Impact of PTV margin reduction (2 mm to 0 mm) on pseudoprogression in stereotactic radiotherapy of solitary brain metastases
| Autor: | Elyas Ghariq, Jan-Huib Franssen, Justine Badloe, Mirjam E. Mast, Anna Petoukhova, Noëlle van der Voort van Zijp, Ruud Wiggenraad |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
lcsh:Medical physics. Medical radiology. Nuclear medicine
medicine.medical_treatment lcsh:R895-920 lcsh:RC254-282 030218 nuclear medicine & medical imaging Stereotactic radiotherapy Dose schedule 03 medical and health sciences 0302 clinical medicine Pseudoprogression Medicine Radiology Nuclear Medicine and imaging In patient Care Planning Reduction (orthopedic surgery) Oncology (nursing) business.industry Health Policy Incidence (epidemiology) food and beverages Brain metastases Ptv margin lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens Single fraction Margins 030220 oncology & carcinogenesis Nuclear medicine business human activities Research Article |
| Zdroj: | Technical Innovations & Patient Support in Radiation Oncology, Vol 17, Iss, Pp 40-47 (2021) Technical Innovations & Patient Support in Radiation Oncology |
| ISSN: | 2405-6324 |
| Popis: | Highlights • Pseudoprogression can be a side effect of SRT of brain metastases. • CTV-PTV margin reduction to 0 mm did not reduce incidence of pseudoprogression. • V12 Gy was not associated with incidence of pseudoprogression. Purpose To determine the influence of PTV-margin (0 mm versus 2 mm) on the incidence of pseudoprogression (PP) and local tumour control (LC) in patients treated with stereotactic radiotherapy (SRT) for solitary brain metastases. Methods Patients were treated on Novalis LINAC. Three dose schedules were used depending on the PTV-size. The PTV-margin was 2-mm prior to 2015 and 0-mm thereafter. MRI-scans were made every three months including a perfusion MRI-scan when pseudoprogression was suspected. We examined the relation of pseudoprogression and local control with the size of PTV-margin. Besides this, the association of dose-volume data of the whole brain (minus GTV) and pseudoprogression was investigated. Results 121 patients were analyzed (2-mm margin in 84 patients; 0-mm margin in 37 patients). There was no difference in GTV (7.6 cc versus 9.1 cc p = 0.2). At 24 months there was no difference in incidence of pseudoprogression (49% and versus 33%, p = 0.5) and local control in the 2-mm and 0-mm group (82% and versus 79%, p = 1.0). The size of PTV-margin was not associated with PP. Both margin and volume of brain receiving 12 Gy (V12) were not associated with pseudoprogression in patients treated with single fraction. Conclusions PTV-margin reduction did not reduce the incidence of pseudoprogression in LINAC-based-SRT for single brain metastases. We did not find a significant association of GTV-PTV margin or V12Gy with the incidence of pseudoprogression in solitary metastases treated with a single fraction. LC rates were similar, indicating margin reduction seems to be safe. |
| Databáze: | OpenAIRE |
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