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Tony Crispino
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Date Joined Dec 2006
Total Posts : 8128
   Posted 3/15/2011 11:07 AM (GMT -6)   
With the terrible crisis in Japan unfolding, I have paid a minor notice to how radiation is being measured from the Dai Ichi nuclear plant in Fukushima. This is a topic where I am a bit weak. We measure our treatment dosages in Gray and the measurements in Japan are measured in Millisieverts. Rolph Sievert was a Swedich physicist who studied dosages in nuclear medicine. His goal was to balance the cancer causing possibilities with radiation, with treating patients with cancer. From my basic, and I mean very basic, understanding, one sievert requires 1 gray of beta or gamma radiation but only 0.05 gray of alpha radiation or 0.1 gray of neutron radiation. . The difference is that gray is a quantity of radiation, and the sievert is a human absorption rate. Here are some examples of absorption rates:

Living near a nuclear power station = less than 0.01 mSv/year
Chest x-ray = 0.04 mSv
Cosmic radiation (from sky) at sea level = 0.24 mSv/year
Terrestrial radiation (from ground) = 0.28 mSv/year
Mammogram = 0.30 mSv
Natural radiation in the human body = 0.40 mSv/year
Brain CT scan = 0.8–5 mSv
Typical individual's natural background radiation: 2 mSv/year; 1.5 mSv/year for Australians, 3 mSv/year for Americans
Radon in the average US home = 2 mSv/year
Chest CT scan = 6–18 mSv
Average American's total radiation exposure: 6.2 mSv/year
New York-Tokyo flights for airline crew: 9mSv/year
Smoking 1.5 packs/day = 13 mSv/year
Gastrointestinal series X-ray investigation = 14 mSv
Current average limit for nuclear workers: 20 mSv/year
Background radiation in parts of Iran, India and Europe: 50 mSv/year
Lowest clearly carcinogenic level: 100 mSv/year
Criterion for relocation after Chernobyl disaster: 350 mSv/lifetime

Clearly in our doses we receive more than the average nuclear worker in our doses. I linked a presentation below on imaging doses that we can receive. Interestingly this paints a different picture than our RO's paint. The presentation clearly shows that X-ray, CT Scans, and MRI in a single year increases risk of secondary cancers. A bit disturbing when you consider we guys who have indeed completed diagnosis, imaging, and in many cases radiation to treat our cancer. With our doses we may actually exceed the Chernobyl exposure rates for a single year. In fact this tidbit caught my attention in the presentation:

“The delivery of 1 rad (0.01Gy) … to a women younger than 35 is estimated to increase her lifetime risk of breast cancer by 13.6%." Great ~ a typical dose for our radiation therapy is around 75 gray over 45 treatments.

Here is that presentation...

I can see where exposure even in prostate cancer delivery protocols are small. But I can also see where a younger man in his thirties has far greater secondary cancer risk than a man 50 and above. Is there enough to be concerned about? I am not clear on that at all from the brief study I just did. The risks, however, are present. There is no clear way to measure how men are affected 30 years after therapy other than with theory. Today's radiation dosing is far safer than even ten years ago as precision has been the technological push. To what degree is safety for younger men? Not sure...

Advanced Prostate Cancer at age 44 (I am 48 now)
pT3b,N0,Mx (original PSA was 19.8) EPE, PM, SVI. Gleason 4+3=7

Da Vinci Surgery ~ 2/16/2007
Adjuvant Radiation Therapy ~ IMRT Completed 8/07
Adjuvant Hormone Therapy ~ 28 months on Casodex and Lupron.
Undetectable PSA.


Post Edited (TC-LasVegas) : 3/15/2011 2:14:58 PM (GMT-6)

Veteran Member

Date Joined Nov 2009
Total Posts : 7201
   Posted 3/15/2011 11:38 AM (GMT -6)   
Sigh...just when I am about to start my SRT

Veteran Member

Date Joined Oct 2006
Total Posts : 1210
   Posted 3/15/2011 2:46 PM (GMT -6)   
Cancer now or cancer later. . . your choice.
Did somebody mention that this cancer really sucks?
Born 1936
PSA 7.9, Gleason Score 3+4=7, 2 of 8 positive
open RP Nov 06, T3a, Gleasons 3+4=7, Seminal vesicles and lymph nodes clear
Catheter out 15 Dec 06, Dry since 11 Feb 07
All PSA tests in 2007 (4) <.04
PSA tests in 2008: Mar.=.04; Jun.=.05; Sept.=.08; at SRT Start=0.1,
Salvage RT completed (33 days-66Gy) 19 Dec 08
PSA: in Jan 09 =.05, all tests to date (Jan 11) <.04

Elite Member

Date Joined Oct 2008
Total Posts : 25380
   Posted 3/15/2011 9:26 PM (GMT -6)   
Gee Tony, the first major radiation I had in 2000, was 70 gys and this time in 2009 was 72, so that's 142 gys just in 9 years, should I feel doomed? lol. Seriously, wonder if the dose from the first time triggered my PC, wonder if that is even possible. And the 2000 radiation was old school and brutal, none of this IMRT or IGRT stuff.

Age: 58, 56 dx, PSA: 7/07 5.8, 10/08 16.3
3rd Biopsy: 9/08 7 of 7 Positive, 40-90%, Gleason 4+3
open RP: 11/08, on catheters for 101 days
Path Rpt: Gleason 3+4, pT2c, 42g, 20% cancer, 1 pos marg
Incont & ED: None
Post Surgery PSA: 2/09 .05,5/09 .1, 6/09 .11. 8/09 .16
Post SRT PSA: 1/10 .12, 4/8 .04, 8/6 .06 2/11 1.24
Latest: 6 Corr Surgeries to Bladder Neck, SP Catheter since 10/1/9, SRT 39 Sess/72 gy ended 11/09, 21 Catheters, Ileal Conduit Surgery 9/10,
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