Series selection
Our series was collected between January 2015 and December 2015.
We performed 28 procedures (12 men and 16 women) in patients with dorsolumbar metastases from breast (14),
lung (8),
kidney (3),
colon (2) and prostate (1) cancer.
12 patients were treated using computed tomography (CT) combined with conventional fluoroscopy imaging guide.
In 16 patients,
the procedure was performed only with multislice CT fluoroscopy.
Lesion diameter ranged from 2,0 – 6,0 cm.
Patients mean age 64 y; range 55-76 y.
In our series,
all treated lesions were osteolytic.
Patient selection
Patient selection was performed by a multidisciplinary team consisting of an anesthesiologist,
an orthopaedic surgeon and a radiologist.
Indications and contraindications were verified at two levels of selection: a first clinical level and a second radiological level.
The first level of selection,
carried out by the anesthesiologist and orthopaedic surgeon,
identified patients with spine metastases accompanied by pain not sufficiently responsive to medical therapy.
All patients were administered the following assessment scales to verify clinical eligibility for the procedures: 10-point visual analogue scale (VAS) (10 worst ever pain; 1 no pain) for pain assessment and 3-point analgesic use scale (3 complete daily coverage; 2 partial daily coverage; 1 occasional coverage) for analgesic use evaluation.
Data from the above assessments were collected in a questionnaire.
The second level of selection involved imaging studies and was the responsibility of the radiologist.
All patients received pre-procedural radiographic assessment and magnetic resonance imaging (MRI) with 1.5-T (Philips-Intera,
Eindoven,
Netherlands) to determine patients’ anatomical compatibility.
Materials
Biopsies were performed with Synthes Bone Access Needles (Moller Medical GmbH,
Wasserkuppenstrabe 29-31,
36043 Fulda,
Germany) with 8-10 gauge calibre biopsy needle.
All biopsies were done under CT guidance (GE Light Speed H16,
GE Healthcare Medical Systems Italia S.p.a.
,
via Galeno 36,
20126 Milano,
Italy).
Percutaneous radiofrequency ablation (RFA) was performed using a StarBurst XL RFA Device (AngioDynamics,
603 Queensbury Avenue,
Queensbury,
NY 12804).
RFA uses thermal energy to destroy tissue surrounding an electrode,
resulting in coagulative necrosis of tissue from high temperatures.
In the short term,
thermal destruction of pain sensitive nerve fibers ceases transmission of pain signals.
Tumor cell necrosis has also been implicated in decreasing the cytokine mediated pain pathways involving interleukins and tumor necrosis factor.
RFA also delays tumor progression to the sensitive periosteum.
The combination of these mechanisms leads to rapid decrease in pain.
In addition,
radiofrequency used just before application of bone cement reduces risk of accidental protrusion of tumor mass into spinal canal during cement introduction [2; 11].
For Cementoplasty we used Synthes Vertecem V+ system (Synthes GmbH,
Elimattstrasse 3,
4436 Oberdorf,
Svizzera) composed of needles with bevel or diamond tip,
12-,
10- and 8-gauge calibre and 12- to 14-cm long,
stop-cock 1-2 ml syringes for the aspiration/injection of acrylic cement that contains 55% ceramic components and only 45% polymethylmethacrylate (PMMA).
Methods
To minimise the risk of infection,
patients received antibiotic prophylaxis 1 days before and 2 day after the procedure.
The procedures were performed in local anesthesia under conscious sedation or in general anesthesia,
according with tumore site or with patient condiction to ensure as much comfort as possible and to facilitate needles access to the lesion.
The patient’s vital signs should be continuously monitored.
Procedure started with biopsy.
Patient was placed in the prone position and a radio-opaque skin marker may be placed to help determine the entry point at the patient’s skin.
Following preliminary axial CT scanning,
the most appropriate slice was selected to plan the most ideal route for directing the needle into the lesion (fig.1).
The selected slice was surface marked on the patient’s skin with a surgical marking pen.
The surgical field was prepared by accurately sterilising the skin and delimiting the needle entry point with large sterile drapes to minimize risks of infection.
After administration of local anaesthesia (1% lignocaine),
the biopsy needle was directed into the lesion under CT guidance (fig.2).
When the pedicles have sufficient diameter and obliquity to reach the central portion of the vertebra,
the approach is transpedicular (20 patients),less frequently parapedicular transcostovertebral (8 patients),
uni- or bilateral.
8 G-11 G cutting needles may be used to obtain material for cytology,
culture and histopathological examination.
After biopsy,
under CT guidance,
the electrode was advanced into the vertebral lesion and deployed to the desired location (fig.3).
The tip of the trocar should be placed approximately 1 cm (for a 3-cm ablation) to 1,5 cm (for a 5-cm ablation) proximal to the center of the target area.
A variable number of temperatures and ablation times were utilized based on size,
shape and location of lesion (usually target temperature 90°,
Set Power at 150 W,
duration 6 minutes after target temp is reached).
Upon completion of the desired ablation,
we retracted the device and the cementoplasty needle was placed into the tumor.
Preparation of the acrylic cement was done after having placed the needle into the lesion to obtain the optimal viscosity.
To monitoring the cement injection we used radiofluoroscopic and CT-guidance that check its distribution and identify possible leakages (fig.
4-5).
The amount of acrylic cement injected in each lesion ranged from 4 cc to 11 cc.
After the procedure we obtained a series of MPR CT scans to evaluate and document distribution of the cement,
possible leaks and soft tissues haematomas (fig.
6).
Patients rested in supine position for about 1-3 h after the procedure.
All patients were discharged from hospital within 24 h
Statistical analysis
Statistical analyses were performed using IBM SPSS Statistics version 17.0 for Windows (Microsoft,
Redmond,
WA).
Differences between the average VAS score and analgesic-use score at baseline,
24h,
1 week and month 1 post-procedure were evaluated using Student's t test,
for unpaired data.
p<0.05 was considered statistically significant.