[Multiple spinal myeloma and its surgical management].

INTRODUCTION AND AIM: The management of spinal multiple myeloma (MM) is a complex process, including causal treatment (i.e. efforts to suppress the tumor clone), as well as supportive therapy, including surgery. The aim of this article is to present retrospective evaluation of surgical indications in patients with MM or solitary spinal plasmocytoma.

MATERIAL: A total of 10 patients (8 males and 2 females) aged from 32 to 74 years (the mean age of 53.3) were included in the study. The enrolment criteria were the following: patients operated for MM or solitary spinal plasmocytoma during the past 7-year period, with the minimum follow up period of 6 months. The procedures were indicated for progressing neurological deficit (Frankel score) and for axial spinal pain (VAS classification), not responding to conservative therapy. The extent of the disease was assessed based on plain x-ray, MRI and whole- body 18F-FDG PET/CT. Paliative vertebroplasty was indicated in patients with no neurological deficit to control pain, paliative laminectomy without stabilization in subjects with partial neurological lesions, with transpedicular fixation in concomitant pathological fractures or kyphotizations. More radical approach, i.e. the procedure included somatectomy, was indicated in patients with solitary plasmocytoma and in procedures on cervical or thoracolumbar regions. Control clinical and MRI examinations were performed at 6 weeks, at 6 months and then at yearly intervals. At the end of the study, the authors evaluated effectivity of the employed surgical procedures, based on all control findings, and the data were compared with prognostic scoring systems in surgery for spinal metastases (Tomita score, Tokuhashi modified score and Bauer score).

RESULTS: No local relapses of the tumor or stabilization failure were detected. The effect of surgery on pain control and on prevention of neurological dysfunction was maintained over the follow up period. The authors concluded that all surgical procedures and their radicality were adequate in all subjects. The agreement between the authors approach (the procedure's radicality) and the Tomita score, the Tokuhashi modified score and the Bauer score were recorded in 50% of patients, 80% of patients and in 50% of patients, respectively.

DISCUSSION: MM is characterized by increased oseteolysis, which is not followed by new bone formation. Despite successful conservative therapy of MM, the bone defects fail to heal, cause spinal pain and may result in spinal instability. These specific MM signs represent the principal factor in the decision- making process concerning indication for surgery. Furthermore, favourable prognosis, with survival times usually exceeding the required expected minimum survival time of 3-6 months, is yet another reason for indication for surgical therapy in patients with spinal MM. Due to advances in chemotherapy and the use of autologic grafts of peripheral stem cells and radiotherapy, the prognosis of patients have significantly improved in last 10 years. The mean survival time has increased from 2.5 years to 4.5 years.

CONCLUSION: 1. Prevention or improvement of neurological dysfuction and pain control are the main indication criteria for surgery in MM. 2. Surgery should be considered in MM with osteolytic spinal disorder and because of favourable prognosis of the disease when surgery is used. 3. Surgical procedures, including paliative methods resulted in sufficient control of spinal stability in all the study subjects. 4. Using all scoring systems for spinal metastases could result in indications for unnecessary more radical procedures. However, Tokuhashi score appeared to be the most suitable existing prognostic scoring system.