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Supratentorial Astrocytomas and
Oligodendrogliomas Treated in the MRI Era
Koh-ichi Sakata,
Masato Hareyama, Takashi Komae, Hiroki
Shirato, Osamu Watanabe, Jiroh Watarai,
Kenji Takai, Shogo Yamada, Emiko
Tsuchida and Kunio Sakai
Department of Radiology, Sapporo
Medical University, School of Medicine, Sapporo [Ko.S., M.H.],
Department of Radiology, Hokkaido University, School of Medicine,
Sapporo [T.K., H.S.], Department of Radiology, Akita University,
School of Medicine, Akita [O.W., J.W.], Department of Radiology,
Tohoku University, School of Medicine, Sendai [K.T., S.Y.] and
Department of Radiology, Niigata University, School of Medicine,
Niigata, Japan [E.T., Ku.S.]. For reprints and all correspondence:
Koh-ichi Sakata, Department of Radiology, Sapporo Medical
University, School of Medicine, S1W16, Chuo-ku, Sapporo
060-8543, Japan. E-mail: sakatako@sapmed.ac.jp.
Background.
There is at present no consensus on the policy for the
treatment of patients with low-grade gliomas (LGGs).
Methods. This report is a
retrospective multi-institutional study of 100 patients
(ages 16–65 years) with astrocytoma (grade II),
oligodendroglioma, anaplastic oligodendroglioma and
anaplastic oligoastrocytoma of the supratentorial areas which
were treated with surgery and postoperative radiotherapy at
five university hospitals in northern Japan between 1990 and
1997 when MRI was routinely used to determine the target volume.
Most patients were irradiated with 50–60 Gy.
The target volume usually covered the areas with T2
prolongation of MRI with a margin of 2 cm.
Results. The
disease-specific 5-year survival rate was 87.4% for
patients with oligodendroglioma and 75.3% for patients with astrocytoma.
Survival for patients with astrocytoma in the MRI era
appears to be improved compared with historical controls in
the literature.
Patients with astrocytoma aged 40 years and under had a
significantly better disease-specific survival rate than
those over 40 years (P < 0.05) and patients with
oligodendroglioma and oligoastrocytoma showed a similar
tendency.
Patients with astrocytoma who had over 50% of their tumor
removed had a significantly better survival rate than those
who had less than 50% removed (P < 0.05).
Chemotherapy appeared to improve the disease-specific survival
rate of patients with oligodendroglioma but not that of
patients with astrocytoma.
Conclusion.
Oligodendroglioma has a more protracted course of disease
progression than astrocytoma.
This particular feature and the sensitivity of LGGs to
chemotherapy as well as their relevant prognostic factors,
such as age, histopathology and amount of tumor removal,
should be taken into account before any decision on
treatment methods for LGGs is made.
© 2001 Foundation for Promotion of
Cancer Research
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