Implication of FDG-PET/CT in patients with potentially operable colorectal lung metastases

Objectives This prospective study assessed the role of F-18-FDG-PET/CT in clinical staging for patients with colorectal cancer planned for pulmonary metastasectomy by thoracotomy or video-assisted surgery. Patients and methods In addition to conventional imaging, we performed 86 F-18-FDG-PET/CT studies in 76 patients with potentially resectable metastatic colorectal lung metastases. We then investigated the effect that PET/CT had on further clinical management. Based on the results from the 47 thoracotomies performed, we compared the number of pulmonary metastases discovered after histologic examination with the number predicted by the conventional computed tomography (CT) as an independent part of the F-18-FDG-PET/CT examination and by the F-18-FDG-PET component. Results F-18-FDG-PET/CT led to changes in treatment regime and diagnostic planning in many patients. In five patients PET/CT revealed previously undetected local recurrence of the primary colorectal cancer, in four patients hepatic metastases, in three patients bone metastases, in two patients soft-tissue metastases, and in three patients histologically preoperatively proven N2 or N3 station lymph node involvement. These all constituted exclusion criteria, and consequently the previously planned pulmonary metastasectomy was not performed. The sensitivity and positive predictive value (PPV) for detection of pulmonary metastases were 84.2% and 36.4% for CT and 75.0% and 61.6% for F-18-FDG-PET study. The calculated sensitivity, specificity, PPV, and NPV of F-18-FDG-PET/CT for detecting thoracic lymph node involvement were 85.7%, 93.0%, 66.7%, and 97.5%, respectively. Furthermore, we found that F-18-FDG-PET/CT may predict thoracic lymph node involvement based on the SUV of pulmonary nodules. Conclusions F-18-FDG-PET/CT has a clear role in the diagnostic workup for pulmonary metastatic colorectal cancer and may save patients from futile surgery. It cannot, however, be relied on to detect all possible pulmonary and nodal metastases, which surgeons must always consider when making treatment decisions.

Long-Term Outcomes in Percutaneous Radiofrequency Ablation for Histologically Proven Colorectal Lung Metastasis

Introduction To evaluate the long-term outcome of image-guided radiofrequency ablation (RFA) when treating histologically confirmed colorectal lung metastasis in terms of overall survival (OS), progression-free survival (PFS) and local tumour control (LTC). Materials and Methods Retrospective single-centre study. Consecutive RFA treatments of histologically proven lung colorectal metastases between 01/01/2008 and 31/12/14. The primary outcome was patient survival (OS and PFS). Secondary outcomes were local tumour progression (LTP) and complications. Prognostic factors associated with OS/ PFS were determined by univariate and multivariate analyses. Results Sixty patients (39 males: 21 females; median age 69 years) and 125 colorectal lung metastases were treated. Eighty percent (n = 48) also underwent lung surgery for lung metastases. Mean metastasis size (cm) was 1.4 ± 0.6 (range 0.3–4.0). Median number of RFA sessions was 1 (1–4). During follow-up (median 45.5 months), 45 patients died (75%). The estimated OS and PFS survival rates at 1, 3, 5, 7, 9 years were 96.7%, 74.7%, 44.1%, 27.5%, 16.3% (median OS, 52 months) and 66.7%, 31.2%, 25.9%, 21.2% and 5.9% (median PFS, 19 months). The LTC rate was 90% with 6 patients developing LTP with 1-, 2-, 3- and 4-year LTP rates of 3.3%, 8.3%, 10.0% and 10.0%. Progression-free interval < 1 year (P = 0.002, HR = 0.375) and total number of pulmonary metastases (≥ 3) treated (P = 0.037, HR = 0.480) were independent negative prognostic factors. Thirty-day mortality rate was 0% with no intra-procedural deaths. Conclusion The long-term OS and PFS following RFA for the treatment of histologically confirmed colorectal lung metastases demonstrate comparable oncological durability to surgery.