title: Diffusion-Weighted Imaging for Predicting and Monitoring Primary Central Nervous System Lymphoma Treatment Response.
abstract: OBJECTIVE
  Whether ADC value predicts the therapy response and outcomes of primary central system lymphoma remains controversial. This study assessed the minimum ADC correlated with treatment response in patients with primary central nervous system lymphoma undergoing methotrexate-based chemotherapy.
  
  
  METHODS
  Thirty-five patients with primary central nervous system lymphoma underwent conventional MR imaging and DWI before chemotherapy and after 1 and 5 cycles of chemotherapy. Treatment response was determined according to the International PCNSL Collaborative Group criteria and was classified as a complete response, partial response, or progressive disease. Pretreatment minimum ADC, minimum ADC after 1 cycle, minimum ADC after 5 cycles, and change in minimum ADC were compared among the different response groups. The Pearson correlation test was calculated between these ADC parameters and tumor response.
  
  
  RESULTS
  The pretreatment minimum ADC of the progressive disease group was lower than that of the complete response and partial response groups, but there was no significant difference among them. The minimum ADC after 1 cycle and minimum ADC after 5 cycles were statistically significantly higher than the pretreatment minimum ADC. A comparison among groups showed that minimum ADC after 1 cycle, minimum ADC after 5 cycles, minimum ADC change, and the percentage of minimum ADC change were all significantly different among the 3 groups. A significant positive correlation was observed between the percentage of minimum ADC after 1 cycle of chemotherapy and the size reduction percentage after 5 cycles of chemotherapy. The minimum ADC change and the percentage of minimum ADC change performed better in the differentiation of the final treatment response, specifically in complete response and partial response from progressive disease.
  
  
  CONCLUSIONS
  The minimum ADC after 1 cycle and minimum ADC changes were better correlated with the treatment response than the pretreatment minimum ADC. Minimum ADC after early therapy may potentially to be used to predict and monitor the response of primary central nervous system lymphoma to chemotherapy.
authors.affiliation: From the Departments of Radiology (W.-Y.H., J.-J.L.).
authors.forename: W-Y
authors.identifier: http://orcid.org/0000-0003-1606-4845
authors.initials: WY
authors.lastname: Huang
authors.affiliation: Department of Radiology (J.-B.W., B.Y., D.-Y.G.), Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: J-B
authors.identifier: http://orcid.org/0000-0002-3269-2449
authors.initials: JB
authors.lastname: Wen
authors.affiliation: Radiotherapy (G.W.), Hainan General Hospital, Haikou, Hainan, China.
authors.forename: G
authors.identifier: http://orcid.org/0000-0002-1289-2005
authors.initials: G
authors.lastname: Wu
authors.affiliation: Department of Radiology (J.-B.W., B.Y., D.-Y.G.), Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: B
authors.identifier: http://orcid.org/0000-0001-7416-716X
authors.initials: B
authors.lastname: Yin
authors.affiliation: From the Departments of Radiology (W.-Y.H., J.-J.L.) lijianjunhngh@163.com gengdaoying2245@163.com.
authors.forename: J-J
authors.identifier: http://orcid.org/0000-0002-2500-1603
authors.initials: JJ
authors.lastname: Li
authors.affiliation: Department of Radiology (J.-B.W., B.Y., D.-Y.G.), Huashan Hospital, Fudan University, Shanghai, China. lijianjunhngh@163.com gengdaoying2245@163.com.
authors.forename: D-Y
authors.identifier: http://orcid.org/0000-0002-3556-029X
authors.initials: DY
authors.lastname: Geng