Effects of hyperthermia applied to previously irradiated cervical spinal cord in the rat

P Sminia, J Haveman, C Koedooder

Research output: Contribution to journalReview articleAcademicpeer-review

Abstract

Rat cervical spinal cord was X-ray irradiated at doses of 15, 18, 20 and 26 Gy. Ninety days later, approximately the same part of the spinal cord was heated at 42.3 +/- 0.4 degrees C for 50, 60, 75 or 90 min by means of a 434 MHz microwave applicator. After treatment, animals were observed over a period of 18 months for expression of neurological complications. These complications could either be the result of the heat or of the radiation treatment. The time course showed three distinct peaks in the incidence of neurological symptoms. The first peak was due to the acute response to hyperthermia. The ED50 value for neurological complications one day after treatment at 42.3 +/- 0.4 degrees C was 74 +/- 2 min. Previous X-ray irradiation of the spinal cord with 18, 20 and 26 Gy reduced the ED50 to 57 +/- 7, 65 +/- 4 and 55 +/- 5 min (12-26% of control), respectively. Recovery from heat-induced neurological complications was diminished in previously irradiated animals. The second peak (150-300 days after X-rays) concerned the expression of "early delayed" radiation damage. Hyperthermia given 90 days after irradiation did not influence either the percentage of animals with paralysis or the latent period. Neurological symptoms developing after day 300 were due to the "late delayed" radiation response. No significant difference was observed in the data on paralysis induced by radiation alone or radiation followed by heat. The late radiation-induced minor neurological symptoms were, however, influenced by retreatment with heat.

Original languageEnglish
Pages (from-to)60-7
Number of pages8
JournalRadiotherapy and Oncology
Volume22
Issue number1
Publication statusPublished - Sep 1991

Cite this

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title = "Effects of hyperthermia applied to previously irradiated cervical spinal cord in the rat",
abstract = "Rat cervical spinal cord was X-ray irradiated at doses of 15, 18, 20 and 26 Gy. Ninety days later, approximately the same part of the spinal cord was heated at 42.3 +/- 0.4 degrees C for 50, 60, 75 or 90 min by means of a 434 MHz microwave applicator. After treatment, animals were observed over a period of 18 months for expression of neurological complications. These complications could either be the result of the heat or of the radiation treatment. The time course showed three distinct peaks in the incidence of neurological symptoms. The first peak was due to the acute response to hyperthermia. The ED50 value for neurological complications one day after treatment at 42.3 +/- 0.4 degrees C was 74 +/- 2 min. Previous X-ray irradiation of the spinal cord with 18, 20 and 26 Gy reduced the ED50 to 57 +/- 7, 65 +/- 4 and 55 +/- 5 min (12-26{\%} of control), respectively. Recovery from heat-induced neurological complications was diminished in previously irradiated animals. The second peak (150-300 days after X-rays) concerned the expression of {"}early delayed{"} radiation damage. Hyperthermia given 90 days after irradiation did not influence either the percentage of animals with paralysis or the latent period. Neurological symptoms developing after day 300 were due to the {"}late delayed{"} radiation response. No significant difference was observed in the data on paralysis induced by radiation alone or radiation followed by heat. The late radiation-induced minor neurological symptoms were, however, influenced by retreatment with heat.",
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author = "P Sminia and J Haveman and C Koedooder",
year = "1991",
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language = "English",
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journal = "Radiotherapy and Oncology",
issn = "0167-8140",
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Effects of hyperthermia applied to previously irradiated cervical spinal cord in the rat. / Sminia, P; Haveman, J; Koedooder, C.

In: Radiotherapy and Oncology, Vol. 22, No. 1, 09.1991, p. 60-7.

Research output: Contribution to journalReview articleAcademicpeer-review

TY - JOUR

T1 - Effects of hyperthermia applied to previously irradiated cervical spinal cord in the rat

AU - Sminia, P

AU - Haveman, J

AU - Koedooder, C

PY - 1991/9

Y1 - 1991/9

N2 - Rat cervical spinal cord was X-ray irradiated at doses of 15, 18, 20 and 26 Gy. Ninety days later, approximately the same part of the spinal cord was heated at 42.3 +/- 0.4 degrees C for 50, 60, 75 or 90 min by means of a 434 MHz microwave applicator. After treatment, animals were observed over a period of 18 months for expression of neurological complications. These complications could either be the result of the heat or of the radiation treatment. The time course showed three distinct peaks in the incidence of neurological symptoms. The first peak was due to the acute response to hyperthermia. The ED50 value for neurological complications one day after treatment at 42.3 +/- 0.4 degrees C was 74 +/- 2 min. Previous X-ray irradiation of the spinal cord with 18, 20 and 26 Gy reduced the ED50 to 57 +/- 7, 65 +/- 4 and 55 +/- 5 min (12-26% of control), respectively. Recovery from heat-induced neurological complications was diminished in previously irradiated animals. The second peak (150-300 days after X-rays) concerned the expression of "early delayed" radiation damage. Hyperthermia given 90 days after irradiation did not influence either the percentage of animals with paralysis or the latent period. Neurological symptoms developing after day 300 were due to the "late delayed" radiation response. No significant difference was observed in the data on paralysis induced by radiation alone or radiation followed by heat. The late radiation-induced minor neurological symptoms were, however, influenced by retreatment with heat.

AB - Rat cervical spinal cord was X-ray irradiated at doses of 15, 18, 20 and 26 Gy. Ninety days later, approximately the same part of the spinal cord was heated at 42.3 +/- 0.4 degrees C for 50, 60, 75 or 90 min by means of a 434 MHz microwave applicator. After treatment, animals were observed over a period of 18 months for expression of neurological complications. These complications could either be the result of the heat or of the radiation treatment. The time course showed three distinct peaks in the incidence of neurological symptoms. The first peak was due to the acute response to hyperthermia. The ED50 value for neurological complications one day after treatment at 42.3 +/- 0.4 degrees C was 74 +/- 2 min. Previous X-ray irradiation of the spinal cord with 18, 20 and 26 Gy reduced the ED50 to 57 +/- 7, 65 +/- 4 and 55 +/- 5 min (12-26% of control), respectively. Recovery from heat-induced neurological complications was diminished in previously irradiated animals. The second peak (150-300 days after X-rays) concerned the expression of "early delayed" radiation damage. Hyperthermia given 90 days after irradiation did not influence either the percentage of animals with paralysis or the latent period. Neurological symptoms developing after day 300 were due to the "late delayed" radiation response. No significant difference was observed in the data on paralysis induced by radiation alone or radiation followed by heat. The late radiation-induced minor neurological symptoms were, however, influenced by retreatment with heat.

KW - Animals

KW - Cervical Vertebrae/radiation effects

KW - Dose-Response Relationship, Radiation

KW - Hot Temperature

KW - Hyperthermia, Induced

KW - Radiation Injuries, Experimental

KW - Rats

KW - Rats, Inbred Strains

KW - Spinal Cord/radiation effects

M3 - Review article

VL - 22

SP - 60

EP - 67

JO - Radiotherapy and Oncology

JF - Radiotherapy and Oncology

SN - 0167-8140

IS - 1

ER -