ESTRO 2024 - Abstract Book

S209

Brachytherapy - Gynaecology

ESTRO 2024

Our mature long-term data on the treatment patients with locally advanced cervical canecr show that excellent treatment outcomes can be achieved with MRI-based IGABT, as well as acceptable late morbidity.

Keywords: adaptive brachytherapy, uterovaginal brachytherapy

195

Digital Poster

Clinical outcomes of Intracavitary- Interstitial Brachytherapy in locally advanced carcinoma cervix.

Dr Elna Jerod 1 , Dr Tanveer Pasha 1 , Dr Nikhila Radhakrishna 1 , Dr Rekha Reddy Bucchapudi 2 , Dr Naveen Thimmaiah 1 , Dr Pallavi Ramesh 1 , Dr Lokesh Vishwanath 1 1 Kidwai Memorial institute of oncology, Department of Radiation Oncology, Bangalore, India. 2 Kidwai Memorial institute of oncology, Department of Radiation Physics, Bangalore, India

Purpose/Objective:

The standard of care for management of locally advanced cervical cancer (LACC) is external beam radiotherapy (EBRT) with concomitant cisplatin based chemotherapy followed by Brachytherapy. Currently available intracavitary brachytherapy applicators often lead to inadequate coverage for lateral extensions of the residual tumor post external beam radiotherapy. Residual medial parametrial disease (MPD) with near maximum distance (NMD) >1.6cm post External Beam Radiotherapy (EBRT) in Locally advanced cervical cancer (LACC) was observed to have inadequate coverage by Intracavitary Brachytherapy (ICBT)alone in our previous study 1 . Hybrid intracavitary + interstitial brachytherapy (IC-ISBT) allows optimal coverage of such high-risk clinical target volume (HRCTV) with optimal doses to Organs at Risk (OARs) 2 . This study aims to examine the need for IC-ISBT applicators and report local control of LACC with IC-ISBT.

Material/Methods:

LACC patients with residual MPD were assessed using post EBRT MRI and clinical examination and selected for the study. IC-ISBT application was performed using 3D Interstitial ring applicator and needles. Two volume-based plans of 7Gy/Fraction were generated for each patient. First plan A was created with prescription to point A using source loading of tandem and ring alone for a standard ICBT plan with suitable optimization. The second plan B involved additional loading of the needles optimized suitably to cover HRCTV. Standard parameters as per GEC ESTRO recommendations of D2cc (minimum dose received by maximally irradiated 2 cc volume) for organs at risk (OAR) - bladder, rectum and sigmoid and the minimum dose delivered to 90% of HR CTV were recorded for both plans in the same patient. An analysis for adequate volume coverage is then done for both plans and compared. 3 Treatment response was assessed based on clinical examination and Magnetic resonance imaging. Toxicities were recorded as per CTCAE 5.0. Data has been analyzed using R language version 4.2.1 (R Core Team (2022) for statistical computing. Paired samples t–test has been used to compare the difference of parameters between plan A and plan B.

Results:

21 patients of Squamous cell Carcinoma of the Uterine Cervix underwent 40 IC-ISBT applications between January 2022 to January 2023.The mean age of the study group was 46 +/_ 7 years . 80 % of the patients (17/21) were