Histopathologic consideration of fiducial gold markers inserted for real-time tumor-tracking radiotherapy against lung cancer.

PURPOSE: Internal fiducial gold markers, safely inserted with bronchoscopy, have been used in real-time tumor-tracking radiotherapy for lung cancer. We investigated the histopathologic findings at several points after the insertion of the gold markers. METHODS AND MATERIALS: Sixteen gold markers were inserted for preoperative marking in 7 patients who subsequently underwent partial resection of tumors by video-assisted thoracoscopic surgery within 7 days. RESULTS: Fibrotic changes and hyperplasia of type 2 pneumocytes around the markers were seen 5 or 7 days after insertion, and fibrin exudation without fibrosis was detected 1 or 2 days after insertion. CONCLUSIONS: Because fibroblastic changes start approximately 5 days after gold marker insertion, real-time tumor-tracking radiotherapy should be started >5 days after gold marker insertion.

Insertion and fixation of fiducial markers for setup and tracking of lung tumors in radiotherapy.

PURPOSE: Internal 1.5-mm fiducial markers were used in real-time tumor-tracking radiotherapy (RT) for lung cancer. The fixation rate of the markers using the bronchial insertion technique, reliability of the setup using markers around the target volume, dislocation of the markers after real-time tumor-tracking RT, and long-term toxicity of marker insertion were investigated. METHODS AND MATERIALS: Between July 2000 and April 2004, 154 gold markers were inserted into 57 patients with peripheral lung cancer. The distances between the implanted markers in 198 measurements in 71 set-ups in 11 patients were measured using two sets of orthogonal diagnostic X-ray images of the real-time tumor-tracking RT system. The distance between the markers and the chest wall was also measured in a transaxial CT image on 186 occasions in 48 patients during treatment planning and during follow-up. The median treatment time was 6 days (range, 4-14 days). RESULTS: In 115 (75%) of the 154 inserted markers, the gold marker was detected throughout the treatment period. In 122 markers detected at CT planning, 115 (94%) were detected until the end of treatment. The variation in the distances between the implanted markers was within +/-2 mm in 95% and +/-1 mm in 80% during treatment. The variation in the distances between the implanted markers was >2 mm in at least one direction in 9% of the setups for which reexamination with a CT scan was indicated. The fixation rate in the left upper lobe was lower than in the other lobes. A statistically significant relationship was found between a shorter distance between the markers and the chest wall and the fixation rate, suggesting that the markers in the smaller bronchial lumens fixed better than those in the larger lumens. A learning curve among the endoscopists was suggested in the fixation rate. The distance between the markers and the chest wall changed significantly within a median of 44 days (range, 16-181 days) after treatment. CONCLUSION: The fixation of markers into the bronchial tree was useful for the setup for peripheral lung cancer and had an accuracy of +/-2 mm during the 1-2-week treatment period. The relationship between the markers and tumor can change significantly after 2 weeks, suggesting that adaptive four-dimensional RT is required.

Analysis of the response and toxicity to gefitinib of non-small cell lung cancer.

BACKGROUND: Gefitinib is an oral agent that inhibits the tyrosine kinase of epidermal growth factor receptor (EGFR), which had antitumor activity in patients with previously treated non-small cell lung cancer (NSCLC). We analyzed the efficacy, toxicity and overall survival time of gefitinib treatment in patients with NSCLC. PATIENTS AND METHODS: One hundred and twenty-two patients with NSCLC, who received gefitinib between 2002 and 2004 in our institutes, were evaluated retrospectively. RESULTS: The objective response rate was 24.6%. The variables identified as significant in univariate analysis included gender and smoking habit. The median overall survival time was 14.4 months. Significant variables associated with improved survival included good performance status (PS), female, adenocarcinoma and never smoked status, while never smoked status and good PS were independent prognostic factors in multivariate analysis. Four patients (3.3%) developed interstitial pneumonitis associated with gefitinib. CONCLUSION: Gefitinib showed favorable anti-tumor activity in females, never smokers and adenocarcinoma.

Phase I trial of carboplatin and weekly paclitaxel in patients with advanced non-small-cell lung cancer.

OBJECTIVE: This study was designed to determine the maximum tolerated dose of paclitaxel administered weekly in combination with carboplatin and to assess its dose limiting toxicity and preliminary activity in patients with previously untreated, advanced non-small-cell lung cancer. METHODS: Carboplatin was administered at a fixed dose that maintained an area under the curve of 6. Paclitaxel was given over 1 h once a week for 3 weeks starting at 60 mg/m(2) and escalated in 10 mg/m(2) increments. RESULTS: Twenty-one patients were treated with six dose levels (60, 70, 80, 90, 100, 110 mg/m(2)) of paclitaxel. The dose limiting toxicity was infection and the maximum tolerated dose was 110 mg/m(2). Nine of 21 (42.9%) patients demonstrated a therapeutic response. CONCLUSION: Weekly paclitaxel and carboplatin were well tolerated. Based on our results, 100 mg/m(2) of paclitaxel for 3 weeks of a 4-week cycle, in combination with carboplatin, was recommended for a phase II study.