The Anticancer League of Guipuzcoa was founded by Her Royal Majesty the Queen María Cristina in 1928. The League started the creation of El Instituto Anticanceroso under the management of the Diputación de Guipuzcoa. Together with the Diputación de Guipuzcoa and San Sebastián's Town Hall, different institutions such as the old Caja de Ahorros Provincial de Guipuzcoa, contribute several sums to build and equipped the institution which was going to be called Instituto Alfonso XIII.

In 1930 His Majesty Alfonso XIII visited the building which was nearly finished.The construction was stopped for a short period of time, due to the proclamation of the Republic. Finally with new contributions from the Government and the Caja de Ahorros Provincial de Guipuzcoa, the hospital building was finished under the name "Instituto Radio-Quirúrgico de Guipuzcoa". It was opened on the 13th August 1933 as an Institution intended for the active treatment of affected cancer patients, other neoplasias and affections supposedly degenerated or subsidiary of Röntgen-Curietherapy.

Dr. Luis Ayestarán was the founder and first Director of the Institution.

The new radiotherapy equipment (Quadro Contex (Westinghouse), 250 Kw and 15 Ma) was inaugurated in 1946, donated by the Caja de Ahorros Provincial de Guipuzcoa.

Due to the financial difficulties "El Instituto Radioquirúrgico" was going through, the "Caja de Ahorros Provincial de Guipuzcoa", as a demand of the Instituto assumed its maintenance as a Foundation on the 14th February 1952.

The first Collaboration Agreement between the Spanish National Health Service and the "Instituto Oncológico" was signed in 1954.

From: Fototeca-Kutxa.

Thanks to the campaign carried out by the guipuzcoan branch of the Spanish Society against cancer and the financial support of different private companies in this geographic area, the first Cobalt Pump was inaugurated in 1963.

The works for the enlargement of the building started years later and finished in 1974, reaching a capacity for 108 patients. The Department of Radiophysics was created in the same year. The Department of Radiotherapy was also updated in 1974 incorporating a new Cobalt Pump, a type Betratron particle Accelerator and a Simulator.

The first early diagnosis campaign in tumoral localization in the breast and womb took place in 1976.

From: Fototeca-Kutxa.

This year the Nuclear Medicine Department was given a scannicamera.

The Ministry of Health and Consume granted to this Institution the qualification of "Centro Sanitario, Group 7, Level II in June 1983.

In 1986 the Nuclear Committee recognised the Instituto Oncológico as a Technical Protection Unit against ionising radiations, becoming the only authorised centre in Guipuzcoa.

A post-Surgical Re-animation Unit was created in 1989. The Nuclear Medicine equipment was renewed with the acquisition of a Digital Tommogammacamera.

The first Lineal Accelerator was installed in 1991. The Department of Radiodiagnosis improved its equipment with the provision of an ACT equipment.

During 1993 a fundamental change in the functional dynamics of the different services at the Instituto Oncológico took place. Those changes were oriented towards the multidisciplinary approach to all patients. This project ended up with the creation of Multidisciplinary Units.

The stereotactic Radiosurgery team for the treatment of brain tumour and artheriovenous malformations in the brain was introduced the following year.

The acquisition of a new gammacamera with the complete equipment, including the installation for nuclear cardiology was the most important investment in 1996. The most outstanding actions in 1997 were, the re-enlargement of the hospitalisation area, the continuity in the technological innovation consisting of the installation of a second Lineal Accelerator, the setting up of the Oncologic Prevention Centre at Javier Barcaiztegui, and the beginning of the Early Detection Breast Cancer Programme sponsored by the Basque Government Health Department.

The most relevant actions carried out in 1998 were the formalisation of the new Agreement with the Health Department, the complete reform of the surgical site and the acquisition and introduction of the latest technology for the diagnosis and treatment of breast cancer (ABBI System).

In 1999 we started the application of brachitherapy in the prostate. We also undertook the task of remodelling one of the floors to dedicate it to the only and integrated space for the Breast Unit. A notable feature of 2000 was the implementation of a Tumour Bank and the establishment of institutional relations with the Carlos III National Centre for Oncological Research. At the same time, agreements were formalised to allow for our incorporation in the Tumour Bank Network.

In 2002 we obtained ISO 9001/2000 certification for the Mammography Unit. Continuing with our range of brachytherapy treatments for prostate cancer, a new technique was adopted: the application of high doses of Iridium (H.D.R.). The hospital area was also upgraded, allowing the number of single rooms to be increased. 52% of hospital patients are now accommodated in single rooms. In terms of investment, notable acquisitions in 2003 included a new Clinac 2100 CD Accelerator, a new Eclipse Planning System, a Digital Vascular unit and a 1.5 T. Nuclear Magnetic Resonance System. The Caja de Gipuzkoa San Sebastián "Kutxa", has always supported the Instituto Oncológico. KUTXA has always considered the Instituto Oncológico as a Foundation, and thanks to its financial support has made its existence and updating possible. The KUTXA has always financed the Instituto to supply it with the necessary technological means in order to develop its task in the prevention, diagnosis and treatment of cancer.