[{"data":1,"prerenderedAt":1156},["ShallowReactive",2],{"search-all":3,"page-decaylab\u002Fprivacy\u002F":1075},[4,319,561,611,848,978],{"id":5,"title":6,"author":7,"body":8,"date":301,"description":302,"extension":303,"image":111,"meta":304,"navigation":305,"path":306,"published":305,"seo":307,"shareHashtags":308,"shareText":311,"socialImage":312,"socialImageAlt":313,"stem":314,"tags":315,"updated":301,"__hash__":318},"blog\u002Fblog\u002Fdosimetry-is-a-staircase.md","Dosimetry Is a Staircase, Not an On\u002FOff Switch","Carlos Uribe, PhD",{"type":9,"value":10,"toc":291},"minimark",[11,20,23,26,32,38,44,47,52,55,62,65,72,75,79,87,90,96,103,106,112,119,122,125,129,141,146,152,155,158,161,164,168,171,176,179,184,187,193,198,201,205,211,214,233,236,239,250,254,257,260,265,270,275,280,283,286],[12,13,14,15,19],"p",{},"One of the most exciting features of radiopharmaceutical therapy is that, for many treatments, we can image the therapy after it has been given. That may sound simple, but ",[16,17,18],"strong",{},"it is not"," routinely performed.",[12,21,22],{},"With many cancer treatments, we administer therapy and wait to see what happens. We follow symptoms, blood tests, tumour markers, or later imaging. In radiopharmaceutical therapy, the medicine itself carries a radionuclide. When its emissions are suitable for imaging, we can see where that treatment travelled inside the body.",[12,24,25],{},"This gives us a remarkable opportunity to ask three increasingly useful questions:",[12,27,28,31],{},[16,29,30],{},"Where did it go?"," Did the treatment reach known disease? Did it localize in the expected organs? Did it reveal areas we had not appreciated before?",[12,33,34,37],{},[16,35,36],{},"How much got there?"," Can we quantify activity in tumours and normal organs, and understand how long it remained localized there?",[12,39,40,43],{},[16,41,42],{},"Was it enough?"," Did the tumour receive a radiation dose likely to matter? Were normal tissues kept within an acceptable tolerated radiation dose range?",[12,45,46],{},"That last question is where dosimetry begins.",[48,49,51],"h2",{"id":50},"administered-activity-is-not-absorbed-dose","Administered activity is not absorbed dose",[12,53,54],{},"Many radiopharmaceutical therapies are still prescribed using a standard administered activity. This approach has been important: it made treatment simpler to deliver, easier to scale, and available to more patients.",[12,56,57,58,61],{},"But administered activity describes what enters the patient. ",[16,59,60],{},"Absorbed dose describes the energy deposited in tissue."," They are related, but they are not interchangeable.",[12,63,64],{},"Two patients can receive the same administered activity while experiencing very different biodistribution and clearance. One patient’s tumours may take up and retain substantial activity, while for another one it may not. Kidneys, bone marrow, salivary glands, and other normal tissues can also receive very different absorbed doses from one patient to the next.",[12,66,67],{},[68,69],"img",{"alt":70,"src":71},"Two patients receiving the same administered activity but different absorbed doses","\u002Fimg\u002Fblog\u002Fdosimetry-is-a-staircase\u002Fsame-activity-different-dose.svg",[12,73,74],{},"Dosimetry helps us estimate those absorbed doses, which are typically reported in units of Gray (Gy), by combining quantitative measurements with information about how activity changes over time.",[48,76,78],{"id":77},"think-of-dosimetry-as-a-staircase","Think of dosimetry as a staircase",[12,80,81,82,86],{},"People sometimes hear ",[83,84,85],"em",{},"dosimetry"," and imagine an all-or-nothing proposition: multiple scans, complex calculations, specialized software, and a workflow that is impossible to sustain in routine care.",[12,88,89],{},"That framing is not helpful.",[91,92,93],"blockquote",{},[12,94,95],{},"Dosimetry is not an on\u002Foff switch. It is a staircase.",[12,97,98,99,102],{},"We need to start where the clinical workflow can support it and build toward ",[16,100,101],{},"adaptive therapy",".",[12,104,105],{},"A centre may begin without routine post-treatment imaging. The next step might be visual SPECT\u002FCT after therapy. From there, it should add quantitative imaging, simplified or single-time-point approaches where appropriate, more complete patient-specific dosimetry, and eventually adaptive treatment planning in which information from one cycle helps guide the next.",[12,107,108],{},[68,109],{"alt":110,"src":111},"Six ascending levels of the dosimetry staircase, from no post-treatment imaging to adaptive therapy","\u002Fimg\u002Fblog\u002Fdosimetry-is-a-staircase\u002Fdosimetry-staircase.png",[12,113,114,115,118],{},"The message is not that every clinic must jump to the top tomorrow, but that we ",[16,116,117],{},"need to start climbing",". Each step can create value while the people, processes, equipment, and evidence needed for the next step are built.",[12,120,121],{},"This view respects clinical reality. Different therapies, patients, and decisions may require different levels of measurement. Each step can create value while the people, processes, equipment, and evidence needed for the next step are built. In fact, this will help us generate the evidence needed to justify and support the next step.",[123,124],"ad-break",{},[48,126,128],{"id":127},"the-vicious-cycle-of-dosimetry","The vicious cycle of dosimetry",[12,130,131,132,140],{},"There is another reason the staircase matters. Dosimetry has long faced a self-reinforcing implementation problem, described very nicely by my colleagues in Europe ",[133,134,139],"a",{"href":135,"rel":136,"title":138},"https:\u002F\u002Fjnm.snmjournals.org\u002Fcontent\u002Fearly\u002F2025\u002F05\u002F22\u002Fjnumed.124.269378",[137],"nofollow","Rethinking Dosimetry: A European Perspective|Johannes Tran-Gia et al.|Journal of Nuclear Medicine · 2025","here",":",[91,142,143],{},[12,144,145],{},"We do not use dosimetry routinely because we believe there is not enough evidence, and we struggle to generate evidence because dosimetry is not used routinely.",[12,147,148],{},[68,149],{"alt":150,"src":151},"The vicious cycle of radiopharmaceutical therapy dosimetry: no routine use because of limited evidence, and limited evidence because there is no routine use","\u002Fimg\u002Fblog\u002Fdosimetry-is-a-staircase\u002Fdosimetry-vicious-cycle.png",[12,153,154],{},"This cycle affects more than publication counts. Without routine, standardized measurements, it is harder to pool data across centres, establish dose–response and dose–toxicity relationships, compare treatment strategies, or identify which dosimetry approach is sufficient for a particular decision.",[12,156,157],{},"Waiting for definitive evidence before collecting routine dosimetry data can therefore preserve the very evidence gap we need to close.",[12,159,160],{},"The staircase offers a way out. A centre does not need to implement the most complex workflow before it can contribute useful information. Consistent post-treatment imaging, quantitative calibration, harmonized reporting, and carefully chosen simplified methods can all build the datasets and experience needed for the next step.",[12,162,163],{},"In that sense, climbing the staircase is not only an implementation strategy. It is also an evidence-generation strategy.",[48,165,167],{"id":166},"ask-a-better-question","Ask a better question",[12,169,170],{},"The debate is often framed as:",[91,172,173],{},[12,174,175],{},"Should we do dosimetry or not?",[12,177,178],{},"A more useful question is:",[91,180,181],{},[12,182,183],{},"What level of dosimetry does this decision need?",[12,185,186],{},"For some routine cases, visual imaging and quantitative trends may already add useful information. When toxicity risk or cumulative exposure is a concern, organ dosimetry may matter more. For retreatment, dose escalation, clinical trials, combination therapies, or emerging alpha-emitter treatments, more detailed patient-specific dosimetry may become especially valuable.",[12,188,189],{},[68,190],{"alt":191,"src":192},"Four levels of dosimetry matched to progressively more consequential clinical decisions","\u002Fimg\u002Fblog\u002Fdosimetry-is-a-staircase\u002Fdosimetry-for-the-decision.svg",[12,194,195],{},[83,196,197],{},"The appropriate level of dosimetry depends on the clinical question and the consequence of the decision.",[12,199,200],{},"This is a positive, practical way forward. It treats dosimetry not as a burden to apply identically in every situation, but as a tool whose depth should match the decision it needs to support.",[48,202,204],{"id":203},"why-this-matters-for-patients","Why this matters for patients",[12,206,207,208],{},"The goal is straightforward: ",[16,209,210],{},"safer, more effective, and more personalized treatment.",[12,212,213],{},"Dosimetry may help us:",[215,216,217,221,224,227,230],"ul",{},[218,219,220],"li",{},"understand why response varies between patients;",[218,222,223],{},"identify patients who might safely receive more treatment;",[218,225,226],{},"recognize when normal tissues may be approaching a relevant tolerance;",[218,228,229],{},"make better-informed retreatment decisions; and",[218,231,232],{},"design stronger clinical trials and radiopharmaceuticals.",[12,234,235],{},"None of this means that every treatment decision can (or should) immediately be based on dosimetry. Methods, evidence, access, and standardization continue to evolve. Dosimetry is an estimate, and its uncertainties need to be understood and communicated.",[12,237,238],{},"But the direction is compelling:",[215,240,241,244,247],{},[218,242,243],{},"Radiopharmaceutical therapy is often imageable.",[218,245,246],{},"Its therapeutic mechanism is radiation.",[218,248,249],{},"Absorbed dose should be part of the language of theranostics.",[48,251,253],{"id":252},"a-practical-path-forward","A practical path forward",[12,255,256],{},"Theranostics has already made extraordinary progress. Treatments once available only in highly specialized settings are now helping patients around the world.",[12,258,259],{},"The next opportunity is to learn more from every treatment we give.",[12,261,262],{},[16,263,264],{},"Post-treatment imaging is how we stop being blind.",[12,266,267],{},[16,268,269],{},"Quantitative SPECT imaging is how we stop being purely descriptive.",[12,271,272],{},[16,273,274],{},"Dosimetry is how we start adapting treatment.",[12,276,277],{},[16,278,279],{},"Absorbed dose should become part of the language of theranostics.",[12,281,282],{},"The future does not depend on making dosimetry perfect before we use it. It depends on building the staircase together one useful step at a time.",[284,285],"hr",{},[12,287,288],{},[83,289,290],{},"This article is for education and discussion. It is not a substitute for patient-specific medical advice or local clinical protocols.",{"title":292,"searchDepth":293,"depth":293,"links":294},"",2,[295,296,297,298,299,300],{"id":50,"depth":293,"text":51},{"id":77,"depth":293,"text":78},{"id":127,"depth":293,"text":128},{"id":166,"depth":293,"text":167},{"id":203,"depth":293,"text":204},{"id":252,"depth":293,"text":253},"2026-07-25","Dosimetry need not be all or nothing. A practical staircase can help clinics build evidence and move toward safer, more personalized radiopharmaceutical therapy.","md",{},true,"\u002Fblog\u002Fdosimetry-is-a-staircase",{"title":6,"description":302},[309,310],"Dosimetry","Theranostics","Dosimetry does not have to be all or nothing. A practical staircase can help clinics start where they are and build toward safer, more personalized radiopharmaceutical therapy.","\u002Fimg\u002Fblog\u002Fdosimetry-is-a-staircase\u002Fdosimetry-staircase-social.png","Dosimetry is a staircase, not an on\u002Foff switch, illustrated as six glowing steps toward adaptive therapy.","blog\u002Fdosimetry-is-a-staircase",[309,310,316,317],"Radiopharmaceutical Therapy","SPECT\u002FCT","T9JTJPHDB76MKo3ZWNXdaRq6m_vrCrS7q6YwhCwtY7g",{"id":320,"title":321,"author":7,"body":322,"date":551,"description":552,"extension":303,"image":357,"meta":553,"navigation":305,"path":554,"published":305,"seo":555,"shareHashtags":556,"shareText":556,"socialImage":556,"socialImageAlt":556,"stem":557,"tags":558,"updated":556,"__hash__":560},"blog\u002Fblog\u002Fhow-does-spect-create-an-image.md","How Does SPECT Create an Image?",{"type":9,"value":323,"toc":543},[324,327,330,333,337,340,346,349,352,358,363,367,370,376,379,385,388,394,399,403,410,413,416,419,422,428,433,437,440,446,452,455,466,469,475,480,482,486,489,502,505,508,511,521,524,528,531,534,537,539],[12,325,326],{},"If you have ever looked at a SPECT scan, it is easy to assume the camera simply “takes a picture”... Spoiler alert, it does not.",[12,328,329],{},"In fact, a SPECT image is reconstructed from multiple individual measurements collected as the gamma camera rotates around the patient. Understanding that process is one of the biggest \"eureka!\" moments in nuclear medicine imaging.",[12,331,332],{},"Let’s build that intuition.",[48,334,336],{"id":335},"step-1-the-camera-never-sees-the-whole-picture","Step 1: The camera never sees the whole picture",[12,338,339],{},"Imagine a small radioactive source inside the body.",[12,341,342,343,102],{},"As the gamma camera rotates, it only measures how much activity lies along each viewing direction. Each measurement is called a ",[16,344,345],{},"projection",[12,347,348],{},"Think of shining a flashlight through an object and recording only the shadow but not the object itself.",[12,350,351],{},"After one projection, we still do not know exactly where the radioactivity is. But after multiple projections from different angles, we have enough information to reconstruct the image.",[12,353,354],{},[68,355],{"alt":356,"src":357},"Animation of a gamma camera rotating around a patient while collecting projections","\u002Fimg\u002Fblog\u002Fhow-does-spect-create-an-image\u002Fspect-projections.svg",[12,359,360],{},[83,361,362],{},"The gamma camera records a different two-dimensional projection at each viewing angle.",[48,364,366],{"id":365},"step-2-the-sinogram","Step 2: The sinogram",[12,368,369],{},"This is where things become interesting.",[12,371,372,373,102],{},"Instead of displaying each projection separately, we stack them one on top of the other; This is what we call a ",[16,374,375],{},"sinogram",[12,377,378],{},"At first glance, a sinogram does not look anything like an anatomical image. It appears as a collection of curved lines, but those curves are not random.",[12,380,381,382,384],{},"Every bright point inside the patient traces out a smooth sinusoidal path as the camera rotates. This is where the name ",[83,383,375],{}," comes from: the curves resemble sine waves.",[12,386,387],{},"Once you recognize these patterns, you will never look at projection data the same way again.",[12,389,390],{},[68,391],{"alt":392,"src":393},"Animation of projection data building into a sinogram","\u002Fimg\u002Fblog\u002Fhow-does-spect-create-an-image\u002Fsinogram.svg",[12,395,396],{},[83,397,398],{},"Each row contains a projection from one angle. A point source follows a sinusoidal path as the angle changes.",[48,400,402],{"id":401},"step-3-can-we-simply-redistribute-the-projections-back","Step 3:  Can we simply \"redistribute\" the projections back?",[12,404,405,406,409],{},"A surprisingly intuitive idea is to take every projection and spread (or ",[16,407,408],{},"back-project",") its measured counts across the image.",[12,411,412],{},"Repeat this for every angle, and eventually an image starts to appear.",[12,414,415],{},"It works…",[12,417,418],{},"…sort of.",[12,420,421],{},"The reconstructed object becomes blurry because every measurement is spread over an entire line rather than placed exactly where it originated. Even with many projections, simple back-projection produces streaking and a $1\u002Fr$ blur.",[12,423,424],{},[68,425],{"alt":426,"src":427},"Animation showing simple back-projection accumulating into a blurred image","\u002Fimg\u002Fblog\u002Fhow-does-spect-create-an-image\u002Fback-projection.svg",[12,429,430],{},[83,431,432],{},"Each new projection adds information, but it also spreads counts across the image.",[48,434,436],{"id":435},"step-4-filtering-sharpens-the-image","Step 4: Filtering sharpens the image",[12,438,439],{},"The solution is elegant.",[12,441,442,443,102],{},"Before back-projecting, we first ",[16,444,445],{},"filter the projection data",[12,447,448,449,102],{},"This compensates for the blurring introduced by simple back-projection, producing what is known as ",[16,450,451],{},"filtered back projection (FBP)",[12,453,454],{},"Different filters make different trade-offs:",[215,456,457,460,463],{},[218,458,459],{},"sharper images;",[218,461,462],{},"less image noise; or",[218,464,465],{},"a smoother appearance.",[12,467,468],{},"Finding the right balance is one of the classic challenges in medical image reconstruction.",[12,470,471],{},[68,472],{"alt":473,"src":474},"Animated comparison of simple back-projection and filtered back projection","\u002Fimg\u002Fblog\u002Fhow-does-spect-create-an-image\u002Ffiltered-back-projection.svg",[12,476,477],{},[83,478,479],{},"Filtering reduces the characteristic haze of simple back-projection and makes the source easier to localize.",[123,481],{},[48,483,485],{"id":484},"seeing-it-makes-all-the-difference","Seeing it makes all the difference",[12,487,488],{},"When I first started learning and, later on, teaching image reconstruction, I realized that static figures only go so far.",[12,490,491,492,495,496,102],{},"Some of the best animations I have ever used were created by my colleague ",[16,493,494],{},"Adam Kesner",", whose visualizations beautifully show how projections, sinograms, and back-projection work. Those animations have helped generations of students develop an intuitive understanding of tomographic imaging. You can find them on his ",[133,497,501],{"href":498,"title":499,"rel":500},"https:\u002F\u002Fsites.google.com\u002Fa\u002Ffulbrightmail.org\u002Fkesnersmedicalphysics\u002Fhome\u002Feducation\u002F3d-image-reconstruction-explained-with-animated-gifs","3D Image Reconstruction Explained with Animated GIFs|Adam Kesner|Medical physics education resource|Website",[137],"website",[12,503,504],{},"They also inspired me to build something interactive.",[12,506,507],{},"Instead of simply watching the reconstruction happen, I wanted people to be able to play with and control it themselves—changing the number of projections, seeing the sinogram update in real time, and watching the image emerge step by step.",[12,509,510],{},"That became the inspiration for the TheranosticsBytes SPECT Reconstruction Applet.",[12,512,513,514],{},"👉 ",[16,515,516],{},[133,517,520],{"href":518,"title":519},"\u002Ftools\u002Fspect-imaging","SPECT Reconstruction Applet|TheranosticsBytes|Explore projections, sinograms, and image reconstruction|Interactive applet","Try the interactive SPECT reconstruction applet",[12,522,523],{},"I hope it gives you the same \"eureka!\" moment that those original animations gave me.",[48,525,527],{"id":526},"final-thoughts","Final thoughts",[12,529,530],{},"Every SPECT image begins life as a collection of two-dimensional measurements.",[12,532,533],{},"Image reconstruction is the mathematical process that transforms those measurements into a three-dimensional representation of where the radiopharmaceutical is inside the body.",[12,535,536],{},"Once you understand projections, sinograms, and back-projection, the reconstruction process no longer feels like a black box and it becomes a fascinating example of physics, mathematics, and medicine working together.",[284,538],{},[12,540,541],{},[83,542,290],{},{"title":292,"searchDepth":293,"depth":293,"links":544},[545,546,547,548,549,550],{"id":335,"depth":293,"text":336},{"id":365,"depth":293,"text":366},{"id":401,"depth":293,"text":402},{"id":435,"depth":293,"text":436},{"id":484,"depth":293,"text":485},{"id":526,"depth":293,"text":527},"2025-06-14","A visual introduction to how SPECT turns rotating gamma-camera projections into images using sinograms, back-projection, and filtering.",{},"\u002Fblog\u002Fhow-does-spect-create-an-image",{"title":321,"description":552},null,"blog\u002Fhow-does-spect-create-an-image",[317,559],"Image Reconstruction","F5Sg-Yy0rxoVbMIB3NmTh2IRBHJb49xOKXIkBABsaas",{"id":562,"title":563,"author":556,"body":564,"date":556,"description":568,"extension":303,"image":595,"meta":596,"meta_description":597,"navigation":305,"path":598,"photo_source":599,"seo":600,"stem":601,"type_strings":602,"__hash__":610},"pages\u002Fpages\u002Fabout.md","About Me",{"type":9,"value":565,"toc":593},[566,569,572,578,581,584,586],[12,567,568],{},"Hi, I’m Carlos. I’m a medical physicist based in beautiful British Columbia, Canada, and I spend much of my time thinking about how imaging can make cancer care more precise and more personal.",[12,570,571],{},"My work sits at the intersection of physics, medicine, and technology. I work with PET\u002FCT and SPECT\u002FCT, quantitative imaging, dosimetry, theranostics, and increasingly AI and code. What I enjoy most is turning complicated ideas into something useful; whether that is a new method, a small tool, a clear explanation, or a better way for a team to work together.",[12,573,574,577],{},[16,575,576],{},"TheranosticsBytes"," is my little personal space where I share some of that thinking outside the usual format of papers and presentations. You’ll find ideas I’m exploring, questions I keep returning to, and practical notes from the research and clinical worlds. Sometimes that means a deeper article; other times it might be a short reflection, a bit of code, or a side project such as DecayLab.",[12,579,580],{},"I don’t expect to have the final word on any of these topics. My hope is simply to make complex subjects a little more approachable and to contribute to thoughtful conversations about where medical imaging and theranostics are going.",[12,582,583],{},"Thanks for stopping by. If something here sparks a question, an idea, or a possible collaboration, I’d be happy to hear from you.",[284,585],{},[91,587,588],{},[12,589,590],{},[83,591,592],{},"Disclaimer: Any opinions presented in this website are my own and are not official statements on behalf of organizations I might be affiliated with. My posts are for informational purposes only and should not be seen as health\u002Fmedical advice.",{"title":292,"searchDepth":293,"depth":293,"links":594},[],"\u002Fimg\u002Faboutme.png",{},"I am a medical physicist that dreams of a world free of cancer.","\u002Fpages\u002Fabout","Athabasca Falls, Jasper National Park, Alberta, Canada",{"title":563,"description":568},"pages\u002Fabout",[603,604,605,606,607,608,609],"I'm Carlos Uribe, a medical imaging physicist.","I'm Carlos Uribe, I contribute to the development of radiopharmaceuticals.","I'm Carlos Uribe, I use AI to improve the diagnosis of cancer.","I'm Carlos Uribe, I perform dosimetry for radionuclide therapies.","I'm Carlos Uribe, I work with PET, SPECT, and CT.","I'm Carlos Uribe, I dream of a world without cancer.","I'm Carlos Uribe, I want to improve the quality of life for cancer patients.","WO8FBnfHaP1fZ6290JDn7TytxJZz-waUr9-70EH_X_U",{"id":612,"title":613,"author":614,"body":615,"date":839,"description":840,"extension":303,"image":841,"meta":842,"meta_description":843,"navigation":305,"path":844,"photo_source":556,"seo":845,"stem":846,"type_strings":556,"__hash__":847},"pages\u002Fpages\u002Fdecaylab.md","Decay Lab","Carlos Uribe, PhD, MCCPM",{"type":9,"value":616,"toc":830},[617,623,626,632,651,655,658,702,706,727,730,734,737,757,763,767,770,780,784,790,793,798,806,810,817,821,824,827],[12,618,619,620,622],{},"Radioactive decay calculations should take seconds, not interrupt your workflow. ",[16,621,613],{}," is a focused radionuclide decay calculator designed for nuclear medicine professionals, researchers, and students.",[12,624,625],{},"Choose a radionuclide, enter an activity and two points in time, and get the decay-corrected result instantly. No spreadsheets. No searching for half-lives. No internet connection required.",[12,627,629],{"style":628},"margin-bottom:8px;text-align:center;",[16,630,631],{},"Download for iPhone, iPad, and Android.",[12,633,635,636,635,645],{"style":634},"display:flex;align-items:center;justify-content:center;gap:16px;flex-wrap:wrap;","\n  ",[133,637],{"href":638,"target":639,"rel":640,"ariaLabel":643,"style":644},"https:\u002F\u002Fapps.apple.com\u002Fca\u002Fapp\u002Fdecay-lab\u002Fid6746874842","_blank",[641,642],"noopener","noreferrer","Download Decay Lab on the App Store","display:inline-block;width:163px;height:54px;background:url('\u002Fimg\u002Fstore-badges\u002Fapple_app_store.svg') center \u002F contain no-repeat;",[133,646],{"href":647,"target":639,"rel":648,"ariaLabel":649,"style":650},"https:\u002F\u002Fplay.google.com\u002Fstore\u002Fapps\u002Fdetails?id=com.carluri.decay_lab",[641,642],"Get Decay Lab on Google Play","display:inline-block;width:203px;height:78px;background:url('\u002Fimg\u002Fstore-badges\u002Fgoogle_play.png') center \u002F contain no-repeat;",[48,652,654],{"id":653},"radiation-decay-made-simple","Radiation decay made simple",[12,656,657],{},"Decay Lab brings the calculations you reach for most in a nuclear medicine setting into one clean, fast interface:",[215,659,660,666,672,678,684,690,696],{},[218,661,662,665],{},[16,663,664],{},"Calculate decay instantly"," between any reference and target date and time",[218,667,668,671],{},[16,669,670],{},"Follow activity in real time"," with a continuously updated “Activity now” result",[218,673,674,677],{},[16,675,676],{},"Search more than 2,100 radionuclide records"," with verified half-lives",[218,679,680,683],{},[16,681,682],{},"Find clinically relevant radionuclides first",", organized for PET, SPECT, therapy, and generator workflows",[218,685,686,689],{},[16,687,688],{},"Convert every common activity unit at a glance",", Bq, kBq, MBq, GBq, TBq, nCi, µCi, mCi, and Ci",[218,691,692,695],{},[16,693,694],{},"Work completely offline",", wherever the work takes you",[218,697,698,701],{},[16,699,700],{},"Use light or dark mode"," with a native interface built for each platform",[48,703,705],{"id":704},"from-question-to-answer-in-three-steps","From question to answer in three steps",[707,708,709,715,721],"ol",{},[218,710,711,714],{},[16,712,713],{},"Choose the radionuclide."," Browse by element or search the catalog. Nuclear medicine radionuclides are shown first, with clear PET, SPECT, therapy, and generator labels.",[218,716,717,720],{},[16,718,719],{},"Enter the reference."," Set the known activity, unit, date, and time.",[218,722,723,726],{},[16,724,725],{},"Read the result."," See the activity now and at your target time, in the unit that fits your workflow.",[12,728,729],{},"Need a conversion instead? Enter one value once and see the full becquerel and curie families together, no repetitive pair-by-pair conversions.",[48,731,733],{"id":732},"built-for-the-work-of-nuclear-medicine","Built for the work of nuclear medicine",[12,735,736],{},"Use Decay Lab when you need to:",[215,738,739,742,745,748,751,754],{},[218,740,741],{},"Decay-correct a radiopharmaceutical activity before administration or imaging",[218,743,744],{},"Estimate the activity remaining at a future time",[218,746,747],{},"Work backward from a target time to a reference activity",[218,749,750],{},"Convert quickly between SI and curie-based units",[218,752,753],{},"Check a radionuclide half-life without searching online",[218,755,756],{},"Teach or learn the relationship between activity, time, and half-life",[12,758,759,760,102],{},"It is a practical companion for ",[16,761,762],{},"nuclear medicine physicians, nuclear medicine technologists, medical physicists, radiation safety professionals, researchers, educators, and students",[48,764,766],{"id":765},"accurate-by-design","Accurate by design",[12,768,769],{},"Both the Apple and Android apps use the same radionuclide catalog and the same tested decay physics. Unit conversions route through Becquerels as the common base, and clinically relevant nuclear states are curated so the app presents the state that matters, not just the first database match.",[12,771,772,773,779],{},"Decay Lab was created by ",[16,774,775],{},[133,776,778],{"href":777},"\u002Fabout\u002F","me",", and I want it to make a common calculation feel as quick and easy as it should.",[48,781,783],{"id":782},"what-comes-next","What comes next",[12,785,786,787,102],{},"Decay Lab is only the beginning. I have more ideas for features and workflow improvements, and I will continue developing the app over time with one goal: ",[16,788,789],{},"to make the small, repetitive parts of our nuclear medicine work easier every day",[12,791,792],{},"The people who use Decay Lab can help shape what comes next. If there is a calculation you reach for often, a step that feels more cumbersome than it should, or an improvement that would make the app more useful in your work, I would love to hear about it.",[12,794,795],{"style":628},[16,796,797],{},"Ready to make decay correction the easy part?",[12,799,635,800,635,803],{"style":634},[133,801],{"href":638,"target":639,"rel":802,"ariaLabel":643,"style":644},[641,642],[133,804],{"href":647,"target":639,"rel":805,"ariaLabel":649,"style":650},[641,642],[48,807,809],{"id":808},"private-by-default","Private by default",[12,811,812,813,102],{},"Decay Lab performs calculations locally on your device and does not send calculation inputs to the developer. The app works without an account. It displays ads through Google AdMob, which may process device and usage information as described in the dedicated ",[133,814,816],{"href":815},"\u002Fdecaylab\u002Fprivacy\u002F","Decay Lab privacy policy",[48,818,820],{"id":819},"support-and-feedback","Support and feedback",[12,822,823],{},"If Decay Lab has been useful to you, consider leaving an honest rating or review on the App Store or Google Play. Reviews help other nuclear medicine professionals discover the app and help me understand what is working well.",[12,825,826],{},"For support, bug reports, feature ideas, or a radionuclide you would like to see reviewed, contact me through any of the social links in the footer of this page. That is the best way to reach me directly and help shape future versions of Decay Lab.",[12,828,829],{},"Decay Lab is a calculation aid. Always follow your institution’s procedures and independently verify results used for clinical decisions.",{"title":292,"searchDepth":293,"depth":293,"links":831},[832,833,834,835,836,837,838],{"id":653,"depth":293,"text":654},{"id":704,"depth":293,"text":705},{"id":732,"depth":293,"text":733},{"id":765,"depth":293,"text":766},{"id":782,"depth":293,"text":783},{"id":808,"depth":293,"text":809},{"id":819,"depth":293,"text":820},"2026-08-22","Radioactive decay calculations should take seconds, not interrupt your workflow. Decay Lab is a focused radionuclide decay calculator designed for nuclear medicine professionals, researchers, and students.","\u002Fimg\u002Fdecaylab.webp",{},"Fast, accurate radionuclide decay calculations and activity-unit conversions for nuclear medicine. Available on iPhone, iPad, and Android.","\u002Fpages\u002Fdecaylab",{"title":613,"description":840},"pages\u002Fdecaylab","KJFvYZTpO7n0DVQai0KIFzqXYEH8Fo_3PxbfjghlCf8",{"id":849,"title":850,"author":556,"body":851,"date":971,"description":292,"extension":303,"image":841,"meta":972,"meta_description":973,"navigation":305,"path":974,"photo_source":556,"seo":975,"stem":976,"type_strings":556,"__hash__":977},"pages\u002Fpages\u002Fdecaylab\u002Fprivacy.md","Decay Lab Privacy Policy",{"type":9,"value":852,"toc":962},[853,857,860,863,866,870,873,887,890,904,908,911,920,924,927,930,934,937,941,944,948,957],[48,854,856],{"id":855},"information-decay-lab-keeps-on-your-device","Information Decay Lab keeps on your device",[12,858,859],{},"Decay Lab performs radionuclide decay calculations on your device. The calculation inputs and results you enter or generate are not sent to the developer or to Google AdMob.",[12,861,862],{},"The app may store preferences and calculation state locally on your device so that your settings and recent work remain available when you return. This local information is used only to provide the app's calculation and preference features.",[12,864,865],{},"Decay Lab does not require an account, and the developer does not operate a server that receives your calculation inputs, calculation results, or locally stored preferences.",[48,867,869],{"id":868},"advertising-and-information-processed-by-google-admob","Advertising and information processed by Google AdMob",[12,871,872],{},"Decay Lab displays advertising through the Google Mobile Ads SDK (AdMob), a service provided by Google. When an ad is requested or you interact with an ad, the SDK may automatically collect and share information with Google, including:",[215,874,875,878,881,884],{},[218,876,877],{},"Your device's IP address, which may be used to estimate approximate or general location",[218,879,880],{},"Device or account identifiers, such as the advertising identifier and app set identifier, where available",[218,882,883],{},"App and advertising interactions, such as app launches, taps, ad views, and video views",[218,885,886],{},"Diagnostic and performance information, such as app launch time, hang rate, energy usage, and non-user-related crash logs",[12,888,889],{},"Google may use this information to provide and measure advertising, perform analytics, improve performance, maintain security, and prevent fraud and abuse. Data transmitted by the Google Mobile Ads SDK is encrypted in transit.",[12,891,892,893,898,899,102],{},"The information AdMob processes and the identifiers available to it may vary by platform, device settings, region, consent choice, SDK version, and whether ads are personalized, non-personalized, or limited. For more information, see ",[133,894,897],{"href":895,"rel":896},"https:\u002F\u002Fpolicies.google.com\u002Ftechnologies\u002Fpartner-sites",[137],"Google's explanation of how it uses information from apps that use its services"," and ",[133,900,903],{"href":901,"rel":902},"https:\u002F\u002Fpolicies.google.com\u002Fprivacy",[137],"Google's privacy policy",[48,905,907],{"id":906},"consent-and-privacy-choices","Consent and privacy choices",[12,909,910],{},"Where required by applicable law, Decay Lab presents a consent or privacy message before requesting advertising that uses data requiring consent. Depending on your region and the choices available there, you may be able to consent to or decline personalized advertising and related processing, or receive non-personalized or limited ads.",[12,912,913,914,919],{},"You can manage ad personalization in ",[133,915,918],{"href":916,"rel":917},"https:\u002F\u002Fmyadcenter.google.com\u002F",[137],"Google's My Ad Center"," and reset or delete your advertising identifier in your device's privacy settings. The exact controls vary by operating-system version and region.",[48,921,923],{"id":922},"data-retention-and-deletion","Data retention and deletion",[12,925,926],{},"Preferences and calculation state stored by Decay Lab remain on your device until the app or operating system removes them. You can normally remove this local data by deleting the app. Your device may also provide controls to clear an app's storage. Data restored from an operating-system backup may reappear if you reinstall the app.",[12,928,929],{},"Information processed by Google through AdMob is retained and deleted according to Google's policies and your Google and device settings. The developer cannot directly delete data held by Google that the developer cannot identify or access.",[48,931,933],{"id":932},"children","Children",[12,935,936],{},"Decay Lab is intended for nuclear medicine professionals, researchers, educators, and students and is not directed to children. The developer does not knowingly collect personal information directly from children through the app.",[48,938,940],{"id":939},"changes-to-this-policy","Changes to this policy",[12,942,943],{},"This policy may be updated when Decay Lab's features, advertising services, or legal obligations change. The effective date at the top identifies the latest version.",[48,945,947],{"id":946},"contact","Contact",[12,949,950,951,102],{},"For questions or requests about this privacy policy, email ",[16,952,953],{},[133,954,956],{"href":955},"mailto:dev@theranosticsbytes.com","dev@theranosticsbytes.com",[12,958,959],{},[83,960,961],{},"This policy describes Decay Lab's current data practices and is not legal advice.",{"title":292,"searchDepth":293,"depth":293,"links":963},[964,965,966,967,968,969,970],{"id":855,"depth":293,"text":856},{"id":868,"depth":293,"text":869},{"id":906,"depth":293,"text":907},{"id":922,"depth":293,"text":923},{"id":932,"depth":293,"text":933},{"id":939,"depth":293,"text":940},{"id":946,"depth":293,"text":947},"2026-09-05",{},"How the Decay Lab mobile app handles local calculation data, preferences, advertising data, consent, and privacy choices.","\u002Fpages\u002Fdecaylab\u002Fprivacy",{"title":850,"description":292},"pages\u002Fdecaylab\u002Fprivacy","7erPyH7MXITmc1a0PMsBQoTCmlNfXjZsu_hS3LYBFWc",{"id":979,"title":980,"author":556,"body":981,"date":556,"description":987,"extension":303,"image":556,"meta":1069,"meta_description":1070,"navigation":305,"path":1071,"photo_source":556,"seo":1072,"stem":1073,"type_strings":556,"__hash__":1074},"pages\u002Fpages\u002Fprivacy.md","Privacy & Cookies",{"type":9,"value":982,"toc":1060},[983,988,991,995,998,1009,1012,1016,1019,1023,1026,1029,1033,1036,1040,1043,1047,1050,1052,1055],[12,984,985],{},[16,986,987],{},"Last updated: July 25, 2026",[12,989,990],{},"TheranosticsBytes is a personal educational website. This page explains what information may be processed when you visit and the choices available to you.",[48,992,994],{"id":993},"advertising","Advertising",[12,996,997],{},"This site uses Google AdSense to display advertising. Third-party vendors, including Google, may use cookies or similar technologies to serve ads based on your visits to this site or other websites. Google's use of advertising cookies enables Google and its partners to show personalized ads where you have consented and non-personalized or limited ads where appropriate.",[12,999,1000,1001,1004,1005,102],{},"You can control how Google personalizes ads in ",[133,1002,918],{"href":916,"rel":1003},[137],". You can also learn ",[133,1006,1008],{"href":895,"rel":1007},[137],"how Google uses information from sites that use its services",[12,1010,1011],{},"Ads are visually identified as advertisements. TheranosticsBytes does not select individual ads and does not receive information that directly identifies you from an ad click.",[48,1013,1015],{"id":1014},"analytics","Analytics",[12,1017,1018],{},"This site uses Google Analytics to understand aggregate site usage, such as which pages are visited and how visitors find the site. Google Analytics may process device, browser, approximate location, and interaction information. Where consent is required, analytics storage should follow the choice made in the site's consent message.",[48,1020,1022],{"id":1021},"consent-and-cookies","Consent and cookies",[12,1024,1025],{},"Visitors in regions where consent is required may be shown a privacy message supplied through Google's consent management platform. That message lets you choose whether eligible advertising and analytics technologies may use cookies or similar storage. A privacy and cookie settings link is provided by that message so you can revisit your choice.",[12,1027,1028],{},"Your browser can also block or delete cookies. Doing so may affect site features or the relevance of ads.",[48,1030,1032],{"id":1031},"other-third-party-services","Other third-party services",[12,1034,1035],{},"Articles may use third-party services for features such as comments, mathematical typesetting, fonts, or externally hosted links. When you load or interact with those services, their providers may receive technical information such as your IP address, browser details, and the referring page, subject to their own privacy policies.",[48,1037,1039],{"id":1038},"information-you-provide","Information you provide",[12,1041,1042],{},"TheranosticsBytes does not offer user accounts or directly collect payment information. If you contact the site owner or post through a third-party commenting service, the information you choose to provide is handled through that service or communication channel.",[48,1044,1046],{"id":1045},"changes","Changes",[12,1048,1049],{},"This notice may be updated as the site or its services change. The date at the top indicates the latest revision.",[48,1051,947],{"id":946},[12,1053,1054],{},"For privacy questions, contact Carlos Uribe through one of the profiles linked in the site footer.",[12,1056,1057],{},[83,1058,1059],{},"This notice describes the site's current practices and is not legal advice.",{"title":292,"searchDepth":293,"depth":293,"links":1061},[1062,1063,1064,1065,1066,1067,1068],{"id":993,"depth":293,"text":994},{"id":1014,"depth":293,"text":1015},{"id":1021,"depth":293,"text":1022},{"id":1031,"depth":293,"text":1032},{"id":1038,"depth":293,"text":1039},{"id":1045,"depth":293,"text":1046},{"id":946,"depth":293,"text":947},{},"How TheranosticsBytes uses analytics, advertising, cookies, and related privacy controls.","\u002Fpages\u002Fprivacy",{"title":980,"description":987},"pages\u002Fprivacy","O0K1M7QZWMjTvfAmN2PsbjKeomyBIy-HnFGLTYbZCVQ",{"id":849,"title":850,"author":556,"body":1076,"date":971,"description":292,"extension":303,"image":841,"meta":1154,"meta_description":973,"navigation":305,"path":974,"photo_source":556,"seo":1155,"stem":976,"type_strings":556,"__hash__":977},{"type":9,"value":1077,"toc":1145},[1078,1080,1082,1084,1086,1088,1090,1100,1102,1110,1112,1114,1119,1121,1123,1125,1127,1129,1131,1133,1135,1141],[48,1079,856],{"id":855},[12,1081,859],{},[12,1083,862],{},[12,1085,865],{},[48,1087,869],{"id":868},[12,1089,872],{},[215,1091,1092,1094,1096,1098],{},[218,1093,877],{},[218,1095,880],{},[218,1097,883],{},[218,1099,886],{},[12,1101,889],{},[12,1103,892,1104,898,1107,102],{},[133,1105,897],{"href":895,"rel":1106},[137],[133,1108,903],{"href":901,"rel":1109},[137],[48,1111,907],{"id":906},[12,1113,910],{},[12,1115,913,1116,919],{},[133,1117,918],{"href":916,"rel":1118},[137],[48,1120,923],{"id":922},[12,1122,926],{},[12,1124,929],{},[48,1126,933],{"id":932},[12,1128,936],{},[48,1130,940],{"id":939},[12,1132,943],{},[48,1134,947],{"id":946},[12,1136,950,1137,102],{},[16,1138,1139],{},[133,1140,956],{"href":955},[12,1142,1143],{},[83,1144,961],{},{"title":292,"searchDepth":293,"depth":293,"links":1146},[1147,1148,1149,1150,1151,1152,1153],{"id":855,"depth":293,"text":856},{"id":868,"depth":293,"text":869},{"id":906,"depth":293,"text":907},{"id":922,"depth":293,"text":923},{"id":932,"depth":293,"text":933},{"id":939,"depth":293,"text":940},{"id":946,"depth":293,"text":947},{},{"title":850,"description":292},1788635615107]