Equivalent dose in 2 Gy (EQD2) to pelvic lymph nodes using volume based prescription for three brachytherapy applicators — a dosimetric retrospective analysis

Autor: Janaki Manur Gururajachar, Revathy T, Ram Charith Alva, Kirthi Koushik As, Mohan Kumar S, Nishant Vidyasagar, Arul Ponni Thiruraj
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Reports of Practical Oncology and Radiotherapy
ISSN: 2083-4640
1507-1367
Popis: BACKGROUND: Pelvic lymph node (PLN) metastasis has been included in the FIGO staging, so there is a need to determine the dose contribution from brachytherapy to ascertain the total delivered dose to the pelvic lymph nodes in cervical cancer. The aim of the study was to calculate the equivalent dose in 2 Gy (EQD2) of the pelvic lymph nodes (PLNs) based on volume prescription using three applicators. Materials and methods: Forty-one patients who had undergone external beam radiotherapy followed by brachytherapy using tandem ovoids (TO), tandem ring (TR) and TO + free hand interstitial needles (TO + FH) applicators were taken for this study. 26 Gy in 4 fractions was prescribed to HRCTV. The external iliac node (ELN), internal iliac node (ILN) and obturator (OBT) were contoured and the median EQD2 of the lymph nodes was calculated. RESULTS: The median bilateral EQD2 values of ELN were 1.55 Gy (TR), 1.75 Gy (TO), 1.9 Gy (TO + FH), of ILN these were 2.57 Gy (TR), 3.27 Gy (TO), 3.04 Gy (TO + FH), and of OBT these were 3.69 Gy (TR), 4.46 Gy (TO), 4.69 Gy (TO + FH), respectively. The total median EQD2 values of TR, TO and TO + FH were 52.71 Gy, 53.03 Gy, and 53.88–62.73 Gy, respectively. CONCLUSION: Our study calculated the median EQD2 to the pelvic lymph nodes using three types of applicators in brachytherapy. This could serve as reference to decide on the EBRT boost dose while treating patients with enlarged pelvic lymph nodes.
Databáze: OpenAIRE