scholarly journals A novel external beam radiotherapy method for cervical cancer patients using virtual straight or bending boost areas; an in-silico feasibility study

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Luca Cozzi ◽  
Sushil Beriwal ◽  
Esa Kuusela ◽  
Supriya Chopra ◽  
Hester Burger ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
At Risk ◽  
Organs At Risk ◽  
External Beam Radiotherapy ◽  
Locally Advanced ◽  
Target Volume ◽  
Cervix Uteri ◽  
External Beam ◽  
Dose Volume Histograms ◽  
Variable Position

Abstract Aim To investigate the potential role of a novel spatially fractionated radiation therapy (SFRT) method where heterogeneous dose patterns are created in target areas with virtual rods, straight or curving, of variable position, diameter, separation and alignment personalised to a patient’s anatomy. The images chosen for this study were CT scans acquired for the external beam part of radiotherapy. Methods Ten patients with locally advanced cervical cancer were retrospectively investigated with SFRT. The dose prescription was 30 Gy in 5 fractions to 90% target volume coverage. Peak-and-valley (SFRT_1) and peak-only (SFRT_2) strategies were applied to generate the heterogeneous dose distributions. The planning objectives for the target (CTV) were D90% ≥ 30 Gy, V45Gy ≥ 50–55% and V60Gy ≥ 30%. The planning objectives for the organs at risk (OAR) were: D2cm3 ≤ 23.75 Gy, 17.0 Gy, 19.5 Gy, 17.0 Gy for the bladder, rectum, sigmoid and bowel, respectively. The plan comparison was performed employing the quantitative analysis of the dose-volume histograms. Results The D2cm3 was 22.4 ± 2.0 (22.6 ± 2.1) and 13.9 ± 2.9 (13.2 ± 3.0) for the bladder and the rectum for SFRT_1 (SFRT_2). The results for the sigmoid and the bowel were 2.6 ± 3.1 (2.8 ± 3.0) and 9.1 ± 5.9 (9.7 ± 7.3), respectively. The hotspots in the target volume were V45Gy = 43.1 ± 7.5% (56.6 ± 5.6%) and V60Gy = 15.4 ± 5.6% (26.8 ± 6.6%) for SFRT_1 (SFRT_2). To account for potential uncertainties in the positioning, the dose prescription could be escalated to D90% = 33–35 Gy to the CTV without compromising any constraints to the OARs Conclusion In this dosimetric study, the proposed novel planning technique for boosting the cervix uteri was associated with high-quality plans, respecting constraints for the organs at risk and approaching the level of dose heterogeneity achieved with routine brachytherapy. Based on a sample of 10 patients, the results are promising and might lead to a phase I clinical trial.

scholarly journals The Relationship Between Late Morbidity and Dose–Volume Parameter of Rectum in Combined Intracavitary/Interstitial Cervix Cancer Brachytherapy: A Mono-Institutional Experience

2021 ◽  
Vol 11 ◽  
Author(s):  
Ning Zhang ◽  
Ying Liu ◽  
Dongmei Han ◽  
Xin Guo ◽  
Zhuang Mao ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
At Risk ◽  
Clinical Target Volume ◽  
Organs At Risk ◽  
Locally Advanced ◽  
Probit Model ◽  
Target Volume ◽  
Advanced Cervical Cancer ◽  
Locally Advanced Cervical Cancer ◽  
Dose Volume

PurposeTo establish a dose volume–effect relationship for predicting late rectal complication (LRC) in locally advanced cervical cancer patients treated with external beam radiotherapy (EBRT) followed by combined intracavitary/interstitial brachytherapy (IC/IS-BT).Materials and MethodsA retrospective analysis was performed in 110 patients with locally advanced cervical cancer who underwent definitive radiotherapy combined with IC/IS-BT from July 2010 to September 2018. We report the 90% of the target volume receiving the minimum dose for high risk clinical target volume (HR-CTV D90) and intermediate risk clinical target volume (IR-CTV D90), and the minimum doses to the most exposed 0.1, 1, and 2 cm³ D0.1cm3,D1cm3,D2cm3 doses at the International Commission on Radiation Units and Measurements (DICRU) for organs at risk (OARs). The total dose of EBRT plus brachytherapy was transformed to the biologically equivalent dose in 2 Gy fractions (EQD2) with α/β value of 10 Gy for target, 3 Gy for organs at risk using the linear quadratic model. The morbidity was scored according to the Radiation Therapy Oncology Group (RTOG) criteria. The Probit model was used to establish a prediction model on rectum between the organs at risk for dose and LRC. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of dose volume parameters for LRC.ResultsThe median follow-up time was 72.3 months. The mean ( ± standard deviation) D2cm3,D1cm3,D0.1cm3, and DICRU values of rectum were 64.72 ± 7.47 GyEQD2, 70.18 ± 5.92 GyEQD2, 79.32 ± 7.86 GyEQD2, and 67.22 ± 7.87 GyEQD2, respectively. The Probit model showed significant relationships between D1cm3 or D0.1cm3, and the probability of grade1–4, grade 2–4 rectal events at 1 year, and between D1cm3and the probability of grade2–4 rectal events at 3 and 5 years. The dose values for 10% complication rates (ED10) of D1cm3were 74.18 (70.42–76.71) GyEQD2, 67.80 (59.91, 71.08) GyEQD2, 66.37 (52.00, 70.27) GyEQD2 for grade 2–4 with rectal morbidity at 1, 3, and 5 years, respectively.ConclusionOur study proved that D1cm3 andD0.1cm3were considered as useful dosimetric parameters for predicting the risk of grade1–4 and grade2–4 LRC at 1-year, and D1cm3might be an indicator for predicting grade2-4 LRC at 3/5years. The patients with rectal D1cm3>66.37–74.18 GyEQD2 should be closely observed for grade2–4 LRC.

A PROSPECTIVE RANDOMIZED STUDY TO COMPARE THE CONCURRENT CHEMO-RADIATION VERSUS HYPO-FRACTIONATED CHEMO-RADIATION IN LOCALLY ADVANCED CERVICAL CANCER.

2021 ◽  
pp. 40-42
Author(s):  
Arpan Jana ◽  
Pabitra Das ◽  
Poulami Gupta ◽  
Phalguni Gupta
Keyword(s):  
Cervical Cancer ◽  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
External Beam Radiotherapy ◽  
Locally Advanced ◽  
Intracavitary Brachytherapy ◽  
External Beam ◽  
Carcinoma Cervix ◽  
Advanced Carcinoma

Background: Concurrent chemo-radiation is the standard treatment worldwide for locally advanced squamous Cell carcinoma cervix. However, conventional chemo-radiotherapy is also associated with unacceptable local and systemic failure rates for locally advanced disease. Biologically squamous cell carcinoma of head- neck cancer and cervical cancer behaves quite similarly in response to radiotherapy. So, it can be expected that, altered fractionation can increase the local control in case of squamous cell carcinoma cervix than conventional radiotherapy. There is no randomised control trial for carcinoma cervix till date, which compares conventional chemo-radiation with hypo-fractionated chemo-radiation. Aims And Objectives: The present study was planned to compare local disease control and acute toxicity of conventional chemo-radiation with hypo-fractionated chemo-radiation in locally advanced carcinoma cervix. Materials And Methods: In Conventional Chemo-radiation Arm A patients (n=30) received external beam radiotherapy 50 Gy in 25 fractions in 5 weeks accompanied by weekly intravenous Cisplatin 40mg/m2 followed by intracavitary brachytherapy 7 Gy per fraction once in a week for 3 weeks. The second group of hypo-fractionated Arm B received external beam radiotherapy 45 Gy in 20 fractions in 4 weeks accompanied by weekly intravenous Cisplatin 40mg/m2 followed by intracavitary brachytherapy 9 Gy per fraction once in a week for 2 weeks. Results: Grade II diarrhea were seen more in Arm B 17 (56.66%) compare to Arm A 12(40%) and grade III diarrhea was seen 4 (3.33%) in Arm B and 2(6.66%) in Arm A. At 2 months and 6 months after completion of treatment Complete response were 25 (83.4%) in Arm A compare to 22 (73.3%) in Arm B and 20 (74.1%) in Arm A and 18 (72%) in Arm B respectively. Conclusion: Hypo-fractioned radiotherapy may be used as an alternate protocol for treatment of locally advanced carcinoma cervix with acceptable toxicities.

scholarly journals Clinical Validation and Treatment Plan Evaluation Based on Auto-Delineation of the Clinical Target Volume for Prostate Cancer Radiotherapy

2022 ◽  
Author(s):  
Jing Shen ◽  
Yinjie TAO ◽  
Hui GUAN ◽  
Hongnan ZHEN ◽  
Lei HE ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
At Risk ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Statistical Significance ◽  
Locally Advanced ◽  
Target Volume ◽  
Ct Scans ◽  
Dice Similarity Coefficient ◽  
Treatment Plans

Abstract Purpose Clinical target volumes (CTV) and organs at risk (OAR) could be auto-contoured to save workload. The goal of this study was to assess a convolutional neural network (CNN) for totally automatic and accurate CTV and OAR in prostate cancer, while also comparing anticipated treatment plans based on auto-contouring CTV to clinical plans. Methods From January 2013 to January 2019, 217 computed tomography (CT) scans of patients with locally advanced prostate cancer treated at our hospital were collected and analyzed. CTV and OAR were delineated with a deep learning based method, which named CUNet. The performance of this strategy was evaluated using the mean Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (95HD), and subjective evaluation. Treatment plans were graded using predetermined evaluation criteria, and % errors for clinical doses to the planned target volume (PTV) and organs at risk(OARs) were calculated. Results The defined CTVs had mean DSC and 95HD values of 0.84 and 5.04 mm, respectively. For one patient's CT scans, the average delineation time was less than 15 seconds. When CTV outlines from CUNetwere blindly chosen and compared to GT, the overall positive rate in clinicians A and B was 53.15% vs 46.85%, and 54.05% vs 45.95%, respectively (P>0.05), demonstrating that our deep machine learning model performed as good as or better than human demarcation Furthermore, 8 testing patients were chosen at random to design the predicted plan based on the auto-courtoring CTV and OAR, demonstrating acceptable agreement with the clinical plan: average absolute dose differences of D2, D50, D98, Dmean for PTV are within 0.74%, and average absolute volume differences of V45, V50 for OARs are within 3.4%. Without statistical significance (p>0.05), the projected findings are comparable to clinical truth. Conclusion The experimental results show that the CTV and OARs defined by CUNet for prostate cancer were quite close to the ground reality.CUNet has the potential to cut radiation oncologists' contouring time in half. When compared to clinical plans, the differences between estimated doses to CTV and OAR based on auto-courtoring were small, with no statistical significance, indicating that treatment planning for prostate cancer based on auto-courtoring has potential.

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