAT vs 0.41 ± 0.19 in 3DCRT, P &lt; 0.001; CI, 1.61 ± 0.44 in Hybrid VMAT vs 2.10 ± 0.56 in 3DCRT, P &lt; 0.001). The mean irradiated ipsilateral lung dose was not significantly different in both plans (12.0 ± 2.4 Gy in Hybrid VMAT vs 11.8 ± 2.8 Gy in 3DCRT, P &lt; 0.533). Regarding toxicity, there were no patients who developed ≥grade 3 acute toxicity and ≥grade 2 pneumonitis during the follow-up. Hybrid VMAT for postoperative breast cancer including regional lymph nodes was a reasonable technique that improved the homogeneity and conformity of the irradiation dose to the planning target volume while keeping the irradiation dose to organs at risk to a minimum.

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