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        <TotalAmt>2511</TotalAmt>
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        <ExplanationTxt>ROI IS THE SUPPORTING ORGANIZATION FOR THE AMERICAN SOCIETY FOR RADIATION ONCOLOGY (ASTRO), A 501(C)(6) ORGANIZATION. ROI PERFORMED THE 509(A)(2) TEST FOR ASTRO AND FOUND THAT ASTRO'S SUPPORT PERCENTAGE EXCEEDS THE 33% MINIMUM OF PUBLIC SUPPORT THAT WOULD BE A REQUIREMENT IF ASTRO WERE DESCRIBED AS SUCH AN ENTITY. ACCORDINGLY, ROI IS ELIGIBLE TO SUPPORT ASTRO.</ExplanationTxt>
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      <FootnoteTextInd>X</FootnoteTextInd>
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      <SupplementalInformationDetail>
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      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>PART X, LINE 2:</FormAndLineReferenceDesc>
        <ExplanationTxt>ROI PERFORMED AN EVALUATION OF UNCERTAINTY IN INCOME TAXES FOR THE YEAR ENDED DECEMBER 31, 2019, AND DETERMINED THAT THERE ARE NO MATTERS THAT WOULD REQUIRE RECOGNITION IN THE FINANCIAL STATEMENTS OR THAT MAY HAVE ANY EFFECT ON ITS TAX-EXEMPT STATUS.</ExplanationTxt>
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          <BusinessNameLine1Txt>THE UNIVERSITY OF CHICAGO</BusinessNameLine1Txt>
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        <RecipientEIN>362177139</RecipientEIN>
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        <PurposeOfGrantTxt>RESEARCH AWARDS</PurposeOfGrantTxt>
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      <RecipientTable>
        <RecipientBusinessName>
          <BusinessNameLine1Txt>MD ANDERSON CANCER CENTER</BusinessNameLine1Txt>
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        <PurposeOfGrantTxt>RESEARCH AWARDS</PurposeOfGrantTxt>
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      <RecipientTable>
        <RecipientBusinessName>
          <BusinessNameLine1Txt>THE OHIO STATE UNIVERSITY</BusinessNameLine1Txt>
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          <AddressLine1Txt>410 W 10TH AVENUE D259</AddressLine1Txt>
          <CityNm>COLUMBUS</CityNm>
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        <PurposeOfGrantTxt>RESEARCH AWARDS</PurposeOfGrantTxt>
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      <RecipientTable>
        <RecipientBusinessName>
          <BusinessNameLine1Txt>OREGON HEALTH &amp; SCIENCE UNIVERSITY</BusinessNameLine1Txt>
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      <RecipientTable>
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        <ExplanationTxt>SIGNED AWARD LETTERS OUTLINE THE TERMS AND CONDITIONS OF ACCEPTANCE AND USE OF THE RESEARCH AWARD. AS PER THE SIGNED AGREEMENT, AN INTERIM PROGRESS REPORT AND A FINAL REPORT ARE COLLECTED WHICH SUMMARIZE PROGRESS MADE AND EXPENDITURES.</ExplanationTxt>
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      <SupplementalNonqualRtrPlanInd>0</SupplementalNonqualRtrPlanInd>
      <EquityBasedCompArrngmInd>0</EquityBasedCompArrngmInd>
      <CompBasedOnRevenueOfFlngOrgInd>0</CompBasedOnRevenueOfFlngOrgInd>
      <CompBsdOnRevRelatedOrgsInd>0</CompBsdOnRevRelatedOrgsInd>
      <CompBsdNetEarnsFlngOrgInd>0</CompBsdNetEarnsFlngOrgInd>
      <CompBsdNetEarnsRltdOrgsInd>0</CompBsdNetEarnsRltdOrgsInd>
      <AnyNonFixedPaymentsInd>0</AnyNonFixedPaymentsInd>
      <InitialContractExceptionInd>0</InitialContractExceptionInd>
      <RltdOrgOfficerTrstKeyEmplGrp>
        <PersonNm>LAURA I THEVENOT</PersonNm>
        <TitleTxt>EX-OFFICIO, EXECUTIVE DIRECTOR</TitleTxt>
        <BaseCompensationFilingOrgAmt>0</BaseCompensationFilingOrgAmt>
        <CompensationBasedOnRltdOrgsAmt>506386</CompensationBasedOnRltdOrgsAmt>
        <BonusFilingOrganizationAmount>0</BonusFilingOrganizationAmount>
        <BonusRelatedOrganizationsAmt>100087</BonusRelatedOrganizationsAmt>
        <OtherCompensationFilingOrgAmt>0</OtherCompensationFilingOrgAmt>
        <OtherCompensationRltdOrgsAmt>64211</OtherCompensationRltdOrgsAmt>
        <DeferredCompensationFlngOrgAmt>0</DeferredCompensationFlngOrgAmt>
        <DeferredCompRltdOrgsAmt>39000</DeferredCompRltdOrgsAmt>
        <NontaxableBenefitsFilingOrgAmt>0</NontaxableBenefitsFilingOrgAmt>
        <NontaxableBenefitsRltdOrgsAmt>43140</NontaxableBenefitsRltdOrgsAmt>
        <TotalCompensationFilingOrgAmt>0</TotalCompensationFilingOrgAmt>
        <TotalCompensationRltdOrgsAmt>752824</TotalCompensationRltdOrgsAmt>
        <CompReportPrior990FilingOrgAmt>0</CompReportPrior990FilingOrgAmt>
        <CompReportPrior990RltdOrgsAmt>0</CompReportPrior990RltdOrgsAmt>
      </RltdOrgOfficerTrstKeyEmplGrp>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>PART I, LINE 3</FormAndLineReferenceDesc>
        <ExplanationTxt>ROI DOES NOT DIRECTLY HIRE OR COMPENSATE EMPLOYEES. ALL EMPLOYEES ARE EMPLOYEES OF THE AMERICAN SOCIETY FOR RADIATION ONCOLOGY (ASTRO), A RELATED ORGANIZATION EXEMPT UNDER SECTION 501(C)(6). AN INDEPENDENT CONSULTANT PERFORMED A MARKET SURVEY TO DEVELOP SALARY STRUCTURE AND RANGES. ASTRO'S PRACTICE IS TO COMPLETE A MARKET SURVEY EVERY THREE YEARS; THIS WAS LAST COMPLETED FOR THE EX-OFFICIO, EXECUTIVE DIRECTOR IN 2019. THE EX-OFFICIO, EXECUTIVE DIRECTOR'S COMPENSATION IS DETERMINED BY A SUBCOMMITTEE OF THE BOARD USING COMPARABLE SALARIES OF SIMILAR EXECUTIVE DIRECTOR POSITIONS OF NONPROFIT MEDICAL ORGANIZATIONS. THIS REVIEW WAS DISCUSSED WITH THE BOARD OF DIRECTORS AND THE FINAL DETERMINATION WAS MADE BY THE EXECUTIVE COMMITTEE.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleJ>
    <IRS990ScheduleO documentId="RetDoc1044400001">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 3</FormAndLineReferenceDesc>
        <ExplanationTxt>ALL MANAGEMENT FUNCTIONS OF ROI ARE CONTROLLED BY THE AMERICAN SOCIETY FOR RADIATION ONCOLOGY (ASTRO), A RELATED ORGANIZATION EXEMPT UNDER SECTION 501(C)(6).</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 11B</FormAndLineReferenceDesc>
        <ExplanationTxt>THE FEDERAL FORM 990 IS PREPARED BY OUR EXTERNAL TAX ACCOUNTANTS. THE DRAFT IS PROVIDED TO OUR FINANCE STAFF FOR REVIEW BEFORE BEING SUBMITTED TO THE VP FINANCE &amp; ADMINISTRATION, CEO, AND TREASURER OF ASTRO FOR THEIR REVIEW AND APPROVAL. THE REVISED DRAFT IS THEN PROVIDED TO THE FULL BOARD OF DIRECTORS PRIOR TO FILING WITH THE INTERNAL REVENUE SERVICE.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 12C</FormAndLineReferenceDesc>
        <ExplanationTxt>ROI'S OFFICERS, DIRECTORS, KEY EMPLOYEES, AND VOLUNTEERS ARE REQUIRED TO FILL OUT DISCLOSURE FORMS ON AN ANNUAL BASIS AND TO UPDATE THEIR DISCLOSURE FORMS UPON ANY MATERIAL CHANGE IN THE INTERIM. THESE DISCLOSURE FORMS ARE REVIEWED IN ORDER TO IDENTIFY AND ADDRESS ANY POTENTIAL CONFLICTS OF THESE INDIVIDUALS.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION C, LINE 19</FormAndLineReferenceDesc>
        <ExplanationTxt>THE SUMMARY FINANCIAL STATEMENTS, GOVERNING DOCUMENTS, AND CONFLICT OF INTREST POLICY ARE AVAILABLE UPON REQUEST.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
    <IRS990ScheduleR documentId="RetDoc1043400001">
      <IdRelatedTaxExemptOrgGrp>
        <DisregardedEntityName>
          <BusinessNameLine1Txt>AMERICAN SOCIETY FOR RADIATION ONCOLOGY</BusinessNameLine1Txt>
        </DisregardedEntityName>
        <USAddress>
          <AddressLine1Txt>251 18TH STREET SOUTH 8TH FLOOR</AddressLine1Txt>
          <CityNm>ARLINGTON</CityNm>
          <StateAbbreviationCd>VA</StateAbbreviationCd>
          <ZIPCd>22202</ZIPCd>
        </USAddress>
        <EIN>420943164</EIN>
        <PrimaryActivitiesTxt>MEMBERSHIP SOCIETY</PrimaryActivitiesTxt>
        <LegalDomicileStateCd>IL</LegalDomicileStateCd>
        <ExemptCodeSectionTxt>501(C)(6)</ExemptCodeSectionTxt>
        <PublicCharityStatusTxt>N/A</PublicCharityStatusTxt>
        <DirectControllingNACd>N/A</DirectControllingNACd>
        <ControlledOrganizationInd>0</ControlledOrganizationInd>
      </IdRelatedTaxExemptOrgGrp>
      <ReceiptOfIntAnntsRntsRyltsInd>0</ReceiptOfIntAnntsRntsRyltsInd>
      <GiftGrntOrCapContriToOthOrgInd>1</GiftGrntOrCapContriToOthOrgInd>
      <GiftGrntCapContriFromOthOrgInd>1</GiftGrntCapContriFromOthOrgInd>
      <LoansOrGuaranteesToOtherOrgInd>0</LoansOrGuaranteesToOtherOrgInd>
      <LoansOrGuaranteesFromOthOrgInd>0</LoansOrGuaranteesFromOthOrgInd>
      <DivRelatedOrganizationInd>0</DivRelatedOrganizationInd>
      <AssetSaleToOtherOrgInd>0</AssetSaleToOtherOrgInd>
      <AssetPurchaseFromOtherOrgInd>0</AssetPurchaseFromOtherOrgInd>
      <AssetExchangeInd>0</AssetExchangeInd>
      <RentalOfFacilitiesToOthOrgInd>0</RentalOfFacilitiesToOthOrgInd>
      <RentalOfFcltsFromOthOrgInd>0</RentalOfFcltsFromOthOrgInd>
      <PerformOfServicesForOthOrgInd>0</PerformOfServicesForOthOrgInd>
      <PerformOfServicesByOtherOrgInd>0</PerformOfServicesByOtherOrgInd>
      <SharingOfFacilitiesInd>1</SharingOfFacilitiesInd>
      <PaidEmployeesSharingInd>1</PaidEmployeesSharingInd>
      <ReimbursementPaidToOtherOrgInd>1</ReimbursementPaidToOtherOrgInd>
      <ReimbursementPaidByOtherOrgInd>1</ReimbursementPaidByOtherOrgInd>
      <TransferToOtherOrgInd>0</TransferToOtherOrgInd>
      <TransferFromOtherOrgInd>0</TransferFromOtherOrgInd>
      <TransactionsRelatedOrgGrp>
        <OtherOrganizationName>
          <BusinessNameLine1Txt>AMERICAN SOCIETY FOR RADIATION ONCOLOGY</BusinessNameLine1Txt>
        </OtherOrganizationName>
        <TransactionTypeTxt>C</TransactionTypeTxt>
        <InvolvedAmt>88600</InvolvedAmt>
        <MethodOfAmountDeterminationTxt>ACTUAL</MethodOfAmountDeterminationTxt>
      </TransactionsRelatedOrgGrp>
      <TransactionsRelatedOrgGrp>
        <OtherOrganizationName>
          <BusinessNameLine1Txt>AMERICAN SOCIETY FOR RADIATION ONCOLOGY</BusinessNameLine1Txt>
        </OtherOrganizationName>
        <TransactionTypeTxt>N</TransactionTypeTxt>
        <InvolvedAmt>96070</InvolvedAmt>
        <MethodOfAmountDeterminationTxt>FMV</MethodOfAmountDeterminationTxt>
      </TransactionsRelatedOrgGrp>
      <TransactionsRelatedOrgGrp>
        <OtherOrganizationName>
          <BusinessNameLine1Txt>AMERICAN SOCIETY FOR RADIATION ONCOLOGY</BusinessNameLine1Txt>
        </OtherOrganizationName>
        <TransactionTypeTxt>O</TransactionTypeTxt>
        <InvolvedAmt>347393</InvolvedAmt>
        <MethodOfAmountDeterminationTxt>FMV</MethodOfAmountDeterminationTxt>
      </TransactionsRelatedOrgGrp>
      <TransactionsRelatedOrgGrp>
        <OtherOrganizationName>
          <BusinessNameLine1Txt>AMERICAN SOCIETY FOR RADIATION ONCOLOGY</BusinessNameLine1Txt>
        </OtherOrganizationName>
        <TransactionTypeTxt>Q</TransactionTypeTxt>
        <InvolvedAmt>71011</InvolvedAmt>
        <MethodOfAmountDeterminationTxt>ACTUAL</MethodOfAmountDeterminationTxt>
      </TransactionsRelatedOrgGrp>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>SCHEDULE R, PART V, LINE 2</FormAndLineReferenceDesc>
        <ExplanationTxt>THE $71,011 IS A FINAL BALANCE OF THE DUE TO/FROM ACCOUNT THAT IS A COMBINATION OF OVERHEAD, CREDIT CARD DONATION PAID THROUGH ASTRO FOR ROI, AND JOINT INVOICES PAID THROUGH ASTRO FOR ROI.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleR>
  </ReturnData>
</Return>