N.H. Admin. Code § He-P 4035.55

Current through Register No. 45, November 7, 2024

Section He-P 4035.55 - Periodic Spot-Checks for Teletherapy Units, Remote Afterloader Units, and Gamma Stereotactic Radiosurgery Units

(a) A licensee authorized to use teletherapy units for medical use shall perform output spot-checks on each teletherapy unit once in each calendar month that include determination of:

(1) Timer accuracy and timer linearity over the range of use;

(2) "On-off" error;

(3) The coincidence of the radiation field and the field indicated by the light beam-localizing device;

(4) The accuracy of all distance measuring and localization devices used for medical use;

(5) The output for 1 typical set of operating conditions measured with the dosimetry system described in He-P 4035.53(g); and

(6) The difference between the measurement made in He-P 4035.55(a)(5) and the anticipated output, expressed as a percentage of the anticipated output (, the value obtained at last full calibration corrected mathematically for physical decay).

(b) A licensee shall perform spot-checks required by He-P 4035.55(a) in accordance with written procedures established by the authorized medical physicist. That individual need not actually perform the spot check measurements.

(c) A licensee shall have the authorized medical physicist review the results of each output spot-check within 15 days. The authorized medical physicist shall promptly notify the licensee in writing of the results of each output spot-check.

(d) A licensee authorized to use a teletherapy unit for medical use shall perform safety spot-checks of each teletherapy facility once in each calendar month and after each source installation, to assure proper operation of:

(1) Electrical interlocks at each teletherapy room entrance;

(2) Electrical or mechanical stops installed for the purpose of limiting use of the primary beam of radiation restriction of source housing angulation or elevation, carriage or stand travel, and operation of the beam "on-off" mechanism;

(3) Source exposure indicator lights on the teletherapy unit, on the control console, and in the facility;

(4) Viewing and intercom systems;

(5) Treatment room doors from inside and outside the treatment room; and

(6) Electrically assisted treatment room doors with the teletherapy unit electrical power turned "off".

(e) A licensee shall lock the control console in the "off" position if the results of the checks required in He-P 4035.55(d) indicates the malfunction of any system, and not use the unit except as may be necessary to repair, replace, or check the malfunctioning system.

(f) A licensee shall maintain a record of each spot-check required by He-P 4035.55(a) and (d) for 3 years.

(g) The record shall include:

(1) The date of the spot-check;

(2) The manufacturer's name, model number, and serial number of the teletherapy unit, source, and instrument used to measure the output of the teletherapy unit;

(3) An assessment of timer linearity and constancy;

(4) The calculated "on-off" error;

(5) A determination of the coincidence of the radiation field and the field indicated by the light beam-localizing device;

(6) The determined accuracy of each distance measuring or localization device;

(7) The difference between the anticipated output and the measured output;

(8) Notations indicating the operability of each entrance door electrical interlock, each electrical or mechanical stop, each source exposure indicator light, the viewing and intercom system and doors; and

(9) The name of the individual who performed the periodic spot-check and the signature of the authorized medical physicist who reviewed the record of the spot-check.

(h) A licensee shall retain a copy of the procedures required by He-P 4035.55(b) until the licensee no longer possesses the teletherapy unit.

(i) A licensee authorized to use a remote afterloader unit for medical use shall perform spot-checks of each remote afterloader facility and on each unit:

(1) Before the first use of a high dose-rate, medium dose-rate, or pulsed dose-rate afterloader unit on a given day;

(2) Before each patient treatment with a low dose-rate remote afterloader unit; and

(3) After each source installation.

(j) A licensee shall perform the measurements required by He-P 4035.55(i) in accordance with written procedures established by the authorized medical physicist. That individual need not actually perform the spot check measurements.

(k) A licensee shall have the authorized medical physicist review the results of each spot-check within 15 days. The authorized medical physicist shall promptly notify the licensee in writing of the results of each spot-check.

(l) To satisfy the requirements of He-P 4035.55(i), spot-checks shall, at a minimum, assure proper operation of:

(1) Electrical interlocks at each remote afterloader unit room entrance;

(2) Source exposure indicator lights on the remote afterloader unit, on the control console, and in the facility;

(3) Viewing and intercom systems in each high dose-rate, medium dose-rate, and pulsed dose-rate remote afterloader facility;

(4) Emergency response equipment;

(5) Radiation monitors used to indicate the source position;

(6) Timer accuracy;

(7) Clock (date and time) in the unit's computer; and

(8) Decay source(s) activity in the unit's computer.

(m) If the results of the checks required in He-P 4035.55(l) indicate the malfunction of any system, a licensee shall lock the control console in the "off" position and not use the unit except as may be necessary to repair, replace, or check the malfunctioning system.

(n) A licensee shall retain a record of each check required by He-P 4035.55(l) for 3 years. The record shall include, as applicable:

(1) The date of the spot-check;

(2) The manufacturer's name, model number, and serial number for the remote afterloader unit and source;

(3) An assessment of timer accuracy;

(4) Notations indicating the operability of each entrance door electrical interlock, radiation monitors, source exposure indicator lights, viewing and intercom systems, and clock and decayed source activity in the unit's computer; and

(5) The name of the individual who performed the periodic spot-check and the signature of the authorized medical physicist who reviewed the record of the spot-check.

(o) A licensee shall retain a copy of the procedures required by He-P 4035.55(j) until the licensee no longer possesses the remote afterloader unit.

(p) A licensee authorized to use a gamma stereotactic radiosurgery unit for medical use shall perform spot-checks of each gamma stereotactic radiosurgery facility and on each unit:

(1) Monthly;

(2) Before the first use of the unit on a given day; and

(3) After each source installation.

(q) A licensee shall:

(1) Perform the measurements required by He-P 4035.55(p) in accordance with written procedures established by the authorized medical physicist. That individual need not actually perform the spot check measurements.

(2) Have the authorized medical physicist review the results of each spot-check within 15 days. The authorized medical physicist shall promptly notify the licensee in writing of the results of each spot-check.

(r) To satisfy the requirements of He-P 4035.55(p)(1), spot-checks shall, at a minimum:

(1) Assure proper operation of:

a. Treatment table retraction mechanism, using backup battery power or hydraulic backups with the unit off:

b. Helmet microswitches;

c. Emergency timing circuits; and

d. Stereotactic frames and localizing devices (trunnions).

(2) Determine:

a. The output for one typical set of operating conditions measured with the dosimetry system described in He-P 4035.53(g);

b. The difference between the measurement made in He-P 4035.55(r)(2)a. and the anticipated output, expressed as a percentage of the anticipated output (i.e., the value obtained at last full calibration corrected mathematically for physical decay);

c. Source output against computer calculation;

d. Timer accuracy and linearity over the range of use;

e. "On-off" error; and

f. Trunnion centricity.

(s) To satisfy the requirements of He-P 4035.55(p)(2) and (p) (3), spot-checks shall assure proper operation of:

(1) Electrical interlocks at each gamma stereotactic radiosurgery room entrance;

(2) Source exposure indicator lights on the gamma stereotactic radiosurgery unit, on the control console, and in the facility;

(3) Viewing and intercom systems;

(4) Timer termination;

(5) Emergency "off" buttons; and

(6) Radiation monitors used to indicate room exposures.

(t) A licensee shall arrange for repair of any system identified in He-P 4035.55(r) that is not operating as soon as possible.

(u) If the results of the checks required in He-P 4035.55(s) indicate the malfunction of any system, a licensee shall lock the control console in the "off" position and not use the unit except as may be necessary to repair, replace, or check the malfunctioning system.

(v) A licensee shall retain a record of each check required by He-P 4035.55(r) and (s) for 3 years. The record shall include:

(1) The date of the spot-check;

(2) The manufacturer's name, model number, and serial number for the gamma stereotactic radiosurgery unit and the instrument used to measure the output of the unit;

(3) An assessment of timer linearity and accuracy;

(4) The calculated "on-off" error;

(5) A determination of trunnion centricity;

(6) The difference between the anticipated output and the measured output;

(7) An assessment of source output against computer calculations;

(8) Notations indicating the operability of radiation monitors, helmet microswitches, emergency timing circuits, emergency "off" buttons, electrical interlocks, source exposure indicator lights, viewing and intercom systems, timer termination, treatment table retraction mechanism, and stereotactic frames and localizing devices (trunnions); and

(9) The name of the individual who performed the periodic spot-check and the signature of the authorized medical physicist who reviewed the record of the spot-check.

(w) A licensee shall retain a copy of the procedures required by He-P 4035.55(r) and (s) until the licensee no longer possesses the gamma stereotactic radiosurgery unit.

N.H. Admin. Code § He-P 4035.55

(See Revision Note at part heading for He-P 4035) #6942, eff 2-1-99; ss by #8800, INTERIM, eff 2-1-07, EXPIRED: 7-31-07

New. #8959, eff 8-7-07; ss by #10897, INTERIM, eff 7-22-15, EXPIRES: 1-18-16; ss by #11011, eff 1-15-16; amd by #12054, eff 11-19-16

Amended by Volume XXXV, Number 32 Filed August 13, 2015, Proposed by #10897, Effective 7/22/2015, Expires1/18/2016.

Amended by Volume XXXVI Number 01, Filed January 7, 2016, Proposed by #11011, Effective 1/15/2016, Expires 1/15/2026.

Amended by Volume XXXVI Number 49, Filed December 8, 2016, Proposed by #12054, Effective 11/19/2016, Expires 11/19/2026.

Amended by Volume XL Number 24, Filed June 11, 2020, Proposed by #13048, Effective 6/2/2020, Expires 6/2/2030.