TY - JOUR
T1 - Dosimetric Evaluation of a Flexible Dual Balloon-Constructed Applicator in Treating Anorectal Cancer
AU - Kuo, Hsiang Chi
AU - Mehta, Keyur J.
AU - Yaparpalvi, Ravindra
AU - Lee, Alan
AU - Mynampati, Dinesh
AU - Bodner, William
AU - Garg, Madhur
AU - Huang, David
AU - Tomé, Wolfgang A.
AU - Kalnicki, Shalom
N1 - Publisher Copyright:
© The Author(s) 2017.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Background and Purpose: To assess the dosimetric flexibility of a dual balloon brachytherapy applicator developed for the treatment of anorectal lesions. Materials and Methods: Different amounts of water were infused into the inner and outer balloon separately to study the asymmetrical distribution of the catheter, the radial distance of the active source channel to the inner surface of the global target volume, the space between the active source channels, and their dosimetric impact to target tissues and uninvolved rectum. Results: Increasing inner balloon volume directly increased both the space between the active source channels and the radial distance of the active source channel to the inner surface of the global target volume. The space between the active source channels and the percentage of global target volume received 150% or more of the prescribed dose to target had a strong inverse correlation (−0.881/P =.007, −0.976/P =.001, respectively) with the radial distance of the active source channel to the inner surface of the global target volume. Conformity index, dose to 2 cm3 of rectum, and total reference air kerma were strongly correlated with the radial distance of the active source channel to the inner surface of the global target volume, with values of 0.952 (P =.001), 0.833 (P =.015), and 0.922 (P =.002), respectively. Percentage of global target volume received 150% or more of the prescribed dose was significantly correlated with the space between the active source channels (0.81/P =.022), and conformity index was strongly inversely correlated with the space between the active source channels (−0.833/P =.015). Conclusion: The dual balloon-constructed Anorectal Applicator offers a flexible way to adjust the distances of the active source positions to the target in relation to uninvolved rectal wall. This flexibility simplifies planning which results in a highly conformal dose distribution to the target lesion while minimizing dose to normal rectal tissue.
AB - Background and Purpose: To assess the dosimetric flexibility of a dual balloon brachytherapy applicator developed for the treatment of anorectal lesions. Materials and Methods: Different amounts of water were infused into the inner and outer balloon separately to study the asymmetrical distribution of the catheter, the radial distance of the active source channel to the inner surface of the global target volume, the space between the active source channels, and their dosimetric impact to target tissues and uninvolved rectum. Results: Increasing inner balloon volume directly increased both the space between the active source channels and the radial distance of the active source channel to the inner surface of the global target volume. The space between the active source channels and the percentage of global target volume received 150% or more of the prescribed dose to target had a strong inverse correlation (−0.881/P =.007, −0.976/P =.001, respectively) with the radial distance of the active source channel to the inner surface of the global target volume. Conformity index, dose to 2 cm3 of rectum, and total reference air kerma were strongly correlated with the radial distance of the active source channel to the inner surface of the global target volume, with values of 0.952 (P =.001), 0.833 (P =.015), and 0.922 (P =.002), respectively. Percentage of global target volume received 150% or more of the prescribed dose was significantly correlated with the space between the active source channels (0.81/P =.022), and conformity index was strongly inversely correlated with the space between the active source channels (−0.833/P =.015). Conclusion: The dual balloon-constructed Anorectal Applicator offers a flexible way to adjust the distances of the active source positions to the target in relation to uninvolved rectal wall. This flexibility simplifies planning which results in a highly conformal dose distribution to the target lesion while minimizing dose to normal rectal tissue.
KW - brachytherapy
KW - dual balloon
KW - rectal cancer
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U2 - 10.1177/1533034617707433
DO - 10.1177/1533034617707433
M3 - Article
C2 - 28481175
AN - SCOPUS:85039446415
SN - 1533-0346
VL - 16
SP - 879
EP - 884
JO - Technology in Cancer Research and Treatment
JF - Technology in Cancer Research and Treatment
IS - 6
ER -