Does standardization of radiofrequency hyperthermia benefit patients with malignancies?

Abstract

Background: Hyperthermia has not been approved as a standard treatment method in oncology. One of the major problems is that there is no reference point for this therapy. Another problem is that radiofrequency hyperthermia has a fatal flaw, the hot spot phenomenon, which does not allow continuation of treatment without lowering the output. Patients and Methods: Hyperthermia treatment was administered either alone or concomitantly with chemotherapy and/ or radiotherapy to 76 consecutive patients with malignancies, using Thermotron RF-8, between December 2011 and April 2014. Radiofrequency hyperthermia was administered 5 times for 5 weeks with 50 min irradiation in all patients. Results: Complete response (CR) was seen in 35.2% of primary cases, but in 4.5% of recurrent cases, and this rate was higher in patients with three days after first chemoradiation. There was significant correlation among the initial irradiation output at which complications occurred, initial time at which complications occurred and the physical status of the patients, such as visceral fat area. All patients with CR had significantly higher increased body temperature than the other patients. However, patients with progressive disease and 17 or more Hidaka output points showed significantly higher increased body temperature than patients with partial response or stable disease. Conclusions: Patients with CR had higher temperatures, but some patients with higher temperature also showed progressive disease. Further studies to examine the discrepancy between the clinical and histological response by using a large sample of surgically resected cases and to validate and reconfirm our findings are warranted.

The first thermic treatment predicts following chemoradiation response with concurrent thermal therapy for the treatment of rectal cancer

“…Thermic treatment was administered using the Thermotron-RF 8 (Yamamoto Vinita Co., Ltd., Osaka, Japan) once per week for 5 weeks with 50 min irradiation. Precise methods of thermal therapy were described elsewhere (16,17,19,20).…”

“…Meanwhile, radiofrequency (RF) hyperthermia using the Thermotron-RF 8 has been administered mainly in Japan but incurs a risk of the 'hotspot' phenomenon, a potentially fatal complication induced by RF treatment itself. To resolve this problem, we established thermal therapy with standardized power escalation principles, i.e., 'neothermia,' and devised a predictive formula for output-limiting symptoms (16,17) which had an adjusted R 2 of 0.99 and variance inflation factor (VIF) values <2. This formula, is as follows: Initial energy output at which an output limiting symptom occurred (Watt)=initial time at which an output limiting symptom occurred (min) x6.162-the thickness of the fat of the abdominal wall (mm)…”

Heating Preciosity—Trends in Modern Oncological Hyperthermia

“…Interestingly, a recent study found that the local control was better when less energy was administered than was prescribed [55].…”

Gross tumor volume is a good predictor of rectal cancer tumor response before chemoradiation with concurrent thermal therapy

“…address the former, we established a standardized thermic treatment 16,17) . To address the latter, we developed a predictive formula for output limiting symptoms 18) , which had an adjusted R 2 of 0.99 and variance inflation factor (VIF) values < 2.…”

“…T her m ic t reatment was per for med usi ng t he Thermotron-RF8 (Yamamoto Vinita Co., Ltd., Japan) once a week for 5 weeks each with 50 min irradiation. Precise methods of thermal therapy were described elsewhere 16,17) . A sensor catheter with four temperature points was attached to the skin on the lateral abdomen of 68 patients.…”