Primary peritoneal clear cell carcinoma treated with IMRT and interstitial HDR brachytherapy: a case report

Abstract

Primary peritoneal clear cell carcinoma (PP‐CCC), which is a rare tumor with poor prognosis, is typically managed with surgery and/or chemotherapy. We present a unique treatment approach for a patient with a pelvic PP‐CCC, consisting of postchemotherapy intensity‐modulated radiation therapy (IMRT) followed by interstitial high‐dose–rate (HDR) brachytherapy. A 54‐year‐old female with an inoperable pelvic‐supravaginal 5.6 cm T3N0M0 PP‐CCC tumor underwent treatment with 6 cycles of carboplatin and taxol chemotherapy. Postchemotherapy PET/CT scan revealed a residual 3.3 cm tumor. The patient underwent CT and MR planning simulation, and was treated with 50 Gy to the primary tumor and 45 Gy to the pelvis including the pelvic lymph nodes, using IMRT to spare bowel. Subsequently, the patient was treated with an interstitial HDR brachytherapy implant, planned using both CT and MR scans. A total dose of 15 Gy in 5 Gy fractions over two days was delivered with Ir‐192 HDR brachytherapy. The total prescribed equivalent 2 Gy dose (EQD2) to the HDR planning target volume (PTV) from both the EBRT and HDR treatments ranged between 63 and 68.8thinmathspaceGy2 due to differential dosing of the primary and pelvic targets. The patient tolerated radiotherapy well, except for mild diarrhea not requiring medication. There was no patient‐reported acute toxicity one month following the radiotherapy course. At four months following adjuvant radiation therapy, the patient had near complete resolution of local tumor on PET/CT without any radiation‐associated toxicity. However, the patient was noted to have metastatic disease outside of the radiation field, specifically lesions in the liver and bone. This case report illustrates the feasibility of the treatment of a pelvic PP‐CCC with IMRT followed by interstitial HDR brachytherapy boost, which resulted in near complete local tumor response without significant morbidity.PACS number: 87.55.‐x

Clear cell adenocarcinoma of the peritoneum: a case report and literature review

“…One report cited a multicystic mass with a multiseptate appearance and a heterogeneous solid part arising from the peritoneum, suggesting the occurrence of a CCAP [12]. …”

“…The search was limited to the English literature and CCAP cases. We identified 10 cases that are summarized in Table 1 [ 3 – 12 ]. These limited cases were reviewed to provide characteristics of CCAP and identify potentially effective treatments.…”

“…Eight cases received chemotherapy (seven postoperatively and one with primary chemotherapy). The chemotherapy regimens performed were TC [ 6 , 12 ], irinotecan hydrochloride + cisplatin (CPT-P) [ 9 ], and cyclophosphamide + carboplatin + cisplatin (CCP) [ 6 ].…”

“…The chemotherapy regimens performed were TC [ 6 , 12 ], irinotecan hydrochloride + cisplatin (CPT-P) [ 9 ], and cyclophosphamide + carboplatin + cisplatin (CCP) [ 6 ].…”

“…CCAP can closely resemble ovarian clear cell adenocarcinoma (OCC) and it is difficult to distinguish CCAP from OCC by preoperative imaging alone, especially if the tumor is located in the pelvis close to the ovary or uterus, even though the radiological features of CCAP have been reported in some cases. One report cited a multicystic mass with a multiseptate appearance and a heterogeneous solid part arising from the peritoneum, suggesting the occurrence of a CCAP [ 12 ].…”