How best to choose a biopsy site:
Carefully review indication,
history and imaging,
ensuring there are no contraindications to biopsy.
It is important to interrogate all available imaging for the most amenable lesion and if not already performed,
consider PET,
MR or bone scan to identify target sites for best biopsy route (See Fig.
1).
Technique:
Localization of lesion: A preliminary scout CT is performed followed by placement of radio-opaque markers on the skin over the target lesion and marking of the skin (See Fig.
2).
The procedure must be performed with informed consent and aseptic technique.
There is no need for sedation for the vast majority. Lidocaine is injected to anesthetize the skin,
soft tissues and periosteum.
The type and amount of local anaesthetic varies however 5-8mls of 1% lidocaine is favoured by our Musculoskeletal Radiologists. A small skin incision may be necessary.
Position and approach: The position (supine,
prone,
or lateral) and approach (transpedicular,
transcostovertebral or posterolateral) will vary depending on the level and position of the lesion5 (See Fig.
3).
The cervical vertebral body can be accessed from the anterolateral or posterolateral approach,
depending on the carotid artery position in relation to the bone lesion and the level of the lesion; posterolaterally being more appropriate for lower cervical lesions.
See Fig.
4 for cervical biopsy case.
The thoracic vertebral body can be accessed via the transcostovertebral or transpedicular approach.
The lumbar vertebral body is generally accessed via a transpedicular or a posterolateral approach.
See Figs. 5-9 for thoracic biopsy cases. See Figs. 10-13 for lumbar biopsy cases.
The sacrum is a less common site for metastasis,
however,
can also be biopsied (case 14).
Biopsy: The biopsy needle is inserted to the periosteum overlying the lesion by fine-tuning of needle positioning over sequential scans.
Depending on the type of needle/system used,
the biopsy may be co-axial or tandem.
Perform core biopsy,
remove needle and apply dressing.
Post procedure instructions: Bedrest and analgesia.
The patient should be monitored for complications,
and in most cases can be discharged home two hours after the procedure.