Between September 1985 and December 1986, 44 N3 (TNM-UICC) metastatic squamous cell cervical lymph-nodes were randomized to receive conventionally fractionated radical irradiation (RT) to a total dose of 64-70 Gy, or conventionally fractionated radical irradiation plus twice a week local microwave hyperthermia (Ht). The two major end points of this study were (a) local control rates evaluated at 3 months after the end of combined therapy and (b) incidence of acute local toxicity. Thirty-six nodes (82%) were evaluable as of December 1986, at which time there was a premature closure of this study due to ethical reasons. An interim analysis had revealed a statistically significant difference in complete response rates in favor of the combined arm (p = 0.0152). The complete response rates were 82.3% (14/17) for the combined treatment arm versus 36.8% (7/19) for the control irradiation arm, leading to an iso-dose thermal enhancement ratio (TER) value of 2.23. Both arms are comparable in average total RT dose delivered (RT: 67.05 Gy; RT + Ht: 67.85 Gy) and in average maximum node diameter (RT arm: 4.81 cm; RT + Ht: 4.88 cm). Acute local toxicities were similar in irradiated and heated plus irradiated neck regions; only one skin burn was observed. As possible treatment related death, one patient in the RT + Ht arm died 2 months after completion of therapy with a carotid rupture associated with extensive tumor necrosis. These results confirm previous non-randomized reports suggesting that hyperthermia in combination with full dose conventionally fractionated irradiation significantly enhances the chance of early local control of fixed N3 neck nodes without exhibiting an increase of acute local toxicity.

Radical radiation alone versus radical radiation plus microwave hyperthermia for N3 (TNM-UICC) neck nodes: a prospective randomized clinical trial

The Bezold-Jarisch reflex is an eponym for a triad of responses (apnea, bradycardia, and hypotension) following intravenous injection of veratrum alkaloids in experimental animals. The observation was first reported in 1867 by von Bezold and Hirt, and confirmed in 1938–1940 by Jarisch. The triad depends on intact vagi and is mediated through cranial nervous medullary centers controlling respiration, heart rate, and vasomotor tone. The respiratory effects are mediated through pulmonary vagal afferents and the bradycardia and vasodepression through cardiac vagal afferents. The veratrum alkaloids activate all known receptors in the carotid-aortic and cardiopulmonary areas. The cardiopulmonary receptors (baroreceptors, cough receptors, and parenchymal stretch receptors) also respond to other chemical substances: nicotine, capsaicin, venom, antihistaminics, halogenated anesthetics, diguanides, and serotonin (5-hydroxytryptamine). Derivatives of last-mentioned amine activate Type 1, 2, or 3 receptors and have potential therapeutic use. Since several types of cardiopulmonary receptors participate in the Bezold-Jarisch reflex, it has been difficult to develop a blockade to one type of receptor for therapeutic use (cough, bronchospasm, pulmonary hypertension, or coronary vasospasm). Axon reflexes influence pulmonary blood vessels, bronchial blood vessels, and bronchial smooth muscles. These intrapulmonary reflexes need further study as to how they relate to the Bezold-Jarisch reflex in health and disease. The cardiopulmonary and carotid-aortic reflexes can serve as defense mechanisms against chemical hazards that are likely to be inhaled in the workplace and in the environment.

The Bezold-Jarisch Reflex

Particle beam therapy (hadrontherapy): basis for interest and clinical experience.

Neon ion radiotherapy possesses biologic and physical advantages over megavoltage X rays. Biologically, the neon beam reduces the oxygen enhancement ratio and increases relative biological effectiveness. Cells irradiated by neon ions show less variation in cell-cycle related radiosensitivity and decreased repair of radiation injury. The physical behavior of heavy charged particles allows precise delivery of high radiation doses to tumors while minimizing irradiation of normal tissues. In 1979 a Phase I-II clinical trial was started at Lawrence Berkeley Laboratory using neon ions to irradiate patients for whom conventional treatment modalities were ineffective. By the end of 1988 a total of 239 patients had received a minimum neon physical dose of 1000 cGy (median follow-up for survivors 32 months). Compared with historical results, the 5-year actuarial disease-specific survival (DSS5) and local control (LC5) rates suggest that neon treatment improves outcome for several types of tumors: a) advanced or recurrent macroscopic salivary gland carcinomas (DSS5 59%; LC5 61%); b) paranasal sinus tumors (DSS5 69%; LC5 69% for macroscopic disease); c) advanced soft tissue sarcomas (DSS5 56%, LC5 56% for macroscopic disease); d) macroscopic sarcomas of bone (DSS5 45%; LC5 59%); e) locally advanced prostate carcinomas (DSS5 90%; LC5 75%); and f) biliary tract carcinomas (DSS5 28%; LC5 44%). Treatment of malignant gliomas, pancreatic, gastric, esophageal, lung, and advanced or recurrent head and neck cancer has been less successful; results for these tumors appear no better than those achieved with conventional x-ray therapy. These findings suggest that Phase III trials using the neon beam should be implemented for selected malignancies.

Neon ion radiotherapy: Results of the phase I/II clinical trial

The present paper overviews the current knowledge about effects of hyperthermia at temperatures used in clinical oncology on the peripheral nervous system. From the experimental studies it may be concluded that the heat sensitivity of the nerve is determined by the sensitivity of the nerve vasculature. These studies show that in order to avoid induction of severe neuropathy, application of heat to the peripheral nerves should not be in excess of doses of 30 min at 44 degrees C or equivalent. Using modern equipment for application of loco-regional hyperthermia the incidence of even mild neurological complications is very low. In hyperthermic isolated limb perfusion (HILP) neurotoxicity is an often-mentioned side effect, this is in spite of the fact that in all studies a relatively mild hyperthermic temperature is used that, based on the experimental studies, should be well tolerated by the nerves and other normal tissues in the limbs. It seems that the neurotoxicity observed after HILP results from thermal enhancement of drug toxicity, very probably combined with effects of a high tourniquet pressure that is used to isolate the blood flow in the leg. Whole body hyperthermia (WBH), using anesthesia and appropriate monitoring to avoid cardiovascular stress is at present considered a safe procedure. Still in the recent past cases of neuropathy after treatment have been described. When chemotherapy, and notably cisplatin, is administered before or during hyperthermia there are several clinical and experimental observations that indicate a limited tolerance of the peripheral nervous tissue in such case. Also previous radiotherapy may limit the tolerance of nerves to hyperthermia, notably when radiation is applied with a large field size. Experimental studies show that combined treatment with radiation and heat leads to enhancement of effects of radiation (enhancement ratio approximately 1.5 at 60 min at 44 degrees C). A clear contraindication for the application of hyperthermia in patients is the presence of a neurodegenerative disease, such as multiple sclerosis. Vigilance is also required in the treatment of diabetic patients with hyperthermia, this based on experimental animal studies, but so far no clear clinical data are available.

https://www.tandfonline.com/doi/pdf/10.1080/02656730310001637631

Effects of hyperthermia on the peripheral nervous system: a review

Sixteen patients with inoperable soft tissue sarcomas were treated definitively with fast neutrons at the University of Washington between August, 1970 and May, 1982. Eleven of these 16 patients were treated with curative intent and form the basis of this report. Actuarial plots are shown for local tumor control and survival. This work is placed in the context of worldwide experience in using fast neutrons to treat unresectable soft tissue sarcomas.

Fast neutron radiotherapy for soft tissue sarcomas. University of Washington experience and review of the world's literature.

A case report of a hypotensive episode occurring during a microwave hyperthermia treatment is reported. Microwave hyperthermia was delivered using 915 MHz externally applied energy. The tumor being treated was either a superficial lymph node or local recurrence in the subdigastric region overlying the carotid artery. During the patient's treatment, she reported symptomatology consistent with a neuropathy which is characterized by its association with microwave energy. As the treatment progressed the patient developed syncopy, hypotension, and bradycardia similar to a Bezold-Jarisch reflex. All of these conditions promptly self-corrected when the microwave energy was discontinued. This event can be explained by a transient microwave induced neuropathy specifically involving the carotid body or sinus.

J. D. Del Rowe

Papers

Fast neutron radiotherapy for soft tissue sarcomas. University of Washington experience and review of the world's literature.

A transient hypotensive episode (Bezold-Jarisch effect) occurring in a patient treated with microwave hyperthermia.

Fast neutron radiotherapy for soft tissue sarcomas: University of Washington experience and review of the world's literature

A single-arm open label phase II study of intravenously administered tirapazamine for glioblastoma multiforme (GBM)—An RTOG study