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Background: Clinical Laser-Induced Thermotherapy (LITT) currently lacks precise control of tissue temperature increase during the procedure. This study presents a new method to automatically regulate the maximum temperature increase in vivo at different positions by adjusting LITT power delivered by multiple laser probes using real-time volumetric MR-thermometry., Methods: The regulation algorithm was evaluated in vivo on a pig leg muscle. Temperature regulation was performed in volumes surrounding each laser probe tip. The power delivered to each laser probe was automatically adjusted every second using a feedback control algorithm by processing on-the-fly MR-thermometry images (10 slices/second) on a 1.5 T clinical scanner (1.56 mm × 1.56 mm x 3 mm resolution), using the proton-resonance frequency (PRF) shift technique. Several experimental conditions were tested with predefined temperature-time profiles corresponding to conditions of thermal ablation (+30 °C above body temperature) or moderate hyperthermia (+10 and + 15 °C). Control images were acquired after injection of Gadolinium at the end of experiment and were compared with the thermal dose images calculated from the thermometry images., Results: The mean difference and root mean squared error between target temperatures and measured ones remained below 0.5 °C and 2 °C respectively, for 5 min duration. Lesion sizes observed on thermal dose and on images acquired after gadolinium injection were in good agreement., Conclusion: Automatic regulation of in vivo temperature increase during LITT procedures with multiple laser emitters control is feasible. The method provides an adaptative solution to improve the safety and efficacity of such clinical procedures., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Manon Desclides reports a relationship with Certis Therapeutics that includes: employment. Bruno Quesson reports a relationship with Certis Therapeutics that includes: consulting or advisory and equity or stocks. Valery Ozenne reports a relationship with Certis Therapeutics that includes: consulting or advisory and equity or stocks. Pierre Bour reports a relationship with Certis Therapeutics that includes: employment. Thibaut Faller reports a relationship with Certis Therapeutics that includes: employment. Stephane Chemouny reports a relationship with Certis Therapeutics that includes: employment and equity or stocks. Guillaume Machinet reports a relationship with ALPhANOV Optical and Laser Technological Centre that includes: employment. Christophe Pierre reports a relationship with ALPhANOV Optical and Laser Technological Centre that includes: employment. Julie Carcreff reports a relationship with ALPhANOV Optical and Laser Technological Centre that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)