Multi-Organizational Insights Into Radiological Safety Standards in High-Dose Rate Brachytherapy

The review provides an extensive study of regulations and recommendations set forth by organizations worldwide in the domain of high-dose rate (HDR) brachytherapy for the prevention and mitigation of radiation hazards. The relevant reports and publications by the International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA), American Association of Physicists in Medicine (AAPM), United States (US) Nuclear Regulatory Commission (NRC), and Atomic Energy Regulatory Board (AERB) were accessed, and necessary information was compiled to clarify and understand concepts, similarities, and differences in safety standards concerning to the topic. The regulations and guidance are categorized under three major components of safety, namely layout, equipment, and source. Layout category accesses structure, design, layout, and survey. The equipment category summarizes the requirements of equipment, installation, commissioning, quality assurance (QA) and performance, safety precautions and preparedness, safety procedures, and instructions. The source category includes requirements for sealed source possession and use, calibration, categorization, certification, licensing, QA tests, and security. IAEA gives inclusive guidance on radiation protection and regulatory requirements, forming the basis of reference for other organizations worldwide. AERB regulates the radiation facilities in India; therefore, most set-ups follow their safety standards and instructions.


Introduction And Background
Brachytherapy uses sealed radioactive sources to deliver radiation internally or beside the tumor.Brachytherapy treatments began shortly after the discovery of radium.Low, medium, and high-dose rates were used in the past, but high is the most widely used now.Different cases of concern and radiation mishaps involving the safety of medical personnel increased with the increase of high-dose rate (HDR) brachytherapy procedures and have changed radiation protection systems, safety procedures, and management [1].The International Commission on Radiological Protection (ICRP) was founded in 1928 at the second International Congress of Radiology.The organization provides concepts, definitions, and recommendations for ionizing radiation quantities and units based on biological impacts to safeguard people, animals, and the environment.ICRP recommendations, published in the Annals of ICRP, underpin radiation protection policy, regulations, guidelines, and practices worldwide [2].The National Commission on Radiation Protection and Measurements (NCRP) was founded simultaneously in the United States (US) for the radiation protection of workers and the public [3].
The International Atomic Energy Agency (IAEA), a United Nations (UN) agency founded in 1957, advises on safe and peaceful nuclear energy use.The American Association of Physicists in Medicine (AAPM) was unanimously approved in 1958 as a scientific, educational, and professional medical physics organization.The AAPM issues radiation safety and efficiency guidelines for medicine.The US Nuclear Regulatory Commission (NRC) was founded in 1975 after the Energy Reorganisation Act 1974 [4,5].It produces yearly references, regulatory programs, legislation, and regulations to ensure nuclear radiation safety.The President of India established the Atomic Energy Regulatory Board (AERB) in 1983 under the Atomic Energy Act of 1962.In India, the AERB provides safety codes and safety guides and oversees medical radiation facility installation and operation [6].
Every safety advice, guideline, and report aims to enhance the safety of radiation consumption for patients, personnel, and the public.The safety laws and requirements are established based on previous accidents or evidence obtained through various methodologies, while the recommendations are suggested as the furthest level of safety procedures.The organizations using sealed radioactive sources in medicine must abide by the regulatory body and the established compliances according to the territory, state, or country and the

Results
The review covers HDR brachytherapy facility installation and operation safety, categorizing data into layout, equipment, and source.Layout is the location and infrastructure for starting the facility, including design, construction, shielding, etc.The equipment category evaluates the RAL HDR unit's requirements, approvals, design, installation, commissioning, and quality assurance (QA) tests.The source category includes sealed source possession and use, calibration, categorization, certification, licensing, QA tests, and security.
In 2014, IAEA Safety Standards Series No. General Safety Requirements Part 3, Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards replaced the 1996 publication.It covers mainly the safety and protection standards and the roles of different people at different levels.The guideline covers planned, emergency, and existing exposures.Most HDR brachytherapy scenarios are planned exposure situations for the patient and, to a certain extent, are expected for the personnel.Emergency exposure situations, such as a malevolent act, accident, or natural disaster, are rare but require immediate intervention.Existing exposure applies to residual radioactive material from earlier operations that were not regulated or that exists after an emergency exposure event.Even with strict definitions, there may be scenarios when the exposure is difficult to classify as planned, emergency, or existent.The General Safety Requirements (GSR) recommends classifying such situations by assessing practical implementation and necessary actions [8].
IAEA Specific Safety Guide, Radiation Protection and Safety in Medical Uses of Ionizing Radiation, Specific Safety Guide (SSG) No. SSG-46, a successor to IAEA Safety Report Series No. 38, discusses radiation protection and safety in medical uses of ionizing radiation in sections 2 and 5 [9].IAEA Safety Report Series No. 47, Radiation Protection in the Design of Radiotherapy Facilities, covers shielding materials, calculation methods, and radiation surveys.This review does not include shielding calculations; readers should consult the report series for a diagrammatic explanation [10].AAPM Medical Physics Practice Guidelines (MPPG) 13.a: HDR brachytherapy, section A, details the practical implementation of the pre-established regulations for brachytherapy application and distinguishes between mandatory and recommended actions [11].
In 1972, NCRP published Report No. 40, Protection Against Radiation from Brachytherapy Sources, which addressed personnel safety in terms of maximum permissible dose (MPD) equivalent and other equipment facilities, safety precautions in clinical application, contamination and accidents, and general working conditions for low-dose rate (LDR) and HDR sources.Since this study was issued during the development of RAL units in brachytherapy, little is written regarding the RAL method and its specific recommendations [12].Sections 3, 4, and 7 of NCRP Report No. 49, Structural Shielding Design and Evaluation for Medical Use of Rays and Gamma Rays of Energies up to 10 MeV, were cited for shielding materials, details, and general brachytherapy safety.In NCRP Report No. 40, barrier thickness calculation for brachytherapy sources is explained.This report covers treatment vault design and construction [13].In April 2019, NCRP Report 182, Radiation Safety of Sealed Radioactive Sources, updated 1998 guide NCRP Report 127, Operational Radiation Safety Program, on radioactive source safety, was published, which covers source safety from sealed source, fabrication, manufacturing, acquisition, safety during use, testing, disposal, and emergency preparedness.The appendix section of Report 182 clarifies source inventory procedures and license requirements [14].
The AERB Safety Guide (SG), Security of Radioactive Sources in Radiation Facilities, Guide No. AERB/RF-RS/SG-1 covers security concepts, source categorization, and security procedures for Indian radiation facilities.Source security measures are compiled in the report under subheadings of technical and physical protective measures for LDR, HDR, and other radiation facilities.The guide specifies source processing and storage based on security, usage, and customary practice [15].The AERB Safety Code (SC), Radiation Therapy Sources, Equipment and Installations, Code No. AERB/RF-MED/SC-1 (Rev.1)concentrates on modern radiation therapy sources and applications, listing requirements under titles like safety specifications for radioactive sources, radiation therapy equipment and protective devices (teletherapy, brachytherapy, new equipment, etc.), radiation therapy installation, operational safety, QA, and management of radiation emergency [16].
The US Nuclear Regulatory Commission Regulations Title 10, Code of Federal Regulations (CFR), covers nuclear energy applications.Part 35 covers the guidelines for medical use of byproducts (radioactive material).It discusses the specifications for certain types of brachytherapy equipment, their required specifications, and the handling and regulations for mobile radiation facilities.Parts 20 and 36 cover radiation protection standards, licenses, and safety [17].
Table 1 briefly elaborates on the layout recommendations made by various organizations viz.IAEA, NCRP, AERB, AAPM, and NRC.In column 1, sections 2-4 of the GSR by IAEA are compiled, which elaborate on safety considerations for the planned exposure situation, including any radiation installation emergency [8].Individual medical radiation facility safety values by IAEA SSG 46 [9] and suggestions regarding the layout and construction from SRS 47 are also combined [10].Recommendations from the NCRP Reports 40, 49, and 182 on vault shielding, design, and construction are summarized in column 2 [12][13][14].In column 3, the compilation of recommendations by AERB SGs and SCs is provided [15,16].In column 4, the suggestions regarding the layout construction and design from MPPG 13.a are compiled [11].A brief mention of layout recommendations from NRC CFR 10 has been covered in column 5 [17].the barrier [8,9].Concrete is the most costeffective construction material, but higher-density materials may be necessary for spaceconstrained environments [8,9].
Patients should be treated on non-radiopaque tables if shared with a simulator room [11].

Radiation survey
The facility should be equipped  Table 2 mainly describes the parameters of the equipment for the above-mentioned organizations.In column 1, the requirements for RAL equipment design, safety, and also therapy-related computers have been included from IAEA GSR Part 3 [8].From NCRP Report 40, only the essential components regarding equipment parameters and source safety parameters have been included in column 2 [12].In column 3, the inclusion of equipment requirements as per the AERB SC and guide has been provided [15,16].In column 4, the acceptance testing, commissioning, and QA regulations as per AAPM MPPG 13.a are given [11].Column 5 includes a summary of NRC requirements for HDR equipment as per CFR 10 [17].[17].

Quality assurance
In   the sealed radioactive source-related recommendations are included in column 2 [12][13][14].Column 3 briefs the source storage, remote afterloading, source and zone monitoring requirements, dosimetric concerns for instruments, dose delivery, quality checks, radiation emergency management, and regulatory controls from AERB SG and SC [15,16].AAPM recommends source recipients as mentioned in column 4 [11].As per the NRC requirement for medical use of radioactive byproducts, the regulations are compiled in column 5 [17].-A licensee must ensure the accurate positioning of a brachytherapy source within applicators before its first medical use [17].

Layout
The term layout, or the room layout, refers to the design, dimensions, construction, and shielding of the treatment room or treatment vault of the RAL HDR installation to ensure safety when the machine is ON.The broad term encompasses various construction requirements as guided by organizations, the structure of the room, its design, shielding, and the radiation survey that has to be performed at the beginning and regular intervals during as well as after construction.

Requirements for a RAL Installation
To install a RAL HDR brachytherapy machine, the organization or individual has to start with the necessary setup for a correctly placed and functional room that can and will accommodate the machine, along with the source, and facilitate the delivery of treatment in a way that is safe for patient, personnel, and public.This entails a few mandatory requirements and others that suggest safer practices.

Structure
The facility's structure refers to the floor plan and dimensions of the treatment room or vault.AAPM makes suggestions for the creation of a dedicated treatment room for brachytherapy procedures [11].NRC Guideline 37.53 of 10 CFR specializes in mobile therapy equipment and the necessary structure requirements [17].

Design
Designing the facility concerns the efficient and effective placement of necessary components of the treatment vault to maximize the setup's functionality and safety.NCRP Report Number 40 also shares the maintenance of sinks [12].

Shielding
The specially designed and constructed barrier attenuating the primary, secondary, and scattered radiations from the source in both ON and OFF states is compelled and needed to protect professionals and the general public.

Radiation Survey
This comprises monitoring the layout/installation after installation of the source, which is being considered in different aspects in different reports.

Requirements for RAL Unit
The defined requirements for an RAL unit apply to the organization or user who intends to acquire and operate an RAL unit and the manufacturer.

Installation
Installing involves purchasing the equipment and placing it in the treatment vault before commissioning it for usage.

Commissioning
After the installation, there is a need to verify the structures, systems, and components of a brachytherapy facility in accordance with design specifications to make the setup functional for use and check the performance according to the set criteria.

Quality Assurance (QA)
Many international and national organizations and regional professional bodies have published detailed guidance on the range of acceptance, commissioning, and quality control tests that should be performed on radiation therapy equipment and software, how they should be performed, applicable tolerances and desired action levels, and recommended frequencies.Due to improper post-repair testing, significant medical exposure occurred.IAEA rules provide RAL and applicator QA.The AERB and AAPM suggest RAL unit and guide tube test frequency and techniques.The NRC document regulates the same and advises licensees to complete and record checks [8,11,[15][16][17].

Equipment
Equipment, in general, refers to the machine or unit used to deliver the radiation dose in the current most widely practiced form of HDR brachytherapy.The equipment is the remote afterloading unit, which contains, stores, and safeguards the source and delivers treatment on an instruction basis from the treatment console itself.This device is solely responsible for minimizing the radiation dose to professionals as the applicators are inserted and connected before treatment delivery.No one except the patient is inside the treatment vault while the source is out of the shielded position.The equipment section will also consider the guide tubes and applicators used in the process.

Performance of RAL Unit
Performance of RAL unit refers to equipment functionality and efforts to maintain optimal performance.This may include other needs, procedures, and actions for a well-functioning and equipped brachytherapy setup.SSG-46 recommends translating operation manuals and comparable instructions into the local language.The operating instructions are used by certified professionals and technicians who may not speak any major world language.To avoid operating faults and assure understanding, the translation needs QA.The same goes for maintenance instructions for service engineers and technicians [9].

Safety Precautions, Safety Procedures, and Instruction
While the RAL HDR unit is operating and functioning daily, certain procedures and precautions must be mandated to maintain safety.These procedures are specific to the actual afterloading unit but generally involve a standard sequence.This needs a well-educated and well-trained staff for everyday and emergency procedures and actions.

Therapy-Related Computers
Treatment planning system (TPS) capabilities have grown with computers and computing.Complex threedimensional (3D) or four-dimensional (4D) image manipulation and dosage estimates may be available, depending on the TPS.Source calibration must utilize the same unit of activity as the TPS.SSG-46 cautions that such circumstances can cause serious errors.NRC Guideline 35 lists that testing should be done before TPS patient planning [9,17].

Source
The gamma-emitting radioactive materials used for the brachytherapy treatment are sealed inside capsules of certain shapes, sizes, and materials.In the context of HDR brachytherapy, these sealed radioactive materials are generally called sources, which have a cylindrical structure and are attached to a guidewire that facilitates the motion of the sealed material in the guide tube/applicator.This is unarguably the central component of the HDR brachytherapy procedure, and the manufacturing, possession, and use of these sources require immense regulatory compliance and trained individuals at work all over the chain of the source suppliers.The specific requirements are discussed below.

Conditions for Supplier of the Source
The source manufacturer and supplier, to make HDR brachytherapy source, has to meet certain requirements and standards given by international organizations.This includes the safety, sealing, design, and certification of the sources as required by the organizations.

Requirements for the Possession of Source
This section highlights the prerequisites for any individual to possess a source for medical use.

Requirements for the Use of Source
The most basic requirement for radioactive source use is to obtain permission from the competent authority of the state or country.

Calibration of Source
Calibration is nothing but the measurement of source strength and activity in the specified units.This is first done at the supplier end and then cross-checked by the user with necessary decay corrections.

Categorization of Source and Security Level
The various radioactive materials are classified primarily by IAEA guidelines into different categories according to the hazard they impose on the surrounding people and environment.Accordingly, the security level is suggested for the source/material, which defines the number of precautions to be taken during the delivery, use, and return of the source.Broadly, they are Category 2 Security Level B (demanding high security) sources [8][9][10].

Identification, Certification, and Licensing
The source supplied by the manufacturer and supplier, and possessed and used by the employer and licensee, must have a certificate specifying the radioactive material, its strength, and other necessary details.It shall be acquired along with a proper license for specified use.

Source Housing Integrity, Source Storage, and Security
The source housing is the part of the machine where the source is stored by default when not in use, whereas other storage containers are designed and used as needed and generally made of lead material.Both the container and housing have to meet certain design specifications.Source security refers to the security requirements that must be met at the organizational level.

Quality Assurance
QA is defined as the set of procedures required to be performed to ensure the safety of practice and establish the security of the professionals working at the facility.

Discussion
The mentioned reports, guidelines, and other auxiliary documents show that the formulation, commencement, and delivery of an HDR brachytherapy begins with the construction of a safe and secure layout for the installation and delivery of the procedure; then the choice, installation, and commissioning of the RAL unit, and finally the acquisition, installation, and commissioning of the source.

Layout
IAEA SSG 46 also recommends that radiation therapy institutions that use radioactive sources adopt technical measures apart from routine interlocks like closed circuit television (CCTV) cameras to detect malevolent activity.HDR brachytherapy and external beam radiation therapy should not share a shielded treatment room because it can slow down procedures.Electrical and mechanical systems should only be operated by authorized personnel who understand medical radiological equipment standards.As medical radiological equipment safety is critical, electrical and mechanical maintenance should be included in the quality assurance program and performed by the manufacturer or an authorized agent at a frequency recommended by the manufacturer [9].NCRP Report 49 recommends visual inspection during construction to ensure specification compliance and identify faulty materials or workmanship that can be fixed more economically.Readers can see the detailed list in the report [13].According to AERB Safety Code SC-1, radiation therapy installations should be assessed for flooding or fires and preventive measures applied.Consultation with firefighters and radiation therapy equipment manufacturers/suppliers to supply suitable firefighting systems should be done [16].The AAPM report does not recommend combining the brachytherapy room with the operating room.It can complicate the interlock, shield, storage, and security of the afterloader, increase training of non-radiation oncology personnel, and create high-pressure treatment planning time constraints because anesthesia duration should be minimized and operating room time is costly [11].

Equipment
IAEA SSG-46 of the IAEA Safety Standards covers safety practices to prevent or reduce accidents.For RALtype HDR units, the guideline's paragraphs 5.316-5.319provide precise instructions.If the source gets stuck, one should keep a shielded container large enough for the largest applicator set next to the device [9].All practical techniques are listed in SRS-47, and section 7.3 of the report details the procedures [10].The AERB study emphasizes the employer/licensee's responsibility to create an emergency preparation plan, identify accountable parties, and outline emergency procedures for certain circumstances [15,16].The NCRP Report 40 suggests standard radioactive cleanup procedures [12].The NRC provides radiation emergency regulations [17].

Source
In addition to the above regulations, the IAEA SSG-46 recommends marking source storage facilities as radioactive and providing emergency contact information for the radiation safety officer (RSO), medical physicist, or other radiation safety professional [9].NCRP Report 40 outlines source loss protocols.Any source loss must be notified to the radiation protection supervisor promptly.Prevention of acute local injury from direct contact with sealed sources requires all linen, dressings, clothing, equipment, and garbage containers to be held in a patient's cubicle until the radiation protection supervisor releases them or all sources are accounted for.In NCRP Report 40 appendix E, tables 6 and 7, and appendix B provide dosage estimates for such situations [12].According to NCRP Report 182, any sealed source loss beyond an exempt quantity must be notified to the regulatory authority.Notification time depends on source category, licensing regulations, and regulatory agencies.Source theft can lead to regulatory action for failing to control radioactive material and serious health and safety issues for workers and the public [14].
Radioactive material leaks from sealed sources are usually caused by source containment damage.Regulated sealed sources must be leak-checked periodically to ensure containment.A typical sealed HDR brachytherapy source must withstand -40°C (20 minutes) to 600°C (1 hour), pressure of 25 kiloPascal (kPa) to 2 MegaPascal (MPa), and an impact of 50 g from 1 m.The leakage radiation dosage rate for unrestricted access and restricted access at 5 cm from the storage surface is 10 microGray/hour (µGy/h) and 100 µGy/h, respectively, and at 1 m from the source is 1 and 10 µGy/h [15,16].AERB recommends building a physical protection system, which includes all systems and equipment that physically protect the radioactive source or site.These systems are designed on physical protection principles, which can be achieved through human actions and equipment.A good physical protection system combines human supervision and equipment.Vulnerability assessments are used in its design and evaluation [15,16].According to AAPM, each facility must evaluate its on-site activity for source security and licensing needs.Due to the rapidity of dose delivery in HDR brachytherapy, the AAPM recommends that an authorized medical physicist (AMP) and authorized user (AU) be present for all patient treatments.The AMP must be immediately available throughout treatments; however, an emergency physician may substitute the AU.Radiation accidents are infrequent when radioactive sources are secure and safety measures during procedures are taken [11].

Future direction
As per the current international status regarding safety, various organizations are publishing guidelines, regulations, and codes for safety in HDR brachytherapy.This may become hectic for professionals to go through or opt for when it comes to applying safety standards at a given center.The current norm is to follow the guidelines established by the national regulatory authority and follow IAEA recommendations in the absence of the same.In the future, it can be of great ease if the international standards of safety come to a level of alignment with each other just like the dosimetric standards in radiotherapy.This will not only reduce the hassle of meeting different safety requirements but also will establish a common checkpoint for the correlation of standards and correction of wrong practices, if any.

Conclusions
Radiation safety for patients, workers, and the public must be prioritized.Equipment safety and environmental preservation are also of equal importance.Facility management should be authorized, managed, and regulated according to the legal framework.Following protocols keeps occupational worker radiation doses under safe limits.IAEA provides a complete summary of regulatory requirements for radiation protection standards.Other organizations reference IAEA standards for their region/state/country.AERB regulates radiation facilities in India; therefore, most set-ups follow safety standards and instructions.As described by the standard organizations, the prime responsibility for maintaining radiation safety and compliance with radiation safety protocols is shared by the employer, licensee, the RSO, and working professionals.Meanwhile, the RSO in India is appointed by the hospital administration and is an individual who is an expert in matters of radiation safety and is licensed by the AERB of India.As defined by standard organizations, employers, licensees, RSO, and working professionals share the primary responsibility for radiation safety and protocol compliance.In India, the hospital's RSO is a radiation safety specialist nominated by the AERB, and the primary responsibility is attributed to the RSO.
reception area, clinical consulting areas, EBRT room, brachytherapy room, imaging, and treatment planning room.The structure should consider workload, staff, and patient flow.The size of a treatment room is guided by the choice of equipment and the type of equipment, patient type, and the use of special equipment for research and teaching.Construction costs must be considered against future convenience or the need for additional equipment the dose rate at a treatment room should be monitored.Barrier source applicators should be positioned at the patient's position and exposed without phantom.The radiation survey report should include the type of radiation unit, location, date of survey, person responsible, /licensee must ensure that medical radiological equipment and software meet the standards of the International Radioactive sources must be transported in a way that does not exceed the maximum permissible dose equivalent or dose limit.Protection should be provided through distance or shielded containers, with This code mandates that prevent unauthorized use, with a key required for energizing the system and restricting access to authorized staff [8].containers being appropriately labeled.Factors to consider when designing transport containers include lead as the most practical shielding material, long handles on handcarried containers, and the need for shielded containers with wheels for large sources.Devices with sealed sources must be classified for their intended use and constructed and tested according to industry and consensus standards.Design specifications for sealed sources should include critical features, sealed source containment, movement, mounting, shutter controls, and tamper-resistant features.Special provisions should be made for portable devices.Sealed source certificates and device registrations should be associated with specific information, and certificate holders may need to justify licensing or control levels [12-14].radiation therapy sources and equipment must meet design safety specifications.Manufacturers and vendors must obtain design certification from competent authorities before marketing and manufacturing.Local manufacturers must obtain a No Objection Certificate (NOC) or type approval certificate for supply, while vendors must obtain an NOC for import.The equipment must also comply with mechanical, electrical, fire, and environmental safety specifications (IEC 6061-1-1, IEC 6061-1-2, IEC 6061-1-3, IEC 6061-1-4) [15,16].-The use of photon emitting after the loader unit is used should be approved in the sealed sources and device registry or in accordance with the safety conditions described in the same.For remote afterloaders, the licensee shall account for all sources before departure from the client's address of use and check the survey instrument.The copy of permission to use the afterloader and the radioactive material at the client's address should be retained for three years [17]applications should be tailored to the specific source or compatible with it [8-10].The manufacturer must test each sealed source/device model in accordance with regulatory requirements to ensure its integrity during normal use, foreseeable mishaps, handling, maintenance, storage, and transportation [12-14].The supplier must confirm if the radiotherapy unit is type approved by AERB or issued an NOC to the local supplier.A valid certificate is required for radiotherapy unit sales in the country.AERB issues NOCs for new models imported for the first time [15,16].-The installation, replacement and relocation of RAL should be performed by a person authorized to do so.Also, any kind of maintenance, adjustment, and repair of the unit should be done by authorized personnel [17].physicists identify, measure, and compile data for clinical use, validate the data, define quantities and measures, and set baseline values for periodic quality control tests.This process ensures equipment and software compatibility with other equipment with interfaces [9,10].-The accuracy regarding the source positioning, sequence, and electronic timer, linearity, and reproducibility must be checked at commissioning and periodically.The dose-effect due to transit or end dose on dose delivery must also be verified.A battery-powered backup power supply system must be included in case of unplanned power failure.The applicator must position the radiation source(s) correctly and ensure that any structures used for attenuation of radiation, such as bladder and rectal shields, have not been shifted by radiography during initial use or following malfunctions and that dummy and active sources are coincident.The evaluation includes anatomical data input, TPS beam definition, TPS errors and inaccuracies, and TPS functional capabilities and

SGT
the case of an RAL unit, applicators, and accuracy of guide tubes have to be examined.Annual QA includes a verification of the source inventory dose calculation algorithm and simulation of emergency conditions [15,16].Daily QA includes source positioning, timing, electrical interlocks, emergency source retraction buttons, last person's out button, treatment interrupt button, audio/visual systems, emergency response kit, independent radiation room monitor, calibrated survey meter, console computer date and time accuracy, and catheter misconnect/channel/interrupt check and timer linearity for RAL.At the time of source change, strength measurement, positioning accuracy, retraction with backup battery failure, timer accuracy, emergency buttons, LMO, interrupts, source out indicator, computer date and time, TPS to console communication, and decay source strength should be verified.For applicators, on a daily basis, a visual inspection of integrity should be done and the annual length of the applicator and at the afterloading unit, manual retraction of the source, surveying the patient and afterloader, removing the applicator and placing it in an emergency container, and The source custodian must conduct periodic inventories of all sources, with the hospital radiation protection supervisor checking them at intervals of no more than six months [12-14].Emergency response procedures for sealed sources are required, and NRC regulatory guidance documents provide general direction for various source types.Emergency instructions should be brief and direct, focusing on dose control, contamination control, and concerns of management The emergency action plan at the or jammed sources.Highdose rate remote afterloader units need an authorized user and medical physicist during the initiation and continuation of treatments to be physically removing the patient from the vault source is disrupted, trained personnel should be available to assist in decontamination.Untrained individuals should not attempt to examine or clean up spilled radioactive material.For Cobalt-60 and Iridium-192, a traffic control program should be instituted to minimize contamination tracking.Equipment like respirators should be assembled, and vacuum cleaning should be performed before wet mopping or scrubbing.Masking tape can be used for adhesion removal, and damp mopping with a detergent and chelating agent can help remove the remaining contamination [12-14].

For
allowed to use sealed sources or devices that are manufactured/labeled/packaged/distributed under a license issued under 10 CFR Part 30 and 10 CFR 32.74 equivalent requirements of an Agreement State [17].source order, issuance, and return.To obtain licensed sealed sources, individuals must apply for a radioactive material license from the National Radioactive Council or an Agreement State.RSOs must ensure the sealed source is properly inspected upon arrival, added to the institution's inventory, does not exceed license limitations, completes leak testing, and ensures proper user training in safe storage and use [12-14].sources or brachytherapy sources must follow the manufacturer's radiation safety instructions and undergo leakage tests before use.Tests should be conducted at time intervals not exceeding six months or at appropriate intervals approved by the Commission or an Agreement State.If the source fails to meet requirements, licensees must withdraw the sealed sources and file a report within five days [17].Requirement for use of source Individuals or organizations planning to use a radioactive source must apply to the regulatory body for authorization, either through registration or licensing [8-10].A radioactive materials license is required for procuring and possessing sealed sources, and all users and staff should receive proper radiation safety training and programmatic control.Employers should ensure that only personnel work with brachytherapy sources after training and provide physical protection, including a locked enclosure in a secure room.Manufacturers should include items that could impact the source's performance and provide clear use limitations in instructions.consent for sealed sources and radioactive-containing equipment for manufacture -A licensee shall use sealed sources that are RAL-approved and are in accordance with the one provided in the Sealed Source and Device Registry [17].appropriate corrective action must be taken before re-using the sources.Also, a report of that shall be sent to the competent authority [15,16].-A licensee must determine source output and mathematically correct outputs for physical decay, before first medical use of a brachytherapy source, at intervals consistent with 1% decay [be provided with a detailed description of all sources containing radionuclide and their capsules.Regulations dictate markings for sealed sources/devices, which should be durable and legible.This information can be engraved or etched onto the device, or affixed to a metal tag.Labels should be mounted on the device's portion, not on a detector housing or guard barrier.They should be easily visible to users or personnel near the device [12-14].exposure, provide adequate shielding in occupied or potentially occupied areas near source storage areas, and protect sealed sources from hazards like damage, fire, and Remote afterloading brachytherapy equipment source housing must maintain source integrity and shielding, with a fail-safe mechanism in the unit and room to prevent personnel be stored securely and not left in the applicator.In case of a failure of the afterloading unit, the radiation therapy facility should have a storage container, remote manipulator, wire cutters, and a radiation monitoring instrument.Security measures should be taken to prevent unauthorized access and detect unauthorized access.For storage sources, a locked container, locked room, access control, and the capability to detect unauthorized access are necessary.For HDR sources, used in a locked room or controlled area, constant surveillance and control of access to the area by unauthorized people are required [8-10].Brachytherapy sources and applicators should be stored in a protective, locked enclosure to reduce exposure rates.The outer surface should be made of fireproof materials.Separate compartments should be provided for different source activities.Licensees must maintain records of receipt, transfer, and disposal of sealed sources, with records maintained for at least three years after disposal.The inventory should provide easy access to storage locations, usage dates, leak testing results, and final disposition.Stored sources should minimize exposure to workers and the public and deter loss, theft, or damage [12-14].on sealed sources are required, with frequency specified by local, state, and federal regulations.If tests reveal 0.005 or more removable contamination, the source is leaking.It has to be removed, sealed, and returned to the supplier or a qualified person for repair or disposal.Typically, leak tests occur at intervals of no more than six months.

TABLE 1 : Layout recommendations by organization
IAEA: International Atomic Energy Agency; NCRP: National Commission on Radiation Protection and Measurements; AERB: Atomic Energy Regulatory Board; AAPM: American Association of Physicists in Medicine; NRC: Nuclear Regulatory Commission; EBRT: External beam radiotherapy, LINAC: Linear accelerator; HDR: High-dose rate; MPD: Maximum permissible dose; CFR: Code of Federal Regulations; RAL: Remote afterloading; US: United States.

Table 3
[9,10]es the regulations and recommendations stated for source designing, handling, transportation, safety, and QA given by the above-mentioned organizations.Column 1 includes detailed comments on requirements and regulations for source possession, licensing, storage, and QA as set by IAEA GSR Part 3[8]and other guidelines from SSG 46 and SRS 47[9,10].As per NCRP Reports 40, 41, and 182, all

TABLE 3 : Source recommendations by organizations IAEA
: International Atomic Energy Agency; NCRP: National Commission on Radiation Protection and Measurements; AERB: Atomic Energy Regulatory Board; AAPM: American Association of Physicists in Medicine; NRC: Nuclear Regulatory Commission; RAKR: Reference air kerma rate; HDR: High-dose rate; CFR: Code of Federal Regulations; RAL: Remote afterloading; RSO: Radiation Safety Officer.