Computed tomography findings of bony regeneration after radiotherapy for nasopharyngeal carcinoma with skull base destruction: Implications for localcontrol
Fm. Fang et al., Computed tomography findings of bony regeneration after radiotherapy for nasopharyngeal carcinoma with skull base destruction: Implications for localcontrol, INT J RAD O, 44(2), 1999, pp. 305-309
Citations number
15
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Onconogenesis & Cancer Research
Journal title
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
Purpose: To evaluate the response of bony destruction (BD) of the skull bas
e following radiotherapy in nasopharyngeal carcinoma (NPC) and investigate
the implications of bony regeneration (BR) on local control and its related
factors.
Methods and Materials: Ninety patients with NPC with skull base destruction
clearly demonstrated on computed tomography (CT) were reviewed. These pati
ents have completed the prescribed treatment and received regular CT follow
-up. A total of 338 sets of CT images of the head and neck were reviewed. T
he tumor response and the appearance of BR in the previous destructive part
of the skull base were recorded and analyzed. The tumor response was divid
ed into complete, partial, or no response, BR was defined as recalcificatio
n or sclerotic change with partial or complete healing in the previous oste
olytic bony defect. Local failure was confirmed either by pathological or m
erely by imaging studies showing progression of tumor in consecutive radiol
ogical pictures.
Results: The distribution of specific sites of bony destruction (BD) in the
se patients included the sphenoid bone (68%), paracavernous sinus area (48%
), petrous apes (47%), clivus (44%), pterygoid plates (20%), and others (7%
). The CT showed 57 patients (63%) had BR. All were observed within 1 year
after treatment. Sixty-two patients (69%) had complete tumor response after
treatment, Analyzed by logistic regression method, tumor response after tr
eatment was found to have a statistically significant correlation with BR (
p = 0.0004). Most BR (55/57) was demonstrated in patients with complete tum
or response, The 3-year actuarial local control rate was 54 % in these pati
ents. The local control was quite different in the comparison of patients w
ith BR versus those with persistent ED (77% vs, 21%,p < 0.0001), Multivaria
te analysis showed that patients with complete tumor response or with BR on
imaging had statistically better local control than those without either o
f the two findings (p < 0.05),
Conclusion: Appearance of BR at previous destructive skull base following r
adiotherapy for NPC patients could be clearly demonstrated on CT, Bony rege
neration significantly correlated with treatment response and local control
, Although the underlying significance of BR was unknown, to predict the ou
tcome after treatment, the appearance of BR shown on CT may imply the compl
ete eradication of tumor in this area. (C) 1999 Elsevier Science Inc.