Int J Cancer Manag. 2020 November; 13(11):e108299. Published online 2020 November 21. doi: 10.5812/ijcm.108299. Research Article Intravesical Instillation of Sodium Hyaluronate (Cystistat ® ) for the Treatment of Patients with Radiation Cystitis-Randomized Clinical Trial Farzad Allameh 1 , Abbas Basiri 1 , Saleh Ghiasy 2 , Atefeh Javadi 3 , Seyyed Ali Hojjati 4, * and Amir Hossein Rahavian 5 1 Urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Laser Application in Medical Science Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3 Department of Physical Medicine and Rehabilitation, Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran 4 Men’s health and Reproductive Health Research Center, Shahid Beheshti university of Medical Sciences, Tehran, Iran 5 Department of Urology, Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran * Corresponding author: Department of Urology, Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Email: sah_hojjati@yahoo.com Received 2020 August 12; Revised 2020 October 07; Accepted 2020 October 10. Abstract Background: Radiotherapy (RT) is a choice to manage pelvic organ malignancies that can affect bladder; therefore, it causes radi- ation cystitis with some bothering urinary symptoms and decreasing the patient’s quality of life. Intravesical hyaluronic acid (HA) is an agent with promising results in some studies for cystitis, and Cystistat is a derivative of hyaluronic acid. Objectives: This clinical trial aimed at evaluating the effects of intravesical instillation of Cystistat on symptoms of radiation cystitis and quality of life (QOL). Methods: A total of 58 patients with radiation cystitis were randomized in 2 groups (case: 30, control: 28). One group received intrav- esical Cystistat, the other received normal saline weekly for up to 4 weeks and then monthly for up to 2 months. Hematuria, Visual Analog scale (VAS) and QOL based on King’s Health questionnaire were compared before and 3, 6 and 9 months after intravesical instillation. Results: The mean age of the patients was 63.93 ± 10.89 years old. The mean of each sub-category of QOL and total score of QOL, as well as, VAS score were significantly improved in comparison to the control group at each time of follow-ups (P < 0.05). Hematuria was significantly different in the 3rd, 6th and 9th month of follow-ups (P < 0.05). Conclusions: Findings showed that patients with radiation cystitis could significantly benefit from intravesical instillation of HA, their hematuria would be successfully resolved rather than control group in addition to lowering the VAS score, so their QOL would be improved. Keywords: Sodium Hyaluronate, Hematuria, Hyaluronic Acid, Cystitis 1. Background Malignancy and the management methods of cancer can lead to several side effects by direct and indirect mech- anisms (1). Radiation cystitis is bladder lining urothelium inflammation as a complication of bladder irradiation due to pelvic organs malignancies (2). Pelvic organs malignan- cies are more common in men. However, prostate (3-7) and bladder cancer in men and uterine and ovarian can- cer in women are more common than pelvic organs ma- lignancies (8). Radiation therapy (RT) is a therapeutic op- tion to manage the pelvic organs malignancies and blad- der is one of the organs irritating during pelvic region radi- ation, 6% - 21% of these patients experienced lower urinary tract symptoms (LUTS) and 9% of men who radiated due to prostate cancer suffered from moderate to severe radi- ation cystitis symptoms (2, 9, 10). Radiation-induced cysti- tis symptoms vary from microscopic hematuria and LUTS to gross hematuria, urinary incontinence, fistulae forma- tion, and death (11). The concept of a defective glycosaminoglycan (GAG) barrier is thought to be related to the pathogenesis of sev- eral vesical situations, including urinary tract infection, calculi, idiopathic detrusor overactivity, interstitial cystitis (IC), and chemical or radiation cystitis, as such may assign different approaches to the management of those diseases (12, 13). There is an increasing body of evidence that introduces Copyright © 2020, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.