Combining Mitomycin C and Regional 70 MHz Hyperthermia in Patients with Nonmuscle Invasive Bladder Cancer: A Pilot Study

Evaluation of thermal dose effect in radiofrequency-induced hyperthermia with intravesical chemotherapy for nonmuscle invasive bladder cancer

PURPOSE

In nonmuscle invasive bladder cancer (NMIBC) patients who fail standard intravesical treatment and are unfit or unwilling to undergo a radical cystectomy, radiofrequency (RF)-induced hyperthermia combined with intravesical chemotherapy (RF-CHT) has shown promising results. We studied whether higher thermal dose improves clinical NMIBC outcome.

METHODS AND MATERIALS

The cohort comprised 108 patients who started with RF-CHT between November 2013 and December 2019. Patients received intravesical mitomycin-C or epirubicin. Bladder hyperthermia was accomplished with an intravesical 915 MHz RF device guided by intravesical thermometry. We assessed the association between thermal dose parameters (including median temperature and Cumulative Equivalent Minutes of T50 at 43 °C [CEM43T50]) and complete response (CR) at six months for patients with (concomitant) carcinoma in situ (CIS), and recurrence-free survival (RFS) for patients with papillary disease.

RESULTS

Median temperature and CEM43T50 per treatment were 40.9 (IQR 40.8-41.1) °C and 3.1 (IQR 0.9-2.4) minutes, respectively. Analyses showed no association between any thermal dose parameter and CR or RFS (p > 0.05). Less bladder spasms during treatment sessions was associated with increased median temperature and CEM43T50 (adjusted OR 0.01 and 0.34, both p < 0.001).

CONCLUSIONS

No significant association between thermal dose and NMIBC outcome was found. Possibly thermal dose effect in patients of the current cohort exceeds a certain threshold value. On the other hand, occurrence of bladder spasms had a thermal dose limiting effect. We advise to treat patients with temperatures >40.5 °C for at least 45 min while respecting individual tolerability, including occurrence of bladder spasms.

A scalable hyperthermic intravesical chemotherapy (HIVEC) setup for rat models of bladder cancer

Hyperthermic intravesical chemotherapy (HIVEC)—whereby the bladder is heated to ± 43 °C during a chemotherapy instillation—can improve outcomes of non-muscle invasive bladder cancer (NMIBC) treatments. Experiments in animal models are required to explore new hyperthermia based treatments. Existing HIVEC devices are not suitable for rodents or large-scale animal trials. We present a HIVEC setup compatible with orthotopic rat models. An externally heated chemotherapeutic solution is circulated in the bladder through a double-lumen catheter with flow rates controlled using a peristaltic pump. Temperature sensors in the inflow channel, bladder and outflow channel allow temperature monitoring and adjustments in real-time. At a constant flow rate of 2.5 mL/min the system rapidly reaches the desired bladder temperature of 42–43 °C with minimal variability throughout a one-hour treatment in a rat bladder phantom, as well as in euthanised and live rats. Mean intraluminal bladder temperatures were 42.92 °C (SD = 0.15 °C), 42.45 °C (SD = 0.37 °C) and 42.52 °C (SD = 0.09 °C) in the bladder phantom, euthanised, and live rats respectively. Thermal camera measurements showed homogenous heat distributions over the bladder wall. The setup provides well-controlled thermal dose and the upscaling needed for performing large scale HIVEC experiments in rats.

A Narrative Review of Regional Hyperthermia: Updates From 2010 to 2019

The role of hyperthermia (HT) in cancer therapy and palliative care has been discussed for years in the literature. There are plenty of articles that show good feasibility of HT and its efficacy in terms of tumor response and survival improvements. Nevertheless, HT has never gained enough interest among oncologists to become a standard therapy in clinical practice. The main advantage of HT is the enhancement of chemotherapy (CHT), radiotherapy (RT), chemoradiotherapy (CRT), and immunotherapy benefits. This effect has been confirmed in several types of tumors: esophageal, gastrointestinal, pancreas, breast, cervix, head and neck, and bladder cancers, and soft tissue sarcoma. HT effects include oxygenation and perfusion changes, DNA repair inhibition and immune system activation as a consequence of new antigen exposure. The literature shows a wide variety of randomized, nonrandomized, and observational studies and both prospective and retrospective data to confirm the advantage of HT association to CHT and RT. There are still many ongoing trials on this subject. This article summarizes the available literature on HT in order to update the current knowledge on HT use in association with RT and/or CHT from 2010 up to 2019.

Heating technology for malignant tumors: a review

The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.

Hyperthermia Improves Solubility of Intravesical Chemotherapeutic Agents

BACKGROUND: Nearly 70% of all new cases of bladder cancer are non-muscle invasive disease, the treatment for which includes transurethral resection followed by intravesical therapy. Unfortunately, recurrence rates approach 50% in part due to poor intravesical drug delivery. Hyperthermia is frequently used as an adjunct to intravesical chemotherapy to improve drug delivery and response to treatment. OBJECTIVE: To assess the solubility profile of intravesical chemotherapies under varying conditions of pH and temperature. METHODS: Using microplate laser nephelometry we measured the solubility of three intravesical chemotherapy agents (mitomycin C, gemcitabine, and cisplatin) at varying physical conditions. Drugs were assessed at room temperature (23°C), body temperature (37°C), and 43°C, the temperature used for hyperthermic intravesical treatments. To account for variations in urine pH, solubility was also investigated at pH 4.00, 6.00, and 8.00. RESULTS: Heat incrementally increased the solubility of all three drugs studied. Conversely, pH largely did not impact solubility aside for gemcitabine which showed slightly reduced solubility at pH 8.00 versus 6.00 or 4.00. Mitomycin C at the commonly used 2.0 mg/mL was insoluble at room temperature, but soluble at both 37 and 43°C. CONCLUSIONS: Hyperthermia as an adjunct to intravesical treatment would improve drug solubility, and likely drug delivery as some current regimens are insoluble without heat. Improvements in solubility also allow for testing of alternative administration regimens to improve drug delivery or tolerability. Further studies are needed to confirm that improvements in solubility result in increased drug delivery.

Locoregional peritoneal hyperthermia to enhance the effectiveness of chemotherapy in patients with peritoneal carcinomatosis: a simulation study comparing different locoregional heating systems

Introduction: Intravenous chemotherapy plus abdominal locoregional hyperthermia is explored as a noninvasive alternative to hyperthermic intraperitoneal chemotherapy (HIPEC) in treatment of peritoneal carcinomatosis (PC). First clinical results demonstrate feasibility, but survival data show mixed results and for pancreatic and gastric origin results are not better than expected for chemotherapy alone. In this study, computer simulations are performed to compare the effectiveness of peritoneal heating for five different locoregional heating systems.Methods: Simulations of peritoneal heating were performed for a phantom and two pancreatic cancer patients, using the Thermotron RF8, the AMC-4/ALBA-4D system, the BSD Sigma-60 and Sigma-Eye system, and the AMC-8 system. Specific absorption rate (SAR) distributions were optimized and evaluated. Next, to provide an indication of possible enhancement factors, the corresponding temperature distributions and thermal enhancement ratio (TER) of oxaliplatin were estimated.Results: Both phantom and patient simulations showed a relatively poor SAR coverage for the Thermotron RF8, a fairly good coverage for the AMC-4/ALBA-4D, Sigma-60, and Sigma-Eye systems, and the best and most homogeneous coverage for the AMC-8 system. In at least 50% of the peritoneum, 35-45 W/kg was predicted. Thermal simulations confirmed these favorable peritoneal heating properties of the AMC-8 system and TER values of ∼1.4-1.5 were predicted in at least 50% of the peritoneum.Conclusion: Locoregional peritoneal heating with the AMC-8 system yields more favorable heating patterns compared to other clinically used locoregional heating devices. Therefore, results of this study may promote the use of the AMC-8 system for locoregional hyperthermia in future multidisciplinary studies for treatment of PC.

Recent technological advancements in radiofrequency- andmicrowave-mediated hyperthermia for enhancing drug delivery

Hyperthermia therapy is a potent enhancer of chemotherapy and radiotherapy. In particular, microwave (MW) and radiofrequency (RF) hyperthermia devices provide a variety of heating approaches that can treat most cancers regardless the size. This review introduces the physics of MW/RF hyperthermia, the current state-of-the-art systems for both localized and regional heating, and recent advancements in hyperthermia treatment guidance using real-time computational simulations and magnetic resonance thermometry. Clinical trials involving RF/MW hyperthermia as adjuvant for chemotherapy are also presented per anatomical site. These studies favor the use of adjuvant hyperthermia since it significantly improves curative and palliative clinical outcomes. The main challenge of hyperthermia is the distribution of state-of-the-art heating systems. Nevertheless, we anticipate that recent technology advances will expand the use of hyperthermia to chemotherapy centers for enhanced drug delivery. These new technologies hold great promise not only for (image-guided) perfusion modulation and sensitization for cytotoxic drugs, but also for local delivery of various compounds using thermosensitive liposomes.

Thermal Intravesical Chemotherapy Reduce Recurrence Rate for Non-muscle Invasive Bladder Cancer Patients: A Meta-Analysis

Background: Non-muscle invasive bladder cancer accounts for nearly 80% of newly diagnosed bladder cancer cases, which often recur and progress. This meta-analysis was evaluated by the adverse events and recurrence rate of thermal intravesical chemotherapy vs. normal temperature intravesical chemotherapy in the treatment of non-muscle invasive bladder cancer. Methods: A systematic review and cumulative analysis of studies reporting adverse events and recurrence rate of thermal intravesical chemotherapy vs. normal temperature intravesical chemotherapy was performed through a comprehensive search of Pubmed, Embase, Cochranelibrary.com, CNKI, Wanfang Med Online database and VIP database. All analyses were performed using the Revman manager 5. Result: Twelve studies (11 randomized controlled trials and 1 retrospective study) including 888 patients, 445 in the thermal intravesical chemotherapy group, and 443 in the normal temperature intravesical chemotherapy group, met the eligibility criteria. Patients in the thermal intravesical chemotherapy group had a lower risk of disease recurrence than those who had normal temperature intravesical chemotherapy (24 months follow-up group: RR = 0.30, 95% CI: 0.21-0.43, P < 0.00001, I ² = 0%; 36 months follow-up group: RR = 0.27, 95% CI: 0.14-0.54, P = 0.0002, I ² = 0%) while no significant difference in adverse events rate (RR = 0.89, 95% CI = 0.53-1.52; P = 0.67, I ² = 78%). Conclusions: When compared with normal temperature intravesical chemotherapy, thermal intravesical chemotherapy can reduce the recurrence rate without increasing incidence of adverse events in patients with non-muscle invasive bladder cancer.

Development of a high-precision bladder hyperthermic intracavitary chemotherapy device for bladder cancer and pharmacokinetic study

BACKGROUND

Bladder hyperthermic intracavitary chemotherapy (HIVEC) has good effectiveness for bladder cancer, but conventional HIVEC systems lack precision and convenient application. To test the safety of a new HIVEC device (BR-TRG-II-type) in pigs and to perform a preliminary clinical trial in patients with bladder cancer.

METHODS

This device was tested on six pigs to optimize the temperature and time parameters. Then, 165 patients (HIVEC after transurethral resection (TUR), n = 128; or HIVEC, n = 37) treated between December 2006 and December 2016 were recruited. Mitomycin C (MMC) was the chemotherapeutic agent. A serum pharmacokinetic study was performed. The primary endpoints were tumor recurrence, disease-free survival (DFS), and cumulative incidence rate (CIR) during follow-up. The adverse effects were graded.

RESULTS

The animal experiment showed that 45 °C for 1 h was optimal. HIVEC was successful, with the infusion tube temperature stably controlled at about 45 °C, and outlet tube temperature of about 43 °C in all patients, for three sessions. Serum MMC levels gradually increased during HIVEC and decreased thereafter. The mean DFS was 39 ± 3.21 months (ranging from 8 to 78 months), and the DFS rate was 89.1% during follow-up. No adverse events occurred.

CONCLUSION

The use of the BR-TRG-II-type HIVEC device is feasible for the treatment of bladder cancer. Future clinical trials in patients with different stages of bladder cancer will further confirm the clinical usefulness of this device.

TRIAL REGISTRATION

chictr.org.cn: ChiCTR1900022099 (registered on Mar. 252,019). Retrospectively registered.

Heated Intravesical Chemotherapy: Biology and Clinical Utility

Non-muscle-invasive bladder cancer can be a challenging disease to manage. In recent years, hyperthermia therapy in conjunction with intravesical therapy has been gaining traction as a treatment option for bladder cancer, especially if Bacillus Calmette-Guerin might not be available. Trials of intravesical chemotherapy with heat are few and there has been considerable heterogeneity between studies. However, multiple new trials have accrued and high-quality data are forthcoming. In this review, we discuss the role of combined intravesical hyperthermia and chemotherapy as a novel approach for the treatment of bladder cancer.

Re‑irradiation plus hyperthermia for recurrent pediatric sarcoma; a simulation study to investigate feasibility

Recurrent pediatric tumors pose a challenge since treatment options may be limited, particularly after previous irradiation. Positive results have been reported for chemotherapy and hyperthermia, but the combination of re‑irradiation and hyperthermia has not been investigated thus far, although it is a proven treatment strategy in adults. The theoretical feasibility of re‑irradiation plus hyperthermia was investigated for infield recurrent pediatric sarcoma in the pelvic region and the extremities. A total of 46 recurrent pediatric sarcoma cases diagnosed at the Academic Medical Center (Amsterdam, The Netherlands) between 2002 and 2017 were evaluated. Patients not previously irradiated, outfield recurrences and locations other than the pelvis and extremities were excluded, ultimately yielding four eligible patients: Two with sarcomas in the pelvis and two in an extremity. Re‑irradiation and hyperthermia treatment plans were simulated for 23x2 Gy treatment schedules and weekly hyperthermia. The radiosensitizing effect of hyperthermia was quantified using biological modelling with a temperature‑dependent change in the parameters of the linear‑quadratic model. The possible effectiveness of re‑irradiation plus hyperthermia was estimated by calculating the equivalent radiotherapy dose distribution. Treatment planning revealed that tumors located in the pelvis and the extremities can be effectively heated in children. Equivalent dose distributions indicated that hyperthermic radiosensitization can be quantified as a target‑selective additional D95% of typically 10 Gy, thereby delivering a possibly curative dose of 54 Gy, without substantially increasing the equivalent dose to the organs at risk. Therefore, re‑irradiation plus hyperthermia is a theoretically feasible and possibly effective treatment option for recurrent pediatric sarcoma in the pelvic region and the extremities, and its clinical feasibility is worthy of evaluation.

Clinical validation of a novel thermophysical bladder model designed to improve the accuracy of hyperthermia treatment planning in the pelvic region

PURPOSE

Hyperthermia treatment planning for deep locoregional hyperthermia treatment may assist in phase and amplitude steering to optimize the temperature distribution. This study aims to incorporate a physically correct description of bladder properties in treatment planning, notably the presence of convection and absence of perfusion within the bladder lumen, and to assess accuracy and clinical implications for non muscle invasive bladder cancer patients treated with locoregional hyperthermia.

METHODS

We implemented a convective thermophysical fluid model based on the Boussinesq approximation to the Navier-Stokes equations using the (finite element) OpenFOAM toolkit. A clinician delineated the bladder on CT scans obtained from 14 bladder cancer patients. We performed (1) conventional treatment planning with a perfused muscle-like solid bladder, (2) with bladder content properties without and (3) with flow dynamics. Finally, we compared temperature distributions predicted by the three models with temperature measurements obtained during treatment.

RESULTS

Much higher and more uniform bladder temperatures are predicted with physically accurate fluid modeling compared to previously employed muscle-like models. The differences reflect the homogenizing effect of convection, and the absence of perfusion. Median steady state temperatures simulated with the novel convective model (3) deviated on average -0.6 °C (-12%) from values measured during treatment, compared to -3.7 °C (-71%) and +1.5 °C (+29%) deviation for the muscle-like (1) and static (2) models, respectively. The Grashof number was 3.2 ± 1.5 × 10⁵ (mean ± SD).

CONCLUSIONS

Incorporating fluid modeling in hyperthermia treatment planning yields significantly improved predictions of the temperature distribution in the bladder lumen during hyperthermia treatment.

Immunology, Immunotherapy, and Translating Basic Science into the Clinic for Bladder Cancer

The Fourth Annual Albert Institute Bladder Cancer Care and Research Symposium was held from September 14th–16th in Houston, Texas. The symposium covered a range of topics relevant to bladder cancer, including basic science aspects of immunology and immunotherapy that inform clinical management; intravesical therapy for non-muscle invasive disease; understanding the nuances of carcinoma in situ; and optimizing patient care and outcomes following therapy. The moving landscape of bladder cancer from an industry perspective was also discussed.

In the following sections we discuss intrinsic and extrinsic factors, including the immune microenvironment and sex bias, in the context of bladder cancer; how these influence tumor development, progression, and treatment strategies; and how the interpretation of immune features in relation to molecular subtypes informs both treatment decisions and response. We conclude with a summary of key points that will need to be addressed to ensure best use of new knowledge in this area for improved clinical management of patients with bladder cancer.

The effect of air pockets in the urinary bladder on the temperature distribution during loco-regional hyperthermia treatment of bladder cancer patients

PURPOSE

Loco-regional hyperthermia combined with mitomycin C is used for treatment of nonmuscle invasive bladder cancer (NMIBC). Air pockets may be present in the bladder during treatment. The aim of this study is to quantify the effect of air pockets on the thermal dose of the bladder.

METHODS

We analysed 16 patients treated for NMIBC. Loco-regional hyperthermia was performed with the in-house developed 70 MHz AMC-4 hyperthermia device. We simulated treatments with the clinically applied device settings using Plan2Heat (developed in-house) including the air pockets delineated on CT scans made following treatment, and with the same volume filled with urine. Temperature distributions simulated with and without air pockets were compared.

RESULTS

The average air and fluid volumes in the bladder were 6.0 ml (range 0.8 - 19.3 ml) and 183 ml (range 47-322 ml), respectively. The effect of these air pockets varied strongly between patients. Averaged over all patients, the median bladder wall temperature (T₅₀) remained unchanged when an air pocket was present. Temperature changes exceeded ±0.2 °C in, on average, 23% of the bladder wall volume (range 1.3-59%), in 6.0% (range 0.6-20%) changes exceeded ±0.5 °C and in 3.2% (range 0.0-7.4%) changes exceeded ±1.0 °C. There was no correlation between the differences in temperature and the air pocket or bladder volume. There was a positive correlation between air pocket surface and temperature heterogeneity.

CONCLUSION

Presence of air causes more heterogeneous bladder wall temperatures and lower T₉₀, particularly for larger air pockets. The size of air pockets must therefore be minimized during bladder hyperthermia treatments.

Locoregional hyperthermia of deep-seated tumours applied with capacitive and radiative systems: a simulation study

BACKGROUND

Locoregional hyperthermia is applied to deep-seated tumours in the pelvic region. Two very different heating techniques are often applied: capacitive and radiative heating. In this paper, numerical simulations are applied to compare the performance of both techniques in heating of deep-seated tumours.

METHODS

Phantom simulations were performed for small (30 × 20 × 50 cm³) and large (45 × 30 × 50 cm³), homogeneous fatless and inhomogeneous fat-muscle, tissue-equivalent phantoms with a central or eccentric target region. Radiative heating was simulated with the 70 MHz AMC-4 system and capacitive heating was simulated at 13.56 MHz. Simulations were performed for small fatless, small (i.e. fat layer typically <2 cm) and large (i.e. fat layer typically >3 cm) patients with cervix, prostate, bladder and rectum cancer. Temperature distributions were simulated using constant hyperthermic-level perfusion values with tissue constraints of 44 °C and compared for both heating techniques.

RESULTS

For the small homogeneous phantom, similar target heating was predicted with radiative and capacitive heating. For the large homogeneous phantom, most effective target heating was predicted with capacitive heating. For inhomogeneous phantoms, hot spots in the fat layer limit adequate capacitive heating, and simulated target temperatures with radiative heating were 2-4 °C higher. Patient simulations predicted therapeutic target temperatures with capacitive heating for fatless patients, but radiative heating was more robust for all tumour sites and patient sizes, yielding target temperatures 1-3 °C higher than those predicted for capacitive heating.

CONCLUSION

Generally, radiative locoregional heating yields more favourable simulated temperature distributions for deep-seated pelvic tumours, compared with capacitive heating. Therapeutic temperatures are predicted for capacitive heating in patients with (almost) no fat.

Solubilization and Stability of Mitomycin C Solutions Prepared for Intravesical Administration

BACKGROUND

Mitomycin C (MMC) is an antitumor agent that is often administered intravesically to treat bladder cancer. Pharmacologically optimized studies have suggested varying methods to optimize delivery, with drug concentration and solution volume being the main drivers. However, these MMC concentrations (e.g. 2.0 mg/mL) supersede its solubility threshold, raising major concerns of inferior drug delivery.

OBJECTIVE

In this study, we seek to confirm that the pharmacologically optimized MMC concentrations are achievable in clinical practice through careful modifications of the solution preparation methods.

METHODS

MMC admixtures (1.0 and 2.0 mg/mL) were prepared in normal saline using conventional and alternative compounding methods. Conventional methodology resulted in poorly soluble solutions, with many visible particulates and crystallates. However, special compounding methods, which included incubation of solutions at 50 °C for 50 min followed by storage at 37 °C, were sufficient to solubilize drug. Chemical degradation of MMC solutions was determined over 6 h using high-performance liquid chromatography (HPLC) analytics, while physical stability was tested in parallel.

RESULTS

Immediately following the 50 min incubation, both MMC solutions exhibited approximately 5-7% drug degradation. Based on the measured concentrations and linear regression of degradation plots, additional storage of these solutions at 37 °C for 5 h retained chemical stability criterion (< 10% overall drug loss). No physical changes were observed in any solutions at any test time points.

CONCLUSION

We recommend that the described alternative preparation methods may improve intravesicular delivery of MMC in this urological setting, and advise that clinicians employing these changes should closely monitor patients for MMC toxicities and pharmacodynamics (change in clinical outcomes) that result from the potential enhancement of MMC exposure in the bladder.

Bladder intracavitary hyperthermic perfusion chemotherapy for the prevention of recurrence of non-muscle invasive bladder cancer after transurethral resection

Preventing the recurrence of non-muscle invasive bladder cancer (NMIBC) post-transurethral resection (TUR) remains challenging. The aim of the present study was to investigate the effectiveness and safety of bladder intracavitary hyperthermic perfusion chemotherapy (BHPC) for prevention of NMIBC recurrence post-TUR. Between December 2006 and December 2014, 53 patients with NMIBC who underwent TUR were randomly assigned to receive BHPC (BHPC group, 28 patients) or intravesical chemotherapy alone (chemotherapy group, 25 patients) at the Intracelom Hyperthermic Perfusion Therapy Center of Guangzhou Medical University Cancer Hospital (Guangzhou, China). BHPC was performed by combining perfusion-based hyperthermia with chemotherapeutic agent mitomycin C (MMC) in the bladder, and the chemotherapy group of patients received bladder MMC perfusion. The concentration of MMC in the perfusion fluid and serum were assessed at different time-points. Tumor recurrence, disease-free survival (DFS), and side-effects were recorded and compared between the 2 groups. Results revealed that BHPC was performed smoothly, at ~44̊C in the bladder cavity. Patients tolerated BHPC, and no side-effects were observed. Both BHPC and intravesical chemotherapy achieved a high MMC concentration in the bladder perfusion liquid, but low MMC concentration in the serum, although serum MMC concentrations in the BHPC group were significantly higher (P<0.05). The tumor recurrence rate was significantly lower (10.7 vs. 28.0%; P=0.02) and the DFS period was significantly longer (37±1.2 vs. 19±0.9 months; P=0.001) in the BHPC group than in the chemotherapy group. Our results demonstrated that BHPC is safe and effective for preventing NMIBC recurrence post-TUR and prolongs DFS.

New developments in the management of nonmuscle invasive bladder cancer

PURPOSE OF REVIEW

In this review, we summarize the core principles in the management of nonmuscle invasive bladder cancer (NMIBC) with an emphasis on new developments that have emerged over the last year.

RECENT FINDINGS

NMIBC has a propensity to recur and progress. Risk stratification has facilitated appropriate patient selection for treatment but improved tools, including biomarkers, are still needed. Enhanced cystoscopy with photodynamic imaging and narrow band imaging show promise for diagnosis, risk stratification, and disease monitoring and has been formally recommended this year by the American Urological Association. Attempts at better treatment, especially in refractory high-risk cases, include the addition of intravesical hyperthermia, combination and sequential therapy with existing agents, and the use of novel agents such as mycobacterial cell wall extract. New data are emerging regarding the potential role of early cystectomy in bacillus Calmette-Guerin-refractory NMIBC patients.

SUMMARY

NMIBC represents an assortment of disease states and continues to pose management challenges. Continued research is needed to bolster the evidence needed for patients and providers to make data-driven treatment decisions.

A systematic review of regional hyperthermia therapy in bladder cancer

CONTEXT

Bladder cancer therapy remains suboptimal as morbidity and mortality remain high amongst those with non-muscle-invasive and muscle-invasive disease. Regional hyperthermia therapy (RHT) is a promising adjunctive therapy being tested in multiple clinical contexts.

OBJECTIVE

The aim of this study was to systematically review the literature on the efficacy and toxicity of RHT.

EVIDENCE ACQUISITION

This systematic review was registered with the PROSPERO database (Registration number: CRD42015025780) and was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. We queried PubMed, EMBASE, and Cochrane libraries. Two reviewers reviewed abstracts independently and a third reviewer arbitrated disagreements. The last search was performed on 28 August 2015. A descriptive analysis was performed and quality assessment was conducted using the Newcastle-Ottawa Quality Assessment Scale for observational studies, and the Cochrane Risk of Bias Assessment Tool for trials.

EVIDENCE SYNTHESIS

We identified 859 publications in the initial search, of which 24 met inclusion criteria for full-text review. Of these, we were able to obtain data on the outcomes of interest for 15 publications.

CONCLUSIONS

The review underscores the limited nature of the evidence; definitive conclusions are elusive. However, the promising results of RHT in the setting of intravesical chemotherapy, chemotherapy and radiotherapy show a trend towards legitimate efficacy.

Natural biology and management of nonmuscle invasive bladder cancer

PURPOSE OF REVIEW

This article reviews the natural biology of noninvasive bladder cancer and its management strategies while summarizing the most recent advances in the field.

RECENT FINDINGS

Nonmuscle invasive bladder cancer (NMIBC) has a tendency to recur and progress. Risk stratification has helped triage patients but improved tools, including biomarkers, are still needed. Enhanced endoscopy with photodynamic imaging, narrow band imaging, optical coherence tomography and confocal laser endomicroscopy show promise for diagnosis, risk stratification and disease monitoring. Attempts at better treatment, especially in refractory high-risk cases, include the addition of intravesical hyperthermia, combination and sequential therapy with existing agents and the use of novel agents such as mycobacterial cell wall extract. New data are emerging regarding the potential role of active surveillance in low-risk patients.

SUMMARY

NMIBC represents a variety of disease states and continues to pose management challenges. As our understanding of tumor biology improves and technology advances, achieving better outcomes through individualized care may be possible.

Improving efficacy of hyperthermia in oncology by exploiting biological mechanisms

It has long been established that hyperthermia increases the therapeutic benefit of radiation and chemotherapy in cancer treatment. During the last few years there have been substantial technical improvements in the sources used to apply and measure heat, which greatly increases enthusiasm for the clinical use of hyperthermia. These advances are converging with a better understanding of the physiological and molecular effects of hyperthermia. Therefore, we are now at a juncture where the parameters that will influence the efficacy of hyperthermia in cancer treatment can be optimised in a more systematic and rational manner. In addition, the novel insights in hyperthermia's many biological effects on tumour cells will ultimately result in new treatment regimes. For example, the molecular effects of hyperthermia on the essential cellular process of DNA repair suggest novel combination therapies, with DNA damage response targeting drugs that should now be clinically explored. Here, we provide an overview of recent studies on the various macroscopic and microscopic biological effects of hyperthermia. We indicate the significance of these effects on current treatments and suggest how they will help design novel future treatments.

Chemohyperthermia in non-muscle-invasive bladder cancer: An overview of the literature and recommendations

Non-muscle-invasive bladder cancer (NMIBC) is characterised by a high risk of recurrence for the present standard treatment of transurethral resection of the bladder (TURB) followed by intravesical instillation of Mitomycin-C (MMC) or bacillus Calmette-Guérin (BCG). To decrease this high recurrence rate, alternative treatments are studied. Intravesical MMC combined with hyperthermia could be an interesting alternative active treatment for intermediate- and high-risk NMIBC, and has been investigated in the past years. Hyperthermia, raising tumour temperatures to 40-44 °C, can be achieved with several hyperthermia systems, based on three different techniques: 1) intravesical microwave induced heating, 2) conductive heating, and 3) loco-regional, using external radiofrequency antennas. In this review an overview is given of the available hyperthermia systems and the reported outcomes. Future directions are discussed. Optimal implementation of a combined regimen of MMC and hyperthermia requires further clinical trials to identify patients who will benefit most from this treatment, to optimise treatment schedules and to compare the efficacy of different hyperthermia devices.

Rationale of hyperthermia for radio(chemo)therapy and immune responses in patients with bladder cancer: Biological concepts, clinical data, interdisciplinary treatment decisions and biological tumour imaging

Bladder cancer, the most common tumour of the urinary tract, ranks fifth among all tumour entities. While local treatment or intravesical instillation of bacillus Calmette-Guerin (BCG) provides a treatment option for non-muscle invasive bladder cancer of low grade, surgery or radio(chemo)therapy (RT) are frequently applied in high grade tumours. It remains a matter of debate whether surgery or RT is superior with respect to clinical outcome and quality of life. Surgical resection of bladder cancer can be limited by acute side effects, whereas, RT, which offers a non-invasive treatment option with organ- and functional conservation, can cause long-term side effects. Bladder toxicity by RT mainly depends on the total irradiation dose, fraction size and tumour volume. Therefore, novel approaches are needed to improve clinical outcome. Local tumour hyperthermia is currently used either as an ablation therapy or in combination with RT to enhance anti-tumour effects. In combination with RT an increase of the temperature in the bladder stimulates the local blood flow and as a result can improve the oxygenation state of the tumour, which in turn enhances radiation-induced DNA damage and drug toxicity. Hyperthermia at high temperatures can also directly kill cells, particularly in tumour areas which are poorly perfused, hypoxic or have a low tissue pH. This review summarises current knowledge relating to the role of hyperthermia in RT to treat bladder cancer, the induction and manifestation of immunological responses induced by hyperthermia, and the utilisation of the stress proteins as tumour-specific targets for tumour detection and monitoring of therapeutic outcome.

Hyperthermia treatment planning for cervical cancer patients based on electrical conductivity tissue properties acquired in vivo with EPT at 3 T MRI

Introduction The reliability of hyperthermia treatment planning (HTP) is strongly dependent on the accuracy of the electric properties of each tissue. The values currently used are mostly based on ex vivo measurements. In this study, in vivo conductivity of human muscle, bladder content and cervical tumours, acquired with magnetic resonance-based electric properties tomography (MR-EPT), are exploited to investigate the effect on HTP for cervical cancer patients. Methods Temperature-based optimisation of five different patients was performed using literature-based conductivity values yielding certain antenna settings, which are then used to compute the temperature distribution of the patient models with EPT-based conductivity values. Furthermore, the effects of altered bladder and muscle conductivity were studied separately. Finally, the temperature-based optimisation was performed with patient models based on EPT conductivity values. Results The tumour temperatures for all EPT-based dielectric patient models were lower compared to the optimal tumour temperatures based on literature values. The largest deviation was observed for patient 1 with ΔT90 = -1.37 °C. A negative impact was also observed when the treatment was optimised based on the EPT values. For four patients ΔT90 was less than 0.6 °C; for one patient it was 1.5 °C. Conclusions Electric conductivity values acquired by EPT are higher than commonly used from literature. This difference has a substantial impact on cervical tumour temperatures achieved during hyperthermia. A higher conductivity in the bladder and in the muscle tissue surrounding the tumour leads to higher power dissipation in the bladder and muscle, and therefore to lower tumour temperatures.

Overview of bladder heating technology: matching capabilities with clinical requirements

Moderate temperature hyperthermia (40-45°C for 1 h) is emerging as an effective treatment to enhance best available chemotherapy strategies for bladder cancer. A rapidly increasing number of clinical trials have investigated the feasibility and efficacy of treating bladder cancer with combined intravesical chemotherapy and moderate temperature hyperthermia. To date, most studies have concerned treatment of non-muscle-invasive bladder cancer (NMIBC) limited to the interior wall of the bladder. Following the promising results of initial clinical trials, investigators are now considering protocols for treatment of muscle-invasive bladder cancer (MIBC). This paper provides a brief overview of the devices and techniques used for heating bladder cancer. Systems are described for thermal conduction heating of the bladder wall via circulation of hot fluid, intravesical microwave antenna heating, capacitively coupled radio-frequency current heating, and radiofrequency phased array deep regional heating of the pelvis. Relative heating characteristics of the available technologies are compared based on published feasibility studies, and the systems correlated with clinical requirements for effective treatment of MIBC and NMIBC.