1. IMRT: Global View
Arno J. Mundt MD
Professor and Chair
Department of Radiation Oncology
University of California San Diego, La Jolla CA

2. A Walk Down Memory Lane

3. “…further refining of delivery technology and the inverse planning
system, gaining clinical experience to address target definition and
dose inhomogeneity within the targets, and understanding the partial
volume effect on normal tissue tolerance are needed for IMRT to
excel in the treatment of head and neck cancer….”

4. Today
IMRT is no longer a “new” or “novel”
technology
IMRT has literally “grown up”
Pre-IMRT era seems like a long time
ago

5. IMRT
A major revolution in
our field
Fundamentally
changed the way we
plan and deliver
radiation therapy

6. IMRT Revolution
“There are no non-violent
revolutions…”
Malcolm X
Resulted in the upheaval of
the daily lives of all of us
(physicians and medical
physicists alike)

7. IMRT Revolution
Proposed over 40 years ago by
Takahashi in Japan
Takahashi et al. Acta Radiol 1965;242
1st attempted in the late 1960s by
Hellman and colleagues (JCRT)
Deemed infeasible due to excessive
planning and delivery times

8. IMRT Implementation
In mid-1990s, IMRT began to be used
at select academic centers
Not till the late 1990s with the
availability of commercial treatment
planning systems did IMRT start to
become widely available
Currently, 10 commercial planning
systems and 7 commercial delivery
systems

9. Commercial Planning Systems
BrainLAB (brainlab.com) BrainScan
CMS, Inc. (cmsrtp.com) Xio IMRT
Elekta (elekta.com) PrecisePlan
NOMOS (nasmedical.com) CORVUS
Philips (medical.philips.com) Pinnacle-PRO
Prowess Inc (prowess.com) Panther DAO
RAHD (rahd.com) 3D/Pro, Konrad
Siemens (siemens.com) Konrad
Tomotherapy (tomotherapy.com) Hi-Art
Varian (varian.com) Eclipse
Hamilton et al. Treatment Planning
IMRT: A Clinical Perspective. Mundt A, Roeske J (editors)
BC Decker, Toronto, 2005

10. Commercial Delivery Systems
brainlab.com
BrainLAB
elekta.com
Elekta
nasmedical.com
NOMOS
Southeastern Radiation
seradiation.com
Products
siemens.com
Siemens
tomotherapy.com
Tomotherapy
varian.com
Varian
Saw C, Ayyangar K, Krishna K, Wu A, Kalnicki S
Delivery Systems
IMRT: A Clinical Perspective. Mundt A, Roeske J (editors)
BC Decker, Toronto, 2005

11. What is the Current Level of
IMRT Use?

12. IMRT Surveys
Two surveys performed to assess the
level of IMRT use in the United States
2002 Survey (450 Radiation Oncologists)
Mell LK, Roeske JC, Mundt AJ.
Cancer 2003;204-211
2004 Survey (500 Radiation Oncologists)
Mell LK, Mehrotra AK, Mundt AJ.
Cancer 2005;104:1296-1301

13. IMRT Surveys
Adoption was at first slow, but later
occurred at a very rapid rate
In the 2002 survey, 32% of radiation
oncologists were using IMRT
In the 2004 survey, this percentage
increased to 74%

14. Cumulative IMRT Adoption (USA)
100%
90%
80%
Percent of Physicians
70%
60%
50%
40%
30%
20%
10%
0%
1992 1995 1998 2001 2004*
*As of 8/04
Year
Mell LK, Mundt AJ. Survey of IMRT Use in the USA - 2004
American Radium Society Barcelona Spain 2005

15. IMRT Adoption
Initially only used at a few academic
institutions with home-grown systems
With advent of commercially available
planning systems, tremendous adoption
seen in private practice community

16. IMRT Utilization
Private and Academic Physicians
100%
90%
80%
80%
70%
71%
60%
Private
50%
47%
40% Academic
30%
23%
20%
10%
0%
2002 2004
P = 0.14
P = 0.003

17. IMRT Utilization
Wide variety of sites are now being
treated
Top 3
Prostate, Head and Neck, CNS
In recent years, increasing interest in
other sites
Gynecology, GI, Breast

18. IMRT Practice Survey (2004)
Top Treated Sites
Site % __
Prostate 85%
Head and Neck 80%
CNS 64%
Gynecology 35%
Breast 28%
GI 26%
Sarcoma 20%
Lung 22%
Pediatrics 16%
Lymphoma 12%
Mell LK, Mundt AJ. Survey of IMRT Use in the USA- 2004
Cancer 2005;104:1296

19. IMRT Use
While commonly available, it is being
used to treat only a subset of patients at
most centers
Rarely used in a large percentage of
patients under treatment

20. IMRT Use
100%
Majority of IMRT 80%
users (73%) treat 60%
<1/4 of their
40%
patients with IMRT
20%
<5% use it in >1/2
of their current 0%
% Percentage
patients
<25% 25-50%
51-75% >75%

21. Clinical Impressions
2004 Survey asked clinical impressions
of IMRT users
Overwhelmingly favorable
Most only able to comment on acute
toxicity
Few could comment on chronic toxicity
or tumor control

22. Acute Toxicity
Most (87%) felt 50
acute toxicity was 45
similar or better 40
than conventional 35
30
RT 25
13% felt it was 20
worse (primarily in 15
head/neck cancer*) 10
5
*many of these also reported 0
↓acute toxicity in prostate pts Better Same Worse

23. Chronic Toxicity
55% could assess
chronic toxicity 80
70
Of these, great
majority (73%) felt 60
it was better than 50
standard RT 40
Only 1 felt it was 30
worse 20
10
No 2nd tumors
noted (even among 0
Better Same Worse
long-term users)

24. Tumor Control
60
47% could assess
tumor control 50
Of these, the 40
majority felt it was 30
superior or similar
20
None felt it was
worse 10
0
Better Same Worse

25. Future IMRT Use
IMRT use will continue to grow
Majority of current radiation oncology
residents are taught IMRT
Survey of Chief Residents at 77
programs → 87% hands on experience
>50% planned and treated >25 IMRT pts
Wide variety of tumor sites
Malik R, Mundt AJ et al.
Survey of Resident Education in IMRT
Technol Cancer Res Treat 2005;4:303-309

26. Disease Sites Treated
Resident Survey
Site %
Head and Neck 92%
Prostate 81%
CNS Tumors 56%
Pediatrics 38%
Gynecology 24%
Recurrent/Palliative 24%
Breast 21%
GI 21%
Lung 15%
Lymphoma 7%

27. Why is IMRT so popular????

28. Cynical Answer
$$$$

29. Reasons for Adopting IMRT
Normal Gain
Tissue Escalate Competitive Remain
Advantage Competitive
Sparing Dose
100
90
92%
80
89%
70
60
50
Research
40
30 38%
36%
Other*
20
10
10%
0
1 2 3 4 5 6
*”…don’t all boys love new toys?”

30. Motivations
Financial reasons are common
New billing codes added in 2001 making
reimbursement 4 times conventional
In 2004, reimbursement rates revised
down to 2.8 times conventional RT

31. Financial Motivations
Led some physicians to make false
claims about IMRT
Internet is full of such misinformation
Review of IMRT websites → 42% have
false and/or misleading information
(including many academic sites!)
Schomas D, Mell LK, Mundt AJ.
IMRT and the Internet: Evaluation of Content and
Quality of Patient-Oriented Information
Cancer 2004;101:412-20

32. Example Statements
Conventional prostate RT can leave the patient
impotent and incontinent…IMRT dramatically
decreases these problems
IMRT is a kindler and gentler treatment because it
leaves healthy tissues alone
IMRT beams intersect on the tumor by turning
corners
The promise of IMRT lies in its ability to focus
treatment only on the tumor

33. Why is IMRT so popular???

34. Less Cynical View
Improves sparing of normal tissues,
reducing the risk of acute and chronic
sequelae → Improving patient quality of
life
Improves ability to dose escalate high
risk patients, cover of difficult targets
and even safely re-irradiate patients →
Improving tumor control

35. And Importantly…..
IMRT rests on an
ever growing foundation
of convincing clinical
data

36. IMRT Literature
Initially devoted exclusively to physics
issues, e.g. tongue and groove effect,
QA, etc.
Clinical studies have become
increasingly common in recent years

37. IMRT Clinical Studies*
559
364 (65%) 195 (35%)
Dosimetric Outcome
*as of 1/1/07

38. IMRT Clinical Studies
160
140
120
100
80
60
40
20
0
'96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06

39. 0
20
40
60
80
100
120
140
160
180
200
H ea d/N
e ck
P ro s ta t
e
B re a s t
C NS
G yn e
L un g
GI
P ed s
S ar co m
IMRT Clinical Studies
a
O th e r

40. IMRT Outcome Studies
100
90
80
70
60
50
40
30
20
10
0
er
S
k
st
I
e
ds
te
G
ec
yn
CN
ea
th
ta
Pe
/N
G
os
O
Br
ad
Pr
He

41. Clinical Studies
160
140
120
100
80
60
40
20
0
'96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Larger series
Early Small Series
Longer follow-up
Very limited follow-up
Wide variety of disease
Mostly prostate and
sites
head/neck

42. Every Red J now has IMRT outcome studies
Mackley et al.
IMRT for pituitary adenomas: preliminary report of the Cleveland
Clinic Experience
Daly et al.
IMRT for malignancies of the nasal cavity and paranasal sinuses
Bossi et al.
IMRT for preoperative posterior abdominal wall irradiation of
Retroperitoneal liposarcomas

43. Lessons from the Literature
A number of reports highlight various
issues/problems/toxicities in IMRT
patients
Such reports improve the quality and
delivery of IMRT
Teach us how to do IMRT and how not
to do it

44. Mundens et al. (MD Anderson)
Radiation Injury to the liver after IMRT in patients
with mesothelioma: An unusual CT appearance
AJR 2005;184:1091-5
Lee N et al. (UCSF)
Skin toxicity due to IMRT for head/neck cancer
Int J Radiat Oncol Biol Phys 2002;53:630-7
Uy et al. (Baylor)
IMRT for meningioma
Int J Radiat Oncol Biol Phys 2002;53:1265-7
De Neve W et al.
Lethal pneumonitis in a phase I study of chemotherapy
And IMRT for lung cancer
Radiother Oncol 2005

45. And a cautionary note…….

47. IMRT Studies
Prospective cooperative group trials
evaluating IMRT are now appearing
Most importantly, Phase III clinical trials
are being undertaken

48. ASTRO Meeting 2006
Philadelphia

49. “IMRT Era”
Truly an exciting time for IMRT
Becoming standard in many disease sites
Also being used in ever more
sophisticated ways

50. IMRT will become
increasingly common
in the treatment
recurrent disease
Stephanie Milker-Zabel (Heidelberg)
IMRT for Recurrent Spinal Metastasis
IMRT: A Clinical Perspective BC Decker 2005

51. Electron IMRT
Isodose distribution of
a parotid cancer planned
with electron IMRT
↑conformity and sparing
of underlying tissues
Song Y, Boyer A, Xing L et al. (Stanford)
Modulated Electron Radiation Therapy
IMRT: A Clinical Perspective BC Decker 2005

52. “Repair” of Unacceptable Brachytherapy
Prostate Implants
Original Brachy IMRT Brachy + IMRT
Li XA, Wang JZ (U Maryland)
Repair of Unacceptable Implants
IMRT: A Clinical Perspective BC Decker 2005

53. Replacement of Brachytherapy
Cervical Cancer
Applicator-Guided
HDR
IMRT
Low DA (Washington U)
Applicator-Guided IMRT
IMRT: A Clinical Perspective BC Decker 2005

54. Accelerated
Concomitant Boost IMRT
Breast Cancer
Whole breast: 40.5 in 2.7 Gy
fractions per day
Lumpectomy Site: 48 Gy in
3.2 Gy fractions per day
Tot al time = 3 weeks (15 fx)
Eugene Lief, Silvia Formenti (NYU)
Accelerated Concomitant Boost IMRT
IMRT: A Clinical Perspective BC Decker 2005

55. Proton IMRT
IM-proton plan in
a 10 year old girl with
a lumbar chordoma
Lomax A
Intensity Modulated Proton Therapy
IMRT: A Clinical Perspective BC Decker 2005

56. Revolution Continues
IMRT
Image Guided
IMRT
Varian Trilogy

57. But one must always remember to
keep an eye on the ball

58. Key to Successful IMRT
Optimal Target Delineation

59. The value and importance of conferences such as
these will never diminish…..

60. Thank You
Enjoy the Conference