Permanent implant brachytherapy

1. INTRODUCTION TO
PERMANENT IMPLANT
BRACHYTHERAPY
Dr. V. Lokesh M.D.
Professor & Head of the Department
Department of Radiation Oncology
Kidwai Memorial Institute of Oncology, Bangalore
August 2022

2. Introduction
⦿ Brachytherapy (Curietherapy) is defined as a
short-distance treatment of malignant
disease with radiation emanating from small
sealed (encapsulated) sources.
⦿ The sources are placed directly into the
treatment volume or near the treatment
volume

3. Advantages of brachytherapy
• Improved localized dose delivery to the
target
• Sharp dose fall-off outside the target
volume
• Better conformal therapy
Disadvantages of brachytherapy
• Only good for well localized tumors
• Only good for small lesions
• Very labor intensive

5. Importance of History & Origin of
various Brachytherapy techniques in
different continents

6. History :
Tribute to

7. 1896 : Natural Radioactivity
Professor Henri Becquerel Pierre Curie Maria Skłodowska

8. 1898: Marie Curie : Polonium & Radium

9. 1901: Alexander Danlos & Paul
Bloch : 0.398 g Radium

10. 1903: Margret A Cleaves : Gyn
Brachy Uterine Radium Applicator 50 to 100 mg (mCi) of Ra-226 - 7000 to 8000
milligram-hours.

11. ⦿ 1909: Wikhalm & Degrais: Radium therpay Book
⦿ 1909: Marie Cure - Institute of Radium : Paris
⦿ 1910: Gosta Forssell – Radiumhemmet Stockholm

12. 1900 : Ernst Friedrich Dorn
⦿ discovery of radon

13. 1913, Memorial Sloan Kettering
“Radium Hospital.”

14. 1917 - Radon
⦿ Radium ~ 4 gms
⦿ Dogulas : glass 0.3 mm Capillary tube & needle
⦿ Gioacchino Failla : gold capillary tube
encasement – filtered beta particles
⦿ Barringer : implanted 20 gold radon seed

15. Radon seed Implater

16. 1920-30s Radon Seed 2 millicuries of radon

17. The Newton of the Atom

18. 1919 Ernest Rutherford:
nuclear transmutation by
bombarding it with alpha
particles

19. 1930 : Irene Joliot-Curie
Artificial radioactivity
• Co-60
•Au-198
•Cs-137
•Ir-192
•Sr-90

20. ⦿ " revolutionizing the field of radiation
therapy and improving the quality of life "
of thousands of cancer patients

21. 1948 Gilbert H. Fletcher, M.D
first head of Radiation Oncology at MD Anderson
Cancer Center from it inception
⦿ .

22. Era of low energy sources
1960

23. Dr Ulrich henschke
Memorial Cancer Center of New York
•125-I seeds
•After loading techniques
1955: Man who influenced
modern Brach therapy

25. 1958 Nelson and Meurk
⦿ Computerized
brachytherapy treatment
planning software was
initially developed

26. Low energy radionuclides -
⦿ radium & radon
⚫ Very expensive
⚫ Scarce
⚫ Professional concerns
○ Harmful effects of radium exposure –
⚫ Doctors
⚫ Nursing staff
⚫ Visitors
⚫ Fedral regulations
○ Technical difficulties
⚫ Source construction
⚫ Radium dose calculation
⚫ α emitter
⚫ ~ 10 dys of hospitalization after implant
⦿ Impetus for introduction of Iodine-125
⚫ Longer half life
⚫ 27 to 35 keV

27. Substitute for high energy seeds
1958 Harper & colleagues Proposed use of low energy
radionuclides substitutes
Cesium 131 &
palladium 103
D.C.Lawrence
H.Nuclear.S.C Calif
Proposed use of Fission by product
Iodine
Iodine-125
Dr Ulrich Henschke
Memorial Hospital
•Reduce radiation exposure to background levels
•improved implantation technique – thro reduced
shielding requirements.
•Easily transported and stored in small metal
container
•Longer half life – more practical to use than
radon/gold seeds

28. 1958
Basil S Hilaris M.D grant from Radiological bureau – to demonstrate
radiation exposure can be significantly reduced,
could replace radon and gold seeds
Dr John Laughlin Instrumental in developing computerized
dosimetry for all brachy applications
Rebirth of Brachytherapy

30. Dr John Laughlin
Medical Physics, MSKCC
Instrumental in developing
computerized dosimetry for
permanent and temporary implants

31. 1964 Memorial Hospital & Squibb Hq –
discussing the manufacture of low energy seeds

32. 1965 Iodine-125 Commercially available
1966-67 Hillaris & Holt First clinical investigative
study with low energy
Iodine 125 seeds at
Memorial Hospital
N = 86
Isodose distribution
computed IBM 1800
Iodine 125+TPS
Promising substitute.
Radiation exposure to
Personnel's had been
significantly reduced
Optimal activity 0.5 – 0.7
mCi with optimal seeds
spacing of 1-1.5 cms
Optimal min tumour dose
– 100-140Gy

33. 1968-1971 Jean St GermainConcluded
Basil S Hilaris
M.D
Comprehensive
investigation on
I 125 Seeds
• the shielding for I-125 seeds
• easily constructed
• light weight (in contrast to radon 222 & gold-198),
• easy shielding
• no patient discomfort
• significant reduction is external exposure levels after implant as
attenuation of radiation was achieved inside patients tissue .
• Reducing exposure to nurses giving nursing care to I-125
patients.
• Considerable reduction of exposure to operating room
personnel,
• it reduced body exposure but also to fingers.
• No restriction for visitors,
• patient could be discharged on the same day
Challenges faced:
⦿ No dosimetry
⦿ radon activity equivalent
⦿ After trying various activities (0.5 to 2 mci)
⦿ 0.5 mci – caused fewer side effects with the same beneficial results as
stronger radon source of 1 mci

34. Felix W. Mick
Mick Radio-Nulcear Instruments, Inc.

35. Garrett Holt – 2nd report
⦿ After considerable experimentation
⦿ Titanium for encapsulation
⦿ Absolute calibration of I-125 established
⦿ Dosimetry of interstitial implant with I -125 great
challenge – low energy absorption
⦿ Conventional methods did not readily apply
⦿ Computerized system of dosimetry – developed
⦿ Investigations – compute dose distribution
around the implant
⦿ Out side implanted zone – marked falloff in
radiation dose with I-125 seeds observed.

38. Average monthly radiation
exposure from 1965-69

39. Basil S Hillaris 3 rd report
⦿ Implant Kit – Felix Mick

40. 1968 B S Hillaris
Usage of low energy I-125
seeds
⦿ Key problem: determination of
proper dose
⦿ Review of implants:
⦿ arrived at an estimate of the dose
for permanent implant volume –
presented in the form of a curve
⦿ recommended dose for I-125
implants (dotted line) against
implanted volume
⦿ A minimum dose of 160Gy delivered
over a period of 1 year, was
recommended as minimum dose for
a medium size implant only.
⦿ For smaller volume- much higher
dose – considered safe.

41. Henschke
⦿ The Calculation system developed for
I-125 seeds was determined by the
average dimension system
⦿ 3 dimensions of the implanted tumor
measured in cms (metal ruler) – average
dimension
⦿ Multiplied by empirical factor 5 (form P&P)
for I-125 seeds = recommended activity of
I-125 in mCi for the implant, which would
deliver curve recommended dose
⦿ Applicable for Cube or rectangular volume
⦿ Deduct
⚫ 20%- Spherical
⚫ 10% - Cylindrical
⦿ the number of seeds – found by dividing
total millicuries by average activity of the
available seeds
Cevec 1968 (published)

42. Optimal activity
⦿ 0.4 to 0.6 mCi
⦿ Min Tumour Dose 160Gy – optimal effect
⦿ Avr Size 15 to 65 cc
⦿ Well tolerated without undesirable side effects
⦿ Tumor regression complete by 1st half life 60 dys
⦿ Morphologically intact cancer cells might be identified for
at least 2.5 half lives (180 dys) – cells were non-
reproductively viable with rare late recurrences

43. 1932 - Patterson Parker Rule
Ralston Patterson
Holt Radium Institute , Manchester
Herbert Parker
G Holt & B Hillaris 1968 –
analysis disclosed the average
dose delivered by 125-I
implant was ~ represented by
Patterson Parker Dose

48. 1980 Martinez and
colleagues
new brachytherapy
approaches to the treatment
of prostate cancer were
initiated
temporary seeds
inserted using a
transperineal
approach
Dr Puthawala and
colleagues
pioneered a temporary seed
technique of placing the
needles, while visualizing them
through an open laparotom
Dr Whitmore and
colleagues MSKCC
began to insert I-125 seeds as a
sole treatment through an
open incision
mid-
1980s
transrectal ultrasound-guided,
template-guided I-125
implantation procedure has
become the primary technique
of permanent seed
implantation

49. 1983 Hans Henrik Holm use of transrectal ultrasound to
visualize the permanent placement
of I-125 seeds via needles inserted
through the perineum directly into
the prostate
implanting I-125 seeds
into cancerous prostates,
under the direction of
axial imaging from a
rectal probe mounted on
a sledge-stepper
(stepping unit).
1985 Blasko and Ragde the first transperineal, ultrasound-
guided approach in the United States
ultrasound-guided
approach resulted in
increased accuracy of
needle and seed
placement and relatively
even distribution of
seeds throughout the
prostate
it allowed computerized treatment
planning of the implant rather than
the use of simple nomograms
ensuring the proper
number, strength, and
positioning of
radioactive sources.

50. 2019 KMIO

51. BARC BRIT 125-I Seeds

61. Future Directions

70. Thank You