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14/05/2015

SPECT/CT  in  degenera/ve  facet  disease  

Tim  Van  den  Wyngaert  MD  PhD  Department  of  Nuclear  Medicine  -­‐  Antwerp  University  Hospital  Faculty  of  Medicine  and  Health  Sciences  -­‐  University  of  Antwerp  

Antwerp,  BELGIUM    

ESNR Spine Course

•  Principles  of  bone  scin.graphy  

•  Op.mal  image  acquisi.on  for  assessment  of  facet  joints  

•  Can  SPECT  predict  benefit  of  intra-­‐ar.cular  treatment  

•  Op.mal  treatment  strategy  of  SPECT-­‐posi.ve  facet  joints  

•  Addi.onal  value  of  SPECT/CT  

•  Radia.on  exposure  issues  in  SPECT/CT  

•  Conclusions  

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Overview  

•  Bone  scan  ≠ Bone  scan  •  Technique  maGers!  

3

Nuclear  medicine  techniques  

1950 1960 1970 2015

PET(/CT)  

SPECT(/CT)  

Bone  scin/graphy  reflects  local  bone  turnover  

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Principle  of  bone  scin.graphy  

Adapted from Weilbaecher KN, Guise TA, McCauley LK. Nat Rev Cancer 2011; 11: 411-425. Ballinger JR. In I. Fogelman et al. (eds.), Radionuclide and Hybrid Bone Imaging, Springer-Verlag Berlin Heidelberg 2012.

Osteoblast RANK RANKL

HSC

Pre-osteoclast

M-CSF • Growth factors • Calcium

MSC

Pre-osteoblast

Osteoblast

Osteocyte

Osteoprotegerin

Osteoid

•  High  sensi.vity  •  Local  blood  supply  •  Low  specificity  •  Improved  techniques  

Causes  •  Normal  ageing  •  Accelerated  degenera.on  and  increased  stress  in  the  mo.on  

segments  adjacent  to  fusion  aMer  spinal  surgery  Consequences  •  Pain  •  May  lead  to  spondylolysis  and  spondylolisthesis  

(postopera.ve  incidence  between  11  -­‐  14%[1])  Controversies  •  How  to  determine  who  will  benefit  from  treatment?  •  Overlap  with  asymptoma.c  degenera.ve  findings[2]  

Degenera.ve  facet  joint  disease  

1.  Hambly  MF,  et  al.  Spine.  1998;23(16):1785-­‐92.  2.  Vogt  MT,  et  al.  Spine.  1998;23(23):2640-­‐7.    6

Limita.ons  of  planar  imaging  

PLANAR  

ANTERIOR  

POSTERIOR  

SPECT/CT  SPECT  

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SPECT  outperforms  planar  bone  scan  in  iden/fying  pain  generators,  including  facet  joint  disease  •  Higher  sensi.vity  because  of  improved  contrast    •  BeGer  3D  anatomical  localiza.on  of  abnormali.es  •  But  spa.al  resolu.on  of  SPECT  is  lower  than  planar  imaging      

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SPECT  is  superior  to  planar  images  

Author,  year   N   Technique   Comparator   Popula/on†  

Sudhakar,  2010   20   SPECT   ç   Planar   Back  pain  or  spinal  lesion  on  other  imaging  

Ryan,  1992   34   SPECT   ç   Planar   Pa.ents  with  chronic  low  back  pain  

Gates,  1988   100   SPECT   ç   Planar   Pa.ents  with  lumbosacral/pelvic  pain  

1.  Sudhakar  P,  et  al.  Indian  J  Nucl  Med  2010;  25:  44-­‐8.    2.  Ryan  PJ,  et  al.  Radiology  1992;  182:  849-­‐854.  3.  Gates  GF.  Clin  Nucl  Med  1988;  13:  907-­‐914.    

†  Studies  conducted  exclusively  in  cancer  pa.ents  are  not  listed  “ç”  indicates  the  superior  technique  

What  is  the  prevalence  of  SPECT  posi/ve  facet  joints?  •  Retrospec.ve  study  (n=534)  •  Pa.ents  with  spinal  pain,  389  with  low  back  pain  •  Percentage  with  facet  joint  uptake:  44.5%  (173/389)  •  Prevalence  increased  with  age    Æ Increased  facet  joint  uptake  

is  a  frequent  finding  on  SPECT  Æ Important  to  exclude  other  spinal  

abnormali/es  before  interpre/ng  as  clinically  relevant  pain  generator  

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SPECT-­‐posi.ve  facet  joints  

Makki  D,  et  al.  Spine  J.  2010  Jan;10(1):58-­‐62.  

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Trea.ng  SPECT-­‐posi.ve  joints  

Dolan  AL,  et  al.  Br  J  Rheumatol.  1996  Dec;35(12):1269-­‐73.  

0

10

20

30

40

50

60

70

0 1 3 6

Mean  score

Months  after  therapy

SPECT  +  SPECT  -­‐  

SPECT  +  McGill  pain  score  

SPECT  -­‐  

VAS  pain  score  

*

* *

*  p<0.05  

Can  SPECT  select  pa/ents  who  will  benefit  from  therapy?  •  Prospec.ve  study  (n=58)  •  Suspicion  of  facet  joint  disease  •  Outcome  of  infiltra.on  of    

SPECT-­‐posi.ve  joints    compared  to  infiltra.on  of    joints  adjacent  to  symptoms  

•  Excluded  if  signs  of  nerve    root  compression  

•  Outcomes  at  1,  3,  and  6  months  Æ SPECT  predicts  short-­‐term  benefit  

Intra-­‐ar/cular  versus  medial  branch  nerve  block?  •  Double-­‐blind  randomized  trial  in  pa.ents  with  SPECT-­‐posi.ve  

facet  joints  (n=46)  •  Exclusion  if  MRI  evidence  of  lumbar  disc  hernia.on    •  Numeric  Pain  Intensity  Scores  (NPIS  0-­‐10)  and  Oswestry  

Disability  Index  scores  (ODI  0-­‐50)  •  Outcomes  at  3  months  reported  (IA  vs  MB  injec.on)  

–  Pain  relief:  61%  vs  26%  (p<0.05)  – Disability  reduc.on:  53%  vs  31%  (p<0.05)  

Æ Intra-­‐ar/cular  facet  joint  injec/ons  are  more  effec/ve  than  medial  branch  nerve  blocks  in  SPECT-­‐posi/ve  pa/ents  

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Trea.ng  SPECT-­‐posi.ve  joints  

Ackerman  WE,  et  al.  South  Med  J.  2008  Sep;101(9):931-­‐4.  

SPECT/CT  useful  in  selected  pa/ents  with  low  back  pain  

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Addi.onal  value  of  SPECT/CT  

Author,  year   N   Technique   Comparator   Popula/on†  

Sharma,  2013   99   SPECT/CT   ç   SPECT  +  Planar   Solitary  indeterminate  lesion  on  planar  BS  

Sumer,  2013   37   SPECT/CT   ç   SPECT  +  Planar   Pain  aMer  lumbar  fusion  surgery  

Jiang,  2013   48   SPECT/CT   ç   SPECT   Solitary  indeterminate  lesion  on  planar  BS  

Franc,  2012   100   SPECT/CT   =   SPECT   Unselected  pa.ents  presen.ng  for  BS  

Zhang,  2011   56   SPECT/CT   ç   SPECT   Back  pain  or  spinal  lesion  on  other  imaging  

1.  Sharma  P,  et  al.  Diagn  Interv  Radiol  2013;  19:  33-­‐40.  2.  Sumer  J,  et  al.  Nucl  Med  Commun  2013;  34:  964-­‐70.  3.  Jiang  L,  et  al.  Ann    Nucl  Med  2013;  27:  460-­‐7.  4.  Franc  BL,  et  al.  Clin  Nucl  Med  2012;  37:  26-­‐34.  5.  Zhang  Y,  et  al.  Nucl  Med  Commun  2011;  32:  1194-­‐200.  

†  Studies  conducted  exclusively  in  cancer  pa.ents  are  not  listed  “ç”  indicates  the  superior  technique  

How  can  SPECT/CT  improve  diagnosis  of  facet  joint  disease?  •  Unlikely  to  increase  sensi.vity  •  Increases  specificity  especially  in  the  post-­‐opera.ve  spine  •  Allows  diagnosis  of  spondylolysis  and  spondylolisthesis  

Does  SPECT/CT  change  diagnos/c  yield  compared  to  SPECT?  •  Retrospec.ve  study  of    

SPECT  (n=174)  and    SPECT/CT  (n=395)  in  pts    with  low  back  pain  

•  Propensity  score  adjust-­‐  ment  to  reduce  bias  

Æ SPECT/CT  increases    diagnos/c  yield  

Æ Reduces  equivocal    findings  and  aXribu/on    to  facet  joint  disease  

Diagnos.c  yield  of  SPECT/CT  SPECT

Spondylolysis 14.93

8.83 Transition anomaly

8.80 Compression fracture

7.41 S urgical complication †

0.11 Equivocal finding

0.01 0.10 1 10 100 Higher reporting rate Lower reporting rate

Disc or end - plate 0.96

Facet joint 0.73

Sacro - iliac joint † 1.30

Other pathology 0.51

0.008

0.035

0.034

0.026

<0.001

0.686

0.001

0.170

0.441

+4.6%

+2.7%

+3.6%

+5.4%

- 15.8%

- 0.3%

- 13.4%

+5.5%

- 0.9%

p ARR (%) RR

Van  den  Wyngaert  T,  et  al.  Eur  J  Nucl  Med  Mol  Imaging  2014;  41  (Suppl  2):  S278  (OP540).  

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SPECT/CT  in  post-­‐opera.ve  spine  •  Pa.ent  referred  for  bone  scin.graphy  15  months  aMer  

lumbar  spine  fusion  surgery  •  SPECT  suggests  facet  joint  involvement  •  SPECT/CT  correctly  localizes  increased  uptake  to  pedicle  

screw.  Associated  radiolucency  raises  suspicion  of  loosening.  

Adjacent  segment  degenera/on  (ASD)  

Facet-­‐joint  degenera.on  

Recurrent low back pain 5 years after PLF L4-L5

Intense  SPECT  uptake  with  defect  of  pars  interar/cularis  on  CT  

Spondylolysis  

Recurrent low back pain 1 year after PLF L4-L5

Grading  of  spondylolysis  on  SPECT/CT  

Spondylolysis  

Grade   SPECT   CT  

0   Normal   Normal  

1   Increased   Normal  /  degenera.ve  changes  

2   Increased   Incomplete  fracture  

3   Increased   Complete  fracture  

4   Normal   Complete  fracture  

Ly  JQ.  Magn  Reson  Imaging  Clin  N  Am.  2007  May;15(2):155-­‐66.  

Pseudoarthrosis  and  spondylolisthesis  

Spondylolisthesis  

2 years post-surgery

•  The  use  of  SPECT/CT  is  associated  with  addi.onal  exposure  to  ionizing  radia.on  from  the  CT  component  

•  Strategies  to  reduce  pa/ent  exposure  –  Bone  scan:  reduce  injected  dose  (MBq)  

•  Novel  reconstruc.on  algorithms  •  Impact  of  count  loss  on  lesion  localiza.on  is  compensated  by  anatomical  data  from  CT  scan  

–  CT  scan:  reduce  exposure  •  Itera.ve  reconstruc.on  algorithm  and  tube  modula.on  •  Reduce  image  quality  if  only  need  for  localiza.on  (kVp)  •  Careful  selec.on  of  scan  length  (FOV)  •  Skip  if  confident  diagnosis  on  planar  imaging  alone  

Dose  vigilance  

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•  Retrospec.ve  study  of  SPECT/CT  studies  of  the  lumbar  spine  (n=395)  

•  Bone  scan  –  Es.mated  dose  of  3.0  mSv  for  typical  adult  

•  CT  scan  –  CT  dose  index  volume  (CTDIvol)  (mGy),  dose  length  product  (DLP)  (mGy.cm)  and  scan  length  (cm)    

– DLP  (mGy.cm)  was  mul.plied  with  the  body  region-­‐specific  conversion  factor  for  the  abdomen  (mSv/mGy.cm),  yielding  an  es.mate  of  the  effec.ve  dose  (mSv)  

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SPECT/CT  radia.on  exposure  

Van  den  Wyngaert  T,  et  al.  Eur  J  Nucl  Med  Mol  Imaging  2014;  41  (Suppl  2):  S278  (OP540).  20

SPECT/CT  radia.on  exposure  

1.  Larkin  AM,  et  al.  Int  J  Mol  Imaging  2011;  doi  10.1155/2011/897202  (Symbia  T6;  130kVp;  tube  current  modula.on).  2.  Sharma  P,  et  al.  Nucl  Med  Commun  2012;  33:  926-­‐32  (Symbia  T6;  130kVp;  tube  current  modula.on).  3.  Van  den  Wyngaert  T,  et  al.  Eur  J  Nucl  Med  Mol  Imaging  2014;  41  (Suppl  2):  S278  (OP540).  

Mean  DLP  189  mGy.cm  (95%  CI  176  –  201)  

 Mean  dose  2.8  mSv  (95%  CI  2.6  –  3.0)    

  Larkin,  et  al[1]    Sharma,  et  al[2]    (n=395)[3]  Low-­‐dose  SPECT/CT  

573   333   189  

Es/mated  mean  total  dose  of  SPECT/CT  study  

5.8  mSv  

≈  2x  natural  annual  exposure  

•  Degenera.ve  facet  joint  disease  can  be  reliably  diagnosed  with  bone  SPECT(/CT)  

•  SPECT/CT  offers  advantages  in  selected  popula.ons,  in  par.cular  aMer  lumbar  spine  surgery  

•  Bone  SPECT(/CT)  can  predict  short-­‐term  benefit  of  facet  joint  infiltra.on  

•  In  SPECT-­‐posi.ve  facet  joints,  intra-­‐ar.cular  infiltra.on  is  preferred  over  medial  branch  nerve  block  

•  The  radia.on  exposure  of  bone  SPECT/CT  is  approximately  equal  to  2  years  of  natural  background  exposure  

•  Bone  scin.graphy  remains  an  adjunct  imaging  modality  for  pa.ents  with  low  back  pain  

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Conclusions