Patient and Staff Radiological Protection in Cardiology

Comments on ICRP ref 4818-2733-7736 (May 20, 2011) Stephen Balter, Ph.D.

Patient and staff Radiological Protection in Cardiology

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Comment

General

Many portions of this report are also found in ICRP Draft 4834-1783-0153 (Radiological protection in fluoroscopically guided procedures performed outside the imaging department)

Identical text and figures should appear in both reports. Recommend that the text in this document (-7736) be used to the extent practicable.

198-199

Please provide references to these findings somewhere in this report

Please indicate the existence of a latent-period for these effects in the executive summary.

212

What are the implications for comforters after a patient is discharged from a radio nuclear imaging procedure (e.g. Th)?

216-217

Training of referring clinicians is important. Both the -7736 and –0513 reports should be expanded to include a brief section on what the referring clinician ought to know.

373

Please include “referring clinicians” in this bullet.

387

Strongly suggest that the glossary be moved to an appendix. Having it at the start of the report will discourage many physicians from reading beyond the definition of absorbed dose.

764

The word disproportionate implies that some of the exposure is unnecessary. There will still be a lot of radiation even when all procedures are both justified and optimized. Suggest changing “disproportionate” to “large”.

837-839

There are two statements here. The first is that dose levels in pediatric procedures can reach adult levels. This is true as the usual definition of pediatric includes all patients under age 18, including those who are of adult size. The second statement seems to say that the same dose distributions are found in both developing and developed countries.

There should not be a general implication that high pediatric doses are only found in developing countries.

845

Given that the intended audience includes physicians and others who may not be comfortable with exponential notation, it is suggested that all such values be expressed as percentages.

931

Consider adding a reference to the pediatric cardiac data published in NCRP Report 168

1282

Consider adding a reference to the 1992 ACR/FDA workshop on fluoroscopy. The proceedings are currently available on the FDA website.

1333

Consider adding a reference to NCRP-168

1431-1433

If similar images are available in the refereed literature they should be used an referenced as a replacement to this hard to access news article.

1501

Please develop some information regarding the latent period for these effects. References outside the ICRP series would also be appreciated.

1533

The Renaud estimate of head dose is also interesting regarding the new limits on eye exposure. This certainly motivates the use of eye protection. Suggest that this reference also be used in the eye section of this report.

1767-1768

Lower pulse rate (frames per second) does not guarantee lower dose rate (mGy/minute). The pulse rate and dose per pulse are independently set in most modern fluoroscopes.  Optimizing pulse rate and dose per pulse is task specific with a requirement of minimizing dose rate to the lowest clinically acceptable value.

2254

An indication of the latent period and time course of these effects also belongs here.

2303

Data is urgently needed for fetal dose attributed to diagnostic and interventional procedures of the chest, abdomen, and pelvis. Data is also needed on fetal dose from abdominal and pelvic CT procedures.

2315

Measured maximum skin dose for ‘medium’ dose rate fluoroscopy actually exceeds 200 mGy/min under worst case conditions (low table and maximum SID).  Maximum fluoro dose rates are actually limited to 88 mGy/min air kerma 30 cm in front of the image receptor. SID tracking will increase the table-top air kerma to about 150 mGy/min. The remainder is backscatter from the patient.

2319-2320

Organ doses exceeding 100 Gy are extremely rare (even peak skin dose) I thing that exceeding 50 Gy is more realistic. On the other hand, effective doses exceeding 100 mSv do occur.

2582

This photo of a MPPS report needs considerable expansion.

Information should be supplied indicating that the 5 listed runs are only acquisition, and that the total PKA and Kar include both cine and fluoroscopy. Also why does this report indicate zero exposures

2686

Recommend changing “regulatory limits” to “ICRP recommendations” as the actual regulatory limits differ from country to country.

2656-2659

Is the ratio of “in lab” to “control room” 1,000 or >10,000?

4339

Given the focus on organ dose effects in this draft, a second figure should indicate heart and thyroid organ doses separately.

4377

Two additional training items

Radiation considerations for referring clinicians

Clinical training in specific procedures for the MPE (qualified medical physicist)

The practical advice offered by the physicist will almost always be enhanced if they have a working knowledge of relevant clinical procedure justification and performance.