Prostate or bone? Comparing the efficacy of image guidance surrogates for pelvis and prostate radiotherapy using accumulated delivered dose.
J Med Imaging Radiat Sci
; 52(1): 14-21, 2021 03.
Article
en En
| MEDLINE
| ID: mdl-33139231
INTRODUCTION: This study assessed the impact of dosimetry to both the target and normal tissue when either bony anatomy (BA) or prostate (PRO) was used as surrogates for image guidance for pelvis and prostate radiotherapy using a dose accumulation process. METHODS: Thirty patients who were prescribed 50-54Gy to the pelvic lymph nodes (PLN) and 78Gy to the prostate/seminal vesicles were included. Daily acquired CBCTs were rigidly registered to the CT using BA and PRO to simulate two different treatment positions. The accumulated delivered dose (DAcc) of PLN, prostate, bladder and rectum for each surrogate were compared with the planned dose. Deviation from the planned dose (ΔDAcc-Plan) of >5% was considered clinically significant. RESULTS: Prostate was displaced from bony anatomy by > 5 mm in 96/755 fractions (12.7%). Deviation between the mean DAcc and the planned dose for PLN and prostate was <2% when either BA or PRO was used. No significant deviation from planned dose was observed for bladder (p > 0.2). In contrary, DAcc for rectum D50 was significantly greater than the planned dose when BA was used (Mean ΔDAcc-Plan = 6%). When examining individual patient, deviation from the planned dose for rectum D50 was clinically significant for 18 patients for BA (Range: 5-21%) and only 8 patients for PRO (Range: 5-8%). CONCLUSIONS: The use of either BA or PRO for image guidance could deliver dose to PLN and prostate with minimal deviation from the plan using existing PTV margins. However, deviation for rectum was greater when BA was used.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Huesos Pélvicos
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Neoplasias de la Próstata
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Radiografía Intervencional
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Tomografía Computarizada de Haz Cónico
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Radioterapia Guiada por Imagen
Tipo de estudio:
Etiology_studies
/
Guideline
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Observational_studies
/
Risk_factors_studies
Límite:
Adult
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Humans
/
Male
Idioma:
En
Revista:
J Med Imaging Radiat Sci
Año:
2021
Tipo del documento:
Article
Pais de publicación:
Estados Unidos