Pretreatment tumor volume as a prognostic factor in metastatic colorectal cancer treated with selective internal radiation to the liver using yttrium-90 resin microspheres

Abstract

Background: Yttrium-90 ( 90 Y)-resin microspheres can prolong intrahepatic disease control and improve overall survival (OS) in patients with metastatic colorectal cancer (CRC). Prognostic factors for improved outcomes in patients undergoing selective internal radiation therapy (SIRT) have been studied, but the relationship between pre-SIRT liver tumor volume and outcomes has not well described. Methods: We retrospectively reviewed the records of patients with metastatic CRC who were treated at our institution with 90 Y-resin microspheres. Each patient underwent either MR or CT imaging of the liver with intravenous (IV) contrast before and within ~2-3 months after SIRT. Imaging data were transferred into our treatment planning system. Each metastatic liver lesion was contoured, and the volume of each lesion was summed to determine the total liver tumor volume at a given time point. We evaluated whether pretreatment liver tumor volume was related to OS. We also evaluated the relationship between pre-SIRT tumor volume and radiographic treatment response by either unidimensional Response Evaluation Criteria in Solid Tumors (RECIST) or three-dimensional volumetric criteria. Results: We included 60 patients with a median age of 59 years (range, 38-97 years); 60% of patients received sequential lobar treatment. The median number of chemotherapy cycles received prior to SIRT was 2. Median follow-up from first SIRT was 8.9 months. Pre-and post-SIRT tumor volumes were primarily calculated on CT (87%). The median pre-SIRT tumor volume was 77 cc (range, 4.5-2,170.4 cc). The median intervals between the first SIRT and the first, second, and third follow-up scans were 2.2, 4.4, and 7.7 months, respectively. No patient experienced a radiographic complete response. Pretreatment volume was a significant predictor for estimating the odds of a patient having stable disease or partial response using volumetric response criteria at first (P=0.016), second (P=0.023), and third (P=0.015) follow-ups. For each unit increase in log volume, a patient's odds of having a stable or partial response were 0.57, 0.63, and 0.61 times as likely at first, second, and third follow-up, respectively. OS was not significantly associated with pretreatment tumor volume. Conclusions: Patients with metastatic CRC with larger overall pretreatment liver tumor volumes, regardless of number of individual liver lesions, are less likely to have radiographic evidence of stable disease or partial response following SIRT using volumetric response criteria. However, pretreatment volume was not significantly associated with OS, and thus SIRT should be considered for patients with larger pretreatment volumetric tumor burden.

Histopathological changes resulting from selective internal radiotherapy (SIRT)

“…The recently published SIRFLOX data demonstrate that SIRT combined with first‐line chemotherapy provided a prolonged control of colorectal liver metastases but failed to improve progression‐free survival . However, the clinical and radiological response rates after SIRT are highly variable, and a complete response is uncommon . When we analyzed the effects of internal radiation on liver tumors on the microscopic level, our data supported the highly variable clinical data: one of our patients showed a complete pathological response, while most of the patients showed a minimal (43%) or partial pathological response (43%).…”

“…3 However, the clinical and radiological response rates after SIRT are highly variable, and a complete response is uncommon. 20 When we analyzed the effects of internal radiation on liver tumors on the microscopic level, our data supported the highly variable clinical data: one of our patients showed a complete pathological response, while most of the patients showed a minimal (43%) or partial pathological response (43%). In nearly all cases (except 1 patient), a relevant proportion of viable tumor cells was found.…”

“…The method has been studied as a first‐line therapy for hepatic colorectal metastases in combination with second‐ or third‐line chemotherapy and as salvage therapy for chemotherapy‐refractory patients . These studies have demonstrated that SIRT can prolong intrahepatic disease control and improve overall survival . The recently published SIRFLOX data demonstrate that SIRT combined with first‐line chemotherapy provided a prolonged control of colorectal liver metastases but failed to improve progression‐free survival .…”

“…18,19 These studies have demonstrated that SIRT can prolong intrahepatic disease control and improve overall survival. 20 The recently published SIRFLOX data demonstrate that SIRT combined with first-line chemotherapy provided a prolonged control of colorectal liver metastases but failed to improve progression-free survival. 3 However, the clinical and radiological response rates after SIRT are highly variable, and a complete response is uncommon.…”

Prognostic influence of 3-dimensional tumor volume on breast cancer compared to conventional 1-dimensional tumor size

“…The application of Tv as a prognostic indicator was applied in previous research focused on various types of malignant tumors including: colorectal cancer [ 4 ], esophageal cancer [ 5 ], laryngeal cancer [ 6 ], hepatocellular carcinoma [ 7 8 ], lung cancer [ 9 ], renal cell carcinoma [ 10 ], gastric cancer [ 11 12 ], malignant melanoma [ 13 ], thyroid cancer [ 14 ], and others [ 15 16 17 18 19 ]. Several papers have reported the prognostic advantages of applying Tv to breast cancer cases [ 20 21 22 23 24 25 26 27 ].…”