Ind. Admin. Code tit. 410, r. 5-6.1-125
Authority: IC 16-41-35-26; IC 16-41-35-29
Affected: IC 16-41-35
Sec. 125. (a) This section and 410 IAC 5-9, excluding 410 IAC 5-9-8(a), 410 IAC 5-9-10(a), 410 IAC 5-9-10(c), and 410 IAC 5-9-10(d), shall apply to medical facilities using therapeutic x-ray or electron systems capable of operating at one (1) MeV or more.
(b) Therapeutic x-ray or electron systems manufactured after January 1, 1985, shall comply with the following:
(c) Therapeutic x-ray or electron systems manufactured on or before January 1, 1985, shall comply with the following:
(d) Adjustable or interchangeable beam-limiting devices shall be provided. Such devices shall transmit no more than two percent (2%) of the useful beam, excluding its neutron component, at the normal treatment distance for the portion of the useful beam which is to be attenuated by the beam-limiting device.
(e) Each filter which is removable from the system shall be clearly marked with an identification number. Documentation shall be available at the control panel describing each filter. For wedge filters, the wedge angle shall be indicated on the wedge or wedge tray. If the absorbed dose rate data required by subsection (t) relates exclusively to operation with a field-flattening or beam-scattering filter in place, such filter shall not be removable by hand.
(f) Those therapeutic x-ray or electron systems manufactured after January 1, 1985, which utilize a system of wedge filters, interchangeable field-flattening filters, or interchangeable beam-scattering filters shall comply with the following:
(g) The registrant shall determine, or obtain from the manufacturer, data sufficient to assure that the following 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 ten (10) cm greater than the practical range of the electrons shall not exceed the values stated in the table in this subdivision. Linear interpolation shall be used for values not stated.
| TABLE III | |
|---|---|
| X-Ray Absorbed Dose | |
| Maximum Energy | as a Fraction of |
| of Electron Beam | Maximum Dose |
| 1 MeV | 0.03 |
| 15 MeV | 0.05 |
| 35 MeV | 0.10 |
| 50 MeV | 0.20 |
Compliance shall be determined using the following:
(2) The absorbed dose at a surface located at the normal treatment distance, at the point of intersection of that surface with the central axis of the useful beam during x-ray irradiation, shall not exceed the limits stated in the table in this subdivision. Linear interpolation shall be used for values not stated.
| TABLE IV | |
|---|---|
| Absorbed Dose at the | |
| Surface as a Fraction | |
| Maximum Photon Energy | of the Maximum Dose |
| 1 MeV | 0.80 |
| 2 MeV | 0.70 |
| 5 MeV | 0.60 |
| 15 MeV | 0.50 |
| 35 MeV | 0.40 |
| 50 MeV | 0.20 |
Compliance shall be determined by measurements made as follows:
(h) All therapeutic x-ray or electron systems shall be provided with one (1) or more dose monitoring chambers, in accordance with the following:
(i) Each dose monitoring chamber shall be removable only by use of tools and shall be interlocked to prevent incorrect positioning. Each dose monitoring chamber shall form part of a dose monitoring system from which readings of the absorbed dose at a reference point in the treatment volume can be calculated in dose monitor units. Each dose monitoring system shall be capable of independently monitoring, interrupting, and terminating irradiation. Each dose monitoring system shall have a legible display located at the control panel.
(j) Therapeutic x-ray or electron systems manufactured after January 1, 1985, shall comply with this subsection. The design of each dose monitoring system shall assure that malfunctioning of one (1) system shall not cause incorrect functioning of the second system. The failure of any element common to both monitoring systems which could affect the correct function of both systems shall terminate irradiation. Each dose monitoring system display shall:
In the event of a power failure, the dose monitoring information displayed at the control panel at the time of the power failure shall be retrievable from at least one (1) dose monitoring system.
(k) For therapeutic x-ray or electron systems manufactured after January 1, 1985, which are inherently capable of producing useful beams with asymmetry exceeding five percent (5%), the asymmetry of the radiation beam in two (2) orthogonal directions shall be monitored before the beam passes through the beam-limiting device. Monitoring devices, indicators, and controls shall be provided so that if the difference in dose rate between one (1) region and another region symmetrically displaced from the central axis of the beam exceeds five percent (5%) of the central axis dose rate, this condition is indicated at the control panel. If the difference exceeds ten percent (10%), the controls shall automatically terminate irradiation.
(l) Irradiation shall not be possible until selection of the number of dose monitor units to be delivered has been made at the control panel. The preselected number of dose monitor units shall be displayed at the control panel until reset manually for the next irradiation. After termination of irradiation, it shall be necessary to reset the dosimeter display to the zero (0) position before subsequent treatment can be initiated.
(m) During stationary beam therapy, the primary dose monitoring system shall terminate irradiation when the preselected number of dose monitor units have been detected by that system. If original design of the equipment included a second dose monitoring system, that system shall be capable of terminating irradiation when the system detects that the preselected number of dose monitoring units set at the control panel indicate either fifteen percent (15%), or greater, or forty (40) dose monitor units, or greater, above the preselected number of dose monitor units set at the control panel. For therapeutic x-ray or electron systems manufactured after January 1, 1985, which are used for stationary beam therapy:
(n) It shall be possible to interrupt irradiation and gantry rotation at any time at the control panel. Following an interruption, it shall be possible for the operator to commence irradiation without reselecting operating conditions. If any change is made of a preselected value during an interruption, irradiation and gantry rotation shall be automatically terminated.
(o) A timer that has a display shall be provided at the control panel. The timer shall have a preset time selector and an elapsed time indicator. The timer shall be a cumulative timer that activates with the production of radiation and retains its reading after irradiation is interrupted or terminated. After irradiation is terminated, it shall be necessary to reset the elapsed time indicator to the zero (0) position before irradiation can be initiated. The timer shall terminate irradiation when a preselected time has elapsed if the dose monitoring systems have not previously terminated irradiation.
(p) Equipment capable of both x-ray therapy and electron therapy shall comply with the following additional requirements:
(q) Equipment capable of generating radiation beams of different energies shall comply with the following:
(r) Equipment capable of both stationary beam therapy and moving beam therapy shall comply with the following:
(6) Therapy systems manufactured after January 1, 1985, shall also comply with the following:
(s) For therapy systems manufactured after January 1, 1985, a system shall be provided from which readings of the absorbed dose rate at a reference point in the treatment volume can be calculated. The dose monitoring chambers specified in subsection (h) may form part of this system. The dose monitor unit rate shall be displayed at the control panel.
(t) The registrant shall determine, or shall obtain from the manufacturer, the location of the target or the virtual source of x-rays with reference to an accessible point on the radiation head. If the equipment is capable of electron therapy, the registrant shall also determine, or shall obtain from the manufacturer, the location of the electron window with reference to an accessible point on the radiation head.
(u) Capability shall be provided for radiation safety interlocks to be checked for proper operation.
(v) Facilities which will house therapeutic x-ray or electron systems capable of operating at more than one (1) MeV shall comply with 410 IAC 5-4 and the following:
(w) Registrants shall have all new therapeutic x-ray or electron facilities, and existing facilities not previously surveyed, surveyed by a radiation oncology physicist approved by the department. Such surveys shall also be performed after any change in the facility or equipment which might cause a significant increase in radiation hazard. The registrant shall obtain a written report of the survey from the radiation oncology physicist, and a copy of the report shall be transmitted by the registrant to the commissioner within thirty (30) days of receipt of the report of the survey. The survey and report shall indicate all locations where the dose equivalent rate exceeds the limits specified in this rule.
(x) The registrant shall establish procedures to check all monitor unit calculations by an independent method or by a second individual before administering thirty percent (30%) of the prescribed total dose to assure that the dose to a single point on the central axis, or to a point of special interest, agrees with the manual or computer generated dose calculation and with the written order of a practitioner of the healing arts. Additionally, the registrant shall verify that the correct central axis depth-dose values, field size factors, off-axis ratios, and beam modifying factors are used and documented.
(y) Calibration of therapeutic x-ray or electron systems subject to this section shall be performed in accordance with an established calibration protocol acceptable to the commissioner, such as the protocol established by the American Association of Physicists in Medicine. The calibrations shall be performed before the system is first used for irradiation of an individual, and thereafter at time intervals not to exceed twelve (12) months. Calibrations shall also be performed after any change which might significantly alter the dose monitor unit, beam energy, spatial distribution, or other characteristics of the therapy beam. Calibration shall be performed by a radiation oncology physicist approved by the department, who is physically present at the facility. Radiation measurements conducted during calibrations required by this subsection shall be performed using a dosimetry system which complies with the following:
(3) Calibration of each therapy beam shall include, but not be limited to, the following determinations:
Records of calibration measurements and dosimetry system calibrations conducted in accordance with this subsection shall be maintained by the registrant for at least five (5) years after completion of such calibration.
(z) An independent check of the output of each therapeutic beam shall be performed annually. The check shall be performed by either of the following:
(aa) Output spot checks shall be performed on therapeutic x-ray or electron systems during spot checks conducted in accordance with subsection (y), and thereafter at intervals not to exceed one (1) month by a radiation oncology physicist approved by the department. Output spot check procedures shall be in writing and shall have been developed by a radiation oncology physicist approved by the department. Output spot check procedures shall specify which tests or measurements to be performed, the frequency the tests or measurements are to be performed, the acceptable tolerance for each parameter measured compared to the value for that parameter as determined in the last calibration conducted in accordance with subsection (y), and the action to be taken if a tolerance has been exceeded for any test or measurement required by the written output spot check procedures. Written output spot check procedures are required for at least the following parameters:
If an output spot check conducted in accordance with this subsection indicates a variance of more than five percent (5%) in output per monitor unit compared to the value determined in the last spot check conducted in this subsection, the radiation oncology physicist shall calibrate the therapeutic x-ray system. Records of each output calibration measurement conducted in accordance with this subsection shall be maintained by the registrant for a minimum of five (5) years from the date the output calibration was performed.
(bb) The registrant shall perform weekly output constancy checks on each of their therapeutic x-ray or electron systems in accordance with written output constancy check procedures developed by a radiation oncology physicist approved by the department. The output constancy check procedures shall specify the following:
At least monthly, a radiation oncology physicist approved by the department shall review the results of all required output constancy checks performed since his or her last such review. If an output constancy check conducted in accordance with this subsection indicates a variance of more than five percent (5%) in output per monitor unit compared to the value determined in the last calibration conducted in accordance with subsection (y), the registrant shall repair the therapeutic x-ray or electron system or undertake other corrective action before the equipment is again used to irradiate patients. The registrant shall also perform an output constancy check to determine whether or not the therapeutic x-ray or electron system is again in compliance with this subsection prior to utilizing the equipment to irradiate patients. A record of each output constancy check performed in accordance with this subsection, and any repairs or corrective action undertaken in compliance with this subsection, shall be maintained by the registrant for a minimum of two (2) years from the date the output constancy check, repair, or corrective action was performed.
(cc) The registrant shall perform checks on treatment planning computers and dose calculation algorithms in accordance with quality assurance procedures developed by a radiation oncology physicist approved by the department. At a minimum, the quality assurance procedures shall require that the registrant do the following:
(dd) The registrant shall establish and maintain a written quality management plan to assure that radiation from an x-ray or electron therapy system is administered as ordered by a practitioner of the healing arts. At a minimum, the quality management plan must assure the following:
(1) Prior to administration, a written order for therapeutic radiation must be prepared by a practitioner of the healing arts. Said order shall specify, at a minimum, the following:
(C) For each treatment site, treatment mode, and beam energy, the following:
(ee) The registrant shall review the radiation oncology chart of patients subjected to irradiation from a therapeutic x-ray or electron system in accordance with written quality assurance procedures developed by a radiation oncology physicist approved by the department. At a minimum, the written quality assurance procedures must require the following:
(ff) The registrant shall submit a written report to the commissioner of any misadministration within fifteen (15) days of discovery of the misadministration. The report shall contain the following:
A copy of the report shall be maintained by the registrant for at least five (5) years after the date of the misadministration.
(gg) If possible, within twenty-four (24) hours of discovery of a misadministration, the registrant shall notify the individual who has been improperly irradiated, or that individual's parent or guardian, if applicable, about the misadministration, unless, in the opinion of a practitioner of the healing arts, such notification would be harmful to that individual. Also, within twenty-four (24) hours of discovery of a misadministration, the registrant shall notify the referring practitioner of the healing arts about the misadministration. At a minimum, the notifications shall briefly describe the nature of the misadministration and any resultant effect on the individual who was improperly irradiated.
(hh) A therapeutic x-ray system shall not be used to administer radiation therapy unless it complies with subsections (u), (y), (z), and (aa) through (cc).
(Indiana Department of Health; 410 IAC 5-6.1-125; filed Oct 29, 1993, 5:00 p.m.: 17 IR 383; readopted filed Jul 11, 2001, 2:23 p.m.: 24 IR 4234; readopted filed May 22, 2007, 1:44 p.m.: 20070613-IR-410070141RFA; readopted filed Sep 11, 2013, 3:19 p.m.: 20131009-IR-410130346RFA; readopted filed Nov 13, 2019, 3:14 p.m.: 20191211-IR-410190391RFA; readopted filed Nov 14, 2025, 11:18 a.m.: 20251210-IR-410240588RFA)