Low dose rate teletherapy and tumour response.
Tumour responses in 25 patients with locally advanced head and neck cancer, treated on an experimental fractionated low dose rate (FLDR) teletherapy program are reported. Treatment was given at dose rates ranging from 1.8 to 3 Gy/h to a range of total doses from 32-38 Gy, with palliative intent. The total doses delivered have been predicted by the linear quadratic formula to be equivalent to 33-41 Gy using conventionally fractionated high dose rate treatment, in terms of acute normal tissue effects. A complete response rate (no visible or palpable disease 2 months after treatment) was observed in 28% of cases. Analysis of these response rates suggests that the linear quadratic formula may underestimate the anti-tumour effect of FLDR teletherapy at the various dose rates and total dose permutations in this study.
Hamilton
C S
CS
Department of Radiation Oncology, Newcastle Mater Misericordiae Hospital, Waratah, NSW, Australia.
Simpson
S A
SA
Ferguson
S
S
Ostwald
P
P
Hsu
W
W
O'Brien
M
M
Denham
J W
JW
D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D010166:Palliative Care; D011446:Prospective Studies; D011867:Radioisotope Teletherapy / Q000379:methods; D011879:Radiotherapy Dosage