MU Plus! is a quality assurance tool for monitor unit calculations performed in radiation oncology clinics. MU Plus! is designed to be used as a verification of treatment planning derived monitor unit settings or hand generated monitor unit settings. Monitor unit calculations for linear accelerators are performed by various staff of radiation oncology clinics, including medical physicists, dosimetrists, and radiation therapists. MU Plus! also contains a diode measurement verification program which predicts an expected diode reading based on a formalism similar to the monitor unit calculations.

Device Description

The MU Plus! monitor unit calculation verification program is designed to operate on an IBM compatible personal computer using Windows 95. Windows NT 4.0, or higher operating system. It is designed to operate independently of any radiation treatment planning system. It does not connect to or control any radiation hardware device. It is designed to verify monitor unit calculations for accelerator produced photons and electrons. It also calculates expected diode readings based on clinical data entered by the user.

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and study for the MU Plus! device:

Acceptance Criteria and Device Performance Study for MU Plus!

Based on the provided 510(k) summary, the MU Plus! device aimed to verify monitor unit (MU) calculations for radiation treatment, demonstrating substantial equivalence to predicate devices and manual lookup methods.

1. Table of Acceptance Criteria and Reported Device Performance

The provided 510(k) summary does not explicitly state specific numerical acceptance criteria (e.g., "MUs must match within X% accuracy"). Instead, it reports qualitative findings of "very closely matched" results. The underlying acceptance criterion appears to be that the MU Plus! calculations for monitor settings and diode readings should align very closely with those derived from predicate devices and manual lookup methods.

Acceptance Criterion (Inferred)	Reported Device Performance
Monitor Unit (MU) Calculations for Photons: Results should match very closely with predicate devices (Prowess).	"Non-clinical tests were conducted using the predicate devices and MU Plus! Standard test cases were used on both systems. The test results matched very closely which supports the claim of substantial equivalence." (Referring to Appendixes A and B for comparison summary, though these appendices are not provided in the input text.)
Monitor Unit (MU) Calculations for Electrons: Results should match very closely with predicate devices (PC Setup Program).	"Non-clinical tests were conducted using the predicate devices and MU Plus! Standard test cases were used on both systems. The test results matched very closely which supports the claim of substantial equivalence." (Referring to Appendixes A and B for comparison summary, though these appendices are not provided in the input text.)
Monitor Unit (MU) Calculations (General): Results should match very closely with manual lookup methods.	"In addition monitor unit settings calculated by MU Plus! were compared against those performed by manual lookup to verify that the program was performing monitor unit calculations correctly. All tests matched very closely." (Referring to Appendixes C and D for comparison summary, though these appendices are not provided in the input text.)
Diode Reading Calculations: The program should correctly calculate expected diode readings based on clinical data, similar to MU calculations.	The "Intended Use" states: "MU Plus! also calculates an expected diode reading which is used to verify proper delivery of radiation therapy treatment." The "Indications For Use" further states: "MU Plus! also contains a diode measurement verification program which predicts an expected diode reading based on a formalism similar to the monitor unit calculations." Although no specific performance data is reported for diode readings beyond its inclusion in the functionality, the implicit acceptance is its ability to perform this calculation.

2. Sample Size Used for the Test Set and Data Provenance

Sample Size: The document does not specify the exact number of test cases or the size of the test set. It mentions "Standard test cases were used on both systems" for comparisons with predicate devices and "All tests matched very closely" for comparisons with manual lookup. Without access to the Appendices (A, B, C, D), the precise sample size for the test set cannot be determined from this text.
Data Provenance: The document does not explicitly state the country of origin of the data or whether it was retrospective or prospective. Given the nature of a software verification tool, the "standard test cases" likely refer to generated or pre-existing clinical scenarios/data rather than patient-specific data from a particular country or time frame.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications

Number of Experts: Not specified.
Qualifications of Experts: Not explicitly stated. For the "manual lookup" comparison, the implication is that qualified professionals (e.g., medical physicists, dosimetrists, radiation therapists, as mentioned in the Indications for Use) would perform these manual calculations. However, the document doesn't detail their involvement in establishing the formal "ground truth" for the test set with specific qualifications. The predicate devices themselves essentially serve as a form of "ground truth" for the comparative tests.

4. Adjudication Method for the Test Set

The document does not describe a formal adjudication method (e.g., 2+1, 3+1). The "ground truth" for comparison was established either by:
* The calculations from established predicate devices (K914698, K980379).
* Manual lookup calculations.
Given that the reported results are simply "matched very closely," it suggests a direct comparison rather than a consensus-based adjudication process among multiple human readers for discrepancies.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not explicitly described. The study focused on the performance of the algorithm itself against predicate devices and manual calculations, rather than assessing an improvement in human reader performance with or without AI assistance.

6. Standalone Performance Study

Yes, a standalone study was presented. The entire description of the "Non-clinical tests" details the performance of the MU Plus! algorithm in isolation. It compares the algorithm's output directly against:

The output of predicate devices.
The results of manual lookup methods.
This demonstrates the algorithm's performance without a human-in-the-loop interaction for the actual calculation process itself, though a human would ultimately use the verification output.

7. Type of Ground Truth Used

The ground truth used was a combination of:

Predicate Device Output: The monitor unit calculations generated by two legally marketed predicate devices (K&S Associates, PC Setup Program (K914698) and SSGI, Prowess Pro-Sim (K980379)).
Manual Calculations/Lookup: Results obtained through traditional, accepted manual methods for calculating monitor units.

8. Sample Size for the Training Set

The document does not specify a separate training set or its sample size. As a calculation verification program, it uses established physical formalisms (equations) rather than machine learning models that typically require a training set. The "formalisms" described (TMR * Sp * Sc * WF * TF * OAFx * OAFy * ISF * Output, etc.) are deterministic equations, not learned parameters.

9. How the Ground Truth for the Training Set Was Established

Since a training set in the machine learning sense is not applicable to this type of deterministic software, there is no description of how ground truth for a training set was established. The software's "knowledge" or "training" comes from the implementation of established physics formalisms and equations used in radiation therapy.

Summary

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K992689
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510(k) Summary

Submitter:	Rad Therapy Solutions, Inc.738 Alden DriveOrmond Beach, FL 32176Tel. (904) 441-7400Email: muplus1@aol.com
Contact:Date:	Steve Gruse, PresidentAugust 7. 1999
Trade Name:	MU Plus!
Common Name:	Monitor Unit Calculation Verification Program
Classification Panel:	Radiology
Classification Name:	Medical Charged Particle Radiation TherapySystem (Accessory)21 CFR 892.5050 (class II)
Substantial Equivalence:	K&S Associates, PC Setup Program510(k) K914698SSGI, Prowess Pro-Sim510(k) K980379

Description:

Intended Use:

The intended use of the MU Plus! monitor unit calculation verification program is the same as for the predicate devices: to calculate monitor unit or timer settings for the purpose of validating a monitor unit or timer setting previously calculated by a radiation treatment planning system or hand calculation. MU Plus! also calculates an expected diode reading which is used to verify proper delivery of radiation therapy treatment.

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Technological Characteristics:

MU Plus! calculates monitor unit settings in a fashion similar to Prowess for photon calculations. MU Plus! calculates monitor unit settings for photons using the following formalism:

Calculated Dose MU = TMR * Sp * Sc * WF * TF * OAFx * OAFy * ISF * Output (cGy/MU)

Prowess calculates monitor settings for photons using the following formalism:

Calculated Dose MU = TMR * OF * (PSF'/PSF) * WF * TF * ISF * Output (cGy/MU)

where: OF * (PSF'/PSF) = Sp * Sc

MU Plus! calculates monitor unit settings in a fashion similar to PC Setup Program for electrons. MU Plus! calculates monitor unit settings for photons using the following formalisms:

Calculated Dose MU = Cone Output Factor * SSD Output Factor * Isodose Prescription

OR

MU = Calculated Dose Calibration Factor * Isodose Prescription

PC Setup Program calculates monitor unit settings for electrons using the following formalism:

Calculated Dose MU = Cone Output Factor * Modifier Factor * Isodose Prescription

Although terms in these formalism may differ slightly, the formalism is essentially the same for both MU Plus! and PC Setup Program.

Non-clinical tests:

Non-clinical tests were conducted using the predicate devices and MU Plus!. Standard test cases were used on both systems. The test results matched very closely which supports the claim of substantial equivalence. See Appendixes A and B for a comparison summary.

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In addition monitor unit settings calculated by MU Plus! were compared against those performed by manual lookup to verify that the program was performing monitor unit calculations correctly. All tests matched very closely. See Appendixes C and D for a comparison summary.

Conclusions:

Based on the technological characteristics, intended use, non-clinical tests, as well as clinical tests, MU Plus! is substantially equivalent to the predicate device. The documentation submitted for review supports this claim.

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Image /page/3/Picture/1 description: The image shows a logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle with three lines representing its wings. The eagle is enclosed in a circle with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES" written around the perimeter of the circle.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

FEB 1 0 2000

Steve Gruse, M.S., DABR President Rad Therapy Solutions, Inc. 738 Alden Drive Ormond Beach, Florida 32176 Re:

K992689

MU Plus ! Dated: November 12, 1999 Received: November 18, 1999 Regulatory Class: II 21 CFR 892.5050/Procode: 90 IYE

Dear Mr. Gruse:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class III (Special Controls) or dass III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597, or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours,

CAPT Daniel G. Schultz, M.D. Acting Director, Division of Reproductive. Abdominal, Ear, Nose and Throat, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Statement of Indications of Use

Applicant: Rad Therapy Solutions. Inc.

15992689 510(k) Number: N/A

Device Name: MU Plus!

Indications For Use:

Prescription Use (Per 21 CFR 801.109)

David A. Segerson
(Division Sign Off)

vision Sign-Off vision of Reproductive, Abdomi d Radiological De 510(k) Number

Regulation Number and Section

§ 892.5050 Medical charged-particle radiation therapy system.

(a)
Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons) intended for use in radiation therapy. This generic type of device may include signal analysis and display equipment, patient and equipment supports, treatment planning computer programs, component parts, and accessories.(b)
Classification. Class II. When intended for use as a quality control system, the film dosimetry system (film scanning system) included as an accessory to the device described in paragraph (a) of this section, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.