Economic impact of PET for selecting patients for surgical resection of colorectal cancer hepatic metastases: UK perspective

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1 Economic impact of PET for selecting patients for surgical resection of colorectal cancer hepatic metastases: UK perspective Poster No.: C-2139 Congress: ECR 2010 Type: Scientific Exhibit Topic: Molecular Imaging Authors: A. C. Sweet 1, D. W. Lee 2, R. A. Dann 1, G. I. Wilson 1 ; 1 Chalfont St. Giles/UK, 2 Waukesha, WI/US Keywords: 18F-FDG-PET, colorectal cancer liver metastases, cost analysis DOI: /ecr2010/C-2139 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 16

2 Purpose After apparently curative treatment for colorectal cancer up to 30% of patients may have metastatic disease in the liver [1,2]. Hepatic resection is the only potentially curative treatment for a subset of these patients. Despite work-up with diagnostic imaging up to 40% of patients eligible for surgery prove to have unresectable liver metastases at the time of surgery [3-6]. Thus more accurate staging of patients with colorectal liver metastases is needed to select patients who will benefit from surgery. The addition of 18F-FDG PET as a staging modality has been shown to have good sensitivity and to change the treatment plan in 25-30% of patients [7-10]. A recent clinical trial showed that using PET to select patients with hepatic metastases from colorectal cancer (CRC) for surgery reduced the relative risk of futile laparotomy by 38%, compared to CT only [11]. The objective of this study was to estimate the economic impact of using PET to select patients for surgical resection of CRC hepatic metastases in the UK. Methods and Materials A simple decision-analytic model compared total treatment costs (imaging, surgery, chemotherapy) for patients who did or did not have PET to inform hepatic resection planning. The model evaluated which strategy (CT only vs. CT+PET) was less costly from a UK NHS perspective. The base case model mirrored the clinical pathway and clinical results [Fig.1: Table 1] on page 4 reported by Ruers et al. [11]. [Fig. 2: Diagram A] on page 4 In the trial, PET results indicating a change in clinical findings or treatment were disregarded for 13% of patients. [Fig. 3: Table 2]on page 5 A second scenario was evaluated utilizing the data on patients with PET findings that were disregarded to show the full potential impact of PET. [Fig.4: Diagram B] on page 6 Page 2 of 16

3 Costs included in the analysis were limited to the costs of the PET scan, liver surgery and chemotherapy for unresectable disease or tumour recurrence. UK costs for PET, liver resection, exploratory laparotomy and chemotherapy were obtained from published and government sources. [Fig.5: Table 3] on page 7 Imaging and surgical procedural costs were taken from NHS Payment by Results tariffs (2009) [12]. For liver surgery, the procedure codes were taken from the HRG4 GA chapter listing. A weighted average cost of liver surgery was calculated based on the case mix for the different hepatic surgical procedure codes as reported in the NHS Hospital Episode statistics for [13]. For patients who underwent laparotomy but for whom liver surgery was cancelled due to finding extra-hepatic disease or more extensive liver disease, the cost of laparotomy was based on exploratory surgery code rather than the full cost of liver resection. It was assumed that patients who are unresectable or who have tumour recurrence within 6 months or who have extra-hepatic disease receive chemotherapy [11]. Chemotherapy costs were taken from previously published studies [14]. For the base case the chemotherapy regimen was assumed to comprise first line treatment of 5-fluorouracil (FU) / leucovorin (FA) and oxaliplatin followed by best supportive care. For this regimen, Hind et al calculated a mean cost per patient of 13,186. For sensitivity analysis on the cost of chemotherapy, we used an upper estimate based on a pessimistic cost calculation by Hind et al ( 17,808 per patient). For a lower estimate, we used the estimate of the average unit cost of palliative chemotherapy for 6 months from Beard et al ( 6669) [15]. The addition of bevacizumab to the regimen by Ruers et al was not included as this is not approved by NICE in the UK for these patients [16]. Page 3 of 16

4 Images for this section: Fig. 1: Table 1: Outcome measures for patients as reported by Ruers et al Page 4 of 16

5 Fig. 2: Diagram A: Decision-analytic model showing the impact of PET on clinical findings and hepatic resection planning (base case as treated in trial) Page 5 of 16

6 Fig. 3: Table 2: 18F-FDG PET findings as reported by Ruers et al Page 6 of 16

7 Fig. 4: Diagram B: Decision-analytic model showing the potential impact of PET when treatment is concordant with PET findings (scenario 2) Page 7 of 16

8 Fig. 5: Table 3: Model inputs: procedure costs Page 8 of 16

9 Results Diagram A (Fig.1) on page 9 shows the treatment received by patients, and associated costs, during the trial. The total costs for the control arm are 769,925 and for the PET arm 689,117. [Fig. 2: Table 4] on page 10 In the base case, adding PET to the work-up to select patients for hepatic surgery reduced total per-patient treatment costs by an estimated 1077 compared to CT only. [Fig.2: Table 4] on page 10 These cost savings were primarily driven by a 30% reduction in the number of patients who received chemotherapy as a result of information obtained by PET. Depending on the chemotherapy regimen cost, the total per-patient treatment costs were reduced by an estimated compared to CT only. [Fig.3: Table 5] on page 11 The costs are also sensitive to clinicians' usage of PET findings. Fig.4: Diagram B on page 12 shows how PET could have changed patient management for an additional 10 patients for whom the clinical team disregarded the PET results. For these patients the PET results predicted more extensive disease and that surgery was unnecessary. In this scenario, adding PET to the work-up reduced total per patient treatment costs y an estimated 1619 compared to CT only. [Fig.5: Table 6] on page 13 This analysis indicates that had all the PET findings been followed, the PET strategy could have reduced per-patient cost by an additional 541. Images for this section: Page 9 of 16

10 Fig. 1: Diagram A: Decision-analytic model showing the impact of PET on clinical findings and hepatic resection planning (base case as treated in trial) Page 10 of 16

11 Fig. 2: Table 4: Base case results of the impact of PET on patient costs Page 11 of 16

12 Fig. 3: Table 5: Impact of varying the cost of chemotherapy treatment on patient costs Page 12 of 16

13 Fig. 4: Diagram B: Decision-analytic model showing the potential impact of PET when treatment is concordant with PET findings (scenario 2) Page 13 of 16

14 Fig. 5: Table 6: Scenario 2: Results of the impact of PET on patient costs when treatment is concordant with PET findings Page 14 of 16

15 Conclusion The addition of PET for hepatic resection planning has been shown to reduce the number of futile laparotomies. This analysis shows the potential of PET to reduce UK costs for the treatment of colorectal liver metastases, especially when treatment decisions are concordant with PET findings. References 1) Galandiuk S, et al. Patterns of recurrence after curative resection of carcinoma of the colon and rectum. Surg Gynecol Obstet. 1992;174: ) Russell AH, et al. Adenocarcinoma of the retroperitoneal ascending and descending colon: sites of initial dissemination and clinical patterns of recurrence following surgery alone. Int J Radiat Oncol Biol Phys. 1983; 9: ) Steele G Jr, et al. A prospective evaluation of hepatic resection for colorectal carcinoma metastases to the liver: Gastrointestinal Tumor Study Group Protocol J Clin Oncol. 1991;9: ) Wiering B, Krabbe PF, Dekker HM, Oyen WJ, Ruers TJ. The role of FDG-PET in the selection of patients with colorectal liver metastases. Ann Surg Oncol. 2007;14: ) Gibbs JF, et al. Intraoperative determinants of unresectability for patients with colorectal hepatic metastases. Cancer. 1998;82: ) Mann CD, et al. Clinical Risk Score predicts yield of staging laparoscopy in patients with colorectal liver metastases. Br J Surg. 2007;94: ) Huebner RH, et al. A meta-analysis of the literature for whole-body FDG PET detection of recurrent colorectal cancer. J Nucl Med. 2000;41: ) Joyce DL, et al. Preoperative positron emission tomography to evaluate potentially resectable hepatic colorectal metastases. Arch Surg. 2006;141: ) Wiering B, et al. The impact of fluor-18-deoxyglucose-positron emission tomography in the management of colorectal liver metastases. Cancer. 2005;104: Page 15 of 16

16 10) Yang YY, Fleshman JW, Strasberg SM. Detection and management of extrahepatic colorectal cancer in patients with resectable liver metastases. J Gastrointest Surg. 2007;11: ) Ruers TJM, et al. Improved Selection of Patients for Hepatic Surgery of Colorectal Liver Metastases with 18F-FDG PET: A Randomized Study. J. Nucl. Med. 2009; 50: ) NHS Payment by Results (PbR) arrangements for : HRG tariff information, Dept. Health, PublicationsPolicyAndGuidance/DH_ ) The NHS Information Centre, Hospital Episode Statistics for England. Inpatient statistics, ) Hind D, et al. The use of irinotecan, oxaliplatin and raltitrexed for the treatment of advanced colorectal cancer: systematic review and economic evaluation. Health Technology Assessment 2008; Vol. 12: No ) Beard S, et al Hepatic resection for colorectal liver metastases: a cost-effectiveness analysis. Ann Surg 2000; 232: ) NICE Bevacizumab and cetuximab for the treatment of metastatic colorectal cancer. Technology Appraisal guidance TA118 May 2007 Personal Information A.C. Sweet, GE Healthcare, Chalfont St. Giles, GB Alison.C.Sweet@ge.com Research funding provided by GE Healthcare. Page 16 of 16