Perma

Permanent Brachytherapy Medical Events: Experiences of

Pennsylvania

Frank CostelloOrganization of Agreement States

August 28, 2012 Milwaukee, Wisconsin

Prostate Seed Implants

• Permanent placement of radioactive seeds directly into the prostate gland

• Seeds are tiny welded titanium canisters

• Primarily I-125, Cs-131, and Pd-103

Prostate Implant

Image Guided Seed Implantation Using Trans-rectal Ultrasound

Seed Implantation

What are the Rules?

• 10 CFR 35.40 – Written Directives

• 10 CFR 35.41 – Procedures Replaced QM Rule

• 10 CFR 35.3045 – Medical Events

10 CFR 35.40 Written Directives

• AU Signature, Date, & Patient Name• Before Implantation

Radionuclide Treatment Site Dose

• After Implantation Radionuclide Treatment site Number of sources and total strength Exposure time or total dose

10 CFR 35.41 Procedures

• Licensee shall develop, implement, and maintain written procedures to provide high confidence:

Patient identity verified before administration Administration in accordance with WD Check Computer and Manual Dose

Calculations Verify computer dose calculations correctly

transferred to therapeutic medical unit console

10 CFR 35.41 Procedures

• Trained and qualified personnel• Appropriate equipment and treatment

planning systems, e.g. VariSeed program• Image guided procedures• Post Treatment Fluoroscopy• 30 Day CT

10 CFR 35.3045 Medical Events

Dose differs from prescribed dose 5 rem Effective Dose Equivalent 50 rem to an organ or tissue 50 rem Shallow Dose Equivalent, AND

Total dose differs from prescribed dose by 20% or more AND/OR

Dose to other than Treatment Site*>50 rem to organ or tissue>50% of expected dose*Excluding permanent implant seeds that were implanted correctly, but migrated outside

the treatment site

Variables affect delivered dose• Changes in anatomy from pre-planning to implant

date to post-implant CT or MRI date (shrinkage from hormone treatment, swelling/shrinkage from tissue trauma).

• Differences in image contrast mechanisms cause prostate to appear differently on ultrasound vs. CT vs. MRI.

• Seed migration.• As a result, post-implant dosimetry calculations

are estimates rather than precise determinations of delivered dose.

PA Permanent Brachytherapy Events

• Date: June 11, 2009 (not reported)• Licensee A• Prescribed Dose: 145 gray• Administered Dose: 92 gray• Comment: Patient sent to another cancer

center for additional brachytherapy treatment to “cold spots” in prostate. Licensee then changed process (Foley catheter bulb).

PA Permanent Brachytherapy Events

• Date: October 5, 2009 (not reported)• Licensee B• Prescribed Dose: 144 gray• Administered Dose: 81.96 gray• Comment: Unreported because it was an

underdose and licensee completed treatment with external-beam therapy.

PA Permanent Brachytherapy Events

• Date: January 21, 2010 (reported)• Licensee A• Prescribed Dose: 145 gray• Administered Dose: 0.5 gray• Comment: No seeds were placed in prostate.

Penile bulb received 161 gray. Doctor’s unfamiliarity with new ultrasound unit may have contributed to event.

PA Permanent Brachytherapy Events

• Date: November 2, 2010 (reported)• Licensee C• Prescribed Dose: 85 gray• Administered Dose: 114 gray• Comment: Incorrect dose was entered into

the VariSeed program. Licensee did not compare written directive with printed treatment plan.

PA Permanent Brachytherapy Events

• Date: January 20, 2012 (reported)• Licensee D• Prescribed Dose: 110 gray• Administered Dose: 75 gray• Comment: Possibly caused by prostate

edema

So, What are the Lessons Learned?

Understand that the determination of medical

events for prostate brachytherapy is difficult. D90

isn’t the sole consideration.

So, What are the Lessons Learned?

Under the current rule, licensees in good faith may struggle to know if a given

event is reportable.

So, What are the Lessons Learned?

Inspection Techniques Ask if there have been any medical events? Spot check the 35.41 procedures How would the licensee identify a medical

event? Review a sample of written directives Talk to RSO, medical physicist, radiation

oncologist, etc.

So, what are the Lessons Learned?• Medical staff may take position that ultrasound

guided implants may meet 10 CFR 35.41 requirement to provide high confidence that treatment is IAW Treatment Plan/WD, and that

a 30 day CT not necessary.

• Patients may not return for 30 day CT due to long distance or lack of motivation.

So, What are the Lessons Learned?

If you identify cases Where the D90 is less than 80% of the

prescribed dose, and/or, Where less than 80% of the seeds are

inside the prostate

Collect the data and bring it back to the office for further review.

Current Rulemaking

• Rulemaking on permanent implant brachytherapy has been in progress for a long time.

• Included in current ongoing Part 35 rulemaking.

• Dose-based rule? Activity-based rule? Combination?

• Hard to achieve consensus.

Modest Suggestions

• Recognize that licensees have a day to make this report after identifying a medical event.

• Avoid notification of patients when their treatment was actually acceptable.

• Create rule that is clear, unambiguous, and acknowledged by the medical community as identifying unacceptable treatments.

• New rule does not have to be consistent with the conclusions of the VA-Philadelphia inspection and enforcement action.

Looking to the Future…

• Similar issues have been identified in PA associated with the use of microspheres in radiation therapy.

• Future presentation…

Questions?

Frank CostelloDEP Radiation Health Physicist

fcostello@pa.govwww.depweb.state.pa.us

484-250-5833