Patients
In total, 360 patients with locally advanced body/tail pancreatic cancer were reviewed in 8 centers, in which 237 patients diagnosed met the inclusion criterion. Diagnoses were confirmed by histological examination and either clinical or radiological findings. The inclusion criteria for the study were as follows: (1) pathologically or radiologically-diagnosed pancreatic cancer in the body/tail ; (2) tumor deemed unresectable due to the advanced stage of the disease as determined by TNM staging according to AJCC [2], which included stageⅡA and beyond; (3) No other confirmed malignant tumors. The exclusion criteria were as follows: (1) patients with mental disorders or with severe cardiopulmonary dysfunction or advanced cachexia, (2) Multiple metastases throughout the body, (3) insufficient coagulation (platelets <30×10/L).
Classification
Patients were assigned to three groups according to their treatment: group A, routine intravenous chemotherapy; group B, transcatheter arterial infusion (TAI) chemotherapy; group C, TAI combined with radioactive particles as therapeutic.
Routine intravenous chemotherapy
For the control group, concurrent chemotherapy was performed. This involved the intravenous administration of GEM 800-1000 mg/m2, no less than 30 min, once a week for 2 weeks, breaking for 1 week, and starting for another course of treatment, totally four courses.
Transcatheter arterial infusion (TAI) chemotherapy
For the TAI treatment group, a 5-Fr arterial sheath was placed in the right femoral artery under local anesthesia and the celiac trunk was selected by 5-Fr RH catheter under digital subtraction angiography (DSA). Then, a combination of GEM 800–1000 mg/m2, was injected via the RH catheter for 2 h at 1/2 dosage, and so was the 5-fluorourcil (FU) 500 mg/m2 but for 20 h.
Radioactive I125 particle implantation
Patients in the TAI combined treatment group received arterial infusion combined with ablation or radioactive particles. For radioactive I125 particle implantation in the TAI combined treatment group, patients first underwent CT (uMI-510 PET-CT, United Imaging, Shanghai, China), and the images were entered into a treatment plan system (TPS, Astro Tech Ltd, Beijing, China). The gross tumor volume (GTV) was confirmed by analysis of the scans by a medical specialist, and 0.5–1.0 cm was added to the boundary of the GTV to include the periphery of the tumor. Then, implantation of I125 radiological particles (radioactivity, 0.55–0.75 mCi; dose, 120–140Gy; dose rate, 0.05–0.10Gy h21; half-life, 59.6 days; effective radius, 1.72 cm; Zhibo Bio-Tech Ltd, Beijing, China) was performed at the periphery of the tumors. The radioactive dose was evaluated 1 week after implantation, and a D90 (the dose to 90% of the volume) of 60–140 Gy was expected. If the actual dose was lower than this, implantation could be repeated.
Therapeutic effect
Changes in imaging and OS, as well as 6, 12, 18 -month survival rates, were used as indicators of efficacy of the treatment. The treatment response was evaluated 4–6 weeks after each treatment using the modified Response Evaluation Criteria in Solid Tumors (mRECIST).
A complete response (CR) was defined as disappearance of any intratumoral arterial enhancement in all lesions; a partial response (PR) was defined as a 30% decrease in the sum of the diameters of viable (contrast enhancement in the arterial phase) lesions; progressive disease (PD) was defined as an increase of 20% in the sum of the diameters of viable lesions; and stable disease (SD) was defined as any case that did not qualify as either PR or PD. The two largest foci were selected among the multifocal lesions for measurement. CR and PR were considered as valid. OS refers to the time starting at initial interventional therapy until death or final follow-up (December 2015).
Follow-up
Follow-up of the patients was conducted from January, 2009, to December, 2015, to assess patient survival. Of the 237 patients enrolled in the study, 9 cases were lost at follow-up, constituting a loss rate of 3.80%.
Statistical analysis
Data were analyzed using the SPSS® version 16.0 software. OS, 6, 12, 18 -month survival rates in the three groups were compared by analysis of variance (ANOVA). OS rates were also estimated by the Kaplan–Meier method, and survival differences were analyzed by the log-rank test. P<0.05 was considered statistically significant.