CT-guided Percutaneous Implantation Of ¹²⁵I Seeds For Treatment Of Early Stage Lung Cancer

Objective: To evaluate the clinical efficacy of CT-guided percutaneous ¹²⁵I radioactive seeds implanted in early stage lung cancer. Methods: The data was obtained from six patients, who were diagnosed with early lung cancer and underwent CT guided percutaneous implantation of ¹²⁵I radioactive seeds in our hospital from June 2012 to April 2015. The data was retrospectively analyzed for this study:, four patients were diagnosed with squamous carcinoma, one was diagnosed with glandular cancer, and one was diagnosed with small cell lung cancer. All cases were further confirmed pathologically. These patients had refused surgery, but all of them had agreed to the radioactive particles implantation procedure. Application of TPS software helped to calculate the therapeutic dose, the quantity of seeds that needed to be implanted, the spacing and distribution of planting site in the therapy area and adjacent tissues. Based on the principle of uniform implantation, a total of 226 radioactive seeds were implanted with spacing of 0.5 1.0 cm. Patient follow-up for CT examination was conducted at 1, 3, 6, 12, 18, 24,30, 36 months post-implantation. RECIST guidelines for efficacy evaluation consisted of the following: disappearance of all target lesions; any pathological lymph nodes?whether target or non-target? must have a reduction in short axis of <10mm, and is defined as complete remission?CR?; at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters, is called partial remission?PR?; no sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease?PD?, is defined as stable disease?SD?; at least a 20% increase in the sum of diameters of target lesions taking as reference the smallest sum on study?this includes the baseline sum if that is the smallest in study?; in addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5mm?Note: the appearance of one or more new lesions is also considered progression?, which is called progressive diseasePD). Results: All six patients' tumors were reduced significantly after radioactive ¹²⁵I seeds were implanted. In the first month after surgery, two patients were in complete remissionand four patients were in partial remission. The effective rate was 6/6 and the disease control rate was 6/6. A follow-uo in the third month, revealed that two patients were in complete remission, four patients were in partial remission. The effective rate was 6/6 and the disease control rate was 6/6. In the sixth month, five patients were followed up. Three of these were in complete remission, while two were in partial remission; In the twelfth month, three patients were still in complete remission, one was in partial remission and one patient was diagnosed with progressive disease, with metastasis of the primary lesion. This patient was re- implanted with radioactive ¹²⁵I seeds to treat the recurrence of lesions and pulmonary CT was performed after the sixth month. The tumor size had decreased by 27.32%, and the patient was considered to have SD. In the eighteenth month, of the four remaining patients, three were still in complete remission, and one was still in partial remission. In the twenty-fourth month, three patients were followed up and were in complete remission. In the thirty-sixth month, one patient was followed up and diagnosed with PD. None of the patients showed any serious complications during the follow-up period, like radiation pneumonia, esophageal fistula or seeds shedding. Conclusions: The clinical data suggests that ¹²⁵I radioactive seeds are safe and reliable for treating early lung cancer. Further studies need to be carried out to gain more insight.