Peter Attia, interviewing Dr. Sanjay Mehta, discusses significant strides in the field of radiation oncology that are minimizing side effects and enhancing the precision of cancer treatments.

Advancements in Targeted Radiation Oncology Reduce Damage

Linacs Replace Cobalt-60 For Precision and Safety

Sanjay Mehta highlights that linear accelerators (LINACs) have replaced Cobalt-60 machines in the U.S. for the past 30 years due to their precision and safety. LINACs are electron guns that fire electrons into a tungsten target to generate X-rays. Cobalt machines, which exposed patients to radioactive isotopes, have largely been decommissioned because LINACs offer higher energy photons and lower skin doses. Although Gamma Knife, which uses Cobalt-60, is still used by some centers for high-resolution treatment, LINAC-based stereotactic radiosurgery has largely replaced it due to its flexibility in treating more than just central nervous system conditions.

Imrt and Igrt Optimize Beams, Sculpting Dose To Tumor and Tracking Its Position

Mehta explains the use of advanced technologies like IMRT (intensity-modulated radiation therapy) and IGRT (image-guided radiation therapy). IMRT allows for high-definition treatment with multiple small "pixels" to precisely sculpt radiation doses. IGRT provides advanced targeting capabilities with the newest form of IMRT.

Advancements in Simulation Enhance Radiation Accuracy

The careful positioning of patients for treatment sessions and advancements in simulation practices were highlighted by Mehta. He discusses the "movie star pose" for breast cancer radiation and the use of devices like vaclocks to create exact molds of a patient’s treatment position, ensuring accuracy and consistency. Modern radiation planning has eliminated the use of grease pencils and physical films, allowing for precisely directed beam angles that spare healthy tissue.

Evolution of Radiation Therapy: From Radical Mastectomies to Lumpectomies With Targeted Irradiation

The conversation with Mehta and Attia showcases the evolution from radical mastectomies to breast conservation methods like lumpectomies combined with radiation therapy. Current radiation treatments are fractionated into small daily amounts over three weeks with optimized doses and schedules, resulting in mastectomy-like outcomes but with minimal long-term side effects.

Modern techniques further improve sparing of the heart, lungs, and other organs at risk during breast cancer radiation. Specialized therapies, like treating large-breasted patients prone, ensure that the radiation maximizes efficiency while minimizing unwanted exposure. These conservative approaches have been supported by evidence indicating that a combination of lumpectomy and radiation therapy leads to the same survival outcomes as total mastectomy.

Prostate Cancer Radiation: More Conformal and Precise Approaches

Discussing prostate cancer, Mehta emphasizes the increased precision of radiation therapy, allowing for very low doses to the sensitive areas such as the penile bulb, rectum, and bladder. This precision has reduced side effects significantly. The introduction of gel spacers helps minimize the dose received by the rectum during treatment.

Patients are advised to prepare for treatment by maintaining a full bladder and empty bowel, which helps to maximize distances between prostate and surrounding organs. Mehta notes that modern radiation planning accounts for ...

The podcast explores the therapeutic role of low-dose radiation therapy (LDRT) in treating various inflammatory conditions, with a focus on how it is more commonly used in Europe compared to the United States.

Low-dose Radiation Therapy in Europe: Decades of Use for Inflammatory Conditions, Limited U.S. Adoption

Peter Attia introduces the concept of utilizing low-dose radiation for healing injuries and expresses curiosity about its infrequent use in the U.S. for managing orthopedic issues.

Ldrt Delivers 3 Gy Total Fractionated Radiation to Reduce Inflammation and Pain

The treatment mentioned by Mehta and Attia consists of 0.5 Gy given six times over two weeks, using very low-energy equipment like electron beam therapy. This results in a total of 3 Gy of radiation to the afflicted area.

Ldrt's Proposed Mechanisms: Modulating Cytokines, Immune Cells, Tissue Repair Stimulation

The therapy's anti-inflammatory effect is likened to that of cortisone injections or NSAIDs. It works potentially by modulating cytokines, immune cells, and stimulating tissue repair.

Ldrt Effective for Achilles Tendinopathy, Plantar Fasciitis, and De Quervain's Tenosynovitis

Mentioning his own experience, Mehta shares that LDRT offers durable pain relief and functional improvements, and serves as an alternative to steroid injections.

Ldrt Offers Durable Pain Relief and Functional Improvements, an Alternative to Steroid Injections or Other Treatments

For conditions not involving arthritis, like De Quervain's tenosynovitis and plantar fibrosis, radiation is also effective without causing side effects such as lymphedema linked with higher doses.

Ldrt's Low Radiation Doses Are Safe, With Minimal Side Effects and Negligible Long-Term Risks

Protocols suggest reassessing the necessity for additional treatment 12 weeks post-therapy. The tr ...

Peter Attia and Sanjay Mehta confront the deep-seated public fears—radiophobia—surrounding radiation, tracing it back to historical events and challenging misconceptions with current scientific understanding.

Radiation in Medicine: Public Radiophobia in the U.S

Historical Events Like Radium Girls and Nuclear Accidents Like Chernobyl and Three Mile Island Contribute to Fears and Misconceptions About Radiation Dangers

Attia and Mehta delve into the origins of radiophobia in the U.S., contrasting it with Europe where radiation is used routinely for non-cancerous conditions like arthritis and tendonitis. They attribute part of the fear to the Cold War's nuclear phobia and incidents like those involving the Radium Girls in the 1920s, who suffered from serious health issues like osteo-radionecrosis after ingesting radium. These cases, along with the broader use of radiation in products showing harmful effects, have significantly contributed to the public's fear.

Linear No-threshold Model Questioned; Evidence Shows Hormesis, Higher Thresholds at Low Doses

The Linear No Threshold Model (LNT), suggesting any amount of radiation exposure carries some cancer risk, is questioned. Mehta points out that low radiation doses seem to cause almost no biological damage, challenging the LNT's notion of a directly proportional risk. The idea of hormesis, where low doses of radiation might have beneficial effects, is also explored, although its acceptance is controversial and primarily based on animal studies. Population studies around Hiroshima and Nagasaki suggest a potential radioprotection effect, with some individuals presenting lower rates of leukemia and thyroid cancer than expected.

Medical Imaging Radiation: Low-risk, Benefits Often Outweigh Minimal Risks

Imaging Advances Minimize Radiation in Ct and Pet-ct Scans

Peter Attia highlights substantial reductions in CT scan radiation exposure due to advancements in technology. He notes a decline from 25 millisieverts in older CT angiograms to only 1 to 3 millisieverts with modern scanners. Mehta agrees, suggesting that while following the ALARA principle, the difference in cancer risk between the higher and lower doses isn't clear due to a lack of data. He emphasizes that the diagnostic quality of the image should be the priority.

Mehta also highlights the evolution of PET CT scans, noting how the amalgamation of anatomical data from CTs with PET data, while increasing radiation dose, is justified due to the enhanced resolution and more detailed results it produces.

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