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[Radiotherapy of malignant gliomas: results from conventional
treatment methods and the prospects of advanced techniques]
[Article in English, Italian]
Rubino G, Sacco P, Cerase A, Volterrani L, Sebaste L, Pepi F, Pirtoli L.
Unita Operative di Radioterapia - Radiologia Universitaria
[PS,VL] - Neurologia Diagnostica e Terapeutica [CA] - Universitaria di Siena ed
Azienda Ospedaliera Universitaria Senese, Siena.
Purpose.The results of post-operative radiation therapy of malignant gliomas
are disappointing, with mean survival time (MST) of 16-70 weeks and 2-year
survival rates ranging from 8.5% to 25% in the literature.
A slightly more
favourable prognosis is found in the following cases: in anaplastic astrocytomas
with respect to glioblastoma multiforme; in younger patients with respect to the
more elderly; the longer the duration of symptoms before diagnosis; and in the
event in which surgery has been macroscopically radical.
An improvement in
treatment outcome is foreseeable with the use of advanced volume definition
techniques for radiation therapy.
Materials and Methods and Results. Our
experience with conventional radiation treatment shows therapeutic results in
agreement with other institutions.
In the overall 134 cases MST was 50 weeks and
the 2-year survival rate was 10%.
In patients affected by anaplastic astrocytoma
MST was 58% and 2-year survival rate was 17%, whereas the figures for
glioblastoma multiforme were 47 weeks and 8% (p>0.05, not statistically
significant, probably due to the small number of cases).
Patients of sixty years
of age or less showed a more statistically favourable prognosis: MST was 59
weeks and 2-year survival rate was 16%, compared with 44 weeks and 4% in
patients above 60 years of age (p<0.05).
The duration of symptoms of 6 months
or less had a less favourable prognosis with respect to symptom onset of greater
than 6 months: in the former MST was 49 weeks and 2-year survival was 7%, and in
the latter the figures were 68 weeks and 40% (P<0.05).
Lastly, the presence
of residual neoplastic tissue after surgery is an unfavourable element: in this
case MST was 41 weeks and 2-year survival was 7%, compared with 68 weeks and 13%
(P<0.05) after macroscopically radical surgery.
Discussion and Conclusions.Computed tomography (CT) is still today an indispensable technique for radiation
therapy planning.
Magnetic Resonance (MR) imaging, nonetheless, provides greater
definition of the neoplastic extension.
The possibility of combining CT and MR
neuroimaging data together with stereotactic radiotherapy techniques enables the
optimal development of the three-dimensional treatment plane.
This translates
into high dose delivery to the neoplastic volumes without affecting the regions
of the brain with no tumour involvement.
Furthermore, a real improvement in the
prognosis of malignant gliomas must also consider the results from research in
the fields of tumour biology and functional neuroimaging.
PMID: 15031704 [PubMed - indexed for MEDLINE]
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