Wednesday 16 August 2023

The effectiveness of hyperbaric oxygen therapy for managing radiation-induced proctitis – results of a 10-year retrospective cohort study

The largest retrospective study of hyperbaric oxygen therapy in radiation-induced proctitis:

Moreira Monteiro A, Alpuim Costa D, Mareco V and Espiney Amaro C (2023). The effectiveness of hyperbaric oxygen therapy for managing radiation-induced proctitis – results of a 10-year retrospective cohort study. Front. Oncol. 13:1235237. doi:10.3389/fonc.2023.1235237 (https://doi.org/10.3389/fonc.2023.1235237).

Tuesday 1 August 2023

Survey: "breast cancer: applicability and limits of international guidelines" (French)

Enquête: "cancer du sein: applicabilité et limites des guidelines internationales".

Quel que soit notre lieu d’exercice, nous connaissons, lisons et utilisons tous les mêmes recommandations internationales. Afin de faire le point sur l'applicabilité et les limites des guidelines internationales concernant la pratique de la radiothérapie mammaire, nous vous remercions de prendre quelques instants pour répondre à ce questionnaire. Ce questionnaire n’est probablement pas exhaustif, n’hésitez pas à amender vos réponses de commentaires dont nous ne manquerons pas de tenir compte lors de l'analyse.


Cette étude est menée conjointement entre la société marocaine de cancérologie (SMC) et la SFRO. Nous vous remercions de prendre quelques minutes afin de répondre à cette enquête avant le 30 aout 2023 ainsi que de la diffuser largement autour de vous.

Thursday 27 July 2023

Survey: "Applicability of international recommendations in the management of cervical cancer" (French)

Enquête: "Applicabilité des recommandations internationales dans la prise en charge du cancer du col utérin": link.
Cette étude est menée conjointement entre la Société Marocaine de Cancérologie (SMC) et la Société Française de Radiothérapie Oncologique (SFRO). Nous vous remercions de prendre quelques minute afin de répondre à cette enquête avant le 15 aout 2023 ainsi que de la diffuser largement autour de vous.

Saturday 18 June 2022

Touchdown: setting up your early career and practice

ARS: the American Interplanetary Society, later the American Rocket Society; ROCKET = Radiation Oncology Knowledge for Early-career and Training; ROVER = Radiation Oncology Virtual Education Rotation.

Friday 27 May 2022

Doctor hierarchy

Source: Roberts, E. (2021, November 29). Guide to the Doctor Hierarchy [Digital image]. Retrieved May 27, 2022, from https://www.verywellhealth.com/types-of-doctors-residents-interns-and-fellows-3157293.

First-year residents are referred to as interns. After that, they are known as resident doctors, resident physicians, or simply "residents".
Fellowship is optional but is required to practice certain subspecialties.
Bibliographic reference: Whitlock, J. (2021, November 29). Doctors, Residents, and Attendings: What's the Difference? Verywell Health. Retrieved May 27, 2022, from https://www.verywellhealth.com/types-of-doctors-residents-interns-and-fellows-3157293.

 

Sunday 20 February 2022

Repeatability

It is a measure of precision. It is the «variation due to the measuring device. It is the variation observed when the same operator measures the same part repeatedly with the same device [1].» It «is similar to uniformity except that it deals with how consistent a particular sensor is against itself. It can be used to describe the ability of a sensor to provide the same result, under the same circumstances, over and over again [2].»

Bibliographic references:
[1] Reliawiki. 2017. Measurement System Analysis. [online] Available at: <https://reliawiki.org/index.php/Measurement_System_Analysis> [Accessed 20 February 2022].
[2] Apogeeinstruments.com. 2022. Uniformity, Repeatability, Stability, and Accuracy. [online] Available at: <https://www.apogeeinstruments.com/uniformity-repeatability-stability-and-accuracy/> [Accessed 20 February 2022].

Stability

It is «a measure of how the accuracy and precision of the system perform over time [1].»

[1]

«Stability deals with the degree to which sensor characteristics remain constant over time. Changes in stability, also known as drift, can be due to components aging, decrease in sensitivity of components, and/or a change in the signal to noise ratio, etc [2].»

Bibliographic references:
[1] Reliawiki. 2017. Measurement System Analysis. [online] Available at: <https://reliawiki.org/index.php/Measurement_System_Analysis> [Accessed 20 February 2022].
[2] Apogeeinstruments.com. 2022. Uniformity, Repeatability, Stability, and Accuracy. [online] Available at: <https://www.apogeeinstruments.com/uniformity-repeatability-stability-and-accuracy/> [Accessed 20 February 2022].

Precision

«Precision describes the variation you see when you measure the same part repeatedly with the same device. It includes the following two types of variation:
  • Repeatability
  • Reproducibility: variation due to the operators and the interaction between operator and part. It is the variation of the bias observed when different operators measure the same parts using the same device.»
Bibliographic reference: Reliawiki. 2017. Measurement System Analysis. [online] Available at: <https://reliawiki.org/index.php/Measurement_System_Analysis> [Accessed 20 February 2022].

Accuracy

«Accuracy describes the difference between the measurement and the actual value of the part that is measured. It includes:
  • Bias: a measure of the difference between the true value and the observed value of a part. If the “true” value is unknown, it can be calculated by averaging several measurements with the most accurate measuring equipment available.
  • Linearity: a measure of how the size of the part affects the bias of a measurement system. It is the difference in the observed bias values through the expected range of measurement [1].»
    [1]
It is «analogous to uncertainty relative to a reference, is in its simplest terms the difference between measured and “true” values [2].»

Bibliographic references:
[1] Reliawiki. 2017. Measurement System Analysis. [online] Available at: <https://reliawiki.org/index.php/Measurement_System_Analysis> [Accessed 20 February 2022].
[2] Apogeeinstruments.com. 2022. Uniformity, Repeatability, Stability, and Accuracy. [online] Available at: <https://www.apogeeinstruments.com/uniformity-repeatability-stability-and-accuracy/> [Accessed 20 February 2022].

Tuesday 25 January 2022

pMMR or dMMR

Proficient or deficient DNA (deoxyribonucleic acid) mismatch repair gene expression.

Sunday 14 November 2021

Integral dose (ID)

This is the total energy absorbed/deposited by ionizing radiation, within a body/in the treated volume (in J = kg × Gy) [1]. It is «one way of comparing dose distributions for different-quality beams. (...) If a mass of tissue receives a uniform dose, then the integral dose is simply the product of mass and dose. However, in practice, the absorbed dose in the tissue is nonuniform so rather complex mathematical formulas are required to calculate it. For a single beam of x- or γ radiation, Mayneord formulated the following expression:

Σ=1.44 D0  A d1⁄2 (1 - e^(0.693 d/d1⁄2))  (1 + (2.88 d1⁄2)/SSD)

where ∑ is the integral dose, D0 is the peak dose along the central axis, A is the geometric area of the field, d is the total thickness of the patient in the path of the beam, d1⁄2 is the half-value depth or the depth of 50% depth dose, and SSD is the source to surface distance. The term (1 + (2.88 d1⁄2)/SSD) is a correction for the geometric divergence of the beam. Because the integral dose is basically the product of mass and dose, its unit is the kilogram-gray or simply joule (since 1 Gy = 1 J/kg). (...) It is generally believed that the probability of damage to normal tissue increases with the increase in the integral dose, (...) [2].»
Bibliographic references:
[1] Beyzadeoglu, M., Ozyigit, G. and Ebruli, C., 2010. Basic radiation oncology. 1st ed. Berlin: Springer, p.23.
[2] Khan, F. and Gibbons, J., 2016. Khan's the physics of radiation therapy. 5th ed. Philadelphia: Wolters Kluwer, p.181.

Addressing Radiation Oncology residency oversupply survey

The City of Hope Department of Radiation Oncology is performing an IRB (Institutional Review Board)-exempted study survey study assessing radiation oncologists’ perceptions on residency oversupply, its possible solutions, and the new ACGME (Accreditation Council for Graduate Medical Education) RCC (Review and Recognition Committee) proposed changes.

If you choose to be in the study, we will ask you to complete a survey. The survey will take about 20 minutes for you to complete. Completion of the survey will indicate your consent to be a part of the study. Your participation is voluntary, and your responses will be anonymous.

Please click on the link below if you are willing to share your thoughts with us. The link will take you to an online anonymous survey.


If you are a program coordinator receiving this survey, we kindly ask that you forward the survey to the residents.

Please contact Dr. Liu at jaliu@coh.org or Dr. Amini at aamini@coh.org or Dr. Glaser at sglaser@coh.org with questions about this study.

Best regards,

Jason Liu MD, City of Hope National Medical Center
Arya Amini MD, City of Hope National Medical Center
Scott Glaser MD, City of Hope National Medical Center

Saturday 16 October 2021

Actuarial (versus actual)

«Its use is often extended (...) to include the Kaplan-Meier (KM) method, (...). Actual is a new term (...) to refer to a technique with several designations in the statistical literature, including cumulative incidence and crude, unadjusted, absolute, or observable probability [1].»
«Actuarial analysis, (...), is used to describe and compare survival probabilities by allowing for partial survival times (censoring). (...) The actuarial event-free (survival) curve for a nonfatal event, such as structural valve deterioration (SVD) of porcine valves, estimates the event-free probability for a population in which death has been eliminated. This overestimates the percentage of valves that will actually fail, because many patients die before the valve fails [2].»
«Unlike cumulative incidence [actual estimates], the KM attempts to predict what the latent failure probability would be if death were eliminated. To do this, the KM method assumes that the risk of dying and the risk of failure are independent. But this assumption is not true for many cardiac applications in which the risks of failure and death are negatively correlated (ie, patients with a higher risk of dying have a lower risk of failure, and patients with a lower risk of death have a higher risk of failure, which is a condition called informative censoring) [3].»
«When used for nonfatal events such as SVD, actual analysis estimates the percentage of patients who will have SVD (or the probability that an individual patient will experience SVD). The KM (actuarial) method attempts to estimate the percentage of SVD that would occur if patients never died. Also, KM depends on the assumption that death and SVD are independent, which they are probably not [1].»

Bibliographic references:
[1] Grunkemeier GL, Wu Y. Actual versus actuarial event-free percentages. Ann Thorac Surg. 2001 Sep;72(3):677-8. Available at: https://doi.org/10.1016/s0003-4975(01)03059-4.
[2] Grunkemeier GL, Jamieson WR, Miller DC, Starr A. Actuarial versus actual risk of porcine structural valve deterioration. J Thorac Cardiovasc Surg. 1994 Oct;108(4):709-18. PMID: 7934107. Available at: https://doi.org/10.1016/S0022-5223(94)70298-5.
[3] Grunkemeier GL, Jin R, Eijkemans MJ, Takkenberg JJ. Actual and actuarial probabilities of competing risks: apples and lemons. Ann Thorac Surg. 2007 May;83(5):1586-92. Available at: https://doi.org/10.1016/j.athoracsur.2006.11.044.