Table 3 Features of the three patients with recurrence at the level Ib LNs after intensity-modulated radiotherapy
| Â | Â | Case 1 | Case 2 | Case 3 |
|---|---|---|---|---|
Tumor involvement | Â | Â | Â | |
| Â | Staging | T4N3a | T3N2 | T4N3b |
| Â | Positive bilateral CLNs | Yes | Yes | Yes |
|  | DLN-IIa ≥20 mm or level IIa lymph nodes with ES | None | Right | Right |
| Â | Oropharynx involvement | Left | None | None |
Irradiation of neck level Ib | Bilateral | Right | Right | |
Recurrence at neck level Ib | Â | Â | Â | |
| Â | Laterality | Left | Right | Left |
| Â | Other regional recurrence | IA + IIb + IV + Vb | IIa + IIb + III | Ib |
| Â | Concomitant failure | Axillary LNs | - | Paranasophrynx+skull base |
| Â | Time to recurrence | 12 months | 12 months | 23 months |
| Â | Salvage treatment | Chemo | Chemo + surgery | Chemo + RT |
| Â | Treatment response | PD | PD | PR |
| Â | Sequential failure | Death due to multiple metastasis | Axillary and mediastinal LNs | Death due to intractable epistaxis |