Effectiveness and security of CT-guided percutaneous implantation of 125I seeds in pancreatic carcinoma

Objective:

To assess the effectiveness and security of CT-guided percutaneous implantation of iodine-125 (¹²⁵I)-labelled seeds in pancreatic carcinoma.

Methods:

A total of 36 patients (25 males and 11 females) with an average age of 57 years (range, 39–84 years) were enrolled and categorized into Stage III (27 cases) and Stage IV (9 cases) of pancreatic cancer. There were 3 tumours in the pancreatic head and 33 tumours in the pancreatic body or tail. The average diameter of the tumours was 37.1 mm (range, 15–65 mm). The implantation of ¹²⁵I seeds was performed by using 18-G needles (length, 150–200 mm) through the anterior, lateral and posterior approaches. Then, ¹²⁵I seeds were loaded and released into the lesions.

Results:

Implantations were performed via the anterior (23 patients), lateral (9 patients) and posterior (4 patients) approaches. During implantation, 3–14 punctures were performed for each patient, and a total of 164 punctures were recorded. Meanwhile, a total of 657 seeds were implanted with an average of 25.27 (range, 12–50) seeds per patient, and the success rate was 100%. The activity of each seed ranged from 0.55 to 0.65 mCi. A main adverse event occurred in one puncture and minor events in seven punctures. No significant relationship between the punctures or adverse events was identified. No serious complication was detected after the implantations during follow-up visits.

Conclusion:

This study suggested that CT-guided percutaneous implantation of ¹²⁵I seeds in a pancreatic carcinoma was relatively safe and effective for treating unresectable pancreatic cancer.

Advances in knowledge:

The CT-guided percutaneous implantation of ¹²⁵I seeds in unresectable pancreatic cancer showed highly successful rates without serious complications.Pancreatic cancer is the sixth most common cause of cancer-related deaths in China and the fourth worldwide.¹ The life quality of a patient with pancreatic cancer is severely influenced, since pancreatic cancer develops rapidly and can lead to abdominal pain, weight loss and jaundice.² Clinically, early pancreatic cancer does not cause obvious symptoms, while the later symptoms are usually non-specific and varied.³ As a result, most patients are diagnosed with mid- and terminal-staged pancreatic cancer that cannot be removed surgically. Although 15–20% of patients are diagnosed at an early stage, only 20–25% of them may survive more than 5 years after a tumour resection.⁴ For all stages of pancreatic cancer, the 5-year relative survival rate is 6%, whereas the 5-year survival rate is approximately 15% for a local tumour.⁵ Local control and distant metastases are the major factors that affect prognoses.⁶ During the past decades, the treatment outcome of locally advanced pancreatic carcinoma has not been improved significantly.⁷Currently, comprehensive therapy (radiotherapy plus chemotherapy) is the most common treatment for locally advanced pancreatic carcinoma.^8,9 Radioactive seeds, interstitial brachytherapy¹⁰ and conformal radiotherapy,⁷ show great curative effects on local control. The implantation methods include intra-operative and ultrasound- and CT-guided implantations.^10–12With the development of modern medical imaging technology, the CT-guided percutaneous implantation technique has been widely applied in clinics.^12,13 Additionally, CT-guided implantation of iodine-125 (¹²⁵I)-labelled seeds shows precision position, minimal invasion and great effectiveness. Also, the slow and continuous release of ¹²⁵I seeds has been radiobiologically advantageous, allowing the repair of non-lethal damage and re-oxygenation of hypoxic areas in normal tissues.⁷ However, the security of percutaneous implantation guided by CT scanning is still contradictory, because the pancreas is surrounded by the liver, stomach, intestines, spleen, kidney and blood vessels.In this present study, we retrospectively analysed 36 cases with unresectable pancreatic carcinoma who underwent CT-guided percutaneous implantation of ¹²⁵I seeds. The security of CT-guided percutaneous implantation of ¹²⁵I seeds in pancreatic carcinoma was assessed, which might provide the basis for individual treatment of CT-guided percutaneous implantation.