Involved field radiotherapy for locally advanced non-small cell lung cancer: isolated mediastinal nodal relapse.

The current standard of care for locally advanced inoperable non-small cell lung cancer is high dose radiotherapy with concurrent chemotherapy. We report on a patient with stage IIIA NSCLC treated with concurrent chemoradiotherapy on the primary tumor and the 18-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) positive hilar and mediastinal lymph nodes. Six months after treatment this patient developed a single isolated contralateral mediastinal nodal relapse outside but in the proximity of the irradiated target volume. This patient was successfully re-irradiated to this isolated nodal relapse after reconstruction of the dose given to the localisation of this regional recurrence. This case describes the clinical problem of a regional recurrence after involved field radiotherapy that occasionally occurs. A possible explanation for those regional recurrences is an under staging of extension of the disease because the time-interval between the staging (18)FDG-PET-CT scan and the start of the irradiation was too long. If the time-interval is 4 weeks or more, we strongly recommend a new (18)FDG-PET-CT because of the possibility of upstaging of the disease.