[Reduced irradiation target volume of mediastinal lymph node drainage in conformal radiotherapy for patients with non-small cell lung cancer after thoracic surgery].

OBJECTIVE: To decrease lung and esophageal radiation injuries by reducing irradiation target volume of mediastinal lymph mode drainage in conformal radiotherapy (CRT) for patients with non-small cell lung cancer (NSCLC) after thoracic surgery. METHODS: Fifty-three patients with NSCLC were randomized into groups A and B to receive 3D-CRT after thoracic surgery. Patients in group A, according to conventional therapy, received preventive nodal irradiation (PNI) of the mediastinal lymph node drainage, and those in group B, according to pathological nodal staging after operation, did not have PNI of the metastasis-free area to reduce the clinical target volume (CTV). Patients in both groups were treated with conventional fractionated radiotherapy (CFRT) at 2 Gy in each fraction, and 5 fractions each week. All patients were followed up for two years to record their 2-year survival rate, local relapse of lymph node drainage and lung and esophageal radiation injuries. RESULTS: The total 2-year survival rate was 58.5%in these patients and comparable between the two groups. The rates of local regional relapse and recurrence out of the CTV were 13.8% and 3.4% in group A and 16.7% and 8.3% in group B, respectively (P=1 and P=0.571). The incidence of radiation pneumonia and lung fibrosis were 6.9% and 62.1% in group A and 0% and 58.3% in group B (P=0.459 and P=0.782), and that of radiation esogphagitis and esophagus stricture rates were 27.6% and 6.9% in group A and 12.5% and 4.2% in group B, respectively (P=0.039 and P=1). CONCLUSION: Reduced CTV does not warrant decrease in the local control but may lower the incidence of acute esophageal radiation injury in postoperative patients with NSCLC.

Three-dimensional conformal radiotherapy versus intracavitary brachytherapy for salvage treatment of locally persistent nasopharyngeal carcinoma.

PURPOSE: To compare the outcomes of three-dimensional conformal radiotherapy (3D-CRT) and intracavitary brachytherapy (ICBT) as salvage treatment for locally persistent nasopharyngeal carcinoma. METHODS AND MATERIALS: Between March 1994 and November 2001, a total of 117 patients with locally persistent nasopharyngeal carcinoma received salvage treatment for 2-8 weeks (median, 4 weeks) after a full course of conventional external beam RT. Of the 117 patients, 54 were salvaged with 3D-CRT (3D group) and 63 with ICBT (BT group). No statistically significant differences were found in the patient characteristics between the two groups (p >0.05). In the 3D group, the planning target volume for 3D-CRT was defined as the persistent disease plus a 5-mm margin; three to seven static conformal coplanar or noncoplanar portals were delivered for each fraction. The median salvage dose was 24 Gy (range, 18-38 Gy), with fraction size of 2.0 Gy/d. In the BT group, a median salvage dose of 20 Gy (range, 15-30 Gy) was delivered with a (192)Ir source, at 5 Gy/fraction, twice weekly. The brachytherapy dose was prescribed at a distance of 1 cm from the center of the surface as defined by the sources, irrespective of the extent of persistent disease. The actuarial rates of survival were estimated using the Kaplan-Meier method. Potential differences in the actuarial outcomes between groups were evaluated using the Mantel log-rank test. Multivariate analyses were performed with the Cox regression proportional hazards model. RESULTS: The 5-year actuarial rates of overall survival, disease-specific survival, and local failure-free survival for the 3D group and BT group were 64.50% vs. 55.78% (p = 0.33), 70.03% vs. 59.56% (p = 0.11), and 88.93% vs. 76.28% (p = 0.07), respectively. Subgroup analysis showed that the 5-year actuarial local failure-free survival rate of patients with initially diagnosed T3-T4 disease for the 3D group and BT group was 84.01% vs. 60.50% (p = 0.03). The incidence of Grade 3-4 late complications was comparable between the two groups. Multivariate analyses performed in the whole group showed that T stage at initial diagnosis and the salvage technique (3D-CRT or ICBT) were the statistically significant, independent prognostic factors for local failure-free survival (p = 0.00 and p = 0.02, respectively). CONCLUSION: 3D-CRT seemed to provide better local control than ICBT as a salvage treatment for locally persistent nasopharyngeal carcinoma, especially in patients with initially diagnosed T3-T4 disease. CT/MRI evaluation of the extent of persistent disease is recommended for technique selection of salvage RT. Patients should be cautioned about the potentially increased complications. The optional time for salvage treatment remains controversial.

Etiological analysis of the sequelae of radiotherapy for nasopharyngeal carcinoma: a follow-up study of 112 cases.

OBJECTIVE: To explore the etiology of the sequelae of radiotherapy for nasopharyngeal carcinoma (NPC) so as to find the possible means for reducing or preventing its occurrence. METHODS: A total of 112 pathologically confirmed patients with nasopharyngeal carcinoma, who had survived for 5 years following the radiotherapy, were included in this study. Sixty-four patients with the primary carcinoma in the nasopharyngeal region received radiotherapy with the radiation field covering the bilateral anterior ear regions, and in the other 48 patients, adjuvent exposure of the anterior nasal region was administered. The metastases in the cervical lymph nodes were exposed to tangential radiation by 40 Gy X-ray followed by approximately 20 Gy vertical electron beam exposure. RESULTS: Limited mouth-opening and dry mouth occurred mostly during the first 2 years after radiotherapy, and hearing loss in the first year. Neck fibrosis tended to increase with the time elapse after the therapy, and posterior cranial nerve damages showed no signs of time-related occurrence. It was found that the occurrence of neck fibrosis, dry mouth and the nerve injuries did not obviously correlate with the dosage of X-ray exposure in the anterior ear regions, while limited mouth-opening and the hearing loss increased with the radiation dosage. The sequelae did not arise from different radiation field selection as adopted in this study. CONCLUSION: The radiation dose should be controlled at around 70 Gy for NPC treatment, and for carcinoma remnant in the nasopharyngeal region, additional dose in the cavity would be appropriate. When the X-ray dose of 65 Gy in the neck region fails to result in satisfactory recession of lymph node metastasis, comprehensive treatment involving multiple modalities should be considered.