Design and Development of In-House Multichannel Applicator for HDR Vaginal Brachytherapy and Dosimetric Comparision with Single Channel Applicator

Abstract

Introduction: Endometrial cancer (EC) is a leading cause of female cancer in developed countries. The total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymph node dissection is the primary management of endometrial cancer. Afterwards vaginal brachytherapy can be preferred either alone or combined with external beam radiotherapy to avoid the vault recurrence. This study was to assess the in-house multichannel applicator for HDR vaginal brachytherapy and dosimetric compression with the single channel applicator through DVHs. The main objective of this study was to design and development of an in-house multichannel applicator for HDR vaginal brachytherapy and dosimetric compression with the single channel applicator through DVHs. Materials and Methods:The multichannel applicator is a solid cylinder with 3 cm diameter, 13 cm length. It has a central channel surrounded by eight channels with a periphery arrangement in a single circle. We randomly selected eleven patients with endometrial carcinoma and 7Gy/per fraction of HDR dose was prescribed to CTV. Retrospectively, two 3D inverse treatment plans were created for each patient, with single channel loading and multichannel loading and the dose distribution of both plans could be compared. CTV coverage, rectum and bladder doses were compared. Results: The DVH analysis showed statistically significant difference between single and multichannel plan, that is for D95 of CTV (p=0.008), D100 of CTV (p=0.004) and 2cc of CTV (p=0.003). The p value for 1cc, 2cc and V70 are 0.003, 0.003 and 0.003 for rectum. On the other hand, bladder DVHs showed large difference between single and multichannel plan yet it is not statistically significant, and the p values for 1cc, 2cc and V 80 are 0.012, 0.009 and 0.225. Conclusion: The authors conclude that in house multichannel applicator with 3D inverse treatment planning techniques improves the dosimetric advantage over single channel applicators.

Intensity-modulated vaginal brachytherapy applicator and single- and multi-channel applicators in vaginal cuff brachytherapy

“…Govindaraj et al . [ 21 ] stated that MC-BRT generally require longer planning time, and the mean value for total planning time was 120 min, with SC-BRT planning time as expected. In contrast to the total planning time, the mean of total dwell time for MC-BRT was significantly lower than for SC-BRT plans ( p = 0.02 for CTVs, and p = 0.01 for CTVv).…”

“…As stated by Govindaraj et al . [ 21 ], there is about 7% risk of wound infections, abscesses, and fat necrosis after interstitial BRT application. All these parameters make interstitial technique challenging in routine clinical practice; therefore, IM-BRT is gaining popularity to create more conformal treatment plans, which may be alternative to interstitial BRT plans [ 22 , 23 ].…”