The Role of Hyperthermic Intrathoracic Chemotherapy (HITHOC) in Thoracic Tumors

Simple Summary Hyperthermic intrathoracic chemotherapy (HITHOC) is an intraoperative and topical administration of chemotherapeutic drugs with simultaneous warming of the thoracic cavity. This procedure was first described by Spratt in 1980 as a thermal transfusion infiltration system, performed on canine models to treat malignant effusions of metastatic abdominal cancers. The main tumors causing malignant pleural effusion, which have been seen to benefit from hyperthermic intrathoracic chemotherapy, are mesothelioma, thymic malignancies and lung cancer: despite the high prevalence of MPE in patients with metastatic breast and ovarian cancers, there are still inadequate data on the use of HITHOC as a treatment option for these malignancies.Abstract Pleural mesothelioma (PM) is a rare but aggressive thoracic tumor with a poor prognosis. Multimodal treatment-including induction chemotherapy, aggressive surgical resection, radiotherapy and immunotherapy in selected cases-currently represents the best therapeutic option. Single-center studies advocate hyperthermic intrathoracic chemotherapy (HITHOC) during surgical resection as an additional therapeutic option, although its impact on post-operative morbidity and survival has not yet been evaluated on a larger scale. HITHOC can be applied not only in the case of mesothelioma, but also in the case of thymoma with pleural involvement or-in very selected cases-in patients with secondary pleural metastases. Despite favorable outcomes and reduced clinical risks, there is no uniform approach to HITHOC, and a wide variety of indications and technical applications are still reported. Based on available data, HITHOC seems to offer a clear benefit in regard to overall survival of all mesothelioma patients; however, multicenter randomized controlled trials are required to validate and standardize this approach. The aim of this review is to focus on the present role of HITHOC in thoracic tumors with pleural involvement as well as on future challenges, particularly in the light of possible combined therapy of thoracic tumors still presenting poor prognoses.