Structural Vulnerability of J-J Stents to Radiotherapy in Cervical Cancer Patients: Implications for Treatment Planning

Abstract

Introduction: Cervical cancer multimodal treatment causes 75% urethral complications. Application of surgery or radiotherapy can induce free radicals and vascular damage of the ureters. J-J stent placement, due to renal function preservation, increase infection, encrustation and obstruction risk. Methodlogy: A 38 year old patient with International Federation of Gynecology and Obstetrics (FIGO) Ib3 cervical cancer, was treated with radical hysterectomy. Bilateral J-J stents were placed due to bilateral renal calculus immediately after. Treatment continued with adjuvant radiotherapy. Following 10 radiotherapy fractions, patient presented with fatigue, fewer, diarrhea, and sepsis signs and symptoms, in absence of apparent infection (negative urine/blood cultures, stent swabs, stool samples, additional imaging procedures) and J-J stents were removed, accompanied by three weeks antibiotic course (quinolones, carbapenems and colistin), with general condition improved and postoperative radiotherapy continued. Upon finalizing the radiotherapy cycle, pelvic MR were conducted - without infection signs. Three weeks later, due to anuria and hydrouretheronephrosis grade 2, control multislice computed tomography (CT) showed distal ureter and bladder fibrosis. Results: Volumetric arc radiotherapy (VMAT) with 40 Gray (Gy)/20 fractions (fr) followed by three cycles brachytherapy (3x600cGy) was conducted, respecting recommendations for organs at risk. During the radiotherapy J-J stent mean dose was 41.71Gy on the left side, 42.49 Gy on the right side, respectively. Determining whether changing in stent structure was caused, under the same conditions J-J stent were irradiated, using 90 Gy/6fr. Stent density prior to radiation was 1884 HU, and after 2225 HU which may indicate a loss of stent elasticity, an increase in strength and a reduction in flexibility that can potentially lead to injury to the ureteral mucosa. Conclusion. All above mentioned factors can be contributing in urethral microenvironment, or J-J stent density alteration after radiotherapy can potentially cause serious urethral damage in symbiosis with microbiota and altered local radiobiological effect.