Original Article
Proof-of-concept assessment of metastatic sentinel node involvement by 18F-FDG positron emission tomography/computerized tomography and prediction of disease progression and survival in colorectal cancer patients with peritoneal carcinomatosis
Abstract
Background: We prospectively studied the clinical significance of metastatic portal, celiac and superior mesenteric (PCS) lymph nodes with positron emission tomography/computerized tomography (PET/CT) in relation to metabolic tumor burden, prediction of disease progression and survival in patients with peritoneal carcinomatosis (PC) from colorectal cancer (CRC).
Methods: Seventy-two patients who underwent colonic cancer resection were prospectively recruited into a 3-year longitudinal study with serial 18F-FDG PET/CT (total 310 scans) examining for PC and/or metastatic PCS nodes. PCS-positive patients were subdivided into 3 groups based on the timing of detection of PCS nodal positivity relative to the detection of peritoneal carcinomatosis; group (I) had positive nodes detected before PC; group (II) had PCS and PC detected in tandem while group (III) had nodal positivity detected after detection of PC. PC burden was quantified by a functional index, PCTLG, defined as “summation of total lesion glycolysis (TLG)” of all PC lesions on the first PET study to detect PC. Predictors for 3-year overall survival (OS) were analyzed.
Results: PCS nodes were positive in 26/72 (36%, Groups I + II + III), negative in 46/72 (64%, Group IV) patients. Mean PCTLG was significantly higher in PCS-positive (106±73) compared with PCS-negative (26±21) patients; however, no significant difference was apparent between PCS-positive groups [PCTLGmean =104±72 (I), 138±73 (II), 50±33 (III); one-way ANOVA, P>0.05]. Patients with positive-PCS nodes or PCTLG ≥27 had significantly shorter median survival and lower 3-year OS rate (PCS+: 16 months, 7.7%; PCTLG ≥27:18 months, 14.3%).
Conclusions: PCS nodal positivity appears to predict development of peritoneal carcinomatosis in which setting it appears to correlate with tumor burden and overall survival. PCS nodes may represent a sentinel tier of drainage and spread in colon cancer.
Methods: Seventy-two patients who underwent colonic cancer resection were prospectively recruited into a 3-year longitudinal study with serial 18F-FDG PET/CT (total 310 scans) examining for PC and/or metastatic PCS nodes. PCS-positive patients were subdivided into 3 groups based on the timing of detection of PCS nodal positivity relative to the detection of peritoneal carcinomatosis; group (I) had positive nodes detected before PC; group (II) had PCS and PC detected in tandem while group (III) had nodal positivity detected after detection of PC. PC burden was quantified by a functional index, PCTLG, defined as “summation of total lesion glycolysis (TLG)” of all PC lesions on the first PET study to detect PC. Predictors for 3-year overall survival (OS) were analyzed.
Results: PCS nodes were positive in 26/72 (36%, Groups I + II + III), negative in 46/72 (64%, Group IV) patients. Mean PCTLG was significantly higher in PCS-positive (106±73) compared with PCS-negative (26±21) patients; however, no significant difference was apparent between PCS-positive groups [PCTLGmean =104±72 (I), 138±73 (II), 50±33 (III); one-way ANOVA, P>0.05]. Patients with positive-PCS nodes or PCTLG ≥27 had significantly shorter median survival and lower 3-year OS rate (PCS+: 16 months, 7.7%; PCTLG ≥27:18 months, 14.3%).
Conclusions: PCS nodal positivity appears to predict development of peritoneal carcinomatosis in which setting it appears to correlate with tumor burden and overall survival. PCS nodes may represent a sentinel tier of drainage and spread in colon cancer.
