Long-term Outcomes of Hypofractionated Stereotactic Radiotherapy for the Treatment of Perioptic Nonfunctioning Pituitary Adenomas

The efficacy of stereotactic radiotherapy (SRT) has been well established for postoperative residual and recurrent nonfunctioning pituitary adenomas (NFPAs). However, the risk of visual impairment due to SRT for lesions adjacent to the optic pathways remains a topic of debate. Herein, we evaluated the long-term clinical outcomes of hypofractionated stereotactic radiotherapy (HFSRT) for perioptic NFPAs. From December 2002 to November 2015, 32 patients (18 males and 14 females; median age 63 years; range, 36–83 years) with residual or recurrent NFPAs abutting or displacing the optic nerve and/or chiasm (ONC) were treated with HFSRT. The median marginal dose was 31.3 Gy (range, 17.2–39.6) in 8 fractions (range, 6–15). Magnetic resonance imaging (MRI) and visual and hormonal examinations were performed before and after HFSRT. The median follow-up period was 99.5 months (range, 9–191). According to MRI findings at the last follow-up, the tumor size had decreased in 28 (88%) of 32 patients, was unchanged in 3 (9%), and had increased in 1 (3%). The successful tumor size control rate was 97%. Visual functions remained unchanged in 19 (60%) out of 32 patients, improved in 11 (34%), and deteriorated in 2 (6%). Two patients had deteriorated visual functions; no complications occurred because of the HFSRT. One patient developed hypopituitarism that required hormone replacement therapy. The result of this long-term follow-up study suggests that HFSRT is safe and effective for the treatment of NFPAs occurring adjacent to the ONC

Rapid immunohistochemistry based on alternating current electric field for intraoperative diagnosis of brain tumors

Rapid immunohistochemistry (R-IHC) can contribute to the intraoperative diagnosis of central nervous system (CNS) tumors. We have recently developed a new IHC method based on an alternating current electric field to facilitate the antigen-antibody reaction. To ensure the requirement of R-IHC for intraoperative diagnosis, 183 cases of CNS tumors were reviewed regarding the accuracy rate of diagnosis without R-IHC. The diagnostic accuracy was 90.7 % (168/183 cases) in which definitive diagnoses were not provided in 17 cases because of the failure of glioma grading and differential diagnosis of lymphoma and glioma. To establish the clinicopathological application, R-IHC for frozen specimens was compared with standard IHC for permanent specimens. 33 gliomas were analyzed, and the Ki-67/MIB-1 indices of frozen specimens by R-IHC were consistent with the grade and statistically correlated with those of permanent specimens. Thus, R-IHC provided supportive information to determine the grade of glioma. For discrimination between glioma and lymphoma, R-IHC was able to provide clear results of CD20 and Ki-67/MIB-1 in four frozen specimens of CNS lymphoma as well as standard IHC. We conclude that the R-IHC for frozen specimens can provide important information for intraoperative diagnosis of CNS tumors

Long-term Outcomes of Hypofractionated Stereotactic Radiotherapy for the Treatment of Perioptic Nonfunctioning Pituitary Adenomas

The efficacy of stereotactic radiotherapy (SRT) has been well established for postoperative residual and recurrent nonfunctioning pituitary adenomas (NFPAs). However, the risk of visual impairment due to SRT for lesions adjacent to the optic pathways remains a topic of debate. Herein, we evaluated the long-term clinical outcomes of hypofractionated stereotactic radiotherapy (HFSRT) for perioptic NFPAs. From December 2002 to November 2015, 32 patients (18 males and 14 females; median age 63 years; range, 36–83 years) with residual or recurrent NFPAs abutting or displacing the optic nerve and/or chiasm (ONC) were treated with HFSRT. The median marginal dose was 31.3 Gy (range, 17.2–39.6) in 8 fractions (range, 6–15). Magnetic resonance imaging (MRI) and visual and hormonal examinations were performed before and after HFSRT. The median follow-up period was 99.5 months (range, 9–191). According to MRI findings at the last follow-up, the tumor size had decreased in 28 (88%) of 32 patients, was unchanged in 3 (9%), and had increased in 1 (3%). The successful tumor size control rate was 97%. Visual functions remained unchanged in 19 (60%) out of 32 patients, improved in 11 (34%), and deteriorated in 2 (6%). Two patients had deteriorated visual functions; no complications occurred because of the HFSRT. One patient developed hypopituitarism that required hormone replacement therapy. The result of this long-term follow-up study suggests that HFSRT is safe and effective for the treatment of NFPAs occurring adjacent to the ONC

RAPID IMMUNOHISTOCHEMISTRY OF IDH-1 FOR THE INTRAOPERATIVE DIAGNOSIS OF GLIOMAS

Immunohistochemistry (IHC) plays a major role in the histopathological diagnosis of central nervoussystem (CNS) tumors. We developed a rapid immunohistochemistry (R-IHC) methodusing an alternating current electric field, which enables the completion of IHC in 20 min. Weperformed intraoperative R-IHC on 16 glioma patients (9 with grade I-III gliomas and 7 with glioblastomas)using the anti-mutant isocitrate dehydrogenase 1 (IDH1) monoclonal antibody (IDH1-R132H ; H09), and the results were validated on permanent formalin-fixed paraffin-embeddedsamples of the same patients by standard IHC. DNA sequencing of the IDH1 gene was also performedfor the 16 patients. Of 6 gliomas, 5 were shown to be positive by both R-IHC and standardIHC, and IDH1 mutation was confirmed by DNA sequencing. According to the results ofR-IHC compared with both standard IHC results and DNA sequencing, the sensitivity of IDH1R-IHC was 83% (5/6) ; specificity, 70% (7/10) ; positive predictive value, 63% (5/8) ; negativepredictive value, 88% (7/8) ; and accuracy, 75% (12/16). Thus, R-IHC using the anti-mutantIDH1 monoclonal antibody has potential applications in the intraoperative identification of IDH1mutations in gliomas