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- Alcorn, Sara R., et al.
(författare)
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Low-Dose Image-Guided Pediatric CNS Radiation Therapy : Final Analysis From a Prospective Low-Dose Cone-Beam CT Protocol From a Multinational Pediatrics Consortium
- 2020
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Ingår i: Technology in Cancer Research & Treatment. - : SAGE PUBLICATIONS INC. - 1533-0346 .- 1533-0338. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lower-dose cone-beam computed tomography protocols for image-guided radiotherapy may permit target localization while minimizing radiation exposure. We prospectively evaluated a lower-dose cone-beam protocol for central nervous system image-guided radiotherapy across a multinational pediatrics consortium.Methods: Seven institutions prospectively employed a lower-dose cone-beam computed tomography central nervous system protocol (weighted average dose 0.7 mGy) for patients <= 21 years. Treatment table shifts between setup with surface lasers versus cone-beam computed tomography were used to approximate setup accuracy, and vector magnitudes for these shifts were calculated. Setup group mean, interpatient, interinstitution, and random error were estimated, and clinical factors were compared by mixed linear modeling.Results: Among 96 patients, with 2179 pretreatment cone-beam computed tomography acquisitions, median age was 9 years (1-20). Setup parameters were 3.13, 3.02, 1.64, and 1.48 mm for vector magnitude group mean, interpatient, interinstitution, and random error, respectively. On multivariable analysis, there were no significant differences in mean vector magnitude by age, gender, performance status, target location, extent of resection, chemotherapy, or steroid or anesthesia use. Providers rated >99% of images as adequate or better for target localization.Conclusions: A lower-dose cone-beam computed tomography protocol demonstrated table shift vector magnitude that approximate clinical target volume/planning target volume expansions used in central nervous system radiotherapy. There were no significant clinical predictors of setup accuracy identified, supporting use of this lower-dose cone-beam computed tomography protocol across a diverse pediatric population with brain tumors.
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2. |
- Alcorn, Sara R, et al.
(författare)
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Practice patterns of photon and proton pediatric image guided radiation treatment : results from an International Pediatric Research consortium
- 2014
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Ingår i: Practical radiation oncology. - : Elsevier BV. - 1879-8500. ; 4:5, s. 336-341
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Image guided radiation therapy (IGRT) has become common practice for both photon and proton radiation therapy, but there is little consensus regarding its application in the pediatric population. We evaluated clinical patterns of pediatric IGRT practice through an international pediatrics consortium comprised of institutions using either photon or proton radiation therapy.METHODS AND MATERIALS: Seven international institutions with dedicated pediatric expertise completed a 53-item survey evaluating patterns of IGRT use in definitive radiation therapy for patients ≤21 years old. Two institutions use proton therapy for children and all others use IG photon therapy. Descriptive statistics including frequencies of IGRT use and means and standard deviations for planning target volume (PTV) margins by institution and treatment site were calculated.RESULTS: Approximately 750 pediatric patients were treated annually across the 7 institutions. IGRT was used in tumors of the central nervous system (98%), abdomen or pelvis (73%), head and neck (100%), lung (83%), and liver (69%). Photon institutions used kV cone beam computed tomography and kV- and MV-based planar imaging for IGRT, and all proton institutions used kV-based planar imaging; 57% of photon institutions used a specialized pediatric protocol for IGRT that delivers lower dose than standard adult protocols. Immobilization techniques varied by treatment site and institution. IGRT was utilized daily in 45% and weekly in 35% of cases. The PTV margin with use of IGRT ranged from 2 cm to 1 cm across treatment sites and institution.CONCLUSIONS: Use of IGRT in children was prevalent at all consortium institutions. There was treatment site-specific variability in IGRT use and technique across institutions, although practices varied less at proton facilities. Despite use of IGRT, there was no consensus of optimum PTV margin by treatment site. Given the desire to restrict any additional radiation exposure in children to instances where the exposure is associated with measureable benefit, prospective studies are warranted to optimize IGRT protocols by modality and treatment site.
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