BACKGROUND: Density changes of healthy lung tissue during radiotherapy as observed by Cone Beam CT (CBCT) might be an early indicator of patient specific lung toxicity. This study investigates the time course of CBCT density changes and tests for a possible correlation with locally delivered dose. METHODS: A total of 665 CBCTs in 65 lung cancer patients treated with IMRT/VMAT to 60 or 66 Gy in 2 Gy fractions were analyzed. For each patient, CBCT lung density changes during the treatment course were related to the locally delivered dose. RESULTS: A dose response is observed for the patient population at the end of the treatment course. However, the observed dose response is highly variable among patients. Density changes at 10th and 20th fraction are clearly correlated to those observed at the end of the treatment course. CONCLUSIONS: CBCT density changes in healthy lung tissue during radiotherapy correlate with the locally delivered dose and can be detected relatively early during the treatment. If these density changes are correlated to subsequent clinical toxicity this assay could form the basis for biological adaptive radiotherapy.
BACKGROUND: Density changes of healthy lung tissue during radiotherapy as observed by Cone Beam CT (CBCT) might be an early indicator of patient specific lung toxicity. This study investigates the time course of CBCT density changes and tests for a possible correlation with locally delivered dose. METHODS: A total of 665 CBCTs in 65 lung cancerpatients treated with IMRT/VMAT to 60 or 66 Gy in 2 Gy fractions were analyzed. For each patient, CBCT lung density changes during the treatment course were related to the locally delivered dose. RESULTS: A dose response is observed for the patient population at the end of the treatment course. However, the observed dose response is highly variable among patients. Density changes at 10th and 20th fraction are clearly correlated to those observed at the end of the treatment course. CONCLUSIONS: CBCT density changes in healthy lung tissue during radiotherapy correlate with the locally delivered dose and can be detected relatively early during the treatment. If these density changes are correlated to subsequent clinical toxicity this assay could form the basis for biological adaptive radiotherapy.
Authors: Michelle K Nielsen; Kyle E Malkoske; Erika Brown; Kevin Diamond; Normand Frenière; John Grant; Natalie Pomerleau-Dalcourt; Jason Schella; L John Schreiner; Laurent Tantôt; J Eduardo Villareal-Barajas; Jean-Pierre Bissonnette Journal: J Appl Clin Med Phys Date: 2016-11-08 Impact factor: 2.102
Authors: Janna E van Timmeren; Wouter van Elmpt; Ralph T H Leijenaar; Bart Reymen; René Monshouwer; Johan Bussink; Leen Paelinck; Evelien Bogaert; Carlos De Wagter; Elamin Elhaseen; Yolande Lievens; Olfred Hansen; Carsten Brink; Philippe Lambin Journal: Radiother Oncol Date: 2019-04-11 Impact factor: 6.280
Authors: Venkatesan Kaliyaperumal; C Jomon Raphael; K Mathew Varghese; Paul Gopu; S Sivakumar; Minu Boban; N Arunai Nambi Raj; K Senthilnathan; P Ramesh Babu Journal: J Med Phys Date: 2017 Jul-Sep