# A Novel Three-Dimension Printed Individualized Curved-Needle-Based Interstitial Brachytherapy for Re-Irradiation in Uterine Fundus-Involving Recurrent Cervical Cancer: A Case Report

## TL;DR

A new 3D-printed curved-needle brachytherapy method was used to treat a rare case of recurrent cervical cancer in the uterine fundus, achieving long-term control and survival.

## Contribution

A novel 3D-printed curved-needle interstitial brachytherapy system for re-irradiation of uterine fundus-involving recurrent cervical cancer.

## Key findings

- The patient achieved 37 months of local control and 45 months of overall survival.
- Treatment was associated with grade 3 proctitis and cystitis but no fistulation or perforation.
- The curved-needle system effectively targeted the distal uterine fundus tumor.

## Abstract

Local treatment for recurrent cervical cancer is a significant challenge. Brachytherapy is an excellent choice for re-irradiation in those case, because of its rapid dose fall-off, preventing severe treatment side effects. Intracavitary brachytherapy combined with interstitial brachytherapy can deliver high conformal dosage to irregularly shaped tumors. However, the traditional straight-needle-based interstitial brachytherapy is not able to reach to some unique relapse locations. In this case, we report on a cervical cancer patient with a recurrent tumor in uterus fundus, treated by a novel curved-needle interstitial brachytherapy, who reached a 37-month local control and 45-month overall survival with acceptable side effects.

Background: Re-irradiation in recurrent cervical cancer presents significant therapeutic challenges, particularly in those with a short interval since prior treatment. Brachytherapy is an ideal re-irradiation method, but regular intracavitary brachytherapy combined with interstitial brachytherapy (ISBT) is restricted by some challenging tumor anatomical locations, which can be optimized through a three-dimensional (3D)-printed curved-needle ISBT system. Case Presentation: A 41-year-old woman diagnosed with cervical mucinous adenocarcinoma developed central pelvic relapse, with tumor extension to the uterine fundus, within two years after completing standard concurrent chemoradiotherapy (CCRT). The patient subsequently received 3D-printed individualized curved-needle-based, MRI-guided adaptive ISBT, in combination with external beam radiotherapy (EBRT) and chemotherapy. This comprehensive treatment approach achieved 45 months of overall survival (OS), 37 months of local control (LC) and progression-free survival (PFS) with grade 3 proctitis and grade 3 cystitis and no fistulation or perforation. Conclusions: The 3D-printed individualized curved-needle ISBT is a re-irradiation option that provides satisfactory LC and prolonged survival with acceptable adverse effects for recurrent tumors located in the distal uterine fundus in cervical cancer. This technique is particularly valuable when intracavitary and traditional interstitial applicators are unsuitable due to the unique location of the tumor.