Total Marrow Irradiation and High-dose Melphalan for Double Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma

Efficacy and Safety of Double Autologous Hematopoietic Stem Cell Transplantation With Sequential Use of Total Marrow Irradiation and High-dose Melphalan in Multiple Myeloma

The purpose of this study is to evaluate if the use total marrow irradiation (TMI) as a sole preparation for the first autologous hematopoietic stem cell transplantation (autoHSCT) followed by high-dose melphalan used prior to second autoHSCT is safe and effective in patients with multiple myeloma (MM).

AutoHSCT is a standard treatment of patients with MM. According to soem clinical evidence double autoHSCT provides survival advantage compared to a single procedure. Most frequently used conditioning regimen consists pf high doses of melphalan (HD-MEL). In some studies it was used in combination with total body irradiation (TBI), which, however was associated with significant toxicity. In our center the standard procedure includes TBI as a single treatment at 1st autoHSCT and HD-Mel at 2nd autoHSCT.

As in MM malignant plasma cells are localized almost exclusively in bone marrow there is rationale to limit irradiation to bones. For this purpose in the current study we substitute TBI with TMI. Additional boosts are provided for active sites of disease based on PET/CT imaging. Our intention is to minimize toxicity while maintaining the treatment efficacy.

Inclusion Criteria:

• Age 18-65 years
• Diagnosis of multiple myeloma
• PR, VGPR or CR at inclusion
• Performance status WHO 0-1
• Written informed consent

Exclusion Criteria:

• Organ dysfunction: elevated ALT, AST, bilirubin, AF; creatinine >1.5 upper normal limit; LVEF <45%
• Active infection
• Unstable diabetes
• Psychiatric diseases
• History of high-dose chemotherapy or irradiation
• Second malignancy
• Pregnancy