Use of specific duodenal dose constraints during treatment planning reduces toxicity after definitive para-aortic radiotherapy for cervical cancer

Objectives: To develop and evaluate a practical automatic treatment planning method for Intensity-Modulated Radiation Therapy (IMRT) in cervical cancer cases. Methods: A novel algorithm named as Optimization Objectives Tree Search Algorithm (OOTSA) was proposed to emulate the planning optimization process and achieve a progressively improving IMRT plan, based on the Eclipse Scripting Application Programming Interface (ESAPI). Thirty previously treated cervical cancer cases were selected from the clinical database and comparison was made between the OOTSA-generated plans and clinical treated plans and RapidPlan-based (RP) plans. Results: In clinical evaluation, compared with plan scores of the clinical plans and the RP plans, 22 and 26 of the OOTSA plans were considered as clinically improved in terms of plan quality, respectively. The average conformity index (CI) for the PTV in the OOTSA plans was 0.86 ± 0.01 (mean ± 1 standard deviation), better than those in the RP plans (0.83 ± 0.02) and the clinical plans (0.71 ± 0.11). Compared with the clinical plans, the mean doses of femoral head, rectum, spinal cord and right kidney in the OOTSA plans were reduced by 2.34 ± 2.87 Gy, 1.67 ± 2.10 Gy, 4.12 ± 6.44 Gy and 1.15 ± 2.67 Gy. Compared with the RP plans, the mean doses of femoral head, spinal cord, right kidney and small intestine in the OOTSA plans were reduced by 3.31 ± 1.55 Gy, 4.25 ± 3.69 Gy, 1.54 ± 2.23 Gy and 3.33 ± 1.91 Gy, respectively. In the OOTSA plans, the mean dose of bladder was slightly increased, with 2.33 ± 2.55 Gy (versus clinical plans) and 1.37 ± 1.74 Gy (versus RP plans). The average elapsed time of OOTSA and clinical planning were 59.2 ± 3.47 min and 76.53 ± 5.19 min. Conclusions: The plans created by OOTSA have been shown marginally better than the manual plans, especially in preserving OARs. In addition, the time of automatic treatment planning has shown a reduction compared to a manual planning process, and the variation of plan quality was greatly reduced. Although improvement on the algorithm is warranted, this proof-of-concept study has demonstrated that the proposed approach can be a practical solution for automatic planning. Advances in knowledge: The proposed method is novel in the emulation strategy of the physicists’ iterative operation during the planning process. Based on the existing optimizers, this method can be a simple yet effective solution for automated IMRT treatment planning.

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Fully Automatic Treatment Planning for External-Beam Radiation Therapy of Locally Advanced Cervical Cancer: A Tool for Low-Resource Clinics

Journal of Global Oncology ◽

10.1200/jgo.18.00107 ◽

2019 ◽

pp. 1-9

Author(s):

Kelly Kisling ◽

Lifei Zhang ◽

Hannah Simonds ◽

Nazia Fakie ◽

Jinzhong Yang ◽

...

Keyword(s):

United States ◽

South Africa ◽

Cervical Cancer ◽

Treatment Planning ◽

South African ◽

The United States ◽

Ct Scans ◽

Low Resource ◽

Fully Automatic ◽

Automatic Treatment

Purpose The purpose of this study was to validate a fully automatic treatment planning system for conventional radiotherapy of cervical cancer. This system was developed to mitigate staff shortages in low-resource clinics. Methods In collaboration with hospitals in South Africa and the United States, we have developed the Radiation Planning Assistant (RPA), which includes algorithms for automating every step of planning: delineating the body contour, detecting the marked isocenter, designing the treatment-beam apertures, and optimizing the beam weights to minimize dose heterogeneity. First, we validated the RPA retrospectively on 150 planning computed tomography (CT) scans. We then tested it remotely on 14 planning CT scans at two South African hospitals. Finally, automatically planned treatment beams were clinically deployed at our institution. Results The automatically and manually delineated body contours agreed well (median mean surface distance, 0.6 mm; range, 0.4 to 1.9 mm). The automatically and manually detected marked isocenters agreed well (mean difference, 1.1 mm; range, 0.1 to 2.9 mm). In validating the automatically designed beam apertures, two physicians, one from our institution and one from a South African partner institution, rated 91% and 88% of plans acceptable for treatment, respectively. The use of automatically optimized beam weights reduced the maximum dose significantly (median, −1.9%; P < .001). Of the 14 plans from South Africa, 100% were rated clinically acceptable. Automatically planned treatment beams have been used for 24 patients with cervical cancer by physicians at our institution, with edits as needed, and its use is ongoing. Conclusion We found that fully automatic treatment planning is effective for cervical cancer radiotherapy and may provide a reliable option for low-resource clinics. Prospective studies are ongoing in the United States and are planned with partner clinics.

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A knowledge-based organ dose prediction tool for brachytherapy treatment planning of patients with cervical cancer

Brachytherapy ◽

10.1016/j.brachy.2020.04.008 ◽

2020 ◽

Vol 19 (5) ◽

pp. 624-634

Author(s):

Tahir I. Yusufaly ◽

Karoline Kallis ◽

Aaron Simon ◽

Jyoti Mayadev ◽

Catheryn M. Yashar ◽

...

Keyword(s):

Cervical Cancer ◽

Treatment Planning ◽

Organ Dose ◽

Prediction Tool ◽

Dose Prediction ◽

Knowledge Based

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Feasibility of MR-alone-based Brachytherapy Treatment Planning Using a Titanium Tandem and Ring Applicator for Cervical Cancer

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2012.07.2150 ◽

2012 ◽

Vol 84 (3) ◽

pp. S803

Author(s):

J. Cai ◽

J. Chino ◽

Y. Qin ◽

T.R. De Oliveira ◽

J. Adamson ◽

...

Keyword(s):

Cervical Cancer ◽

Treatment Planning

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RapidArc treatment planning quality assurance using electronic portal imaging device for cervical cancer

Journal of Radiotherapy in Practice ◽

10.1017/s1460396919000542 ◽

2019 ◽

Vol 19 (2) ◽

pp. 139-144

Author(s):

Hafiz Muhibb ullah Zulkafal ◽

Allah Ditta Khalid ◽

Sajid Anees Minhas ◽

Umair Zafar ◽

Rizwan Hameed ◽

...

Keyword(s):

Cervical Cancer ◽

Quality Assurance ◽

Treatment Planning ◽

Planning System ◽

Electronic Portal Imaging Device ◽

Imaging Device ◽

Portal Imaging ◽

Electronic Portal Imaging ◽

Treatment Plans

AbstractPurpose:The main objective of this study is to assure the quality of cervical cancer treatment plans using an electronic portal imaging device (EPID) in RapidArc techniques.Materials and Methods:Fifteen cases of cervical cancer patients undergoing RapidArc technique were selected to evaluate the quality assurance (QA) of their treatment. The computed tomography (CT) of each patient was obtained with 3-mm-slice thickness and transferred to the Eclipse treatment planning system. The prescribed dose (PD) of 50·4 Gy with 1·8 Gy per fraction to planning target volume (PTV) was used for each patient. The aim of treatment planning was to achieve 95% of PD to cover 97%, and dose to the PTV should not receive 105% of the PD. All RapidArc plans were created using the AAA algorithm and treated on Varian DHX using 6 MV photon beam, with two full arcs. Gamma analysis was used to evaluate the quality of the treatment plans with accepting criteria of 95% at 3%/3 mm.Results:In this study, maximum and average gamma values were 2·53 ± 0·409 and 0·195 ± 0·059 showing very small deviation and indicating the smaller difference between both predicted and portal doses. Gamma Area changes from > 0·8 to > 1·2. SD increased to 5·4% and mean standard error increased to 4·67%.Conclusion:On the basis of these outcomes, we can summarise that the EPID is a useful tool for QA in standardising and evaluating RapidArc treatment plans of cervical cancer in routine clinical practice.

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