1. Use of an intravaginal spacer in young girls treated with brachytherapy for bladder neck rhabdomyosarcoma: Dosimetric impact for organs at risk sparing and acute tolerance
- Author
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Elaine Johanna Limkin, V. Minard, Sophie Espenel, Hélène Martelli, C. Haie-Meder, Cyrus Chargari, Florent Guérin, and M. Terlizzi
- Subjects
Male ,Organs at Risk ,medicine.medical_specialty ,medicine.medical_treatment ,Brachytherapy ,Urinary Bladder ,Urology ,Rectum ,Prostate Rhabdomyosarcoma ,Rhabdomyosarcoma ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Child ,Pelvic Neoplasms ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Radiotherapy Dosage ,medicine.disease ,Neck of urinary bladder ,medicine.anatomical_structure ,Oncology ,Urinary Bladder Neoplasms ,Child, Preschool ,Vagina ,Dose reduction ,Female ,Implant ,business ,Tomography, X-Ray Computed - Abstract
Purpose Interstitial brachytherapy is indicated as part of a conservative strategy for children with bladder and/or prostate rhabdomyosarcoma (RMS), providing high local control probability with acceptable functional results. Vaginal and/or rectal complications were however reported, due to the close proximity to the implanted volume. We investigated the dosimetric impact of a vaginal spacer in terms of rectal and vaginal doses. Methods and patients Medical records of 12 consecutive female patients with bladder neck RMS, median age 32 months (range: 1.3–6 years), were reviewed. Five patients were treated prior to 2017 without a vaginal spacer and seven patients treated after 2017 had their brachytherapy delivered with a vaginal spacer placed at time of implant. Results Minimal doses delivered to the most exposed 2 cm3, 1 cm3, and 0.5 cm3 of the rectum were all statistically significantly lower among patients treated with a vaginal spacer, as compared to those treated without a spacer. Median rectal D2cm3 was 22 GyEQD2 versus 38 GyEQD2 (P = 0.02), D1cm3 was 29 GyEQD2 versus 51 GyEQD2 (P = 0.013), and D0.5cm3 was 32 GyEQD2 versus 61 GyEQD2 (P = 0.017), with and without the vaginal spacer, respectively. The posterior vaginal wall D0.5cm3 dose was also significantly decreased, with median D0.5cm3 of 92 GyEQD2 versus 54 GyEQD2 (P Conclusions The use of vaginal spacers in brachytherapy of female pediatric patients with bladder neck RMS resulted in significantly decreased doses to the rectum and the posterior vaginal wall. Though the clinical impact of such dose reduction remains undemonstrated, routine utilization of a vaginal spacer could be a method to decrease long-term morbidity in these patients.
- Published
- 2021