Omission of elective node irradiation on basis of CT-scans in patients with limited disease small cell lung cancer: a phase II trial

PURPOSE

To evaluate the patterns of recurrence when elective node irradiation was omitted in patients with limited disease small cell lung cancer (LD-SCLC).

METHODS

A prospective phase II study was undertaken in 27 patients with LD-SCLC without detectable distant metastases on CT scan. Chest radiotherapy to a dose of 45 Gy in 30 fractions in 3 weeks (1.5 Gy BID with 6 - 8 h interval) was delivered concurrently with carboplatin and etoposide chemotherapy. Chest radiation started after a mean time of 17.7 days +/- 9.7 days (SD) (range: 0-33 days) after the beginning of chemotherapy. Only the primary tumour and the positive nodal areas on the pre-treatment CT scan were irradiated. A total of five chemotherapy cycles were administered, followed by prophylactic cranial irradiation (PCI) in patients without disease progression. Isolated nodal failure was defined as recurrence in the regional nodes outside of the clinical target volume, in the absence of in-field failure.

RESULTS

After a median time of 18 months post-radiotherapy, 7 patients (26%, 95% CI 19.5-42.5%) developed a local recurrence. Three patients (crude rate 11%, 95% CI 2.4-29%), developed an isolated nodal failure, all of them in the ipsilateral supraclavicular fossa. The median actuarial overall survival was 21 months (95% CI 15.3-26.7), and the median actuarial progression free survival was 16 months (95% CI 6.5-25.5). Eight patients developed an acute, reversible grade 3 (CTC 3.0) radiation oesophagitis (30%, 95% CI 14-50%).

CONCLUSIONS

Because of the small sample size, no definitive conclusions can be drawn. However, the omission of elective nodal irradiation on the basis of CT scans in patients with LD-SCLC resulted in a higher than expected rate of isolated nodal failures in the ipsilateral supraclavicular fossa. The incidence of acute, reversible oesophagitis was in the same range as reported with elective nodal fields. The safety of selective nodal irradiation in NSCLC should not be extrapolated to patients with LD-SCLC until more data are available. In the mean time, elective nodal irradiation should only be omitted in clinical trials.

Selective mediastinal node irradiation based on FDG-PET scan data in patients with non–small-cell lung cancer: A prospective clinical study

PURPOSE

To evaluate the patterns of recurrence when selective mediastinal node irradiation based on FDG-PET scan data is used in patients with non-small-cell lung cancer (NSCLC).

METHODS AND MATERIALS

A prospective Phase I/II study was undertaken on 44 patients with NSCLC without detectable distant metastases on CT and FDG-PET scan, delivering either 61.2 Gy in 34 fractions over 23 days or 64.8 Gy in 36 fractions over 24 days (1.8 Gy b.i.d. with 8-h interval). Only the primary tumor and the positive mediastinal areas on the pretreatment FDG-PET scan were irradiated. Isolated nodal failure was defined as recurrence in the regional nodes outside of the clinical target volume, in the absence of in-field failure.

RESULTS

The CT and FDG-PET stage distribution was as follows: Stage I: 8 patients (18%) and 13 patients (29%); Stage II: 6 patients (14%) and 10 patients (23%); Stage IIIA: 15 patients (34%) and 7 patients (16%); Stage IIIB: 15 patients (34%) and 14 patients (32%), respectively. After a median follow-up time of 16 months (95% confidence interval [CI], 11-21 months) postradiotherapy, 11 patients (25%) developed a local recurrence. Only 1 patient (crude rate, 2.3%; upper bound of 95% CI, 10.3%), with a Stage II tumor on both CT and PET, developed an isolated nodal failure. The median actuarial overall survival was 21 months (95% CI, 14-28 months), and the median actuarial progression-free survival was 18 months (95% CI, 12-24 months).

CONCLUSIONS

Selective mediastinal node irradiation based on FDG-PET scan data in patients with NSCLC results in low isolated nodal failure rates. In the Phase I component of this trial, radiation dose escalation up to 64.8 Gy in 36 fractions over 24 days is feasible.