Read about CLS’ exciting journey from 2006 until now, which started with Professor Karl-Göran Tranberg discovering that laser beams could both destroy cancer and activate the immune system.


  • In line with CLS’ strategy to offer a complete product portfolio supporting the workflow of image-guided laser ablation procedures, the company signed an agreement with Siemens Healthineers. The agreement gives CLS the right to license Siemens Healthineers’ Access-i software to integrate the TRANBERG® Thermal Therapy System, including the new software product Thermoguide, with Siemens Healthineers MRI Magnetom scanners.
  • Sangeet Ghai at Toronto General Hospital presented an interim report from its ongoing study where 14 patients, diagnosed with low-medium risk prostate cancer, are treated with focal laser ablation using the TRANBERG® system. The report shows encouraging oncological and functional short term results for this group of patients.


  • During 2018, the company finalized clinical studies regarding its imILT treatment of pancreatic cancer within the EU Horizon 2020 project initiated in 2016. An interim report was filed with the European Commission. However, a follow up period for the patients treated remains.
  • CLS communicates a new product and development strategy to offer the market advanced technology and products supporting the complete workflow for image-guided laser ablation procedures. A collaboration with Image Guided Therapy (IGT) is initiated in order to perform the product development work necessary for this task. CLS also signs an agreement with ClearPoint Neuro (formerly MRI Interventions) regarding product development as well as distribution. With this collaboration, CLS takes the first step into the neuro and spine area, a space with stringent regulatory demands in both Europe and the U.S.


  • CLS acquires part of the German company Laser- und Medizin-Technologie GmbH (LMTB), and thereby secures access to patents and technology for CLS’ unique diffusor fiber.
  • CLS carries out non-randomized clinical studies regarding imILT treatment of metastatic pancreatic cancer and breast cancer, financially supported by a grant from Horizon 2020. The study’s objective is to obtain safety and feasibility data for the TRANBERG system to support CE approval for the product, but also to get initial efficacy data to serve as guidance for future decisions on further clinical development.
  • CLS single use instruments are evaluated by University of Texas Medical Branch for MR-guided laser ablation prostate treatment. CLS received its first order from another U.S. hospital for its Laser Applicator diffusor type product. During the year, CLS also obtained orders from three additional hospitals in the U.S. through its subsidiary CLS Americas Inc.


  • CLS is granted approximately SEK 20 million in project funding from the EU program Horizon 2020. The project involves three clinical studies and activities related to these.
  • The Company finalizes its first post-market clinical follow-up report. The report is based on eight imILT® treatments with the TRANBERG® System. There have been no serious side effects reported that can be linked to the treatment – the system is safe provided that the treatment instructions are followed.
  • CLS signs a letter of intent with the Department of Radiology at the University of Texas Medical Branch (UTMB).


  • The US FDA grants CLS approval to market and sell its product, the TRANBERG® | Thermal Therapy System, on the US market.
  • In cooperation with the University Hospital of Verona in Italy and the Institut Paoli-Calmettes in Marseille, France, CLS is granted approval to conduct studies of the treatment of pancreatic cancer.


  • The Company releases a supplementary treatment kit that enables percutaneous treatment (i.e. treatment via needle stick approach) of tumors that are up to 35 centimeters deep in the body.
  • CLS submits a 510(k) application to the US Food and Drug Administration (FDA) to seek approval of the TRANBERG® System for the US market.


  • CLS is granted approval for CE marking of the TRANBERG® | Cancer Immunotherapy System.
  • CLS initiates clinical studies in cooperation with a European medical center and begins development of additional treatment kits for outpatient use.


  • The fourth round of funding is secured, providing SEK 20 million.
  • The treatment system is tested and documented in accordance with the Medical Devices Directive 93/42/EEC (MDD).
  • The Company’s partner INTERmedic delivers its first product in the “0 series”.


  • CLS’ quality assurance system is certified in accordance with ISO 13485.
  • A collaboration is established with a US laser fiber supplier.
  • The Company enters into a cooperation agreement with Spanish development and production partner INTERmedic.


  • The third round of funding is secured, providing SEK 16 million.
  • The first prototype is complete.


  • The Company is listed on the Aktietorget stock exchange.
  • The second round of funding is secured, providing SEK 5 million.


  • CLS wins Venture Cup Syd, a business plan competition aimed at promoting the implementation of business ideas.


  • Clinical Laserthermia Systems (CLS) is founded by Karl-Göran Tranberg, Pär Henriksson and Lars-Erik Eriksson with the aim of developing a commercial product based on Professor Tranberg’s discovery that will be used by doctors to treat cancer worldwide.
  • The first round of funding is secured.
  • The Company enters into a cooperation agreement with a Swedish prototype development partner.
  • Professor Karl-Göran Tranberg discovers that heat from laser beams can not only destroy cancer locally under the right conditions, but also stimulate the immune system to attack cancer throughout an organism.

News and insights

19 January, 2023

Press Release from Skåne University Hospital on the Ongoing Study using CLS Products for Neurosurgery inside the MRI Camera

Today Skåne University Hospital (SUS) published a press release with the title “Laser surgery in a magnetic camera – new help for patients with brain tumors”. The PM provides an insight to the ongoing study using CLS products for laser surgery inside a MRI camera. The hospital writes that doctors now can treat patients with hard-to-reach brain tumors that medical care was previously unable to help. So far two patients with brain tumors have been successfully treated as part of the study.

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21 December, 2022

Christmas greeting from CLS - We wish you all a very Happy Holiday season and look forward to a tremendous 2023!

At CLS we can look back on an exciting year where we have made significant progress towards our vision that laser ablation will be introduced as standard treatment in focal therapy and as an alternative to traditional surgery and, in the longer term, as a complementary systemic treatment of metastasized cancer.

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15 December, 2022

Interview with and research by Dr Eric Walser University of Texas Medical Branch

Dr Eric Walser is an internationally recognized interventional radiologist with extensive clinical experience of using non-surgical ablation for the treatment of small tumors as an alternative to traditional surgery. Dr Eric Walser uses the TRANBERG® Thermal Therapy System to treat localized prostate cancer in clinical practice.

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Welcome to Clinical Laserthermia Systems.

Please note that all our products and indications are not yet approved in all markets. Don’t hesitate to contact us for up-to-date market approvals in your area!

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