ESTRO 2024 - Abstract Book

S221

Brachytherapy - Gynaecology

ESTRO 2024

41.15±9.038% post-HG procedure, respectively. There was a statistically relevant decrease in rectal doses due to the addition of HG in both Point-A and optimised plans(p<0.001 for both). Also, the impact of rectal separation by HG was much greater than optimisation alone(20% vs 5%, p<0.001). The mean R0.1cc improved for Point-A plans with optimisation(90.49% vs 82.47%, p=0.046) and rectal separation by HG(90.49% vs 66.09%, p<0.001), with a magnitude of dose reduction being higher with HG instillation(24.4% vs 7.02%, p<0.001). HRCTV D90 coverage was statistically non-significant with the use of HG when normalised to Point-A(114.05% vs 116.14% of the prescription dose, p= 0.279). The median HRCTV D90 dose delivered was 87.8± 2.1Gy The average time lapse between the pre-HG scan and the post-HG scan was 3.2±0.7 hours. The mean volume change of bladder and rectum was not statistically significant between the two scans(Bladder: 13.4±4.88 cc, p= 0.594, and Rectum: 6.37±1.48 cc, p= 0.737), nor between the first and last fraction scans(Bladder: p = 0.623, and Rectum: p=0.584).

The median follow-up was 37 months(range 30-48 months). There were no reported any grade rectal toxicities. All patients had a complete tumor response to the delivered treatment.

Conclusion:

Our initial experience indicates that pre-rectal instillation of HG during image-guided brachytherapy is feasible, safe, and has the potential to improve the therapeutic index in the treatment of locally advanced cervical cancer, even where the anatomy is inconducive.

Keywords: Hydrogel, IGBT, locally advanced cervical cancer

References:

1. Dimopoulos J.C., Potter R., Lang S., et. al.: Dose -effect relationship for local control of cervical cancer by magnetic resonance image-guided brachytherapy. Radiother Oncol 2009; 93: pp. 311-315.

2. Haie-Meder C., Pötter R., Van Limbergen E., et. al.: Recommendations from Gynaecological (GYN) GEC-ESTRO Working Group (I): concepts and terms in 3D image-based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV. Radiother Oncol 2005; 74: pp. 235-245.

411

Digital Poster

Efficacy and toxicity of two-fractions in one application during HDR-Brachytherapy in cancer cervix

Ritusha Mishra, Himanshu Mishra, Ankita Singh, Shreya Singh, Ekta Prakash, Ankur Mourya, Abhijit Mandal

Institute of Medical Sciences ,Banaras Hindu University, Radiotherapy, Varanasi, India

Purpose/Objective: