Types of deviation and review criteria in pretreatment central quality control of tumor bed boost in medulloblastoma—an analysis of the German Radiotherapy Quality Control Panel in the SIOP PNET5 MB trial

Abstract Purpose In Germany, Austria, and Switzerland, pretreatment radiotherapy quality control (RT-QC) for tumor bed boost (TB) in non-metastatic medulloblastoma (MB) was not mandatory but was recommended for patients enrolled in the SIOP PNET5 MB trial between 2014 and 2018. This individual case review (ICR) analysis aimed to evaluate types of deviations in the initial plan proposals and develop uniform review criteria for TB boost. Patients and methods A total of 78 patients were registered in this trial, of whom a subgroup of 65 patients were available for evaluation of the TB treatment plans. Dose uniformity was evaluated according to the definitions of the protocol. Additional RT-QC criteria for standardized review of target contours were elaborated and data evaluated accordingly. Results Of 65 initial TB plan proposals, 27 (41.5%) revealed deviations of target volume delineation. Deviations according to the dose uniformity criteria were present in 14 (21.5%) TB plans. In 25 (38.5%) cases a modification of the RT plan was recommended. Rejection of the TB plans was rather related to unacceptable target volume delineation than to insufficient dose uniformity. Conclusion In this analysis of pretreatment RT-QC, protocol deviations were present in a high proportion of initial TB plan proposals. These findings emphasize the importance of pretreatment RT-QC in clinical trials for MB. Based on these data, a proposal for RT-QC criteria for tumor bed boost in non-metastatic MB was developed.

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246 poster workshop Evaluation and quality control of CT-based attenuation correction for PET/CT: potential influence on target volume delineation in radiotherapy

Radiotherapy and Oncology ◽

10.1016/s0167-8140(04)82113-3 ◽

2004 ◽

Vol 73 ◽

pp. S112

Keyword(s):

Quality Control ◽

Attenuation Correction ◽

Target Volume ◽

Potential Influence ◽

Target Volume Delineation ◽

Volume Delineation ◽

Pet Ct ◽

Workshop Evaluation

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Pretreatment central quality control for craniospinal irradiation in non-metastatic medulloblastoma

Strahlentherapie und Onkologie ◽

10.1007/s00066-020-01707-8 ◽

2020 ◽

Author(s):

Stefan Dietzsch ◽

Annett Braesigk ◽

Clemens Seidel ◽

Julia Remmele ◽

Ralf Kitzing ◽

...

Keyword(s):

Quality Control ◽

High Precision ◽

Negative Impact ◽

Conformal Radiotherapy ◽

Target Volume ◽

Craniospinal Irradiation ◽

High Rate ◽

Tumor Control ◽

Case Review ◽

Dose Uniformity

Abstract Purpose Several studies have demonstrated the negative impact of radiotherapy protocol deviations on tumor control in medulloblastoma. In the SIOP PNET5 MB trial, a pretreatment radiotherapy quality control (RT-QC) program was introduced. A first analysis for patients enrolled in Germany, Switzerland and Austria with focus on types of deviations in the initial plan proposals and review criteria for modern radiation technologies was performed. Methods and patients Sixty-nine craniospinal irradiation (CSI) plans were available for detailed analyses. RT-QC was performed according to protocol definitions on dose uniformity. Because of the lack of definitions for high-precision 3D conformal radiotherapy within the protocol, additional criteria for RT-QC on delineation and coverage of clinical target volume (CTV) and planning target volume (PTV) were defined and evaluated. Results Target volume (CTV/PTV) deviations occurred in 49.3% of initial CSI plan proposals (33.3% minor, 15.9% major). Dose uniformity deviations were less frequent (43.5%). Modification of the RT plan was recommended in 43.5% of CSI plans. Unacceptable RT plans were predominantly related to incorrect target delineation rather than dose uniformity. Unacceptable plans were negatively correlated to the number of enrolled patients per institution with a cutoff of 5 patients (p = 0.001). Conclusion This prospective pretreatment individual case review study revealed a high rate of deviations and emphasizes the strong need of pretreatment RT-QC in clinical trials for medulloblastoma. Furthermore, the experiences point out the necessity of new RT-QC criteria for high-precision CSI techniques.

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Technical illustration of Volumetric arc conformal radiotherapy planning in a case of paratesticular sarcoma

Journal of Radiotherapy in Practice ◽

10.1017/s1460396920001211 ◽

2021 ◽

pp. 1-6

Author(s):

Anil Gupta ◽

Rambha Pandey ◽

Seema Sharma ◽

Vivek Ghosh ◽

Ekta Dhamija ◽

...

Keyword(s):

Organs At Risk ◽

Target Volume ◽

Radiotherapy Planning ◽

Current Evidence ◽

Lower Grade ◽

Malignant Tumours ◽

Target Volume Delineation ◽

Volume Delineation ◽

Delivery Technique ◽

Technical Illustration

Abstract Introduction: Paratesticular sarcoma are extremely rare malignant tumours. Unlike other sites, they tend to be lower grade and have higher propensity of lymphatic spread. They tend to fail locally and occasionally in the regional lymph nodes. In the absence of target volume delineation guidelines and technical illustration of conformal planning, we have made an attempt to illustrate conformal planning methodology and define target volume based on current evidence in a case of paratesticular sarcoma. Methods: We are presenting a case of 62-year-old male who presented with 15-cm scrotal swelling and underwent high inguinal orchidectomy with ligation of spermatic cord. Histopathology presented a well-differentiated leiomyosarcoma of epididymis. Post-operative radiotherapy target volume included the tumour bed, ipsilateral inguinal nodes and lower pelvic nodes as the clinical target volume. Conclusion: Adjuvant radiotherapy using advanced delivery technique such as volumetric arc technique can provide good dose distribution with good sparing of organs at risk. The downside of conformal radiation delivery is that it is a resource-intensive and has no established target volume delineation guidelines.

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Interobserver variability in target volume delineation in definitive radiotherapy for thoracic esophageal cancer: a multi-center study from China

Radiation Oncology ◽

10.1186/s13014-020-01691-4 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Xiao Chang ◽

Wei Deng ◽

Xin Wang ◽

Zongmei Zhou ◽

Jun Yang ◽

...

Keyword(s):

Esophageal Cancer ◽

Gross Tumor Volume ◽

Tumor Volume ◽

Interobserver Variability ◽

Target Volume ◽

Thoracic Esophageal Cancer ◽

Target Volume Delineation ◽

Cancer Centers ◽

Definitive Radiotherapy ◽

Volume Delineation

Abstract Purpose To investigate the interobserver variability (IOV) in target volume delineation of definitive radiotherapy for thoracic esophageal cancer (TEC) among cancer centers in China, and ultimately improve contouring consistency as much as possible to lay the foundation for multi-center prospective studies. Methods Sixteen cancer centers throughout China participated in this study. In Phase 1, three suitable cases with upper, middle, and lower TEC were chosen, and participants were asked to contour a group of gross tumor volume (GTV-T), nodal gross tumor volume (GTV-N) and clinical target volume (CTV) for each case based on their routine experience. In Phase 2, the same clinicians were instructed to follow a contouring protocol to re-contour another group of target volume. The variation of the target volume was analyzed and quantified using dice similarity coefficient (DSC). Results Sixteen clinicians provided routine volumes, whereas ten provided both routine and protocol volumes for each case. The IOV of routine GTV-N was the most striking in all cases, with the smallest DSC of 0.37 (95% CI 0.32–0.42), followed by CTV, whereas GTV-T showed high consistency. After following the protocol, the smallest DSC of GTV-N was improved to 0.64 (95% CI 0.45–0.83, P = 0.005) but the DSC of GTV-T and CTV remained constant in most cases. Conclusion Variability in target volume delineation was observed, but it could be significantly reduced and controlled using mandatory interventions.

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