bone metastases
DESCRIPTION
diagnosing and treatment bone metastases, using PET scand and image guided IMRT to treat cancerTRANSCRIPT
Bone Metastases
Bone Metastases
Cancers that originate at another site (usually breast, prostate or lung) that spread to the bone are called bone metastases
Skeleton
The bones in the spine are numbered
More Spine Anatomy
Bone cancer in the spine can create problems if the tumor compresses the spinal cord inside the neural canal
Pain symptoms are related to the spot in the spine involved
Pelvic Anatomy
ribs
spine
pelvis
femurs
Most common sites for bone
metastases
Some bone mets make the bone look too white (osteoblastic)
others make dark holes (lytic)
Lytic = black hole in the bone
Blastic = abnormal white area
An MRI may show a bone met better than a regular X-ray
Bone Scan
A nuclear medicine bone scan would show bone mets as dark areas
PET scans may show the mets very clearly
PET scans can show bone mets that are in hard to see areas like the ribs or scapula
Chemotherapy can make the bones look abnormal on a PET scan because the bone marrow is working hard to make new blood
Normal looking bones prior to chemoRx
Same patient after receiving chemo
All the bones look active (bright yellow on the scan)
This is normal and not a sign of bone cancer
PET Scans can be used to help targetthe radiation three dimensionally
PET showing the cancer pushing into the back of the right hip bone
Computer generated reconstruction showing the cancer in red and the radiation zone in orange
Bone met at L2
Radiation field
A typical course of radiation is 10 treatments ( in some cases it is necessary to go slower, 20 to 25 trips)
Side Effects of Radiation for Bone mets
•Mild fatigue
•Local skin irritation
•Lower the blood count (anemia or white count)
•The bone can temporarily get weaker before strengthening
Local Side Effects of Radiation for Bone mets
Sore throat or dry mouth
Trouble swallowing or dry cough
Loose bowels or cramps
Bladder or rectal irritation
Radiation Results
•80 - 90% of the time the symptoms improve
•Complete relief in 54%
•Most respond by 10-14 days, 70% by 2 weeks, 90% by 3 months
•55 - 70% pain benefit is sustained for life
Response of bone mets to radiation
Symptoms respond within weeks
The Xrays or scans may take months to show improvement, but eventually may come back to normal
PET showing near complete response by 4 months
2006
2009
Response to Radiation
Breast cancer metastatic to the left iliac bone, 3 years after radiation (still evidence of bone destruction on CT, but no longer hot on PET scan)
Bone Metastases to the Spine
Involved vertebrae on the left and normal on the right
Kidney cancer in the spinal vertebrae surrounding the cord, and appearance after radiation…is it possible to safely radiate further?
Combine a CT scan and linear accelerator to ultimate in targeting (IGRT) and ultimate in delivery (dynamic, helical IMRT) ability to daily adjust the beam (ART or adaptive radiotherapy)