{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T02:43:15Z","timestamp":1789785795296,"version":"4.0.1"},"reference-count":17,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"Special_Suppl","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JNS"],"published-print":{"date-parts":[[2012,12]]},"abstract":"<jats:sec>\n<jats:title>Object<\/jats:title>\n<jats:p>Cellular density is a major factor responsible for changes in apparent diffusion coefficients (ADCs). The authors hypothesized that loss of tumor cells after Gamma Knife surgery (GKS) might alter ADC values. Magnetic resonance imaging, including diffusion-weighted (DW) imaging, was performed to detect cellular changes in brain tumors so that the authors could evaluate the tumor response to GKS as well as the efficacy of the procedure.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Methods<\/jats:title>\n<jats:p>The authors conducted a prospective trial involving 31 patients harboring solid or cystic vestibular schwannomas (VSs) that were treated with GKS. The patients underwent serial MR imaging, including DW imaging, before GKS and at multiple intervals following the procedure. The authors observed the patients over time, evaluating MR imaging findings and clinical outcomes at 6-month intervals. The ADCs were calculated from echo-planar DW images, and mean ADC values were compared at each follow-up.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Results<\/jats:title>\n<jats:p>The mean follow-up period was 36.5 months (range 18\u201360 months). Imaging studies showed a reduction in tumor volume in 19 patients (61.3%) and tumor growth arrest in 9 patients (29%). In the remaining 3 patients (9.7%), tumor enlargement was documented at 18, 36, and 42 months.<\/jats:p>\n<jats:p>The mean ADC value before GKS for all solid VSs was 1.06 \u00b1 0.17 \u00d7 10<jats:sup>\u22123<\/jats:sup> mm<jats:sup>2<\/jats:sup>\/second, which significantly increased 6 months after GKS and continued to increase with time (p = 0.0086). The mean ADC value for treated solid tumors as of the last mean follow-up of 36 months (range 18\u201360 months) was 1.72 \u00b1 0.26 \u00d7 10<jats:sup>\u22123<\/jats:sup> mm<jats:sup>2<\/jats:sup>\/second (range 1.50\u20132.09 \u00d7 10<jats:sup>\u22123<\/jats:sup> mm<jats:sup>2<\/jats:sup>\/second), which was significantly higher than that before GKS (p = 0.0001). Tumor volumes were positively related to ADC values (p = 0.03).<\/jats:p>\n<jats:p>The mean ADC value before GKS for all cystic VSs was 2.09 \u00b1 0.24 \u00d7 10<jats:sup>\u22123<\/jats:sup> mm<jats:sup>2<\/jats:sup>\/second (range 1.80\u20132.58 \u00d7 10<jats:sup>\u22123<\/jats:sup> mm<jats:sup>2<\/jats:sup>\/second). The mean ADC value for treated cystic tumors as of the last mean follow-up of 38 months (range 18\u201348 months) was 1.89 \u00b1 0.22 \u00d7 10<jats:sup>\u22123<\/jats:sup> mm<jats:sup>2<\/jats:sup>\/second.<\/jats:p>\n<jats:p>In 3 patients harboring solid VSs, the tumor enlarged after GKS but the ADC values were higher than those before GKS. The authors considered these tumors to be controlled and continued follow-up in the patients.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Conclusions<\/jats:title>\n<jats:p>Apparent diffusion coefficient values may be useful for evaluating treatment results before any definite volume change is detected on imaging studies and for distinguishing radiation-induced necrosis from tumor recurrence in cases in which other imaging results are not definitive, as in cases of increased tumor volume or no volume change. The authors suggest that ADC measurements be included during routine MR imaging examinations for the evaluation of GKS results.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2012.7.gks121003","type":"journal-article","created":{"date-parts":[[2018,11,16]],"date-time":"2018-11-16T00:55:40Z","timestamp":1542329740000},"page":"63-68","source":"Crossref","is-referenced-by-count":20,"title":["Use of apparent diffusion coefficients in evaluating the response of vestibular schwannomas to Gamma Knife surgery"],"prefix":"10.3171","volume":"117","author":[{"given":"Chun-Chao","family":"Chuang","sequence":"first","affiliation":[{"name":"School of Medical Imaging and Radiological Sciences,"},{"name":"Department of Radiology, Chung Shan Medical University, Taichung;"},{"name":"Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cheng-Siu","family":"Chang","sequence":"additional","affiliation":[{"name":"School of Medicine,"},{"name":"Department of Neurosurgery, and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Sheng","family":"Tyan","sequence":"additional","affiliation":[{"name":"School of Medical Imaging and Radiological Sciences,"},{"name":"Department of Radiology, Chung Shan Medical University, Taichung;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keh-Shih","family":"Chuang","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hsien-Tang","family":"Tu","sequence":"additional","affiliation":[{"name":"School of Medicine, China Medical University; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chuan-Fu","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Medicine, China Medical University; and"},{"name":"Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"key":"b1-1170063","series-title":"J Neurosurg","first-page":"444","article-title":"Stereotactic radiosurgical treatment of brain metastases","volume":"76","author":"Adler","year":"1992"},{"key":"b2-1170063","series-title":"Neurosurgery","first-page":"656","article-title":"Stereotactic radiosurgery for patients with \u201cradioresistant\u201d brain metastases","volume":"51","author":"Brown","year":"2002"},{"key":"b3-1170063","series-title":"Clin Cancer Res","first-page":"1457","article-title":"Monitoring early response of experimental brain tumors to therapy using diffusion magnetic resonance imaging","volume":"3","author":"Chenevert","year":"1997"},{"key":"b4-1170063","series-title":"J Natl Cancer Inst","first-page":"2029","article-title":"Diffusion magnetic resonance imaging: an early surrogate marker of therapeutic efficacy in brain tumors","volume":"92","author":"Chenevert","year":"2000"},{"key":"b5-1170063","series-title":"Surg Neurol","first-page":"62","article-title":"Diffusion magnetic resonance imaging as an evaluation of the response of brain metastases treated by stereotactic radiosurgery","volume":"69","author":"Huang","year":"2008"},{"key":"b6-1170063","series-title":"Neurosurgery","first-page":"282","article-title":"Radiosurgery for acoustic neuromas: results of low-dose treatment","volume":"53","author":"Iwai","year":"2003"},{"key":"b7-1170063","series-title":"NMR Biomed","first-page":"6","article-title":"Monitoring cytotoxic tumour treatment response by diffusion magnetic resonance imaging and proton spectroscopy","volume":"15","author":"Kauppinen","year":"2002"},{"key":"b8-1170063","series-title":"N Engl J Med","first-page":"1426","article-title":"Long-term outcomes after radiosurgery for acoustic neuromas","volume":"339","author":"Kondziolka","year":"1998"},{"key":"b9-1170063","series-title":"Neuroradiology","first-page":"483","article-title":"MR diffusion imaging of human intracranial tumours","volume":"39","author":"Krabbe","year":"1997"},{"key":"b10-1170063","series-title":"J Neurol Neurosurg Psychiatry","first-page":"797","article-title":"Stereotactic radiosurgery","volume":"46","author":"Leksell","year":"1983"},{"key":"b11-1170063","series-title":"J Neurosurg","first-page":"645","article-title":"The radiobiology of human acoustic schwannoma xenografts after stereotactic radiosurgery evaluated in the subrenal capsule of athymic mice","volume":"78","author":"Linskey","year":"1993"},{"key":"b12-1170063","series-title":"Eur Radiol","first-page":"1342","article-title":"Diffusion-weighted echo-planar MR imaging in differential diagnosis of brain tumors and tumor-like conditions","volume":"10","author":"Okamoto","year":"2000"},{"key":"b13-1170063","series-title":"Neurosurgery","first-page":"1299","article-title":"Reduced-dose radiosurgery for vestibular schwannomas","volume":"49","author":"Petit","year":"2001"},{"key":"b14-1170063","series-title":"J Comput Assist Tomogr","first-page":"249","article-title":"Diffusion magnetic resonance imaging of solid vestibular schwannomas","volume":"27","author":"Sener","year":"2003"},{"key":"b15-1170063","series-title":"Comput Med Imaging Graph","first-page":"299","article-title":"Diffusion MRI: apparent diffusion coefficient (ADC) values in the normal brain and a classification of brain disorders based on ADC values","volume":"25","author":"Sener","year":"2001"},{"key":"b16-1170063","series-title":"J Magn Reson Imaging","first-page":"53","article-title":"Usefulness of diffusion-weighted MRI with echoplanar technique in the evaluation of cellularity in gliomas","volume":"9","author":"Sugahara","year":"1999"},{"key":"b17-1170063","series-title":"Radiology","first-page":"985","article-title":"Apparent diffusion coefficient of human brain tumors at MR imaging","volume":"235","author":"Yamasaki","year":"2005"}],"container-title":["Journal of Neurosurgery"],"original-title":[],"link":[{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg\/117\/Special_Suppl\/article-p63.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg\/117\/Special_Suppl\/article-p63.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg\/117\/Special_Suppl\/article-p63.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,3,26]],"date-time":"2023-03-26T23:08:56Z","timestamp":1679872136000},"score":1,"resource":{"primary":{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg\/117\/Special_Suppl\/article-p63.xml"}},"subtitle":["Clinical article"],"short-title":[],"issued":{"date-parts":[[2012,12]]},"references-count":17,"journal-issue":{"issue":"Special_Suppl"},"URL":"https:\/\/doi.org\/10.3171\/2012.7.gks121003","relation":{},"ISSN":["0022-3085","1933-0693"],"issn-type":[{"value":"0022-3085","type":"print"},{"value":"1933-0693","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,12]]}}}