Early response to chemotherapy as an indicator for the management of germinoma-like tumors of the pineal and/or suprasellar regions.
Recent advances in diagnostic imaging and experience with germinomas may allow for the differentiation of central nervous system germinomas from other tumors based on clinical information, without histological verification. We retrospectively analyzed clinically diagnosed germinoma-like tumors of the pineal and/or suprasellar regions. This was done to evaluate the efficacy of our strategy of defining germinoma-compatible tumors based on good responses to initial chemotherapy. The responses to chemotherapy and survival of 34 consecutive patients with germinoma-like tumors who underwent initial treatment from July 2001 to October 2010 were analyzed. The minimum apparent diffusion coefficient (minADC) value and proton magnetic resonance spectroscopy (MRS) were evaluated in recent patients. Twelve patients with histologically verified germinomas and 18 with germinoma-compatible tumors showed early logarithmic decreases in tumor volume in response to initial chemotherapy, typical low minADC values and typical MRS characteristics, including increased choline/creatine ratios, decreased N-acetylasparate/creatine ratios, and large lipid peaks. These patients had good progression-free survival. The other four patients, with histologically verified non-germinomas, showed no response to chemotherapy, and one patient with a pineoblastoma showed a similar minADC value and MRS characteristics to those of patients with germinomas. The response to initial chemotherapy can be used to distinguish germinoma-compatible tumors from non-germinoma in patients with germinoma-like tumors of the pineal and/or suprasellar regions. The evaluation of minADC and proton MRS are useful for distinguishing germinomas from other tumors. However, a subset of non-germinomas may show similar characteristics to germinomas. The benefit of bypassing unnecessary surgical intervention can be achieved, at least in Asian populations with a high incidence of germinomas.
Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
Ryuta
R
Saito
Department of Neurosurgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan. Electronic address: kuma@kitasato-u.ac.jp.
Toshihiro
T
Kumabe
Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
Masayuki
M
Kanamori
Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
Yukihiko
Y
Sonoda
Department of Pathology, Tohoku University Hospital, Sendai, Japan.
Mika
M
Watanabe
Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Shunji
S
Mugikura
Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Shoki
S
Takahashi
Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
Teiji
T
Tominaga
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D016371:Cranial Irradiation; D018572:Disease-Free Survival; D005260:Female; D018237:Germinoma / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010871:Pinealoma / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
Apparent diffusion coefficient; Chemotherapy; Diagnosis; Germinoma; Magnetic resonance spectroscopy