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Due to its increasingly impressive
research and clinical track record, it is considered as
"main-stream" as surgery, chemotherapy, and radiation,
and is now recognized as the "fourth modality" in
approved cancer treatment. However, due to its
relatively recent acceptance in major medical circles,
it is not well known - yet it is a treatment with
genuine promise.
How Hyperthermia Kills
Cancer Cells
Hyperthermia destroys
cancer cells by raising the tumor temperature to a "high
fever" range, similar to the way the body uses fever
naturally when combating other forms of disease. Because
the body’s means of dissipating heat is through cooling
from blood circulation, sluggish or irregular blood flow
leaves cancerous tumors vulnerable to destruction at
elevated temperatures that are safe for surrounding
healthy tissues with normal, efficient blood cooling
systems.
Scientists attribute the
destruction of cancer cells at hyperthermic temperatures
to damage in the plasma membrane, the cytoskeleton and
the cell nucleus. Cancer cells are vulnerable to
hyperthermia therapy particularly due to their high
acidity caused by the inability to properly expel waste
created by anaerobic metabolism. Hyperthermia attacks
acidic cells, disrupting the stability of cellular
proteins and killing them.
Oncological Action of Hyperthermia
1. Greater heat sensitivity of neoplastic tissues to
hyperthermia due to its chronic ischemia and hypoxia and
acid pH.
2. Lethal effect on tumoral cells at a temperature of
43ºC., depending on the application time. The
application of repeated moderate hyperthermia at between
39 - 41 ºC can also produce a temporary growth
stabilisation.
3. Prolongated action of the temperature inside the
tumour - due to lower thermal dissipation caused by a
chronic ischemia, as a result of its reduced vaso-regulation
mechanisms -, that increases to an even greater degree
of its ischemia, hypoxia and acidity typical of tumour
tissue.
4. Alterations in the cycle of the neoplastic cells,
which lead to the blocking of the mitosis in part of the
cell population. The blocking seems to be due to a
disruption in the synthesis phase of DNA (S-phase of the
cell cycle).
5. Hyperthermia has a more marked action on the central
core of tumour -necrotic, ischemic, hypoxic and with low
pH-, which is less sensitive to radiation. In the tumour
periphery -vascularized and with greater cell growth-,
radiotherapy is more effective. The benefits of a
combined action of Hyperthermia and RT and/or ChT were
demonstrated many years ago.
6. It can facilitate apoptosis mechanisms, self
-destruction of cells, which are normally absent in
tumoral cells.
7. The "athermic" effect on cell cultures has shown a
significant decrease of the neoplastic cell population
and no undesirable effects on normal cells. This could
be related to changes of the electrical potential of the
neoplastic tissues.
HYPERTHERMIA RESEARCH
Thermoradiotherapy with curative
intent - breast, head and neck and prostate tumors.
Hyperthermia as a Cancer Therapy .
Survival benefit of hyperthermia in a
prospective randomized trial of brachytherapy boost and
hyperthermia for glioblastroma multiforme .
Comparison of radiotherapy alone with radiotherapy plus
hyperthermia in locally advanced pelvic tumors: a
prospective, randomized, multicenter trial.
Interstitial microwave thermal therapy for prostate
cancer: method of treatment and results of phase
I/II trial.
Radiotherapy and hyperthermia in the treatment of
patients with locally advanced prostate cancer:
preliminary results .
Interstitial hyperthermia in conjunction with
external beam radiotherapy and temporary interstitial
implant in the treatment of adenocarcinoma of the
prostate (ACP).
Regional Hyperthermia in conjunction with definitive
radiotherapy against recurrent or locally advanced
prostate cancer .
Efficacy of irradiation and external hyperthermia in
locally advanced, hormone-refractory or radiation
recurrent prostate cancer: a preliminary report.
Outpatient interstitial
thermoradiotherapy .
Hyperthermia in oncology .
Hyperthermia as an
adjuvant therapy of recurrent or metastatic malignant
melanoma. A multicentre randomized trial by the European
Society for Hyperthermic Oncology .
Report of
long term follow up in a randomized trial comparing
radiation therapy and radiation therapy plus
hyperthermia to metastatic lymph nodes in stage IV head
and neck patients.
Thermoradiotherapy for locally recurrent breast cancer
with skin involvement.
Recurrent
breast cancer results of superficial hyperthermia and
re-irradiation.
Radiotherapy with or without hyperthermia in the
treatment of superficial localized breast cancer:
results from five randomized controlled trials.
Hyperthermia in combined treatment of cancer.
Heating
the patient a promising approach?
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