Dosimetric evaluation of image based brachytherapy using tandem ovoid and tandem ring applicators

Abstract

The results indicate that the OAR doses assessed by DVH criteria were higher than ICRU point doses for the bladder with both tandem-ovoid and tandem-ring applicators whereas DVH based dose was lower than ICRU dose for the rectum. The point B dose, the treated volume and high dose volume was found to be slightly higher with the tandem-ovoid applicator. The mean D2cc dose for the bladder and rectum was lower with tandem-ring applicators. The clinical implication of the above dosimetric differences needs to be evaluated further.

Dosimetric comparison of two different applicators and rectal retraction methods used in inverse optimization-based intracavitary brachytherapy for cervical cancer

“…In terms of bladder doses, Ma et al [20] and Rangarajan [29] reported that there were no significant differences between TO and TR for D 2cm3 value. Similarly, statistically significant difference was not found for the same DVH parameter in the present study.…”

“…TR applicators have recently come into widespread use in IGBT of cervical cancer due to the easiness of application compared to TO applicators. Additionally, it has a predictable and fixed geometry [20,21,29]. All these physical properties of TR applicator make it more advantageous in clinical use.…”

“…All these physical properties of TR applicator make it more advantageous in clinical use. Although TR applicator can be used in all patient groups requiring intracavitary BRT, patients with non-bulky disease, superficial or obliterated vaginal fornix, or narrow vaginal cavity are the ideal patients' group in cervical cancer [20,21,29]. In addition to applicator geometries, a retraction method play an important role to place away rectum from radiation source and to increase the conformity of the BRT treatment plan [22].…”

“…In the literature, the dosimetric comparison of different applicator geometries (TO and TR) and rectal retraction methods (RR, VGP, and tandem Foley balloon) have been studied. Ma et al [20], Rangarajan [29], and Erickson et al [30] reported higher rectal dose in TO compared with TR applicator. In the study performed by Rangarajan [29], it was pointed out that in addition to posterior VGP, RR was used in all TR applications and lower rectum dose in TR applications was attributed to the use of RR.…”

“…Ma et al [20], Rangarajan [29], and Erickson et al [30] reported higher rectal dose in TO compared with TR applicator. In the study performed by Rangarajan [29], it was pointed out that in addition to posterior VGP, RR was used in all TR applications and lower rectum dose in TR applications was attributed to the use of RR. Additionally, Kong et al [22] compared three rectal retraction methods including RR blade, VGP, and a tandem Foley balloon.…”