Regional hyperthermia for soft tissue sarcoma - a survey on current practice, controversies and consensus among 12 European centers.

PURPOSE: To analyze the current practice of regional hyperthermia (RHT) for soft tissue sarcoma (STS) at 12 European centers to provide an overview, find consensuses and identify controversies necessary for future guidelines and clinical trials. METHODS: In this cross-sectional survey study, a 27-item questionnaire assessing clinical subjects and procedural details on RHT for STS was distributed to 12 European cancer centers for RHT. RESULTS: We have identified seven controversies and five consensus points. Of 12 centers, 6 offer both, RHT with chemotherapy (CTX) or with radiotherapy (RT). Two centers only offer RHT with CTX and four centers only offer RHT with RT. All 12 centers apply RHT for localized, high-risk STS of the extremities, trunk wall and retroperitoneum. However, eight centers also use RHT in metastatic STS, five in palliative STS, eight for superficial STS and six for low-grade STS. Pretherapeutic imaging for RHT treatment planning is used by 10 centers, 9 centers set 40-43 °C as the intratumoral target temperature, and all centers use skin detectors or probes in body orifices for thermometry. DISCUSSION: There is disagreement regarding the integration of RHT in contemporary interdisciplinary care of STS patients. Many clinical controversies exist that require a standardized consensus guideline and innovative study ideas. At the same time, our data has shown that existing guidelines and decades of experience with the technique of RHT have mostly standardized procedural aspects. CONCLUSIONS: The provided results may serve as a basis for future guidelines and inform future clinical trials for RHT in STS patients.

Hyperthermia in the treatment of high-risk soft tissue sarcomas: a systematic review.

BACKGROUND: The therapy of high-risk soft tissue sarcomas (STS) remains an interdisciplinary challenge. Regional hyperthermia (RHT) sparked interest as it has been shown to improve overall survival when added to perioperative chemotherapy (CTX). However, questions arise on how RHT should be optimally integrated into current multi-modal therapies. MATERIALS AND METHODS: We performed a systematic literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies written in English and focused mainly on radiative RHT and superficial hyperthermia were evaluated and included. Studies including patients below the age of 18, with metastatic disease or review articles, were excluded. RESULTS: We identified 15 clinical reports from 1990 until July 2022. Three articles combined RHT + CTX, and twelve focused on combined RHT + radiotherapy (RT) or neoadjuvant chemoradiotherapy (CRT). Most treatments were based on invasive thermometry, and less on magnetic resonance imaging (MRI)-based, noninvasive thermometry for STS of the extremities. Perioperative chemotherapy was used for the combination of RHT and CTX, mostly Ifosfamide-based. The effectiveness of RT appeared to be increased by RHT, especially with two RHT sessions/week. The trimodal simultaneous approach of neoadjuvant RHT and CRT was also feasible. No significant toxicity of RHT was reported. CONCLUSIONS: The gathered data strengthen the beneficial role of RHT in the multimodal setting. Further expert consensus and clinical trials are required to determine the optimal integration of RHT in treating STS.

Heat-Triggered Release of Dexamethasone from Thermosensitive Liposomes Using Prodrugs or Excipients.

Dexamethasone (DXM) is a potent glucocorticoid with an anti-inflammatory and anti-angiogenic activity which is widely clinically used. Systemic side effects limit the long-term use of DXM in patients requiring formulations which deliver and selectively release the drug to the diseased tissues. This in vitro study compares the suitability of DXM and commonly used prodrugs dexamethasone-21-phosphate (DXMP) and dexamethasone-21-palmitate (DP) as well as DXM complexed by 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CD) for the use in thermosensitive liposomes (TSL). DXM showed a poor retention and a low final drug:lipid ratio in a 1,2-dipalmitoyl-sn­glycero-3-phosphodiglycerol-based TSL (DPPG2-TSL) and a low-temperature sensitive liposome (LTSL). In contrast to DXM, DXMP and DP were stably retained at 37 °C in TSL in serum and could be encapsulated with high drug:lipid ratios in DPPG2-TSL and LTSL. DXMP showed a rapid release at mild hyperthermia (HT) from both TSL in serum, whereas DP remained incorporated in the TSL bilayer. According to release experiments with carboxyfluorescein (CF), HP-γ-CD and 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) are suitable vehicles for the loading of DXM into DPPG2-TSL and LTSL. Complexation of DXM with HP-γ-CD increased the aqueous solubility of the drug leading to approx. ten times higher DXM:lipid ratio in DPPG2-TSL and LTSL in comparison to un-complexed DXM. Both DXM and HP-γ-CD showed increased release at HT in comparison to 37 °C in serum. In conclusion, DXMP and DXM complexed by HP-γ-CD represent promising candidates for TSL delivery.

Regional hyperthermia with cisplatin added to gemcitabine versus gemcitabine in patients with resected pancreatic ductal adenocarcinoma: The HEAT randomised clinical trial.

BACKGROUND: Regional hyperthermia (RHT) with cisplatin added to gemcitabine showed efficacy in gemcitabine-pre-treated patients with advanced pancreatic ductal adenocarcinoma. We conducted a randomised clinical trial to investigate RHT with cisplatin added to gemcitabine (GPH) compared with gemcitabine (G) in the adjuvant setting of resected pancreatic ductal adenocarcinoma. METHODS: This randomised, multicentre, open-label trial randomly assigned patients to either GPH (gemcitabine 1000 mg/m2 on day 1, 15 and cisplatin 25 mg/m2 with RHT on day 2, 3 and 15,16) or to G (gemcitabine 1000 mg/m2 on day 1,8,15), four-weekly over six cycles. Disease-free survival (DFS) was the primary end-point. Secondary end-points included overall survival (OS) and safety. RESULTS: A total of 117 eligible patients (median age, 63 years) were randomly allocated to treatment (57 GPH; 60 G). With a follow-up time of 56.6 months, the median DFS was 12.7 compared to 11.2 months for GPH and G, respectively (p = 0.394). Median post-recurrence survival was significantly prolonged in the GPH-group (15.3 versus 9.8 months; p = 0.031). Median OS reached 33.2 versus 25.2 months (p = 0.099) with 5-year survival rates of 28.4% versus 18.7%. Excluding eight patients who received additional capecitabine in the G-arm (investigators choice), median OS favoured GPH (p = 0.052). Adverse events CTCAE (Common Terminology Criteria for Adverse Events) grade ≥3 occurred in 61.5% (GPH) versus 63.6% (G) of patients. Two patients in the G-group died because of treatment-related toxic effects. CONCLUSIONS: The randomised controlled Hyperthermia European Adjuvant Trial study failed to demonstrate a significant difference in DFS. However, it suggests a difference in post-recurrence survival and a trend for improved OS. CLINICALTRIALS: gov, number NCT01077427.

A patterns of care analysis of hyperthermia in combination with radio(chemo)therapy or chemotherapy in European clinical centers.

PURPOSE: The combination of hyperthermia (HT) with radio(chemo)therapy or chemotherapy (CT) is an established treatment strategy for specific indications. Its application in routine clinical practice in Europe depends on regulatory and local conditions. We conducted a survey among European clinical centers to determine current practice of HT. METHODS: A questionnaire with 22 questions was sent to 24 European HT centers. The questions were divided into two main categories. The first category assessed how many patients are treated with HT in combination with radio(chemo)therapy or CT for specific indications per year. The second category addressed which hyperthermia parameters are recorded. Analysis was performed using descriptive methods. RESULTS: The response rate was 71% (17/24) and 16 centers were included in this evaluation. Annually, these 16 centers treat approximately 637 patients using HT in combination with radio(chemo)therapy or CT. On average, 34% (range: 3-100%) of patients are treated in clinical study protocols. Temperature readings and the time interval between HT and radio(chemo)therapy or CT are recorded in 13 (81%) and 9 (56%) centers, respectively. The thermal dose quality parameter "cumulative equivalent minutes at 43 °C" (CEM43°C) is only evaluated in five (31%) centers for each HT session. With regard to treatment sequence, 8 (50%) centers administer HT before radio(chemo)therapy and the other 8 in the reverse order. CONCLUSION: There is a significant heterogeneity among European HT centers as to the indications treated and the recording of thermometric parameters. More evidence from clinical studies is necessary to achieve standardization of HT practice.

Susceptibility artifact correction in MR thermometry for monitoring of mild radiofrequency hyperthermia using total field inversion.

PURPOSE: MR temperature monitoring of mild radiofrequency hyperthermia (RF-HT) of cancer exploits the linear resonance frequency shift of water with temperature. Motion-induced susceptibility distribution changes cause artifacts that we correct here using the total field inversion (TFI) approach. METHODS: The performance of TFI was compared to two background field removal (BFR) methods: Laplacian boundary value (LBV) and projection onto dipole fields (PDF). Data sets with spatial susceptibility change and B0 -drift were simulated, phantom heating experiments were performed, four volunteer data sets at thermoneutral conditions as well as data from one cervical cancer, two sarcoma, and one seroma patients undergoing mild RF-HT were corrected using the proposed methods. RESULTS: Simulations and phantom heating experiments revealed that using BFR or TFI preserves temperature-induced phase change, while removing susceptibility artifacts and B0 -drift. TFI resulted in the least cumulative error for all four volunteers. Temperature probe information from four patient data sets were best depicted by TFI-corrected data in terms of accuracy and precision. TFI also performed best in case of the sarcoma treatment without temperature probe. CONCLUSION: TFI outperforms previously suggested BFR methods in terms of accuracy and robustness. While PDF consistently overestimates susceptibility contribution, and LBV removes valuable pixel information, TFI is more robust and leads to more accurate temperature estimations.

Hyperthermia-induced doxorubicin delivery from thermosensitive liposomes via MR-HIFU in a pig model.

PURPOSE: Encapsulation of cytotoxic drugs for a localized release is an effective way to increase the therapeutic window of such agents. In this article we present the localized release of doxorubicin (DOX) from phosphatidyldiglycerol (DPPG2) based thermosensitive liposomes using MR-HIFU mediated hyperthermia in a swine model. MATERIALS AND METHODS: German landrace pigs of weights between 37.5 and 53.5 kg received a 30-min infusion of DOX containing thermosensitive liposomes (50 mg DOX/m2). The pigs' biceps femoris was treated locally in two separate target areas with mild hyperthermia using magnetic resonance guided high intensity focused ultrasound, starting 10 min and 60 min after initiation of the infusion, respectively. The pharmacokinetics and biodistribution of DOX were determined and an analysis of the treatment parameters' influence was performed. RESULTS: Compared to untreated tissue, we found a 15-fold and a 7-fold increase in DOX concentration in the muscle volumes that had undergone hyperthermia starting 10 min and 60 min after the beginning of the infusion, respectively. The pharmacokinetic analysis showed a prolonged circulation time of DOX and a correlation between the AUC of extra-liposomal DOX in the bloodstream and the amount of DOX accumulated in the target tissue. CONCLUSIONS: We have demonstrated a workflow for MR-HIFU hyperthermia drug delivery that can be adapted to a clinical setting, showing that HIFU-hyperthermia is a suitable method for local drug release of DOX using DPPG2 based thermosensitive liposomes in stationary targets. Using the developed pharmacokinetic model, an optimization of the drug quantity deposited in the target via the timing of infusion and hyperthermia should be possible.

DPPG2-based thermosensitive liposomes as drug delivery system for effective muscle-invasive bladder cancer treatment in vivo.

PURPOSE: Recommended treatments for muscle-invasive bladder cancer (MIBC) come with considerable morbidity. Hyperthermia (HT) triggered drug release from phosphatidylglycerol-based thermosensitive liposomes (DPPG2-TSL) might prevent surgical bladder removal and toxicity from systemic chemotherapy. We aimed to assess the efficacy of DPPG2-TSL with HT in a syngeneic orthotopic rat urothelial carcinoma model. METHODS: A total of 191 female Fischer F344 rats were used. Bladder tumors were initiated by inoculation of AY-27 cells and tumor-bearing rats were selected with cystoscopy and semi-randomized over treatment groups. On days 5 and 8, animals were treated with DOX in different treatment modalities: intravenous (iv) DPPG2-TSL-DOX with HT, iv free DOX without HT, intravesical DOX without HT, intravesical DOX with HT or no treatment (control group), respectively. Animals were euthanized on day 14 and complete tumor response was assessed by histopathological evaluation. RESULTS: Iv DPPG2-TSL-DOX + HT resulted in a favorable rate of animals with complete tumor response (70%), compared to iv free DOX (18%, p = .02), no treatment (0%, p = .001), and intravesical DOX with (43%, p = .35) or without HT (50%, p = .41). All rats receiving intravesical DOX with HT and 24% of rats treated with DPPG2-TSL-DOX containing the same DOX dose with HT had to be euthanized before day 14 because of substantial bodyweight loss, which was associated with dilated ureters urine retention in a few rats. CONCLUSION: Treatment with DPPG2-TSL-DOX combined with intravesical HT outperformed systemic and intravesical DOX in vivo. There might be a role for DPPG2-TSL encapsulating chemotherapeutics in the treatment of MIBC in the future.

Primary Chemotherapy in a 47-Year-Old Patient with Giant Ulcerative and Necrotizing Nonseminomatous Testicular Germ Cell Tumor.

Testicular cancer is a rare disease; however, cure rates are high for all tumor stages. Mostly, the disease is diagnosed in an early (local) stage. We report the case of a 47-year-old male patient with a giant nonseminomatous germ cell tumor. At the time of diagnosis, the patient demonstrated a necrotizing and ulcerating growing mass in the left scrotum with an approximate size of 22 × 18 cm. According to the prognostic classification of the International Germ Cell Cancer Collaborative Group (IGCCCG 1997), the patient exhibited a high-risk profile due to alpha-fetoprotein >10,000 ng/mL and lactate dehydrogenase >10× the upper limit of normal in serum. Primary orchiectomy was infeasible due to the tumor's size, the patient's poor general condition and initial intensive care unit treatment. Primary systemic chemotherapy was applied. After 3 cycles of cisplatin, etoposide and bleomycin, along with 1 cycle of cisplatin, etoposide and ifosfamide, tumor resection with histomorphological examination showed a complete pathological response. Despite the delayed initiation of the therapy, primary chemotherapy was completed timely and showed promising results. Reasons for the late hospitalization were personal responsibilities regarding his family. Better awareness and knowledge of testicular cancer among young men might prevent the here reported delay of medical consultation and avoid testicular tumors of such enormous size. Psychosocial assessment and distress management is important as an integral part of comprehensive care of testicular cancer patients.

Perioperative chemotherapy and regional hyperthermia for high-risk adult-type soft tissue sarcomas.

A group of patients with adult-type soft tissue sarcoma is at high risk of local recurrence and distant metastases. Age, tumour site, histological subtype, tumour size and grade have been identified as the most important independent adverse prognostic factors. Macroscopically complete tumour resection is considered as the mainstay of treatment with the addition of preoperative or postoperative radiotherapy for extremity or trunk localisation. Retroperitoneal localisation requires compartmental resection and is associated with a worse prognosis. Here, radiotherapy is of no proven value. Perioperative chemotherapy is considered to treat micrometastatic disease not detectable at the time of diagnosis. The neoadjuvant application gives the risk of distant metastasis the greatest importance as therapy is carried out at the earliest possible time, whereas adjuvant chemotherapy is delayed by surgery and the necessary wound healing. With reported response rates up to 30%, both the operability may be improved and the risk of intraoperative tumour cell dissemination may be reduced, resulting also in reduced local relapse rates. However, the potential risk of early tumour progression may counteract this benefit. Optimised strategies with multimodality approaches including chemotherapy, regional hyperthermia (RHT) and immunotherapeutic agents have been shown to improve survival in high-risk patients. Here, we focus on the data from available randomised studies investigating the use of perioperative chemotherapy in patients with high-risk adult-type soft tissue sarcoma, including the use of RHT for local enhancement of chemotherapy effect and immune induction.

Mechanistic investigation of thermosensitive liposome immunogenicity and understanding the drivers for circulation half-life: A polyethylene glycol versus 1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol study.

Various thermosensitive liposome (TSL) formulations have been described to date and it is currently unclear which are optimal for solid tumor treatment. Sufficient circulation half-life is important and most liposomes obtain this by polyethylene glycol (PEG) surface modification. 1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol (DPPG2) has been described as a promising alternative which increases TSL circulation half-life and facilitates rapid drug release under mild hyperthermia at 20-30 mol%. The present work describes an investigation of the DPPG2-TSL protein corona, blood cell interactions, complement activation in human plasma/blood and hypersensitivity reactions in rats. Furthermore, accelerated blood clearance (ABC) was investigated to obtain a complete assessment of DPPG2-TSL interactions with components of the blood and identify drivers for circulation half-life. A higher mol% DPPG2 increased Apolipoprotein E (ApoE) adsorption and decreased complement activation and granulocyte interaction in vitro. In contrast to PEG-TSL, DPPG2-TSL showed no ABC effect. In vivo hypersensitivity assessment by eicosanoid measurements, platelet and lymphocyte counting resembled the results of in vitro complement activation assays although here all DPPG2-TSL formulations induced hypersensitive responses upon i.v. administration. Prolonged circulation half-life of DPPG2-TSL may be ApoE-induced and the absent ABC effect demonstrates an advantage over PEG-TSL. Low complement activation in human plasma and blood for 20-30 mol% DPPG2-TSL presents a unique formulation attribute with the potential to strengthen clinical evaluation.

DPPG2-Based Thermosensitive Liposomes with Encapsulated Doxorubicin Combined with Hyperthermia Lead to Higher Doxorubicin Concentrations in the Bladder Compared to Conventional Application in Pigs: A Rationale for the Treatment of Muscle-Invasive Bladder Cancer.

PURPOSE: Current treatment options for muscle-invasive bladder cancer (MIBC) are associated with substantial morbidity. Local release of doxorubicin (DOX) from phosphatidyldiglycerol-based thermosensitive liposomes (DPPG2-TSL-DOX) potentiated by hyperthermia (HT) in the bladder wall may result in bladder sparing without toxicity of systemic chemotherapy. We investigated whether this approach, compared to conventional DOX application, increases DOX concentrations in the bladder wall while limiting DOX in essential organs. MATERIALS AND METHODS: Twenty-one pigs were anaesthetized, and a urinary catheter equipped with a radiofrequency-emitting antenna for HT (60 minutes) was placed. Experimental groups consisted of iv low or full dose (20 or 60 mg/m2) DPPG2-TSL-DOX with/without HT, iv low dose (20 mg/m2) free DOX with HT, and full dose (50 mg/50 mL) intravesical DOX with/without HT. After the procedure, animals were immediately sacrificed. HPLC was used to measure DOX levels in the bladder, essential organs and serum, and fluorescence microscopy to evaluate DOX distribution in the bladder wall. RESULTS: Iv DPPG2-TSL-DOX with HT resulted in a significantly higher bladder wall DOX concentration which was more homogeneous distributed, than iv and intravesical free DOX administration with HT. Specifically in the detrusor, DPPG2-TSL-DOX with HT led to a >7- and 44-fold higher DOX concentration, compared to iv free DOX with HT and intravesical DOX, respectively. Organ DOX concentrations were significantly lower in heart and kidneys, and similar in liver, spleen and lungs, following iv DPPG2-TSL-DOX with HT, compared to iv free DOX. Intravesical DOX led to the lowest organ DOX concentrations. CONCLUSION: Iv DPPG2-TSL-DOX combined with HT achieved higher DOX concentrations in the bladder wall including the detrusor, compared to conventional iv and intravesical DOX application. In combination with lower DOX accumulation in heart and kidneys, compared to iv free chemotherapy, DPPG2-TSL-DOX with HT has great potential to attain a role as a bladder-sparing treatment for MIBC.

Regional Hyperthermia Enhances Mesenchymal Stem Cell Recruitment to Tumor Stroma: Implications for Mesenchymal Stem Cell-Based Tumor Therapy.

The tropism of mesenchymal stem cells (MSCs) for tumors forms the basis for their use as delivery vehicles for the tumor-specific transport of therapeutic genes, such as the theranostic sodium iodide symporter (NIS). Hyperthermia is used as an adjuvant for various tumor therapies and has been proposed to enhance leukocyte recruitment. Here, we describe the enhanced recruitment of adoptively applied NIS-expressing MSCs to tumors in response to regional hyperthermia. Hyperthermia (41°C, 1 h) of human hepatocellular carcinoma cells (HuH7) led to transiently increased production of immunomodulatory factors. MSCs showed enhanced chemotaxis to supernatants derived from heat-treated cells in a 3D live-cell tracking assay and was validated in vivo in subcutaneous HuH7 mouse xenografts. Cytomegalovirus (CMV)-NIS-MSCs were applied 6-48 h after or 24-48 h before hyperthermia treatment. Using 123I-scintigraphy, thermo-stimulation (41°C, 1 h) 24 h after CMV-NIS-MSC injection resulted in a significantly increased uptake of 123I in heat-treated tumors compared with controls. Immunohistochemical staining and real-time PCR confirmed tumor-selective, temperature-dependent MSC migration. Therapeutic efficacy was significantly enhanced by combining CMV-NIS-MSC-mediated 131I therapy with regional hyperthermia. We demonstrate here for the first time that hyperthermia can significantly boost tumoral MSC recruitment, thereby significantly enhancing therapeutic efficacy of MSC-mediated NIS gene therapy.

A multi-institution study: comparison of the heating patterns of five different MR-guided deep hyperthermia systems using an anthropomorphic phantom.

INTRODUCTION: Within the hyperthermia community, consensus exists that clinical outcome of the treatment radiotherapy and/or chemotherapy plus hyperthermia (i.e. elevating tumor temperature to 40 - 44 °C) is related to the applied thermal dose; hence, treatment quality is crucial for the success of prospective multi-institution clinical trials. Currently, applicator quality assurance (QA) measurements are implemented independently at each institution using basic cylindrical phantoms. A multi-institution comparison of heating quality using magnetic resonance thermometry (MRT) and anatomical representative anthropomorphic phantoms provides a unique opportunity to obtain novel QA insights to facilitate multi-institution trial evaluation. OBJECTIVE: Perform a systematic QA procedure to compare the performance of MR-compatible hyperthermia systems in five institutions. METHODS AND MATERIALS: Anthropomorphic phantoms, including pelvic and spinal bones, were produced. Clinically relevant power of 600 watts was applied for ∼12 min to allow for 8 sequential MR-scans. The 3D-heating distribution, steering capabilities, and presence of off-target heating were analyzed. RESULTS: The evaluated devices show comparable heating profiles for centric and eccentric targets. The differences observed in the 3D-heating profiles are the result of variations in the exact phantom positioning and applicator characteristics, whereby positioning of the phantom followed current ESHO-QA guidelines. CONCLUSION: Anthropomorphic phantoms were used to perform QA-measurements of MR-guided hyperthermia systems operating in MR-scanners of different brands. Comparable heating profiles are shown for the five evaluated institutions. Subcentimeter differences in position substantially affected the results when evaluating the heating patterns. Integration of advanced phantoms and precise positioning in QA-guidelines should be evaluated to guarantee the best quality patient care.

Effective control of tumor growth through spatial and temporal control of theranostic sodium iodide symporter (NIS) gene expression using a heat-inducible gene promoter in engineered mesenchymal stem cells.

Purpose: The tumor homing characteristics of mesenchymal stem cells (MSCs) make them attractive vehicles for the tumor-specific delivery of therapeutic agents, such as the sodium iodide symporter (NIS). NIS is a theranostic protein that allows non-invasive monitoring of the in vivo biodistribution of functional NIS expression by radioiodine imaging as well as the therapeutic application of 131I. To gain local and temporal control of transgene expression, and thereby improve tumor selectivity, we engineered MSCs to express the NIS gene under control of a heat-inducible HSP70B promoter (HSP70B-NIS-MSCs). Experimental Design: NIS induction in heat-treated HSP70B-NIS-MSCs was verified by 125I uptake assay, RT-PCR, Western blot and immunofluorescence staining. HSP70B-NIS-MSCs were then injected i.v. into mice carrying subcutaneous hepatocellular carcinoma HuH7 xenografts, and hyperthermia (1 h at 41°C) was locally applied to the tumor. 0 - 72 h later radioiodine uptake was assessed by 123I-scintigraphy. The most effective uptake regime was then selected for 131I therapy. Results: The HSP70B promoter showed low basal activity in vitro and was significantly induced in response to heat. In vivo, the highest tumoral iodine accumulation was seen 12 h after application of hyperthermia. HSP70B-NIS-MSC-mediated 131I therapy combined with hyperthermia resulted in a significantly reduced tumor growth with prolonged survival as compared to control groups. Conclusions: The heat-inducible HSP70B promoter allows hyperthermia-induced spatial and temporal control of MSC-mediated theranostic NIS gene radiotherapy with efficient tumor-selective and temperature-dependent accumulation of radioiodine in heat-treated tumors.

Systemic antitumor effect by regional hyperthermia combined with low-dose chemotherapy and immunologic correlates in an adolescent patient with rhabdomyosarcoma - a case report.

Introduction: An abscopal effect is a clinical observation whereby a local treatment is associated with regression of metastatic cancer at a site distant from the primary location of treatment. Here, we describe the clinical systemic effect induced by regional hyperthermia combined with low-dose chemotherapy and provide immunologic correlates.Case presentation: A 15-year-old patient had been diagnosed with alveolar rhabdomyosarcoma (ARMS). All previous treatment options failed in the patient including haploidentical stem cell transplantation and donor lymphocyte infusion. The patient presented with local and metastatic disease, and upon admission, underwent regional hyperthermia combined with low-dose chemotherapy. Immediately following therapy severe skin reactions were observed. Skin biopsies revealed an intraepithelial lymphocytic infiltration dominated by CD3+/CD8+ T cells with a regular network of dendritic cells. Clinical images compared before and during sequential treatment cycles showed complete metabolic response of the local tumor for more than 10 months of therapy. In addition, metastases completely regressed although they were not direct targets of regional hyperthermia. The systemic effect was associated with enhanced frequency of NK cells and T cells expressing the lectin-like natural-killer group 2 D activating receptor (NKG2D), an increase of the CD56bright subset of NK cells, as well as an increase of effector/memory and effector CD8+ and CD4+ T cells in the blood while the percentage of CD25+FOXP3+ regulatory T cells declined.Conclusions: Regional hyperthermia combined with low-dose chemotherapy had the potential to create a systemic effect which was associated with activation of NK cells and T cells.

Effect of Neoadjuvant Chemotherapy Plus Regional Hyperthermia on Long-term Outcomes Among Patients With Localized High-Risk Soft Tissue Sarcoma: The EORTC 62961-ESHO 95 Randomized Clinical Trial.

IMPORTANCE: Patients with soft tissue sarcoma are at risk for local recurrence and distant metastases despite optimal local treatment. Preoperative anthracycline plus ifosfamide chemotherapy improves outcome in common histological subtypes. OBJECTIVE: To analyze whether the previously reported improvement in local progression-free survival by adding regional hyperthermia to neoadjuvant chemotherapy translates into improved survival. DESIGN, SETTING, AND PARTICIPANTS: Open-label, phase 3 randomized clinical trial to evaluate the efficacy and toxic effects of neoadjuvant chemotherapy plus regional hyperthermia. Adult patients (age ≥18 years) with localized soft tissue sarcoma (tumor ≥5 cm, French Federation Nationale des Centers de Lutte Contre le Cancer [FNCLCC] grade 2 or 3, deep) were accrued across 9 centers (6, Germany; 1, Norway; 1, Austria; 1, United States) from July 1997 to November 2006. Follow-up ended December 2014. INTERVENTIONS: After stratification for tumor presentation and site, patients were randomly assigned to either neoadjuvant chemotherapy consisting of doxorubicin, ifosfamide, and etoposide alone, or combined with regional hyperthermia. MAIN OUTCOMES AND MEASURES: The primary end point was local progression-free survival. Secondary end points included treatment safety and survival, with survival defined from date of randomization to death due to disease or treatment. Patients lost to follow-up were censored at the date of their last follow-up. RESULTS: A total of 341 patients were randomized, and 329 (median [range] age, 51 [18-70] years; 147 women, 182 men) were eligible for the intention-to-treat analysis. By December 2014, 220 patients (67%; 95% CI, 62%-72%) had experienced disease relapse, and 188 (57%; 95% CI, 52%-62%) had died. Median follow-up was 11.3 years. Compared with neoadjuvant chemotherapy alone, adding regional hyperthermia improved local progression-free survival (hazard ratio [HR], 0.65; 95% CI, 0.49-0.86; P = .002). Patients randomized to chemotherapy plus hyperthermia had prolonged survival rates compared with those randomized to neoadjuvant chemotherapy alone (HR, 0.73; 95% CI, 0.54-0.98; P = .04) with 5-year survival of 62.7% (95% CI, 55.2%-70.1%) vs 51.3% (95% CI, 43.7%-59.0%), respectively, and 10-year survival of 52.6% (95% CI, 44.7%-60.6%) vs 42.7% (95% CI, 35.0%-50.4%). CONCLUSIONS AND RELEVANCE: Among patients with localized high-risk soft tissue sarcoma the addition of regional hyperthermia to neoadjuvant chemotherapy resulted in increased survival, as well as local progression-free survival. For patients who are candidates for neoadjuvant treatment, adding regional hyperthermia may be warranted. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00003052.

Surrogate MRI markers for hyperthermia-induced release of doxorubicin from thermosensitive liposomes in tumors.

The efficacy of systemically applied, classical anti-cancer drugs is limited by insufficient selectivity to the tumor and the applicable dose is limited by side effects. Efficacy could be further improved by targeting of the drug to the tumor. Using thermosensitive liposomes (TSL) as a drug carrier, targeting is achieved by control of temperature in the target volume. In such an approach, effective local hyperthermia (40-43°C) (HT) of the tumor is considered essential but technically challenging. Thus, visualization of local heating and drug release using TSL is considered an important tool for further improvement. Visualization and feasibility of chemodosimetry by magnetic resonance imaging (MRI) has previously been demonstrated using TSL encapsulating both, contrast agent (CA) and doxorubicin (DOX) simultaneously in the same TSL. Dosimetry has been facilitated using T1-relaxation time change as a surrogate marker for DOX deposition in the tumor. To allow higher loading of the TSL and to simplify clinical development of new TSL formulations a new approach using a mixture of TSL either loaded with DOX or MRI-CA is suggested. This was successfully tested using phosphatidyldiglycerol-based TSL (DPPG2-TSL) in Brown Norway rats with syngeneic soft tissue sarcomas (BN175) implanted at both hind legs. After intravenous application of DOX-TSL and CA-TSL, heating of one tumor above 40°C for 1h using laser light resulted in highly selective DOX uptake. The DOX-concentration in the heated tumor tissue compared to the non-heated tumor showed an almost 10-fold increase. T1 and additional MRI surrogate parameters such as signal phase change were correlated to intratumoral DOX concentration. Visualization of DOX delivery in the sense of a chemodosimetry was demonstrated. Although phase-based MR-thermometry was affected by CA-TSL, phase information was found suitable for DOX concentration assessment. Local differences of DOX concentration in the tumors indicated the need for visualization of drug release for further improvement of targeting.