8560 Dosimetric changes of intensity modulated radiotherapy (IMRT) plan on the follow-up CT acquired during treatment in the patients with nasopharynx cancer

Kim, K.; Park, S.; Cheong, Kwang-Ho; Kang, Sea Yong; Hwang, Te-Long; Lee, M.; Oh, Do Hoon; Bae, Hyo-Sang

doi:10.1016/s1359-6349(09)71651-9

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consistent results were found in the study of Kim et al . [ 16 ]. They also reported insignificant dose changes to targets but significantly higher doses to parotids, brainstem and spinal cord without replanning.…”

Section: Introductionmentioning

confidence: 99%

Developing an adaptive radiation therapy strategy for nasopharyngeal carcinoma

Fung

Teo

2013

Journal of Radiation Research

View full text Add to dashboard Cite

Adaptive radiotherapy (ART) has recently been introduced to restore the planned dose distribution by accounting for the anatomic changes during treatment. By quantifying the anatomic changes in nasopharyngeal carcinoma (NPC) patients, this study aimed to establish an ART strategy for NPC cases. A total of 30 NPC patients treated with helical tomotherapy were recruited. In the pretreatment megavoltage CT images, the anatomic changes of the posterolateral wall of nasopharynx (P-NP), neck region and parotid glands were measured and assessed. One-way repeated measure ANOVA was employed to define threshold(s) at any time-point. The presence of a threshold(s) would indicate significant anatomical change(s) such that replanning should be suggested. A pragmatic schedule for ART was established by evaluating the threshold for each parameter. Results showed the P-NP, parotid gland and neck volumes demonstrated significant regressions over time. Respectively, the mean loss rates were 0.99, 1.35, and 0.39 %/day, and the mean volume losses were 35.70, 47.54 and 11.91% (all P < 0.001). The parotid gland shifted medially and superiorly over time by a mean of 0.34 and 0.24 cm, respectively (all P < 0.001). The neck region showed non-rigid posterior displacement, which increased from upper to lower neck. According to the threshold occurrences, three replans at 9th, 19th and 29th fractions were proposed. This ART strategy was able to accommodate the dosimetric consequences due to anatomic deviation over the treatment course. It is clinically feasible and would be recommended for centers where an adaptive planning system was not yet available.

show abstract

Section: Introductionmentioning

confidence: 99%