Thalidomide/Dexamethasone Treatment And PET Evaluation In Organ Involvemenet of Cardiac Amyloidosis

Inclusion Criteria: 1. Age : more than 18 years old 2. Cardiac amyloidosis (both AL or AH type) patient who meet both (A and B) of the following criteria A. Cardiac involvement: meet one of the following criteria * Echocardiography: mean wall thickness \>12 mm, and no other cardiac cause * NTproBNP \>332 ng/l in the absence of renal failure * Evidence of cardiac amyloidosis in cardiac MRI B. Treatment history: No history of exposure to thalidomide 3. ECOG(Eastern Cooperative Oncology Group) performance status ≤ 3 4. Tolerable major organ function determined by laboratory examination i. Serum creatinine ≤ 3.0 mg/dl ii. Absolute neutrophil count ≥ 1000/μl iii. Platelet ≥ 75000/ μl iv. Hemoglobin ≥ 8.0 mg/dl v. Bilirubin \< 2 times or Alkaline phosphate \< 4 times upper limit of normal 5. Expected survival \> 3 months 6. Female participants of child-bearing potential must have a negative pregnancy test prior to treatment and agree to use dual methods of contraception for the duration of the study and for 30 days following completion of study. Male participants must also agree to use a barrier method of contraception for the duration of the study and for 30 days following completion of study if sexually active with a female of child-bearing potential. Exclusion Criteria: 1. Amyloidosis without cardiac involvement 2. Patients who are planning to receive autologous stem cell transplantation 3. Patients who received autologous stem cell transplantation, remained in hematologic complete response 4. Pregnant, lactating or unwilling to use adequate contraception 5. Systemic infection unless specific anti-infective therapy is employed 6. Known allergies to thalidomide 7. Previous experimental agents or approved anti-tumor treatment within 1 months before the date of registration