Long-term outcome and toxicity of hypofractionated stereotactic body radiotherapy as a boost treatment for head and neck cancer: the importance of boost volume assessment

Table 3 Nine cases of severe late complications

Patient (age/sex)	Treatment site	Elapsed time (months)	SBRT dose schedule (total dose/fraction)	Response	Cumulative BED₁₀ (Gy)	Late toxicity (RTOG late toxicity grade)
31/M	NPC, Lt. skull base	24.4	21/3	CR	101.5	Pontine necrosis (G5^*)
48/M	NPC, Lt. skull base	8.5	21/3	PR	105.8	Lt. base of skull bone and soft tissue necrosis (G4)
48/M	NPC, Rt. skull base	25.9	25/5	CR	107.6	Pontine necrosis (G3)
48/M	NPC, Lt. skull base	4.4, 6.8	21/3	CR	118.5	Lt. nasopharyngeal wall soft tissue necrosis (G4), temporal lobe necrosis (G3)
55/M	SCC, Rt. BOT	15.8	16/2	CR	94.6	Mucosal ulcer and necrosis (G4)
82/M	SCC, Lt. BOT	20.9	24/3	CR	96.3	Unhealing mucosal ulcer and bleeding (G4)
36/F	ACC, Rt. lacrimal gland	30.0, 32.4, 30	25/5	CR	90.6	Radiation retinopathy (G3), temporal lobe necrosis (G3), NVG (G3)
41/F	ACC, Lt. lacrimal gland	28.5, 28.5	20/5	CR	87.5	Radiation retinopathy (G3), NVG (G3)
59/M	ACC, Rt. orbit	15.1	25/5	CR	90.6	Optic neuropathy (G3)

^*Pontine necrosis was the definite cause of death
SBRT, stereotactic body radiotherapy; BED₁₀, biologically equivalent dose in α/β ratio of 10; M, male; NPC, nasopharyngeal carcinoma; CR, complete response; PR, partial response; SCC, squamous cell carcinoma; BOT, base of tongue; F, female; ACC, adenoid cystic carcinoma; NVG, neovascular glaucoma.

ISSN: 1748-717X