its a presentation for nbone

1. Dr R.C.Meena
Senior Professor & Head Of Department
Department Of Orthopaedics
SMS Medical College & Attached Hospitals

2. Introduction
 Recent management strategies favor limb
preservation therapy (LPT) in most patients rather
than amputation as an oncologically safe option in
extremity malignant bone tumors .
 This has been possible because of the
multidisciplinary treatment, which consists of optimal
use of surgery, chemotherapy, and RT.

3.  Most bone tumors occur in the metaphyseal area of
the bones and resection with a wide margin generally
involves sacrifice of the adjoining articular surface.
 Megaprosthesis provides an effective reconstruction
option in a majority of these cases, with good
functional results.

4. • Tumors in the diaphysis are relatively uncommon
• In most of these it may be possible to achieve adequate
margins without sacrificing the adjacent articular
surfaces.
• Reconstruction using prosthesis and biological
options like autografts, allografts, and bone transport
have shown good functional results

5.  In recent times, there has been a lot of interest in
using the patient’s own tumor bone and reimplanting
it after it has been sterilized.
 The described methods of sterilization have included
the use of autoclaving, microwave, pasteurizing, liquid
nitrogen and radiotherapy(ECI)

6.  Extracorporeal irradiation (ECI) and re-implantation
is a useful, convenient, and cost effective method.
 It consists of en-bloc resection of the tumor bearing
bone segment, removal of the tumor and the soft
tissues from the excised segment, irradiation and re-
implantation back in the body.

7. Method of ECI
 The usual treatment policy for osteosarcoma (OS) and
Ewings sarcoma (ESFT) is neoadjuvant chemotherapy
followed by surgery and further treatment according to
pathological findings.
 Different chemotherapy regimens is being used as per
their institutional protocol.

8. • Limb preservation surgery is planned about 4 weeks
after the completion of neoadjuvant chemotherapy.
• It consists of en-bloc resection of the tumor and the
involved bone along with soft-tissues.
• After tumor excision, a sample of the marrow is taken
for a frozen section from both residual ends of the host
bone, to confirm clear margins.

9. The bone specimen is then lavaged with normal saline
and wrapped in Vancomycin-soaked mops. The bone
segment is tightly wrapped in sterile polyethylene
surgical drapes in two separate layers and placed in a
sterile container, which was sent for ECI

10.  The resected specimen is then transferred to a separate
sterile trolley, Under aseptic precautions all the soft
tissue including the periosteum and gross tumor tissue
is stripped from the bone

11.  The bone specimen is then
lavaged with normal saline
and wrapped in
Vancomycin-soaked mops.
The bone segment is tightly
wrapped in sterile
polyethylene surgical drapes
in two separate layers and
placed in a sterile container,
which was sent for ECI

12. • While packing the bone segment, care was taken not
to leave any air gaps that may affect homogenous
radiation dose delivery.
• The resected bone segment enclosed in the sterile
pack is irradiated to a dose of 50 Gy / 1 fraction, (using
6 MV photons or 60Cobalt γ rays with parallel opposing
portals).

13.  The mean treatment time is 28 minutes (range 24 to
36 minutes).
 During the ECI, the operative site is prepared for re-
implantation.
 After the completion of ECI, the sealed package
containing the bone is opened in the operation
theater. The bone was then re-implanted with fixation
devices.

14.  During the post-operative period, immobilization was
continued until the radiographic imaging showed the
evidence of union.
 Full weight bearing was allowed according to the
clinical and radiological progress.

15. Case 1
 18 year old male
 Diaphyseal osteosarcoma
at tibia
 Screening
 Plain xray
 MRI
 HRCT chest
 Whole body
scintigraphy

18. Pre-chemo Post –chemo (3 cycle)

27. 6 months follow up One year

30. Case 2
 13 year old male
 Pain ,swelling, Right arm
since 3 months
 fever
 Lytic lesion at humeral
diaphysis with periosteal
reaction
 On screening:-Non
metastatic
 Pathological fracture

31.  Biopsy:-EWINGS
SARCOMA
 Neoadjuvent
chemotherapy started
 Pathological fracture
treated conservatively
 After 2 months, Fracture
healed
 3 cycle of chemo.
 Tumor tissue reduced in
size, calcification
increased.

32.  Planned for limb
preservation therapy
(LPT)
 ECI & Re-implantation
as described
 Proximal fixation:
PHILOS
 Distal fixation: K wires

33.  Adjuvant Chemotherapy
started after 3 weeks
(suture removal)
 2 months post op.

34. At 8 months union achieved at
both ends of irradiated segment
7 months follow up 8 months follow up

35. Discussion
 Reconstruction of long intercalary defects after tumor
resection is a challenging proposition, especially in
immunocompromised patients receiving cytotoxic
chemotherapy.

36.  Custom-made diaphyseal implants provide the
advantage of immediate weight bearing and
ambulation, but are expensive and issues regarding
loosening, wear, and breakage remain.

37.  Biological reconstructions
 The use of non-vascularized strut autografts is often
limited by the length of the long resection gaps.
 Strut allografts, although a useful option, are limited by
their availability,

38. ECI & Re-implantataion
 Advantage:-
 Provides an anatomically size-matched graft for
biological reconstruction.
 Inexpensive and helps in restoring bone stock.
 The re-implanted bone acts as a scaffold for creeping
substitution and incorporation.
 Avoids the issues of allograft procurement and the risks
associated with the use of allografts, such as, graft
rejection and transmission of viral diseases.

39.  Advantages:-
 The delivery of very high doses of radiation to tumor
bearing bone by ECI, which is otherwise not possible in
the intact bone.
 It is cost effective as compared to the prosthetic devices
 it has psychological advantage as patients feel that their
own bone is being used as prosthesis.

40.  Limitations:-
 not applicable in tumor bones
 which are structurally weak
 in bones with pathological fractures.

41. Local recurrence
 Davidson et al.( J Bone Joint Surg Br 2005 ) reported
only 8% LR in a series of 50 patients treated with
ECRT With a mean follow-up of 38 months (range 12-
92), 84% patients were alive without any disease

42. Local recurrence………
• Poffyn et al. (Int Orthop 2011) recently published a
retrospective analysis of 107 patients with 108
malignant or locally aggressive bone tumors treated by
ECI with 300 Gy, and re-implantation of the bone as an
orthotopic autograft
• At 5 year follow-up, there was no LR and 64% of
patients had well healed graft. The 0% LR rate could
be due to relatively very high dose of ECI (300 Gy) used
in their study.

43. Radiotherapy dose
• a dose of 50 Gy, delivered in a single fraction, is safe
limit for sterilization of the tumor-bearing bone. in
some studies dose up to 300 Gy has been used.
• Higher doses of radiation would increase the total
treatment time and also carry the additional risk of
other possible detrimental effects such as reduction in
strength, revascularization, and osteoconductive
properties, thereby increasing the time for union and
incorporation.

44. complications
 The rate of non-union in ECI & re-implantation is 16%
as compared to intercalary reconstructions with
allografts is 63%
 Nonunion rate is higher in the diaphysis than the
metaphysis.

45.  Risk of wound infection in various ECI series has
been reported to be up to 17%.

46. CONCLUSION
• Extracorporeal irradiation is a useful, convenient ,less
expensive technique for limb salvage when there is
reasonable residual bone stock.
• It is oncologically safe and has good functional results.
• It is a highly technical procedure and the best result
can be obtained in structured musculoskeletal
oncology services.