Radiometric survey of teletherapy treatment rooms in Brazil

Paiva, Eduardo De; Giannoni, R. A.; Velasco, A. F.; Brito, R. R. A.; Dovales, Ana Cristina Murta; Sá, Lidia Vasconcellos de; Rosa, L.A.R. da

doi:10.1093/rpd/ncp264

Cited by 3 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Survey monitoring audits indicated that the most critical noncompliances were observed in uncontrolled areas in the vicinity of

^{60} Co

facility rooms where measured dose rates values like 0.55 and 4.5 mSv/week, (as reported (21) ), were obtained. In many cases the facilities were subjected to nonauthorized project changes, or the person responsible for the facility decided to utilize a higher activity

^{60} Co

source not appropriate to the existing approved irradiator bunker shielding .…”

Section: Resultsmentioning

confidence: 96%

“…In many cases the facilities were subjected to nonauthorized project changes, or the person responsible for the facility decided to utilize a higher activity

^{60} Co

source not appropriate to the existing approved irradiator bunker shielding . ( 21 ) Another possible reason is a

^{60} Co

unit was positioned at an unusual configuration (for instance, forming angles about 45° with the bunker walls), a situation that can generate higher dose rates in the neighborhood of the treatment room (22) …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

An analysis of the regulatory program of quality audits in radiotherapy in Brazil from 1995 to 2007

Paiva

Rosa

Brito

et al. 2011

J Applied Clin Med Phys

View full text Add to dashboard Cite

The Brazilian Institute of Radiation Protection and Dosimetry (IRD/CNEN) carried out quality assurance regulatory audits in Brazilian radiotherapy facilities from 1995 to 2007. In this work, the set of data collected from 195 radiotherapy facilities that use high‐energy photon beams are analyzed. They include results from audits in linear electron accelerators and/or Co‐60 units. The inspectors of IRD/CNEN performed the dosimetry of high‐energy radiotherapy photon beams according to the IAEA dosimetry protocols TRS 277 and TRS 398, and the values of measurements were compared to stated values. Other aspects of radiological protection were checked during on‐site audits such as calibration certification of clinical dosimeters and portable monitors, existence and use of check source, use of barometer and thermometer, individual dose registry and training of staff. It was verified that no check source was available in 38% of the visited facilities; the training of personnel was not adequate in 9% of the facilities and the registry of accumulated individual doses was not being done in 6% of the facilities. Measurements of absorbed dose have indicated deviations in the range ± 3% for 67.6% of the cobalt‐60 units and 79.6% of medical linear accelerators; 18.5% of Co‐60 irradiators and 9.6% of linear accelerators presented deviations in the range 3% <δ≤ 5%. Finally, 13.9% of Co‐60 facilities and 10.8% of linear accelerator facilities presented dosimetry deviations above 5%. The effort in dosimetric quality control performed by IRD/CNEN audits has yielded positive changes that make radiation treatment facilities more reliable.PACS number: 87.55.Qr

show abstract

“…Survey monitoring audits indicated that the most critical noncompliances were observed in uncontrolled areas in the vicinity of

^{60} Co

^{60} Co

source not appropriate to the existing approved irradiator bunker shielding .…”

Section: Resultsmentioning

confidence: 96%

“…In many cases the facilities were subjected to nonauthorized project changes, or the person responsible for the facility decided to utilize a higher activity

^{60} Co

source not appropriate to the existing approved irradiator bunker shielding . ( 21 ) Another possible reason is a

^{60} Co

Section: Resultsmentioning

confidence: 99%

An analysis of the regulatory program of quality audits in radiotherapy in Brazil from 1995 to 2007

Paiva

Rosa

Brito

et al. 2011

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…In Brazil this has been carried out since several decades by Brazilian Nuclear Regulatory Authority (CNEN). The methodology used in this radiometric survey is to measure the instantaneous dose-equivalent rate in Sv/h at strategic points and calculate the weekly rate through a simple equation that involves the weekly workload W (equation (5) below, see for example [1]).…”

Section: Introductionmentioning

confidence: 99%

“…1. Method 1 (historical old method) Radiometric surveys in radiotherapy bunkers have been doing for a long time by measuring only I T , both before the advent of the IMRT technique and after the incorporation of this technique, so that the total weekly dose-equivalent rate, call it R…”

mentioning

confidence: 99%

On methods for radiometric surveying in radiotherapy bunkers

Sergio Santini,

de Oliveira,

Couto

et al. 2024

Biomed. Phys. Eng. Express

View full text Add to dashboard Cite

Radiometric surveys in radiotherapy bunkers have been carried out in Brazil for many years, both by the same radiotherapy facility for verification of shielding as by the regulatory agency for licensing and control purposes.In recent years, the IMRT technique has been gradually incorporated into many facilities. Therefore, it has been necessary to consider the increased leakage component that has an important impact on the secondary walls. For that, a radiometric survey method has been used that considers an increased "time of beam - on" for the secondary walls. In this work we discuss two methods of doing this: the first considers that this "time of beam - on" affects the sum of the two components, leakage and scattered. In another method it is considered that only the leakage component is affected by this extended "time of beam - on ". We compare the methods and show that for secondary walls with $U=1$ the first method overestimates dose rates by important percentages and for secondary walls with $U<1$ it can both overestimate or underestimate the dose rates, depending on the parameters of the project. An optimized procedure is proposed, according to the use factor ($U$) of the secondary wall to be measured.

show abstract

A Multi-Center Shielding Verification Study for Radiotherapy Linac Bunkers in Karachi, Pakistan

Raza

Jafri²,

Uddin

et al. 2017

Radiation Protection Dosimetry

View full text Add to dashboard Cite

The high energy radiotherapy linear accelerators (LINAC) offer considerable risk of radiation hazards to patient, worker and public if adequate safety measures are not taken into the account. Proper bunker designing with appropriate shielding is an important safety measure, which protects workers and member of general public. The present study describes the details of shielding of LINAC bunker in four radiotherapy centers of Karachi city. In order to conduct the study, shielding of five LINAC installed in four radiotherapy centers was assessed by considering real occupancy factor, dose limits for worker and public, etc. to verify that shielding of the bunkers conforms to the national and international standards like International Atomic Energy Agency and National Council on Radiation Protection and Measurement. After the assessment, it was concluded that all bunkers conform to the radiation protection requirements and present adequate shielded. This is an important step to achieve as low as reasonably achievable principle and protect workers and member of general public.

show abstract

Radiometric survey of teletherapy treatment rooms in Brazil

Cited by 3 publications

References 5 publications

An analysis of the regulatory program of quality audits in radiotherapy in Brazil from 1995 to 2007

An analysis of the regulatory program of quality audits in radiotherapy in Brazil from 1995 to 2007

On methods for radiometric surveying in radiotherapy bunkers

A Multi-Center Shielding Verification Study for Radiotherapy Linac Bunkers in Karachi, Pakistan

Contact Info

Product

Resources

About