Exhibit 99.1

21ST CENTURY ONCOLOGY HOLDINGS, INC.

21ST CENTURY ONCOLOGY REPORTS FOURTH QUARTER AND FULL YEAR 2013 FINANCIAL RESULTS

Fourth Quarter 2013 Highlights:

·                  Total company pro forma revenues of $209.2 million, up 23.9% year-over-year, including $5.8 million in pro forma contribution from acquisitions; excluding acquisitions, revenues grew 20.5% year-over-year

·                  Total domestic Radiation Oncology cases completed increased 12.3%

·                  Domestic same market treatments per day increased 7.9%

·                  International cases increased 7.0%

·                  Pro Forma Adjusted EBITDA of $27.2 million

·                  Completed acquisition of OnCure Holdings, Inc. (“Oncure”) on October 25, adding significant scale and opportunity for long term revenue growth and operating synergies

·                  Transitioned corporate identity to 21st Century Oncology brand, recognized globally for high quality integrated cancer care (“ICC”) services

·                  Acquired strategically located radiation therapy facility with certificate of need (“CON”) in Roanoke Rapids, NC; upgrading with advanced technologies and clinical pathways

·                  Entered strategic partnership with ProHealth Care Associates, LLP, the largest physician group practice in the metropolitan New York area, to operate an ICC  practice in Riverhead, NY as well as jointly pursue additional strategic opportunities

Full Year 2013 Highlights:

·                  Total company pro forma revenues of $845.3 million, up 20.7% year-over-year, including $108.8 million in pro forma contribution from acquisitions; excluding acquisitions, revenues grew 6.1% year-over-year

·                  Total domestic Radiation Oncology cases completed increased 13.1%

·                  Domestic same market treatments per day increased 4.3%

·                  International cases increased 5.7%

·                  Pro Forma Adjusted EBITDA of $118.6 million

FORT MYERS, FL, February, 19, 2014 — 21st Century Oncology Holdings, Inc. (“21st Century Oncology”, “21C” or the “Company”), the leading global, physician-led provider of

integrated cancer care (“ICC”) services, announced today its financial results for the fourth quarter and full year ended December 31, 2013.

Dr. Daniel Dosoretz, Founder and Chief Executive Officer, commented, “We made significant progress on all of our major strategic initiatives in 2013, closing a milestone year for 21st Century Oncology. We reported strong organic growth, closed the largest and most transformational acquisition in our history, continued to expand census and saw strong contributions to growth from our ICC and physician liaison initiatives. We also consolidated our corporate identity under our established brand: 21st Century Oncology, which is recognized globally for high quality patient care and a broad range of integrated oncology services in cost-effective settings.”

“From a volume perspective, we saw strong growth in fourth quarter and full year total Radiation Oncology cases completed, up 12.3% and 13.1% respectively. Fourth quarter domestic same-market treatments per day, which include same market acquisitions, grew by 7.9% year-over-year. Additionally, our international business performed well in the quarter, producing an 11.9% year-over-year revenue growth driven by case growth combined with use of more sophisticated treatment protocols. Our international business continues to position itself for significant future growth, through strategic acquisitions, a de-novo with a premier hospital partner, and further expansion of its business development pipeline.”

“Through many years of hard work and dedication, we have evolved into the largest provider of integrated cancer care services, providing academic quality care in low-cost settings on a scale that is unmatched in our industry. Our commitment to patients, physicians and payers has led to highly coordinated cancer care solutions in today’s complicated healthcare delivery system. Our model provides us multiple sources of self-sustaining growth, including organic opportunities and market share growth due to our ICC programs, strategic acquisitions, health system partnerships and strategic payer relationships. Armed with some of the highest quality physicians in a diverse set of specialties, we have an organization that is poised for long term value creation. The acquisition of Oncure has added revenue, exciting new markets with leading physicians and substantial operating synergy opportunities, expanding the platform upon which we can create value on a significantly larger scale,” he concluded.

Fourth Quarter 2013 Results

Total pro forma revenues for the fourth quarter of 2013 were $209.2 million, compared to $168.8 million in revenues in the same quarter of 2012. Fourth quarter pro forma revenues include $5.8 million in revenue contribution from acquisitions, as if the acquisitions had closed on October 1, 2013. The Oncure acquisition closed on October 25, 2013.  The increase in revenue was principally due to increased census, accretive joint ventures and acquisitions and international revenue growth, offset by lower reimbursement rates.

Total domestic Radiation Oncology cases completed increased 12.3% and domestic same market treatments per day increased 7.9% in the fourth quarter of 2013, which includes treatment volumes from our same market acquisition of Premiere Radiation Oncology/Specialist in Urology (“SIU”). This was driven by expansion of our ICC model and increased referrals

through the Company’s physician liaison program. Domestic same market therapy revenue per treatment decreased 7.3% from the fourth quarter of 2012, due to reductions in the reimbursement rates in the Centers for Medicare and Medicaid Services (“CMS”) 2013 Physician Fee Schedule, partially offset by continued improvements in managed care pricing.

Total Relative Value Units (RVUs) per day at same market domestic freestanding centers slightly increased by 0.3% in the fourth quarter versus the same period of the prior year as census growth was partially offset by reductions in the reimbursement rates included in the CMS 2013 Physician Fee Schedule.

Adjusted earnings before interest, taxes, depreciation, amortization, stock-based compensation and other non-cash and pro forma items (“Pro Forma Adjusted EBITDA”) in the fourth quarter of 2013 was $27.2 million, or 13% of total pro forma revenues, compared to $24.2 million, or 14.3% of total pro forma revenues, in the fourth quarter of 2012. Pro Forma Adjusted EBITDA margins declined in the current quarter versus the prior year period primarily due to reductions in the Medicare reimbursement rate, the growth and expanded development activity in establishing integrated cancer care practices, and investments made in key personnel. Reconciliation of net loss attributable to 21st Century Oncology, determined in accordance with generally accepted accounting principles to Pro Forma Adjusted EBITDA and total revenues, determined in accordance with generally accepted accounting principles, to total pro forma revenues for the quarters ended December 31, 2013 and 2012 is included in the attached supplemental financial information.

Income tax expense in the fourth quarter of 2013 was an income tax benefit of $25.3 million, compared to an income tax expense of $1.3 million in the fourth quarter of 2012. The income tax benefit in the fourth quarter of 2013 was due to the effect of the Oncure purchase price adjustments on the valuation allowance recorded against the Company’s net tax assets.   The net loss for the fourth quarter of 2013 was $9.6 million, compared to a net loss of $33.2 million in the fourth quarter of 2012.  The net loss in the fourth quarter of 2012 included impairment charges of $11.1 million, attributable to revisions of the Company’s financial forecasts largely as a result of reductions in reimbursement that resulted in a write down of goodwill, trade name and an investment in a joint venture to their implied fair values as well as lagging economic conditions that existed in 2012 in the U.S.

Full Year 2013 Results

Total pro forma revenues for the full year ended December 31, 2013 were $845.3 million, an increase of 20.7% compared to $700.4 million in revenues for the full year 2012. Full year 2013 pro forma revenues include $108.8 million in revenue contribution from the acquisitions, as if the acquisitions had closed on January 1, 2013. The increase in revenue was principally due to increased domestic census, accretive joint ventures and acquisitions and international revenue growth, offset by lower reimbursement rates.

Total radiation oncology cases increased 9.7% and domestic same market treatments per day increased 4.3% for the full year 2013. This was driven by expansion of our ICC model and increased referrals through the Company’s physician liaison program.  Domestic same market

therapy revenue per treatment decreased 6.2% compared to 2012, due to reductions in the reimbursement rate announced in the CMS 2013 Physician Fee Schedule which were partially offset by improved managed care pricing.

Total RVUs per day at same market domestic freestanding centers decreased 3.5% for the full year 2013 due to reductions in the reimbursement rate included in the CMS 2013 Physician Fee Schedule.

Pro Forma Adjusted EBITDA for the full year 2013 was $118.6 million, or 14.0% of total pro forma revenues, compared to $104.7 million, or 14.9% of total pro forma revenues for the full year 2012.  Pro Forma Adjusted EBITDA margins declined slightly in the current quarter versus the prior year period primarily due to reductions in the Medicare reimbursement rate, the growth and expanded development activity in establishing ICC practices, and investments made in key personnel. A reconciliation of net loss attributable to 21st Century Oncology, determined in accordance with generally accepted accounting principles to Pro Forma Adjusted EBITDA and total revenues, determined in accordance with generally accepted accounting principles, to total pro forma revenues for the full years ended December 31, 2013 and 2012 is included in the attached supplemental financial information.

Income tax expense for the full year 2013 was an income tax benefit of $20.4 million, compared to an income tax expense of $4.5 million in 2012. The income tax benefit in the fourth quarter of 2013 was due to the effect of the Oncure purchase price adjustments on the valuation allowance recorded against the Company’s net tax assets.  The net loss for the full year 2013 was $73.5 million, compared to a net loss of $151.1 million for the full year 2012. The net loss for the full year 2012 included impairment charges of $81.0 million, attributable to revisions of the Company’s financial forecasts largely as a result of reductions in reimbursement that resulted in a write down of goodwill, trade name and an investment in a joint venture to their implied fair values as well as lagging economic conditions that existed in 2012 in the U.S.

Recent Developments

In October, the Company completed the acquisition of Oncure for approximately $125.0 million (excluding capital leases, working capital and other adjustments). The purchase price included $42.5 million in cash and up to $82.5 million in assumed debt ($7.5 million of this assumed debt is subject to escrow conditions and will be released if certain Oncure centers achieve a minimum level of EBITDA). This transformative investment is the largest acquisition in the Company’s history and increased the number of radiation therapy centers by over 25% and is expected to add over 694 average treatments per day. The strategic addition is expected to provide operating synergies, broaden the Company’s ability to provide ICC services across a larger spectrum and offer significant revenue growth for several years to come.

In October, the Company acquired a single radiation therapy center in Roanoke Rapids, NC. The center is the only treatment center in a 30 mile radius and 21C was approved for the transfer of the CON for the facility. The Company is currently upgrading the center and its equipment to improve treatment planning and imaging sophistication and believes these upgrades will improve patient care and increase patient census.

In January 2014, the Company entered a strategic partnership with ProHealth Care Associates, LLP and opened a new de novo state-of-the-art radiation therapy center in Riverhead, New York. ProHealth is the largest physician group practice in the metropolitan New York area with over 500 physicians in over 150 offices treating over 750,000 covered lives.

In February 2014, the Company closed on an equity investment in South Florida Radiation Oncology Holdings, LLC (“SFRO”), which includes a 65% equity interest in SFRO for approximately $60 million. The investment was funded with the proceeds of a new $60 million term loan borrowed by a new direct subsidiary of the Company.  SFRO is expected to generate an annual run rate of approximately $25 million in adjusted EBITDA. This strategic transaction increased the number of centers by approximately 10% and is expected to add over 591 average treatments per day.  Our partnership with SFRO provides further opportunities to leverage the 21C infrastructure, footprint and technology to achieve significant operating synergies and leverage best practices across a clinically strong base of combined physician and management talent.  Furthermore, the enhanced market density should provide for increased opportunity for innovation with health systems and payers.

Conference Call

Management will host a conference call on February 20, 2014 at 10:00 a.m. ET, during which management will discuss its financial results in further detail. The dial-in numbers are (877) 407-9039 for domestic callers and (201) 689-8470 for international callers.  In addition, a telephonic replay of the call will be available until March 6, 2014.  The replay dial-in numbers are (877) 870-5176 for domestic callers and (858) 384-5517 for international callers.  Please use the conference ID number 13575217 to access the replay.

A live webcast and webcast replay of the call will also be available from the Investor Relations section on the corporate web site at www.rtsx.com.

About 21st Century Oncology Holdings, Inc.

21st Century Oncology Holdings, Inc. is the largest global, physician led provider of Integrated Cancer Care Services. The Company offers a comprehensive range of cancer treatment services, focused on delivering academic quality, cost-effective patient care in personal and convenient settings. The Company operates 179 treatment centers, including 145 centers located in 16 U.S. states. The Company also operates 34 centers located in six countries in Latin America. The Company holds market leading positions in most of its domestic local markets and abroad.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Act of 1934, as amended.  Statements preceded by, followed by or that otherwise include the words “believes”, “expects”, “anticipates”, “intends”, “projects”, “estimates”, “plans”, “may increase”, “forecast” and

similar expressions or future or conditional verbs such as “will”, “should”, “would”, “may” and “could” are generally forward-looking in nature and not historical facts. Forward-looking statements are based on management’s current expectations or beliefs about the Company’s future plans, expectations and objectives, including, but not limited to, the Company’s expected financial results and estimates for 2014 and the effects of the CMS’s Final Rule for the 2014 Physician Fee Schedule on its results.  These forward-looking statements are not historical facts and are subject to risks and uncertainties that could cause the actual results to differ materially from those projected in these forward-looking statements including, but not limited to reductions in Medicare reimbursement, healthcare reform, decreases in payments by managed care organizations and other commercial payers  and other risk factors that may be described from time to time in the Company’s filings with the Securities and Exchange Commission.  Readers of this release are cautioned not to place undue reliance on forward-looking statements contained herein, which speak only as of the date stated, or if no date is stated, as of the date of this press release. The Company undertakes no obligation to publicly update or revise the forward-looking statements contained herein to reflect changed events or circumstances after the date of this release, unless required by law.

21ST CENTURY ONCOLOGY HOLDINGS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(in thousands, except share amounts)

21ST CENTURY ONCOLOGY HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

(in thousands)

(unaudited)

21ST CENTURY ONCOLOGY HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(in thousands)

(unaudited)

21ST CENTURY ONCOLOGY HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(in thousands)

(unaudited)

21ST CENTURY ONCOLOGY HOLDINGS, INC.

Supplemental Financial Information (Unaudited)

Reconciliation of Total Pro-forma Revenue and Pro-forma Adjusted EBITDA to Net Loss Attributable

to 21st Century Oncology Holdings, Inc. Shareholder

(1) Pro-forma Adjusted EBITDA is defined as income (loss) before interest expense (net of interest income), income taxes, depreciation and amortization, gain on the sale of an interest in a joint venture, loss on sale leaseback transaction, early extinguishment of debt, fair value adjustment of earn-out liability, impairment loss, foreign currency derivative contract loss (gain), management fees accrued to our sponsor, non-cash expenses including costs relating to stock compensation, amortization of straight-line rent and amortization of capital expenditures relating to repairs and maintenance, non-cash equipment rent, sale-lease back adjustments, acquisition-related costs, other expenses including loss on sale of assets, severance payments related to termination of employee staff reductions, tail premiums on termed physicians, franchise taxes, costs relating to consulting services on Medicare reimbursement, litigation settlements with physicians, expenses associated with the provision for income taxes, costs associated with tradename and rebranding initiatives, expenses associated with idle / closed radiation therapy treatment facilities and pro-forma full period effect of acquisition EBITDA.

(a) Pro-forma amounts related to adjustments to total revenues and Pro-forma Adjusted EBITDA to reflect the full period effect of our acquisitions and Value Added Services contracts completed during 2013 and 2012.  The adjustments reflect the impact to our total revenues and Pro-forma Adjusted EBITDA as if the acquisitions and Value Added Services contracts had occurred at the

beginning of the year.

(b) Management fees are fees accrued to our sponsor, Vestar Capital Partners.

(c) Non-cash expenses including costs relating to stock compensation, amortization of straight-line rent, amortization of capital expenditures relating to warranty arrangements amortized to repairs and maintenance and non-cash equipment rent.

(d) Sale-lease back adjustments relates to the adjustment of benefit derived from the classification of operating leases as finance obligations reflecting a reclassification of interest expense and depreciation and amortization expense as rent expense.

(e) Acquisition related costs associated with ASC 805, “Business Combinations”, including professional fees, corporate development, integration and due diligence costs relating to the acquisition of medical practices.

(f) Other expenses include loss on sale of assets, severance payments related to termination of employee staff reductions, tail premiums paid on terminated physicians, franchise taxes and costs relating to consulting services on Medicare reimbursement.

(g) Litigation settlement relates to costs associated with the termination of physicians during 2012 and 2013.

(h) Expenses related to the costs associated with process improvements in the provision for income taxes.

(i) Expenses related to the costs associated with the Company’s tradename and rebranding initiatives.

(j) Expenses associated with idle / closed radiation therapy treatment facilities.

We believe the Pro-forma Adjusted EBITDA provides useful information about our financial performance to investors, lenders, financial analysts and rating agencies since these groups have historically used EBITDA-related measures in the healthcare industry, along with other measures, to estimate the value of a company, to make informed investment decisions, to evaluate a company’s leverage capacity and its ability to meet its debt service requirements.  Pro-forma Adjusted EBITDA eliminates the uneven effect of non-cash depreciation of tangibles assets and amortization of intangible assets, much of which results from acquisitions accounted for under the purchase method of accounting.  Pro-forma Adjusted EBITDA is also used by us to measure individual performance for incentive compensation purposes and as an analytical indicator for purposes of allocating resources to our operating business and assessing their performance, both internally and relative to our peers, as well as to evaluate the performance of our operating management teams, and for purposes in the calculation of debt covenants and related disclosures.

Pro-forma Adjusted EBITDA is not intended as a substitute for net income (loss) attributable to 21st Century Oncology Holdings, Inc.shareholder, operating cash flows or other cash flow data determined in accordance with accounting principles generally accepted in the United States. Due to varying methods of calculation, Pro-forma Adjusted EBITDA as presented may not be comparable to similarly titled measures of other companies.

21ST CENTURY ONCOLOGY HOLDINGS, INC.

KEY OPERATING STATISTICS

(unaudited)