[27 Pa.B. 5703]
[Continued from previous Web Page] (c) When an interlock system has been tripped, it shall only be possible to resume operation of the accelerator by manually resetting controls at the interlock position, and lastly at the main control console.
(d) Safety interlocks shall be fail-safe, that is, designed so that a defect or component failure in the interlock system prevents operation of the accelerator.
(e) A scram button or other emergency power cutoff switch shall be located and easily identifiable in all high radiation areas. The cutoff switch shall include a manual reset so that the accelerator cannot be restarted from the accelerator control console without resetting the cutoff switch.]
§ 228.23a. Expiration and termination of a license.
(a) Except as provided in § 228.24a (relating to renewal of licenses), and subject to subsection (d)(5)(ii), a specific license expires at the end of the specified day, in the month and year stated in the license.
(b) A licensee shall notify the Department in writing when the licensee decides to permanently discontinue activities involving the accelerator authorized under the license and request termination of the license. The notification and request for termination shall include the reports and information specified in subsection (d)(3)--(5). The licensee is subject to subsections (d) and (e), as applicable.
(c) At least 30 days before the expiration date specified in a specific license, the licensee shall do one of the following:
(1) Submit an application for license renewal under § 228.24a.
(2) Notify the Department in writing if the licensee decides not to renew the license.
(d) If the licensee does not submit an application for license renewal under § 228.24a on or before the expiration date specified in the license, the licensee shall:
(1) Terminate the use of the accelerator.
(2) Properly dispose of incidental radioactive material generated by the operation of the accelerator.
(3) Submit a completed Department form ER-BRP-314, ''Certificate of Disposition of Materials,'' describing the disposition of materials in paragraph (2).
(4) Submit a radiation survey report to confirm the absence of radioactive materials or establish the levels of residual radioactive contamination unless the Department determines a radiation survey report is not necessary. This report shall include:
(i) The levels of beta and gamma radiation (in units of microrems or microsieverts, or in microrads or micrograys per hour) at 1 centimeter and gamma radiation at 1 meter from surfaces, levels of removable and fixed alpha, beta and gamma contamination on surfaces (in becquerels or microcuries per 100 square centimeters), and concentrations of contamination in soils (in units of picocuries or becquerels per gram) or in water (in units of picocuries or becquerels per liter) where soil and water concentrations are reported.
(ii) The survey instrumentation used to perform these surveys.
(5) Proceed with one of the following:
(i) Submit a certification that no detectable radioactive contamination was found if no residual contamination attributable to activities conducted under the license is detected. If the information submitted under this section is adequate, the Department will notify the licensee in writing that the license is terminated.
(ii) Continue the license in effect beyond the expiration date. If necessary, with respect to possession of residual radioactive material present as contamination if detectable levels of residual radioactive contamination attributable to activities conducted under the license are found, until the Department notifies the licensee in writing that the license is terminated. During this time, the licensee shall comply with the requirements of subsection (e), in addition to the information submitted under paragraphs (3) and (4) and this paragraph, the licensee shall submit a plan for decontamination, if necessary.
(e) A licensee who possesses residual radioactive material under subsection (d)(5)(ii) following the expiration date specified in the license, shall:
(1) Limit activities involving radioactive materials to those activities which are solely related to decontamination and other activities related to preparation for release for unrestricted use.
(2) Continue to control entry to restricted areas until the restricted areas are suitable for release for unrestricted use and until the Department notifies the licensee in writing that the license is terminated.
§ 228.24. [Operating procedures] (Reserved).
[(a) Particle accelerators, when not in operation, shall be secured to prevent unauthorized use.
(b) No interlock may be used to turn off the accelerator beam except in an emergency.
(c) A safety and warning device, including interlocks, shall be checked at least every 3 months for proper functioning and shall be repaired as necessary. Results of these checks and repairs shall be maintained at the accelerator facility for inspection by the Department.
(d) In the event of a malfunction of a safety or warning device, the accelerator may not be operated unless appropriate interim precautions are instituted to provide equivalent protection.
(e) If it is necessary to bypass intentionally a safety interlock system or component thereof, the action shall be:
(1) Authorized in writing by the radiation safety officer.
(2) Recorded in a permanent log and a notice posted at the accelerator control console.
(3) Terminated as soon as possible.
(f) A copy of the current operating and the emergency procedures shall be maintained in the accelerator control console area.]
§ 228.24a. Renewal of licenses.
(a) An application for renewal of a specific license shall be filed under § 228.21a (relating to notification and license regulations).
(b) If a renewal application is filed prior to 30 days before the expiration of a license, the existing license does not expire until definitive notice has been given by the Department of its action on the renewal application. This subsection also applies to new license applications incorporating other licenses.
§ 228.25. [Radiation monitoring requirements] (Reserved).
[(a) An accelerator facility shall have appropriate portable monitoring equipment which is operable and has been calibrated for the appropriate radiations being produced at the facility. The equipment shall be tested for proper operation each day it is used and calibrated at least annually and after each servicing or repair.
(b) In addition to the requirements of §§ 219.91 and 219.154 (relating control of access to high radiation areas; and posting of high radiation areas), an independent radiation monitoring system shall be provided so that the individuals entering or present become aware of the existence of the hazard. Area monitors shall be calibrated at least annually and after each servicing or repair.]
§ 228.25a. Amendment of license at the request of the licensee.
A licensee shall file an application for an amendment under § 228.21 (relating to notification and license requirements). The application shall specify the requested amendment and the reason for the amendment.
§ 228.26. [Production of radioactive material] (Reserved).
[(a) Radioactive material produced incidental to the operation of a particle accelerator shall be subject to § 217.48 (relating to a general license for incidental radioactive material produced by a particle accelerator).
(b) Radioactive material intentionally produced by bombarding nonradioactive material with the accelerator beam shall require a specific license under §§ 217.51--217.57 (relating to specific licenses--general conditions).]
§ 228.26a. Department action on applications to renew and amend.
In considering an application by a licensee to renew or amend a license, the Department will apply criteria in the act and this article.
GENERAL RADIATION SAFETY REQUIREMENTS [FOR INDUSTRIAL AND RESEARCH ACCELERATORS] § 228.31. [Warning devices] (Reserved).
[(a) A location designated as a high radiation area and an entrance to the location shall be equipped with easily observable warning lights that operate when, and only when, radiation is being produced.
(b) A high radiation area shall meet the requirements of § 219.43 (Reserved).]
§ 228.31a. Limitations
(a) The facility shall operate within the terms and conditions of the license issued for the operation of the accelerator.
(b) A licensee or registrant may not permit an individual to act as an operator of an accelerator until the individual:
(1) Has been instructed in radiation safety and has demonstrated an understanding thereof.
(2) Has received copies of and instruction in this chapter and Chapters 219 and 220 (relating to standards for protection against radiation; and notices, instructions and reports to workers; inspections), pertinent registration and license conditions and the registrant's or licensee's operating and emergency procedures and demonstrated understanding thereof.
(3) Has demonstrated competence to use the accelerator, related equipment and survey instruments which will be utilized in that individual's assignment.
(c) The radiation safety officer shall have the authority to restrict or terminate operations at an accelerator facility if the action is necessary to minimize danger to health and safety, property or the environment.
§ 228.32. [Circuit diagrams] (Reserved).
[Electrical circuit diagrams of the accelerator and the associated safety, warning and interlock systems shall be kept current and maintained for inspection by the Department and shall be available to the operator at an accelerator facility.]
§ 228.32a. Shielding and safety design requirements.
(a) The registrant or licensee shall consult a qualified expert for the shielding design of accelerator installation and shall have the expert perform a radiation survey prior to the first use of the accelerator and when changes are made in shielding operations, equipment or occupancy of adjacent areas. The expert shall report the findings of these surveys in writing to the registrant or licensee and a copy of this report shall be kept for 5 years and be available for inspection by the Department. The registrant or licensee shall comply with any limitations indicated by the survey.
(b) An accelerator facility shall have primary and secondary protective barriers that are necessary to assure compliance with § 219.51 (relating to dose limits for individual members of the public).
§ 228.33. [Radiation surveys] (Reserved).
[(a) When applicable, periodic surveys shall be made to determine the amount of airborne radioactivity present in areas of airborne hazards.
(b) When applicable, periodic smear surveys shall be made to determine the amount of contamination in target and other pertinent areas.
(c) Area surveys shall be made in accordance with the written procedures established by a qualified expert or the radiation safety officer of the accelerator facility.
(d) Records of surveys shall be kept current and on file at an accelerator facility.]
§ 228.33a. Facility and shielding requirements.
In addition to the requirements in Chapter 219 (relating to standards for protection against radiation), the following are required:
(1) The control panel shall be located outside the treatment or irradiation room.
(2) For accelerators not used in the healing arts, provision shall be made to permit continuous observation of the material being irradiated and any transfer or conveyance of material within the irradiation room.
(3) For accelerators used in the healing arts, provision shall be made to permit continuous observation of and communication with the patient during irradiation.
(4) Windows, mirror systems or closed-circuit television viewing screens used for observing the patient or the material being irradiated shall be located so that the operator can maintain direct surveillance over both the control panel and the patient or the material being irradiated.
(5) If the surveillance conducted under paragraph (4) is provided solely by electronic means, and if a malfunction of this surveillance equipment occurs, irradiation activities shall cease until repair of that surveillance equipment is performed and the equipment is found to be functioning normally.
(6) Irradiation or treatment room entrances shall be provided with warning lights, which will indicate when the useful beam is on in a readily observable position near the outside of access doors.
(7) Interlocks shall be provided so that entrance or access doors are closed before irradiation or treatment can be initiated or continued.
(8) For accelerators used to irradiate materials by means of a transfer or conveyance system, a means shall be provided which either terminates the irradiation or prevents entry if an individual attempts access to the irradiation room.
§ 228.34. [Ventilation systems] (Reserved).
[(a) A registrant shall control the concentration of radioactive material in air to meet the requirements of § 219.31 (relating to occupational dose limits for adults).
(b) A registrant may not vent, release or otherwise discharge airborne radioactive material to an unrestricted area which does not meet the requirements of § 219.51 (relating to dose limits to individual members of the public). Every reasonable effort shall be made to maintain releases of radioactive material to uncontrolled areas as far below these limits as practicable.]
§ 228.34a. Accelerator controls and interlock systems.
(a) Instrumentation, readouts and controls on the accelerator control console shall be clearly identified and easily discernible.
(b) Entrances into a target room or high radiation areas shall have interlocks that meet the requirements of §§ 219.91 and 219.154 (relating to control of access to high radiation areas; and posting of high radiation areas). If the radiation beam is interrupted by a door opening, it shall be possible to reinitiate the radiation exposure only by closing the door first and then by manual action at the control panel.
(c) When an interlock system has been tripped, it shall only be possible to resume operation of the accelerator by manually resetting controls at the interlock position, and lastly at the main control console.
(d) Safety interlocks shall be fail-safe, that is, designed so that a defect or component failure in the interlock system prevents operation of the accelerator.
(e) A scram button or other emergency power cutoff switch shall be located and easily identifiable in all high radiation areas. The cutoff switch shall include a manual reset so that the accelerator cannot be restarted from the accelerator control console without resetting the cutoff switch.
§ 228.35. Operating procedures.
(a) Accelerators, when not in operation, shall be secured to prevent unauthorized use.
(b) An interlock may not be used to turn off the accelerator beam except in an emergency.
(c) Each safety and warning device, including interlocks, shall be checked at least every 3 months for proper functioning and shall be repaired as necessary. Results of these checks and records of repairs shall be maintained for 5 years at the accelerator facility for inspection by the Department.
(d) In the event of a malfunction of a safety or warning device, the accelerator may not be operated unless appropriate interim precautions are instituted to provide equivalent protection.
(e) If it is necessary to bypass intentionally a safety interlock system or component thereof, the action shall be the following:
(1) Authorized in writing by the radiation safety officer.
(2) Recorded in a permanent log and a notice posted at the accelerator operator's position.
(3) Terminated as soon as possible.
(f) A copy of the current operating and the emergency procedures shall be maintained in the accelerator operator area.
(g) For accelerators used in the healing arts, operating procedures shall meet the following requirements:
(1) No individual other than the patient is in the treatment room during treatment of a patient.
(2) If a patient must be held in position during treatment, mechanical supporting or restraining devices shall be used.
(3) The system may not be used in the administration of radiation therapy unless the requirements of this chapter have been met.
(4) Misadministrations, as defined in § 215.2 (relating to definitions), shall be reported as required under § 219.228 (relating to reports of misad- ministrations).
(5) Only auxiliary personnel who have met the applicable requirements of 49 Pa. Code Part I, Subpart A (relating to professional and occupational affairs) shall be permitted to operate accelerators for therapeutic purposes.
(6) Only auxiliary personnel employed by a health care facility regulated by the Department of Health, the Department of Public Welfare or the Federal government shall be permitted to operate accelerator systems for therapeutic purposes in accordance with written job descriptions and employe qualifications.
(7) An individual who operates an accelerator system shall be instructed adequately in the safe operating procedures and be competent in the safe use of the equipment. The instructions shall include, but not be limited to, items included in Appendix A (relating to determination of competence).
§ 228.36. Radiation monitoring requirements.
(a) An accelerator facility shall have appropriate survey equipment which is operable and has been calibrated for the appropriate radiations being produced at the facility. The equipment shall be tested for proper operation each day it is used and calibrated at least annually and after each servicing or repair.
(b) In addition to the requirements of §§ 219.91 and 219.154 (relating control of access to high radiation areas; and posting of high radiation areas), an independent radiation monitoring system shall be provided so that the individuals entering or present become aware of the existence of the hazard. Independent radiation monitors shall be calibrated at least annually and after each servicing or repair.
(c) The calibration of the independent radiation monitoring system described in subsection (b) shall verify the response of the instrument to radiation fields of different intensity, and does not require complete accuracy with respect to radiation energy if the accelerator produces radiations greater than 3.0 MEV.
§ 228.37. Production of radioactive material.
(a) A registrant or licensee who produces radioactive material incidental to the operation of an accelerator shall comply with the general license requirements of § 217.48 (relating to a general license for incidental radioactive material produced by an accelerator).
(b) A registrant or licensee possessing radioactive material intentionally produced by bombarding nonradioactive material with the accelerator beam shall comply with the specific license requirements of §§ 217.51--217.57 (relating to specific licenses--general conditions).
§ 228.38. Surveys.
(a) A facility shall have a survey made by, or under the direction of, a qualified expert as defined under § 221.2 (relating to definitions). A survey shall also be done after a change in the facility or equipment, including a relocation of the equipment within the irradiation or treatment room.
(b) The qualified expert shall report the survey results in writing to the individual in charge of the facility and a copy of the report shall be maintained by the registrant or licensee for 5 years for inspection by the Department. The facility shall be operated in compliance with limitations indicated by the survey.
(c) The report of the survey results shall include:
(1) The date of the measurements.
(2) The reason the survey is required.
(3) The manufacturer's name, model number and serial number of the therapeutic radiation machine accelerator.
(4) The instrument used to measure radiation levels.
(5) A plan of the areas surrounding the treatment room that were surveyed.
(6) The measured dose rate at several points in each area expressed in microsieverts or millirems per hour
(7) The calculated maximum level of radiation over a period of 1 week for each restricted and unrestricted area.
(8) The signature of the individual who conducted or is responsible for conducting the survey.
(d) Safety and warning devices and safety interlocks shall be checked annually and serviced as necessary.
(e) If the survey required by subsection (a) indicates that an individual in an unrestricted area may be exposed to levels of radiation greater than those permitted by § 219.31 or § 219.51 (relating to occupational dose limits for adults; and dose limits for members of the general public), the registrant or licensee shall do the following:
(1) Either equip the unit with beam direction interlocks or add additional radiation shielding to ensure compliance with Chapter 219 (relating to standards for protection against radiation).
(2) Perform the survey required by subsection (a) again.
(3) Prepare and submit the report required by subsection (a). The report shall also include:
(i) The results of the initial survey.
(ii) A description of the modification made to comply with this section
(iii) The results of the second survey.
§ 228.39. Records.
In addition to the requirements of §§ 219.201--219.211 (relating to records), the licensee or registrant shall maintain records of the tests and safety and warning devices described in § 228.35; the surveys described in §§ 228.32a and 228.37; and the radiation monitoring equipment calibrations and repairs of that equipment under § 228.36 (relating to radiation monitoring requirements).
RADIATION SAFETY REQUIREMENTS FOR [ACCELERATORS USED IN THE HEALING ARTS] INDUSTRIAL AND RESEARCH ACCELERATORS
§ 228.41. [Applicable regulations] (Reserved).
[The requirements of §§ 221.81--221.102 (relating to therapeutic systems with energies of 1 MeV and above) shall apply to medical facilities using accelerators with an energy of 1 MeV and above.]
§ 228.41a. Warning devices.
(a) A location designated as a high radiation area and an entrance to the location shall be equipped with easily observable warning lights that operate only when radiation is being produced.
(b) A high radiation area shall meet the requirements of § 219.91 (relating to control of access to high radiation areas).
§ 228.42. Circuit diagrams.
Electrical circuit diagrams of the accelerator and the associated safety, warning and interlock systems shall be kept current and maintained for 5 years for inspection by the Department and shall be available to the operator at an accelerator facility.
§ 228.43. Radiation surveys.
(a) Periodic surveys shall be made to determine the amount of airborne radioactivity present in areas of airborne hazards.
(b) Periodic smear surveys shall be made to determine the amount of contamination in target and other pertinent areas.
(c) Area surveys shall be made in accordance with the written procedures established by a qualified expert or the radiation safety officer of the accelerator facility.
(d) Records of surveys shall be kept current and on file at an accelerator facility. Records of surveys shall be maintained as described in Chapter 219, Subchapter L (relating to records).
§ 228.44. Ventilation systems.
(a) A registrant or licensee shall control the concentration of radioactive material in air to meet the requirements of § 219.34 (relating to determination of internal exposure).
(b) A registrant or licensee may not vent, release or otherwise discharge airborne radioactive material to an unrestricted area which does not meet the requirements of § 219.51 (relating to dose limits for individual members of the public). Every reasonable effort shall be made to maintain releases of radioactive material to uncontrolled areas as far below these limits as practicable. Compliance with this section shall be demonstrated as described in § 219.52 (relating to compliance with dose limits for individual members of the public).
§ 228.45. Portable or mobile accelerators.
Portable or mobile accelerators used for industrial radiography or research shall comply with Chapter 225 (relating to radiation safety requirements for industrial radiographic operations)
RADIATION SAFETY REQUIREMENTS FOR ACCELERATORS USED IN THE HEALING ARTS § 228.61. Leakage radiation to the patient area.
(a) New equipment shall meet the following requirements:
(1) For operating conditions producing maximum leakage radiation, the dose due to leakage radiation, including X-rays, electrons and neutrons, at any point on a circle of 2 meters radius centered on and perpendicular to the central axis of the beam at the isocenter or normal treatment distance and outside the maximum useful beam size, may not exceed 0.1% of the maximum dose of the unattenuated useful beam measured at the point of intersection of the central axis of the beam and the plane surface. Measurements, excluding those for neutrons, shall be averaged over an area up to but not exceeding 100 square centimeters at the position specified. Measurements of the portion of the leakage radiation dose contributed by neutrons shall be averaged over an area up to but not exceeding 200 square centimeters.
(2) For each system, the registrant or licensee shall determine or obtain from the manufacturer the leakage radiation existing at the positions specified in paragraph (1) for the specified operating conditions. The registrant or licensee shall maintain records for 5 years on leakage radiation measurements for inspection by the Department.
(b) Existing equipment shall meet the following requirements:
(1) For operating conditions producing maximum leakage radiation, the absorbed dose due to leakage radiation, including neutrons, at any point on a circle of 2 meters radius centered on and perpendicular to the central axis of the beam 1 meter from the virtual source, may not exceed 0.1% of the maximum absorbed dose of the unattenuated useful beam measured at the point of intersection of the central axis of the beam and the surface of the circular plane. Measurements shall be averaged over an area up to but not exceeding 100 square centimeters at the positions specified.
(2) For each system, the registrant or licensee shall have available the leakage radiation data existing at the positions specified in paragraph (1) for the specified operating conditions, the registrant or licensee shall maintain records on radiation leakage for 5 years for inspection by the Department.
§ 228.62. Leakage radiation outside the patient area for new equipment.
(a) The absorbed dose due to leakage radiation except in the area specified in § 228.61(a)(1) (relating to leakage radiation to the patient area) when measured at any point 1 meter from the path of the charged particles, before the charged particles strikes the target or window, may not exceed 0.1% for X-ray leakage nor 0.5% for neutron leakage of the maximum absorbed dose of the unattenuated useful beam measured at the point of intersection of the central axis of the beam and the circular plane specified in § 228.61(a)(1).
(b) The registrant or licensee shall determine or obtain from the manufacturer, the actual leakage radiation existing at the positions specified in subsection (a) for specified operating conditions. Radiation measurements, including neutrons, shall be averaged over an area up to but not exceeding 200 square centimeters.
§ 228.63. Beam limiting devices.
Adjustable or interchangeable beam limiting devices shall be provided and the devices may transmit no more than 5% of the useful beam at the normal treatment distance. The neutron component of the useful beam may not be included to comply with this requirement.
§ 228.64. Filters.
(a) A filter which is removable from the system shall be clearly identified. Documentation shall contain a description of the filter which includes a drawing showing dimensions and noting materials of construction. For wedge filters, the wedge factor and the wedge angle shall appear on the wedge or wedge tray.
(b) For new equipment which utilizes a system of wedge filters, interchangeable field flattening filters or interchangeable beam scattering filters the following apply:
(1) Irradiation may not be possible until a selection of a filter has been made at the control panel.
(2) An interlock system shall be provided to prevent irradiation if the filter selected is not in the correct position.
(3) An interlock shall be provided to prevent irradiation if a filter selection operation carried out in the treatment room does not agree with the filter selection operation carried out at the control panel.
§ 228.65. Beam quality.
The registrant or licensee shall determine that the following beam quality requirements are met:
(1) The absorbed dose resulting from X-rays in a useful electron beam at a point on the central axis of the beam 10 centimeters greater than the practical range of the electrons may not exceed the values in Table I. Linear interpolation shall be used for values not stated.
TABLE I
X-ray Absorbed Dose as a Maximum Energy of Fraction of Maximum Electron Beam in MeV Absorbed Dose 1 0.03 15 0.05 35 0.10 50 0.20 (2) Compliance with subsection (a) shall be determined using:
(i) A measurement within a phantom with the incident surface of the phantom at the normal treatment distance and normal to the central axis of the beam.
(ii) The largest field size available which does not exceed 15 by 15 centimeters.
(iii) A phantom whose cross-sectional dimensions exceed the measurement radiation field by at least 5 centimeters and whose depth is sufficient to perform the required measurement.
(3) The registrant or licensee shall determine, or obtain from the manufacturer, the maximum percentage absorbed dose due to stray neutrons in the useful beam for specified operating conditions.
§ 228.66. Beam monitors.
(a) Therapy systems shall be provided with radiation detectors in the radiation head.
(b) New equipment shall be provided with at least two radiation detectors incorporated into two separate dose monitoring systems.
(c) Existing equipment shall be provided with at least one radiation detector incorporated into a primary dose monitoring system.
(d) The detector in a dose monitoring system shall be:
(1) Permanently installed and interlocked to prevent incorrect positioning.
(2) Part of a dose monitoring system that provides readings in dose monitor units which can be used to calculate the absorbed dose at a reference point in the treatment volume.
(3) Capable of independently monitoring and controlling the useful beam.
(e) For new equipment, the design of dose monitoring systems shall assure that:
(1) The malfunctioning of one system does not affect the correct functioning of the second system.
(2) The failure of an element common to both systems which could affect the correct function of both systems terminates irradiation.
(f) A dose monitoring system shall have a legible display at the control panel. For new equipment, a display shall:
(1) Maintain a reading until intentionally reset to zero.
(2) Have only one scale and no scale multiplying factors.
(3) Utilize a design so that increasing dose is displayed by increasing numbers and that the absorbed dose may be accurately determined under all conditions of use.
(4) Provide that, in the event of a power failure, the dose monitoring information required in this subsection displayed at the control panel at the time of failure shall be retrievable.
§ 228.67. Beam symmetry.
(a) In new equipment inherently capable of producing useful beams with asymmetry exceeding 5%, at least four different parts of the radiation beam shall be monitored before the beam passes through the beam limiting device.
(b) If the difference in dose rates between two of the different parts required in subsection (a) exceeds 10%, the irradiation shall be terminated.
§ 228.68. Selection and display of dose monitor units.
(a) Irradiation may not be possible until a selection of a number of dose monitor units has been made at the control panel.
(b) The preselected number of dose monitor units shall be displayed at the control panel until reset manually to zero before subsequent treatment can be initiated.
§ 228.69. Termination of irradiation by the dose monitoring system or systems.
(a) A dose monitoring system shall be capable of independently terminating irradiation.
(b) A primary system shall terminate irradiation when the preselected number of dose monitor units has been detected by the system.
(c) A secondary dose monitoring system shall terminate irradiation when either 110% of the preselected number of dose monitor units 10 dose monitor units (whichever is greater) has been detected by the secondary dose monitoring system.
(d) For new equipment, an indicator on the control panel shall show which dose monitoring system has terminated irradiation.
§ 228.70. Interruption and termination switches.
The operator shall be able to interrupt or terminate irradiation and equipment movement at any time from the control panel. Following an interruption, the operator shall be able to resume irradiation without reselection of operating conditions.
§ 228.71. Timer.
(a) The control panel shall have a timer that is graduated in minutes and fractions of minutes or seconds. The timer shall have a preset time selector and an elapsed time indicator.
(b) The timer shall be cumulative and activated only during irradiation and shall retain its reading after irradiation is interrupted or terminated.
(c) The timer shall terminate irradiation when a preselected time has elapsed if the dose monitoring systems fail to do so.
§ 228.72. Selection of radiation type.
Equipment capable of both X-ray therapy and electron therapy shall meet the following additional requirements:
(1) Irradiation may not be possible until a selection of radiation type and appropriate energy has been made and displayed at the control panel.
(2) An interlock system shall be provided to insure that the equipment can emit only the radiation type which has been selected.
(3) An interlock system shall be provided to prevent irradiation if selected operations carried out in the treatment room do not agree with the selected operations carried out at the control panel.
(4) An interlock system shall be provided to prevent:
(i) Irradiation with X-rays except to obtain a port film when electron applicators are fitted.
(ii) Irradiation with electrons when accessories specific for X-ray therapy are fitted.
(5) For new equipment, a system shall be provided to terminate irradiation if the energy of the electrons striking either the X-ray target or electron window deviates by more than +20% or +3 Mev, whichever is smaller, from the selected nominal energy.
§ 228.73. Selection of stationary beam therapy or moving beam therapy.
Equipment capable of both stationary beam therapy and moving beam therapy shall meet the following additional requirements:
(1) Irradiation may not be possible until a selection of stationary beam therapy or moving beam therapy has been made at the control panel.
(2) An interlock system shall be provided to insure that the equipment can operate only in the mode which has been selected.
(3) An interlock system shall be provided to prevent irradiation if any selected operations carried out in the treatment rooms do not agree with the selected operations carried out at the control panel.
(4) The mode of operation shall be displayed at the control panel.
(5) An interlock system shall be provided to terminate irradiation if one of the following occurs:
(i) Movement of the gantry during stationary beam therapy.
(ii) Movement of the gantry stops during moving beam therapy unless the stoppage is a preplanned function.
(6) An interlock system shall be provided to terminate irradiation if the number of dose monitor units delivered along an arc differs by more than 10% from the selected value. Termination of irradiation shall be as required by § 228.70 (relating to interruption and termination switches).
§ 228.74. Absorbed dose rate.
New equipment shall have a system that provides information from which the absorbed dose rate at a reference point in the treatment volume can be calculated. The radiation detectors specified in § 228.66 (relating to beam monitors) may form part of this system. The dose monitor unit rate shall be displayed at the control panel.
§ 228.75. Calibrations.
(a) The calibration of systems subject to this subchapter shall be performed in accordance with an established calibration protocol. The calibration protocol published by the American Association of Physicists in Medicine is accepted as an established protocol. Other protocols which are equivalent will be accepted, but the user shall submit that protocol to the Department for concurrence that the protocol is equivalent. The calibration shall be performed as follows:
(1) Before the system is first used for irradiation of a patient and, at time intervals which do not exceed 1 year.
(2) After a change which alters the calibration, spatial distribution or other characteristics of the therapy beam.
(b) The calibration shall be performed by, or under the direct supervision of, a qualified expert.
(c) Calibration radiation measurements required by subsection (a) shall be performed using a dosimetry system meeting the following specifications:
(1) The system has an exposure calibration factor appropriate to the beam energy measured and traceable to a National standard.
(2) The system has been calibrated within the previous 2 years and after servicing that may have affected its calibration.
(3) The system has been calibrated so that an uncertainty can be stated for the radiation quantities monitored by the system.
(4) The system has had constancy checks performed on the system as specified by a qualified expert.
(d) Calibrations made under this section shall be made so that the dose at a reference point in soft tissue may be calculated as accurately as possible but with an uncertainty of no greater than 5%.
(e) The calibration of the therapy beam shall include, but is not limited to, the following determinations:
(1) Verification that the equipment is operating in compliance with the design specifications concerning the light localizer, the side light and back-pointer alignment with the isocenter when applicable, variation in the axis of rotation for the table, gantry and beam limiting device (collimator) system.
(2) The absorbed dose rate at various depths (depth dose) and beam profile measured in water and the beam flatness and symmetry for the range of field sizes used, for each beam energy.
(3) The uniformity of the radiation field and a dependency upon the direction of the useful beam.
(4) Verification of depth-dose data and isodose curves applicable to the specific machine.
(5) Verification of the applicability of transmission factors of accessories such as wedges, shadow trays, compensators and their effects on electron buildup.
(6) The dose per monitor unit, end effect, linearity and dose rate dependence of the dose monitor systems.
(7) For photon beams, the congruence of the light field and the radiation field.
(8) For electron beams, the determination of the virtual source distance for each electron energy and beam restriction device.
(f) Records of calibration measurements under subsection (a) and dosimetry system calibrations under subsection (c) shall be preserved for 5 years.
(g) A copy of the latest calibration performed under subsection (a) shall be available at the facility.
§ 228.76. Spot checks.
Spot checks shall be performed on systems subject to this subchapter during full calibrations and thereafter once in each calendar month. The spot checks shall meet the following requirements:
(1) The procedures shall be in writing and shall have been developed by a qualified expert.
(2) If a qualified expert does not perform the spot check measurements, the results of the spot check measurements shall be reviewed by a qualified expert within 15 days of the completion of the spot check.
(3) The measurements taken during spot checks shall demonstrate the degree of consistency of the operating characteristics which can affect the radiation output of the system or the radiation delivered to a patient during a therapy procedure.
(4) The spot-check procedures shall specify the acceptable tolerance for each parameter measured in the spot check when compared to the value for that parameter determined in the full calibration.
(5) If a spot check indicates a change in the operating characteristics of a system, as specified in the qualified expert's spot-check procedures, the system shall be recalibrated as required in § 228.75 (relating to calibrations).
(6) Records of spot-check measurements performed under this section shall be maintained by the registrant for a period of 5 years after completion of the spot-check measurements and necessary corrective actions.
(7) Spot check measurements shall be performed using a dosimetry system that has been calibrated in accordance with § 228.75(c). Alternatively, a dosimetry system used solely for spot check measurements may be calibrated by direct intercomparison with a system that has been calibrated in accordance with § 228.75(c). This alternative calibration method shall have been performed within the previous year and after a servicing that may have affected the system calibration.
APPENDIX A
Determination of Competence The following are areas in which an individual shall have expertise for the competent operation of radiation therapy equipment, the administration of radiation therapy treatment and determination of treatment portals.
(1) Familiarization with equipment.
(i) Identification of controls.
(ii) Function of each control.
(2) Radiation protection.
(i) Personnel protection.
(ii) Use of shielding blocks.
(iii) Understanding of dose units.
(iv) Grids.
(3) Film processing.
(i) Able to produce quality films for use by a phycisian.
(ii) Knowledge of portal film exposure factors.
(iii) Film processing parameters.
(4) Procedures.
(i) Knowledge of anatomy and physiology.
(ii) Knowledge of patient immobilization devices to allow treatment with minimal patient movement.
(iii) Able to position patient to allow for treatment of desired area.
(5) Emergency procedures.
(i) Termination of treatment in event of machine primary and secondary and dose monitoring system failure.
(ii) Termination of treatment in the event of patient movement during treatment.
(6) Continuing education. Continuing education annually to include radiation protection
[Pa.B. Doc. No. 97-1777. Filed for public inspection October 31, 1997, 9:00 a.m.]
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