Mild hyperthermia as a localized radiosensitizer for deep-seated tumors: investigation in an orthotopic prostate cancer model in mice (original) (raw)
Related papers
2017
Objective: This study evaluated enhanced induced DNA damages and apoptosis of a spheroid culture of DU145 prostate cancer cells treated by a combination of radiofre-quency hyperthermia (RF HT) with radiation treatment (RT) from an external radiotherapy machine compared to RT alone. Materials and Methods: In this experimental study, DU145 cells were cultured as spheroids until they reached 300 µm in diameter. We exposed these cultures to either: RF HT for 90 minutes at 43˚C originated from a Celsius TCS system, RF HT followed by RT at doses of 2 Gy or 4 Gy (15 MV energy) with 15-minute interval, or RT alone at the above mentioned doses. The trypan blue exclusion assay, alkaline comet assay, and annexin V/PI flow cytometry were performed to measure cell viability, the amount of DNA damage in an individual cell as the tail moment, and percentage of induced cell apoptosis in response to treatments explained. Results: We calculated the thermal enhancement factor (TEF) for the combined tr...
Volume 19, Supplement 1, Spring 2017, 2017
Objective: This study evaluated enhanced induced DNA damages and apoptosis of a spheroid culture of DU145 prostate cancer cells treated by a combination of radiofre-quency hyperthermia (RF HT) with radiation treatment (RT) from an external radiotherapy machine compared to RT alone. Materials and Methods: In this experimental study, DU145 cells were cultured as spheroids until they reached 300 µm in diameter. We exposed these cultures to either: RF HT for 90 minutes at 43˚C originated from a Celsius TCS system, RF HT followed by RT at doses of 2 Gy or 4 Gy (15 MV energy) with 15-minute interval, or RT alone at the above mentioned doses. The trypan blue exclusion assay, alkaline comet assay, and annexin V/PI flow cytometry were performed to measure cell viability, the amount of DNA damage in an individual cell as the tail moment, and percentage of induced cell apoptosis in response to treatments explained. Results: We calculated the thermal enhancement factor (TEF) for the combined treatment regime. RF HT followed by the 4 Gy dose of RT resulted in minimum viability (85.33 ± 1.30%), the highest tail moment (1.98 ± 0.18), and highest percentage of apoptotic cells (64.48 ± 3.40%) compared to the other treatments. The results of the TEF assay were 2.54 from the comet assay and 2.33 according to flow cytometry. Conclusion: The present data suggest that combined treatment of mega voltage X-rays and RF HT can result in significant radiosensitization of prostate cancer cells.
Effects of local tumor hyperthermia on the growth of solid mouse tumors
Cancer research, 1979
The sensitivity to local tumor hyperthermia (43 degrees, 60 min) of a spectrum of eight different solid mouse tumors (Lewis lung carcinoma, M5076 ovarian carcinoma, colon carcinoma 38, colon carcinoma 26, mammary adenocarcinoma C3HBA, mammary adenocarcinoma 16C, glioma 26, and B16 melanoma) was investigated. A microwave (2.45-GHz) apparatus produced localized heating of the tumors without generation of whole-body hyperthermia. The temperature at the center of the heated tumors was regulated to within +/- 0.1 degrees while the temperature uniformity within the tumor was +/- 0.5 degrees. The local hyperthermia treatments reduced the size and retarded the growth of the treated tumors compared with control values for each of the tumors tested. The faster-growing Lewis lung carcinoma and B16 melanoma were the least responsive to treatment, while the slower-growing colon 38 and M5076 ovarian carcinomas were the most responsive. Multiple treatments resulted in longer grwoth delays and grea...
The in vivo effect of regional hyperthermia on dunning R3327 prostatic tumor
The Prostate, 1991
This report describes the in vivo effect of regional hyperthermia on male Copenhagen rats implanted with Dunning R3327 prostatic carcinoma. In six rats, a 22-gauge 1.5-cm needle was inserted into the tumor and heated to 46.5"C for 2 hr. Two hyperthermia treatments were administered 48 hr apart. In a separate group of six rats, the needle was inserted into the tumor, but not heated. After treatment, serial measurements of tumor volume and body weight were made twice a week for 4 weeks. From the first day of measurement to day 22, the tumor size in the treated group compared to control was significantly smaller, P = 0.02.
Cancer, 1975
The present study was undertaken to explore the relationship of the time interval between application of heat and irradiation on enhanced tumor cell sensitivity. Using the Ridgway osteogenic sarcoma grown in AKD2Fl/,J mice, local tumor hyperthermia (42.5f.5OC for 15 minutes) was applied at various time intervals before or after single or fractionated doses of x irradiation. Enhancement of tumor cell sensitivity by combined treatment with radiation and heat, as measured by delay in tumor growth, cure rates, and mean survival times was inversely proportional to the time interval between application of both modalities. The interactions associated with this increased sensitivity appear to be transitory, diminishing with time between treatments. Possible mechanisms of action for thermal sensitization may involve the reduction of oxygen dependence as well as a reduced recovery capacity of tumor cells.
Cancer, 1975
The present study was undertaken to explore the relationship of the time interval between application of heat and irradiation on enhanced tumor cell sensitivity. Using the Ridgway osteogenic sarcoma grown in AKD2Fl/,J mice, local tumor hyperthermia (42.5f.5OC for 15 minutes) was applied at various time intervals before or after single or fractionated doses of x irradiation. Enhancement of tumor cell sensitivity by combined treatment with radiation and heat, as measured by delay in tumor growth, cure rates, and mean survival times was inversely proportional to the time interval between application of both modalities. The interactions associated with this increased sensitivity appear to be transitory, diminishing with time between treatments. Possible mechanisms of action for thermal sensitization may involve the reduction of oxygen dependence as well as a reduced recovery capacity of tumor cells.
The effect of radiofrequency hyperthermia on the Ca755 murine adenocarcinoma
Cancer, 1980
Radiofrequency (RF) was used to induce hyperthermia in the Ca755 murine adenocarcinoma. Thermal kinetic studies revealed a selective heating of tumors over normal tissues during RF, which occurred in larger but not smaller tumors. Small tumors required a significantly greater RF output than did larger neoplasms for heating to the tumoricidal range of 42 C. Rates of tumor growth were not changed after single RF treatments at 42 C, but tumors receiving three applications of RF were significantly smaller than a control group at 28 days tumor age. RF may be of value id the treatment of large neoplasms by using multiple applications; however, microscopic mitoses may not be affected directly without simultaneously damaging normal tissues in the RF field.
Cancer treatment reviews, 2015
Hyperthermia, one of the oldest forms of cancer treatment involves selective heating of tumor tissues to temperatures ranging between 39 and 45°C. Recent developments based on the thermoradiobiological rationale of hyperthermia indicate it to be a potent radio- and chemosensitizer. This has been further corroborated through positive clinical outcomes in various tumor sites using thermoradiotherapy or thermoradiochemotherapy approaches. Moreover, being devoid of any additional significant toxicity, hyperthermia has been safely used with low or moderate doses of reirradiation for retreatment of previously treated and recurrent tumors, resulting in significant tumor regression. Recent in vitro and in vivo studies also indicate a unique immunomodulating prospect of hyperthermia, especially when combined with radiotherapy. In addition, the technological advances over the last decade both in hardware and software have led to potent and even safer loco-regional hyperthermia treatment deliv...
Cancer, 1984
Clinical results of radiothermotherapy applied to 40 radioresistant tumors in 36 patients were reported. Hyperthermia was administered locally using two radiofrequency (RF) capacitive heating equipment systems developed in our institution under the collaboration of Yamamoto Vinyter Co. Ltd. Hyperthermia was given twice weekly immediately after irradiation. Intratumor temperatures of 41 "C to 44°C were maintained for 30 to 60 minutes. Radiation doses varied from 32 Gy to 60 Gy. Of the 40 tumors treated, 21 (53%) showed complete response, 16 (40%) partial response, and 3 (7%) no response when the tumor response was assessed by tumor size measurement, Of eight patients who had matched tumors treated with either radiation alone or radiation plus hyperthermia, six patients showed better response in tumors treated with radiothermotherapy than in tumors treated with radiation alone. Skin reactions following radiothermotherapy and radiation alone were comparable. 'The tumor response was greatly dependent on the tumor size. Greater response was observed in small tumors, although histologic examinations and long-term follow-up studies revealed an excellent effect of radiothermotherapy on the large tumors as well as on the small tumors. Tumor responses correlated with tumor center temperatures but not with histologic features. Our clinical results indicate that R F hyperthermia combined with radiation has a therapeutic benefit in the treatment of radioresistant cancers.