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| Version | User | Scope of changes |
|---|---|---|
| Apr 13 2009, 1:16 AM EDT (current) | JeremiahDonner | 1 word added |
| Apr 12 2009, 4:35 PM EDT | cchambers | 11 words added, 2 words deleted |
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Links:
1. Palladium-103; Wikipedia - http://en.wikipedia.org/wiki/Palladium-103
2. Eye Plaques - http://www.eyecancer.com/Research/Research.aspx?nID=47&Research=About+Iodine-125+and+Palladium-103+Plaques&nResearchCategoryID=1&sResearchCategory=Articles
3. Palladium 103 seeds - BARD. http://images.google.com/imgres?imgurl=http://www.bardurological.com/resources/productImages/b_020_pd.jpg&imgrefurl=http://www.bardurological.com/products/loadProduct.aspx%3FprodID%3D231&usg=__rhz9S969smomBSF94eASlxhAOWk=&h=223&w=172&sz=11&hl=en&start=16&sig2=4S1rhn4KJeAdr9qVheGh1g&um=1&tbnid=clLhCUiTLMT2DM:&tbnh=107&tbnw=83&prev=/images%3Fq%3Dpalladium%2B103%26hl%3Den%26sa%3DN%26um%3D1&ei=8GfdSbTGGI34Mf_hrOQN
4. External Beam along with Brachytherapy-http://www.medicalnewstoday.com/articles/66101.php
References:
1. Khan, Faiz M. The Physics of Radiation Therapy. 3rd Edition. Philadelphia: Lippincott Williams & Wilkins; 2003: p. 358, 364-365,373-375.
2. Wikipedia. Palladium103. Available at: http://en.wikipedia.org/wiki/Palladium-103. Accessed: 11 March 2009.
3. Devlin, Phillip M. Brachytherapy Applications and Techniques. 1st Edition. Philadelphia: Lippincott Williams & Wilkins; 2007: p. 184-187.
4. "Session: 7.05 – Source of Permanent Implants. Stanford Web-Based Dosimetry Training Tool. http://www.dosimetrytrainingtool.com. Accessed: 8 March 2009.
5. Medical radioactive palladium-103. Available at http://www.freepatentsonline.com/EP1008995.html. Accessed on March 30, 2009.
6. Radiation Glossary N.P. Radiation Protection. Available at http://www.epa.gov/radiation/glossary/termnop.html#p. Accessed on April 4, 2009.
7. Palladium-103. Available at http://www.ncbi.nlm.nih.gov/pubmed/12459367. Accessed on April 4, 2009.
8. "Session: 12.03 – Activity Conversions. Stanford Web-Based Dosimetry Training Tool. http://www.dosimetrytrainingtool.com. Accessed: 8 March 2009.
9. Eye Cancer Network. About Iodine 125 and Palladium 103 Eye Plaques. Available at: http://www.eyecancer.com/Research/Research.aspx?nID=47&Research=About+Iodine-125+and+Palladium-103+Plaques&nResearchCategoryID=1&sResearchCategory=Articles Accessed: 6 April 2009.
10. Iodine-125 and Palladium-103 Low Dose Rate Brachytherapy Seeds. Used for Localization of Non-Palpable Lesions. Available at: http://www.nrc.gov/materials/miau/med-use-toolkit/seed-localization.html. Accessed on 8 April 2009.
11. Prostate Cancer - Brachytherapy with Palladium-103 Better Than or Equal to Prostatectomy. Available at: http://www.medicalnewstoday.com/articles/20904.php. Accessed on 8 April 2009.
Group Colors:
Theresa, Brandie, Christy, Jeremiah
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| Relevant Historical Data: | Produced in a reactor by bombarding stable Pd-102 with neutrons.(4) |
| Chemical/Radioactive Composition: | Matrix consists of a porous and mechanically stable inorganic material(5) A steel-white metal, does not tarnish in air, and is the least dense and lowest melting of the platinum group metals.(6) |
| Energy Characteristics: | Photon Energy (MeV) 0.021 avg(1,4) Average gamma energy of 20-23 keV(5) |
| Exposure Rate Constant: | 1.48c (Rcm2/mCi-h)(1,4) |
| Half-life Properties: | 17.0 days(1,4) Pd-103 decays 4% per day and delivers 90% dose in 2 months (56 day).(4) Decays by electron capture to rhodium-103, emitting gamma-rays with 21 keV's of energy. (2) |
| Forms available for use: | Seeds: Palladium-103 - consists of laser-welded titanium tube containing two graphite pallets plated with Palladium-103. There is a lead marker between the pallets that provides radiographic identification.(1) *See Figure labeled 15.5 Brachytherapy optic plaques are sewn to the episclera to cover the base of the intraocular tumor. This is used for uveal melanoma.(7) |
| HVL in lead: | 0.008 mm lead(1) |
| Measurement/Calibrations/QA: | Pd-103; available activities up to 2 mCi (2.2U) & produce initial dose rates up to 20cGy/hr.(4) |
| Used in formula/calculation: | The Modular Dose Calculation Modiel: TG-43. The effects of several physical factors on dose rate disribution are considered separately. (0 is used in place of theta, A is used for dose rate constant) The dose rate, D (r, 0) at point P with polar coordinates (r,0) in a medium from the center of a source of air kerma strength Sk can be expressed as: D(r,0)=ASk ((G(r,0))/(G(1,pi/2))(F(r,0))(g(r)) A is the dose rate constant, defined as the dose rate per unit air kerma strength (U) at 1cm along the transverse axis of the seed and has units of cGyh(-1)U(-1): A=D(1,pi/2)/Sk G(r,0) is the geometry factor that accounts for the geometric falloff of the photon fluence with distance from the source and depends on the distribution of radioactive material. For a point source, G(r,0)=1/rsquared and for unifomly distributed line source, G(r,0)=(02-01)/Ly5. F(r,0) is the anisotropy factor normalized at 0=pi/2, with the geometric factor factored out: F(r,0)=(D(r,0)G(r,pi/2))/(D(r,pi/2)G(r,0)) The anisotropy factor accounts for the angular dependence of photon absorption and scatter in the encapsulation and the medium. The radial dose function, g(r), accounts for radial dependence of photon absorption and scatter in the medium along the transverse axis and is given by: g(r)= (D(r,pi/2)G(1, pi/2))/(D(1, pi/2)G(r,pi/2)) Again the geometric factor is factored out from the dose rates in defining g(r). (1) Due to pd-103 source design and low energy x-ray emitted the "anisotropy" is high and the dosimetry is inherently complex. (11) |
| Uses in Radiation Oncology: | Pd-103 is used in treatment of high grade, permanent "prostate" seed implants.(2,4) It seems to be gaining popularity in see implants.(11) Activity of Pd-103 used for prostate cancer is 1.32mCi (range 0.50 to 1.90mCi) (3); higher initial dose rate compared to I-125 (this is due to the shorter T1/2 : 17 day vs. 59.4 days. (4) Ophthalmic plaque radiation therapy is the most commonly used "eye and vision-sparing" treatment for "choroidal melanoma" (around the world).(9) and/or "Uveal Melanoma" (2) Pd- 103 is also used as a ophthalmic plaque brachytherapy for intraocular melanoma. (7) This is also known as uveal melanoma, as mentioned above. Used for Localization of Non-Palpable tumors - The purpose of radioactive seed localization (RSL) of non-palpable lesions is to localize suspicious tissues for excision with the use of radioactive seeds. RSL uses radioactive seeds previously approved for the treatment of cancerous tumors. For instance, typically, iodine-125 and palladium-103 seeds between 200 – 300 μCi/seed are implanted into a breast lesion using a standard 18-gauge needle. These seeds are normally implanted within mammography or ultrasound suites and removed within surgical suites between 2 and 5 days post implantation. The radioactive seed(s) can be easily located with appropriate instrumentation (using a technique with which surgeons are familiar because of its similarity to sentinel lymph node biopsy and radioguided parathyroidectomy) and surgically removed with minimal injury to non-affected tissue. The seed(s) may be removed from the tissue specimen in surgery, or the tissue specimen containing the seed(s) can be sent to pathology for removal of the seed and analysis of the tissue.(10) |
| Treatment Planning: | Dosimetry for Palladium 103 is sparse.(1) prescription dose for Prostate cancer with Pd-103 in monotherapy brachytherapy is 125Gy and 100Gy if used as a boost following pelvic EBRT of 40-50Gy. (3) For opthalmic plaque brachytherapy, plaques are sewn to the episclera to cover the base of the intraocular tumor. Treatment involved delivery of a mean apical radiation dose of 80.5 Gy during 5-7 days' continuous treatment. (7) |
| One other interesting fact: | Palladium -103 may have a biological advantage in permanent implants because the dose is delivered at a faster rate than with Iodine-125.(1) Palladium-103 decays by "electron capture" with the emission of characteristic x-rays in the range of 20 to 23 keV (average energy 20.9 keV) and "Auger electrons".(1) Palladium-103 may be created from palladium-102.(2) The photon fluence distribution around the source is "anisotropic" due to the self-absorbtion by the source pallets, welds, and the lead x-ray marker.(1) Pd-103 is most effective against dedifferentiated tumors (3) Cold working increases its strength and hardness. It is used in some watch springs. (6) The study, "Palladium-103 Brachytherapy Versus Radical Prostatectomy in Patients with Clinically Localized Prostate Cancer: A 12-Year Experience From A Single Group Practice," showed that high-risk prostate cancer patients treated with brachytherapy using palladium-103 experienced greater success than patients treated with prostatectomy. In fact, high-risk patients treated with seeding showed an 88% cure rate vs. a 43% cure rate obtained with surgery at 12 years. Similarly, the results for intermediate-risk patients were also impressive, with 12-year data reflecting a success rate of 89% with seed therapy vs. a 58% success rate with surgery. In addition, low-risk patients demonstrated comparable results with those treated with seeds experiencing a 99% success rate vs. a 97% success rate with surgery at 10 years. (11) |
Links:
1. Palladium-103; Wikipedia - http://en.wikipedia.org/wiki/Palladium-103
2. Eye Plaques - http://www.eyecancer.com/Research/Research.aspx?nID=47&Research=About+Iodine-125+and+Palladium-103+Plaques&nResearchCategoryID=1&sResearchCategory=Articles
3. Palladium 103 seeds - BARD. http://images.google.com/imgres?imgurl=http://www.bardurological.com/resources/productImages/b_020_pd.jpg&imgrefurl=http://www.bardurological.com/products/loadProduct.aspx%3FprodID%3D231&usg=__rhz9S969smomBSF94eASlxhAOWk=&h=223&w=172&sz=11&hl=en&start=16&sig2=4S1rhn4KJeAdr9qVheGh1g&um=1&tbnid=clLhCUiTLMT2DM:&tbnh=107&tbnw=83&prev=/images%3Fq%3Dpalladium%2B103%26hl%3Den%26sa%3DN%26um%3D1&ei=8GfdSbTGGI34Mf_hrOQN
4. External Beam along with Brachytherapy-http://www.medicalnewstoday.com/articles/66101.php
References:
1. Khan, Faiz M. The Physics of Radiation Therapy. 3rd Edition. Philadelphia: Lippincott Williams & Wilkins; 2003: p. 358, 364-365,373-375.
2. Wikipedia. Palladium103. Available at: http://en.wikipedia.org/wiki/Palladium-103. Accessed: 11 March 2009.
3. Devlin, Phillip M. Brachytherapy Applications and Techniques. 1st Edition. Philadelphia: Lippincott Williams & Wilkins; 2007: p. 184-187.
4. "Session: 7.05 – Source of Permanent Implants. Stanford Web-Based Dosimetry Training Tool. http://www.dosimetrytrainingtool.com. Accessed: 8 March 2009.
5. Medical radioactive palladium-103. Available at http://www.freepatentsonline.com/EP1008995.html. Accessed on March 30, 2009.
6. Radiation Glossary N.P. Radiation Protection. Available at http://www.epa.gov/radiation/glossary/termnop.html#p. Accessed on April 4, 2009.
7. Palladium-103. Available at http://www.ncbi.nlm.nih.gov/pubmed/12459367. Accessed on April 4, 2009.
8. "Session: 12.03 – Activity Conversions. Stanford Web-Based Dosimetry Training Tool. http://www.dosimetrytrainingtool.com. Accessed: 8 March 2009.
9. Eye Cancer Network. About Iodine 125 and Palladium 103 Eye Plaques. Available at: http://www.eyecancer.com/Research/Research.aspx?nID=47&Research=About+Iodine-125+and+Palladium-103+Plaques&nResearchCategoryID=1&sResearchCategory=Articles Accessed: 6 April 2009.
10. Iodine-125 and Palladium-103 Low Dose Rate Brachytherapy Seeds. Used for Localization of Non-Palpable Lesions. Available at: http://www.nrc.gov/materials/miau/med-use-toolkit/seed-localization.html. Accessed on 8 April 2009.
11. Prostate Cancer - Brachytherapy with Palladium-103 Better Than or Equal to Prostatectomy. Available at: http://www.medicalnewstoday.com/articles/20904.php. Accessed on 8 April 2009.
Group Colors:
Theresa, Brandie, Christy, Jeremiah
