Artificial ascites for organs at risk sparing in intrapelvic brachytherapy: a case report of recurrent uterine cervical carcinoma adjacent to the bowel.

Naoya Murakami,Kana Takahashi,Koji Masui,Satoshi Shima,Yuko Nakayama,Kotaro Iijima,Nikolaos Tselis,Jun Itami,Hiroshi Igaki,Koji Inaba,Ken Yoshida,Kae Okuma,Masakazu Uematsu,Tairo Kashihara,Yoshiaki Takagawa

doi:10.1259/bjrcr.20180067

Abstract

Artificial ascites has been reported as an effective technique to reduce the risk of thermal injury in radiofrequency ablation of liver tumors by increasing the distance of collateral organs located next to the ablated sites. In this case report we share our experience with artificial ascites in an attempt to reduce the toxicity of collateral adjacent organs in the setting of re-irradiation for recurrent cervical cancer. A 52-year-old female who developed local recurrence after definitive radiation therapy was treated with interstitial re-irradiation by means of image-guided, (single-implant/multi fraction) high-dose-rate brachytherapy. Because the sigmoid colon was in close proximity to the recurrent tumor lesion, artificial ascites was generated before each treatment fraction by percutaneous injection of a defined amount of saline solution through the abdominal wall to create additional space between the two volumes. Artificial ascites showed a dosimetric improvement by reducing the sigmoid colon D0.1cc per fraction from 286 cGy before to 189 cGy after saline injection. No severe complication was associated with the injection procedure.

Highlights

Radiation therapy (RT) plays an important role in the management of uterine cervical cancer patients both as primary[1,2,3,4] as well as postoperative adjuvant treatment.[5,6]when patients develop locally recurrent disease in pre-irradiated volumes, standard curative treatment consists of total pelvic exenteration (TPE)[7,8] because repeat dose-escalated external beam radiation therapy (EBRT)to the same localized site, technically feasible, is not unreservedly implemented because of the high risk of severe side effects on account of previous RT which lower patient’s quality of life significantly.[9]
When patients develop locally recurrent disease in pre-irradiated volumes, standard curative treatment consists of total pelvic exenteration (TPE)[7,8] because repeat dose-escalated external beam radiation therapy (EBRT)
From the standpoint of organs at risk (OARs) protection, artificial ascites has been used in interventional radiology to avoid diaphragm or gastrointestinal tract damage when treating liver tumors with radiofrequency ablation (RFA).[12,13,14,15]

Summary

Introduction

Radiation therapy (RT) plays an important role in the management of uterine cervical cancer patients both as primary[1,2,3,4] as well as postoperative adjuvant treatment.[5,6]. When patients develop locally recurrent disease in pre-irradiated volumes, standard curative treatment consists of total pelvic exenteration (TPE)[7,8] because repeat dose-escalated external beam radiation therapy (EBRT). There is a significant risk for thermal injury in the case of tumors abutting the diaphragm or close to the gastrointestinal tract, the bile duct, or the gallbladder For those clinical scenarios, artificial ascites has been proven to be an effective method to increase safety space between risk structures and tumor lesions. Our technique of image-guided salvage interstitial BRT for cervical cancer has been described elsewhere.[9,11,16] In the current case, treatment consisted of sole HDR BRT with 48 Gy total physical dose being delivered in 8 fractions at 6 Gy, applied twice-daily with an interfractional interval of at least 6 h. Written informed consent was obtained from the patient for artificial ascites injection and BRT treatment and this case report was approved by the Institutional Review Board of the National Cancer Center Hospital (approval number 2017–331) according to the ethical standards laid down in the Declaration of Helsinki

Discussion

Learning points