Hyperthermic Enhancement of Immunotherapy: Findings of In Vitro Modeling

PURPOSE/OBJECTIVE(S)

Despite advancement in understanding and manipulation of immune checkpoint molecules in immunotherapeutic design, limitations in treatment efficacy persist. Strategies to enhance effectiveness include use of multiple immunotherapeutic agents or combination with radiation therapy. Prior studies have also shown potential for hyperthermia to augment response to both of these therapeutic modalities. We hypothesized that in vitro assessment of moderate hyperthermia effects on the anti-tumor immune response will aid in development of targeted strategies that best combine hyperthermia with other immune manipulating therapies.

MATERIALS/METHODS

To understand the consequences of temperature on carcinogenic phenotypes in vitro, B16-F10 melanoma cells were grown at 37°C or 41°C and biochemical profiles including protein expression were evaluated. Impact of hyperthermia on cell migration and proliferation were also assessed as were changes in the immune milieu including cytokine expression in response to heat. Data obtained was used to define ongoing in vivo experiments in which B16-F10 cells are implanted into C57BL/6 mice, grown to palpable tumors than treated with infrared radiation in combination with either anti-PDL1, anti-PD-1, or IL-15. Future studies based on these initial in vivo studies will explore integration of radiotherapy with hyperthermia and immunotherapy.

RESULTS

B16-F10 cells grown at 41°C decreased cell migration by 70% in 24 hours, and decreased proliferation by 62% at 48 hours and 94% at 72 hours. To assess biochemical orchestrations exemplified by these data, protein expression profiles were evaluated. Expression of pERK and ERK decreased by 86% and 50% and caspase-3 increased by 31% at 41°C. Activation of sphingomyelinase and caspase-3 both rely on caspase-8. Sphingomyelinase activation results in CD95 receptor translocation, leading to cell death initiation in melanoma cells. Cell stress can induce death pathways and the heat shock protein response simultaneously. Of note, Hsp70 has an established role in fostering a tumor specific immune response. Thus, we investigated inducible hsp70 expression. Hsp70 expression increased by 188% at 41°C vs. 37°C. To evaluate the immune milieu, cytokine array data from conditioned media showed that at 41°C, TNFa expression was increased and IL-4 expression was decreased, suggesting a proinflammatory shift in cytokine profiles at hyperthermic temperatures. In support of our data, hyperthermia-induced TNFa apoptotic responses have been reported. In direct relation to clinical practice, we observed that hyperthermic potentiation decreased PDL1 expression in B16-F10 by 35%.

CONCLUSION

Our work to date supports the hypothesis that hyperthermia can enhance immunotherapy via several mechanisms. In vivo study of the ability of hyperthermia to augment immune modulating therapies such as checkpoint blockade and radiation therapy is warranted.

Quality assurance guidelines for interstitial hyperthermia

Quality assurance (QA) guidelines are essential to provide uniform execution of clinical hyperthermia treatments and trials. This document outlines the clinical and technical consequences of the specific properties of interstitial heat delivery and specifies recommendations for hyperthermia administration with interstitial techniques. Interstitial hyperthermia aims at tumor temperatures in the 40-44 °C range as an adjunct to radiation or chemotherapy. The clinical part of this document imparts specific clinical experience of interstitial heat delivery to various tumor sites as well as recommended interstitial hyperthermia workflow and procedures. The second part describes technical requirements for quality assurance of current interstitial heating equipment including electromagnetic (radiative and capacitive) and ultrasound heating techniques. Detailed instructions are provided on characterization and documentation of the performance of interstitial hyperthermia applicators to achieve reproducible hyperthermia treatments of uniform high quality. Output power and consequent temperature rise are the key parameters for characterization of applicator performance in these QA guidelines. These characteristics determine the specific maximum tumor size and depth that can be heated adequately. The guidelines were developed by the ESHO Technical Committee with participation of senior STM members and members of the Atzelsberg Circle.

Prognostic implications for gadolinium enhancement of the meninges in low-grade astrocytomas of childhood

BACKGROUND

Persistent gadolinium enhancement on MRI of the meninges in some children with low-grade astrocytomas (LGA) is a widely recognized phenomenon. The relationship of this finding with the clinical course is unclear.

METHODS

From a consecutive cohort of 282 children with pathologically confirmed LGA we identified all patients with asymptomatic gadolinium enhancement of the meninges found on surveillance MRI. A nested case-control study was performed, comparing patients with meningeal enhancement to controls without enhancement.

RESULTS

Twenty-one children were identified with meningeal enhancement. The median follow-up was 5.2 years with enhancement noted for a median of 2.2 years. The 5-year overall survival for this cohort was 91.2% (Greenwood SE 8.0%), and the 5-year progression-free survival was 20.9% (SE 11.9%). Five patients are now free of disease, while 15 continue to have stable disease. The overall and progression-free survival was not significantly different compared to controls.

CONCLUSIONS

Gadolinium enhancement of the meninges on MRI may occur in a significant number of children with LGA, particularly juvenile pilocytic astrocytoma, but does not appear to affect progression-free or overall survival. Change in management based on this finding alone is unwarranted.

Feasibility and patient tolerance of a novel transrectal ultrasound hyperthermia system for treatment of prostate cancer

This report describes patient tolerance and toxicity of a transrectal ultrasound hyperthermia system used with external beam radiation therapy in treatment of locally advanced prostate cancer. Nine patients with clinical T2B-T3B (4th edition AJCC criteria) disease received external beam radiation therapy, with two hyperthermia treatments scheduled at least 1 week apart during the first 4 weeks of radiation. Five patients also received hormonal therapy. Interstitial and anterior rectal wall thermometry were performed. Median temperature for each treatment (T50) was 40.8 degrees C and mean CEM T90 = 43 degrees C was 3.4 min. Rectal wall temperature was maintained at < or = 40 degrees C. Treatment duration was limited in three of 17 sessions due to positional discomfort which was alleviated with light IV sedation and use of a 'New Life' mattress (Comfortex, Inc. Winoba, MN, USA). Acute toxicity was limited to NCI common toxicity criteria grade 1 and no excess toxicity was noted with full course radiation therapy +/- hormonal therapy. These findings are consistent with those reported in a previous phase I trial assessing this device. Given the favourable toxicity profile demonstrated to date, modification of treatment parameters for this ongoing phase II study have been instituted that should further the efficacy of transrectal ultrasound hyperthermia for treatment of prostate cancer.

Identifying the predictors of acute urinary retention following magnetic-resonance-guided prostate brachytherapy

PURPOSE

Larger prostate gland volumes have been associated with long-term urinary morbidity in prostate interstitial radiation therapy utilizing ultrasound image guidance technique. This study was performed to identify the clinical and technical predictors of acute urinary retention following magnetic-resonance (MR)-guided prostate interstitial brachytherapy.

METHODS AND MATERIALS

Fifty patients underwent MR-guided prostate brachytherapy between December 1997 and March 1999. Patient selection was limited to men with stage T1cNXM0 disease, PSA of less than10 ng/mL, biopsy Gleason score not more than 3 + 4, and endorectal coil MR stage T2 disease. Dosimetry plans were developed in the operating room and (125)Iodine sources were implanted using MR real-time guidance. The peripheral zone (PZ) of the prostate gland was defined as the clinical target volume (CTV) and the minimum prescribed dose to the CTV was 137 Gy. The volumes of the PZ, transition zone (TZ), and total prostate gland volume were also determined by MR. Individual source strength ranged from 0.35 to 0.54 microGym(2)/h (NIST 99, median 0.46 microGym(2)/h) and the total implanted activity ranged from 17.0 to 43.1 mCi (median, 28.1 mCi) using 43-120 seeds (median, 79). The seeds were placed using MR-compatible biopsy needles (14-28, median, 19).

RESULTS

The ability of clinical (MR defined prostate, PZ, and TZ volumes) and technical (number of catheters, number of seeds implanted, and total activity) factors to predict AUR for 50 men undergoing MR-guided prostate interstitial brachytherapy were evaluated using univariable and logistic regression multivariable analyses. Six men (12%) experienced AUR within 24 h after removal of the Foley catheter subsequent to prostate brachytherapy. The total number of seeds (p = 0.05), MR determined prostate volume (p < 0.01), and the MR-determined TZ volume (p < 0.01) were significant predictors of AUR on univariable analysis. Utilizing a multivariable logistic regression analysis, the TZ volume was the only significant predictor of AUR (p < 0.01). The prostate volume is highly correlated to the TZ volume (Spearman correlation coefficient of 0. 91) and was thus significant in the univariable analysis; however, the prostate volume did not add prognostic value in multivariable analysis.

CONCLUSION

Benign prostatic hyperplasia (BPH) resulting in an enlarged TZ volume, is the most important predictor of AUR following MR-guided prostate interstitial radiation therapy. Although AUR was significant (60%) in men with moderate BPH (TZ volume >/= 50 cc), it was also self-limiting.

Three-dimensional real-time magnetic resonance-guided interstitial prostate brachytherapy optimizes radiation dose distribution resulting in a favorable acute side effect profile in patients with clinically localized prostate cancer

PURPOSE

A large number of men are diagnosed with early-stage prostate cancer as a result of prostate-specific antigen (PSA) screening. For many of these men, prostatectomy results in long-term freedom from biochemical and clinical failure. Despite limited follow-up data, ultrasound-guided prostate brachytherapy has gained acceptance as a treatment for early-stage prostate cancer, in part due to its favorable side effect profile and brief recovery period. We report on the use of three-dimensional real-time magnetic resonance (MR) guidance, which has several advantages compared with biplanar ultrasound guidance for prostate brachytherapy, including enhanced geometric and dosimetric feedback during the procedure.

MATERIALS AND METHODS

Median clinical target volume coverage of 96% was achieved using MR guidance. The ability to define more precisely the clinical target volume with MR and the use of real-time assessment of dose distribution resulted in an excellent acute side effect profile. Only 19% of patients required oral alpha1 blockers for postimplant urethritis and 9% required temporary reinsertion of the Foley catheter due to acute urinary obstruction.

CONCLUSIONS

These results compare favorably to those of ultrasound-guided brachytherapy. Further follow-up is needed to ascertain the impact this technique will have on cancer control and long-term quality of life.

Nuclear morphometry predicts disease-free interval for clinically localized adenocarcinoma of the prostate treated with definitive radiation therapy

Men treated for prostate cancer often have unexpected outcomes despite predictive models based on stage, grade and prostate-specific antigen (PSA). Previous results have indicated that nuclear morphometry can predict patient outcome in urologic malignancies. Application of this analytical method in prostate cancer treated with radiation therapy is limited. We have evaluated the predictive ability of nuclear morphometry in such patients. Histologic sections from 23 men with clinically localized adenocarcinoma of the prostate treated with radiation therapy were studied. Nuclear morphometric parameters were assessed using a previously described and validated system. Univariate and multivariate logistic regression analyses and a Cox proportional hazards model were used to assess the ability of nuclear morphometric parameters to predict recurrence and disease-free interval. Ten patients had no recurrence with median follow-up of 47. 5 months, while 13 had recurrence. Gleason grade was not predictive of treatment outcome. Pre-treatment PSA data, available for only 11 patients, were predictive of treatment outcome. Several nuclear morphometric parameters predicted recurrence, including upper quartile of suboptimal circle fit and upper quartile of feret-diameter ratio. A prognostic factor score incorporating these 2 parameters was derived, which predicted disease-free interval (p = 0.0014). Int. J. Cancer (Pred. Oncol.) 84:594-597, 1999.

Comparison of bacteraemic community-acquired lobar pneumonia due to Streptococcus pneumoniae and Klebsiella pneumoniae in an intensive care unit

In a study of 41 consecutive patients with bacteraemia-associated community-acquired lobar pneumonia due to Streptococcus pneumoniae and Klebsiella pneumoniae an attempt was made to determine whether distinguishing criteria of disease due to these organisms could be identified according to demographic features and the results of initial clinical and laboratory investigations. Such information would aid in the early initiation of appropriate antimicrobial therapy. The most significant difference between the two groups of patients was the lower platelet count in the K. pneumoniae group (p less than 0.005). In addition leucopenia (p less than 0.05), higher serum albumin (p less than 0.05), and the male sex (p less than 0.05) featured with an increased frequency in patients with pulmonary infection due to K. pneumoniae. Initial antimicrobial therapy in critically ill patients with community-acquired lobar pneumonia and thrombocytopenia, particularly when associated with leucopenia and in male patients, should include agents effective against K. pneumoniae.

Community-acquired pneumonia of diverse aetiology: prognostic features in patients admitted to an intensive care unit and a "severity of illness" core

In a retrospective study of 73 patients with community-acquired lobar pneumonia of diverse aetiology admitted to an intensive care unit, an attempt was made to identify those factors among the demographic and clinical features and results of initial laboratory investigations that were predictive of the ultimate outcome. A lower mean white cell count (p = 0.03), platelet count (p = 0.02), total serum protein (p = 0.005) and albumin (p = 0.02) and a higher mean serum creatinine (p = 0.03) and phosphate level (p = 0.02) appeared to be predictive of a poor prognosis. The most significant variable predictive of mortality, was the presence of bacteraemia (p = 0.0005). Severity of illness scoring systems by omitting microbiological data appear to underestimate predicted patient mortality. The mortality rate of critically ill patients with community-acquired lobar pneumonia remains high, despite advances in antimicrobial chemotherapy and intensive care unit facilities, particularly in the presence of certain negative prognostic factors of which the presence of bacteraemia is the most important.

Ankylosing spondylitis lung disease and Mycobacterium scrofulaceum

The development of apical pulmonary fibrosis and bullous disease is a rare but well recognized extra-articular manifestation of ankylosing spondylitis (AS). The fibrobullous disease is usually asymptomatic and diagnosed at an incidental radiological examination. When symptoms do develop, they are usually due to superimposed colonization or infection by bacteria, fungi or mycobacteria. Only six cases of non-tuberculous mycobacterial superinfection in AS have been reported. We report a patient with AS and progressive apical fibrobullous disease in whom Mycobacterium scrofulaceum was repeatedly cultured over a 12-year period.

Transbronchial biopsy during mechanical ventilation

The diagnostic yield and risks of transbronchial biopsy (TBB) during mechanical ventilation were assessed in 13 patients with progressive pulmonary infiltrates. TBB was of considerable diagnostic value in ten patients and useful in excluding potentially treatable infections in the remaining three patients. Complications included two pneumothoraces, pulmonary hemorrhage in one case, and supraventricular tachycardia in another. No fatalities were attributable to TBB. TBB proved to be a relatively safe procedure, with a high diagnostic yield in these critically ill patients.

Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) has become one of the most important of the opportunistic pulmonary infections of the 1980s. In view of the rapidly expanding population of immunosuppressed patients, many more cases of PCP may be expected in the future. The history, microbiology, pathogenesis, pathology, clinical and laboratory features, diagnosis, treatment, course and prognosis of this disease are reviewed.

Pneumocystis carinii pneumonia in Johannesburg

Pneumocystis carinii pneumonia is today an opportunistic infection of major importance, occurring in immunosuppressed patients. Twelve cases of P. carinii pneumonia were seen by the Pulmonology Unit in Johannesburg between November 1984 and December 1985. The clinical presentation, laboratory and radiographic features, method of diagnosis, treatment, complications of therapy and outcome of these 12 cases are described.

Blastomycosis. A case report

Blastomycosis was once thought to be restricted to North America; it has rarely been found in the RSA. The first case reported in the RSA was associated with a diffuse pulmonary infiltrate and cavitation; the patient responded to amphotericin B.

Toxic irreversible encephalopathy induced by lithium carbonate and haloperidol. A report of 2 cases

Toxic irreversible encephalopathic syndromes developed in 2 patients treated with lithium carbonate and haloperidol. Symptoms consisted of lethargy, fever, tremulousness, confusion, and extrapyramidal and cerebellar dysfunction, accompanied by leucocytosis and elevated serum enzyme, blood urea nitrogen, creatinine and fasting blood glucose levels. One patient suffered widespread irreversible brain damage; the other was left with persistent dyskinesias. Although causal factors have not been identified, this report and others in the literature suggest that diffuse irreversible encephalopathy may occasionally develop in individuals with abnormal brain sensitivity to the lithium carbonate/haloperidol combination. Evidence for this is based on the fact that in our patients and others mentioned in the literature the dosage and blood levels of lithium were not high.

The gonococcal arthritis-dermatitis syndrome. A case report

A case of gonococcal arthritis-dermatitis syndrome is reported and discussed. A plea is made for a greater awareness of its occurrence since a high index of suspicion is often required to make the diagnosis.