Systemic hyperthermia with improved temperature sensing apparatus and method

An improvement in a method of treating cancer by systemic hyperthermia which comprises measuring the patient's core body temperature in the bladder and controlling the inducement of systemic hyperthermia in accordance with the bladder temperature measured.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates to the treatment of cancer by hyperthermia and more 
particularly to improvements in the control of whole body or systemic 
hyperthermia for purposes of retarding the growth of cancel cells. 
In my application, Ser. No. 802,033, filed May 31, 1977, now U.S. Pat. No. 
4,181,132, there is disclosed a method of effecting whole body or systemic 
hyperthermia within an individual for anticancer purposes. The method as 
disclosed involves the establishment and utilization of a sterile 
extracorporeal flow path for blood having an inlet, an outlet and a 
temperature control zone therebetween. The extracorporeal flow path is 
connected with the patient by establishing communication of the inlet of 
the extracorporeal flow path with the patient's blood stream so that the 
blood can be withdrawn and supplied to the extracorporeal flow path 
without adversely affecting the blood circulation in the areas from which 
the blood is withdrawn. The extracorporeal flow path is also connected 
with the patient by establishing communication of the outlet of the 
extracorporeal flow path with the patient's blood stream so that blood 
flowing from the extracorporeal flow path is returned to the blood stream 
in such a way as to be distributed systemically. The blood withdrawn from 
the patient's blood stream is pumped along the extracorporeal flow path 
through the temperature control zone at a controlled rate of at least 
approximately one liter per minute for return to the patient's blood 
stream. The temperature of the blood flowing along the extracorporeal flow 
path through the temperature control zone is controlled in accordance with 
the patient's core body temperature. The apparatus for sensing the 
patient's core temperature disclosed in my prior patent is a rectal probe 
or an esophageal probe. 
Experimental practice of the method as disclosed in my prior patent has 
indicated that it is highly desirable in the efficacy of the treatment to 
be able to control the body temperature within 0.1.degree. to 0.2.degree. 
C. To secure this control there are two aspects which must be present. 
First, the method utilized to induce the systemic heat must provide such 
accuracy; and second, the method of sensing the systemic body temperature 
must likewise be capable of such accuracy. Clearly, to secure maximum 
effect it is desirable to provide the highest possible heat which is 
within the tolerance of the patient. This efficacy cannot be achieved by a 
system capable of inducing such heat if temperature sensing means is not 
available to determine within the same degree of accuracy just what 
temperature is being induced. Likewise, the greatest efficacy is not 
achieved if sufficient accuracy is provided in the temperature sensing of 
the patient but the means for inducing the systemic temperature is not 
sufficiently accurate. 
Experimental use of the procedures disclosed in my prior patent clearly 
indicate that the desired accuracy can be obtained by the utilization of 
an extracorporeal heating circuit in the manner disclosed therein. 
However, the full efficacy of the procedure has not been consistently 
realized by the sensing of the patient's body core temperature at the 
traditional locales of the rectum or esophagus or even the possible third 
traditional location of the tympanic membrane. For example, when utilizing 
an esophageal probe there are found to exist three temperature zones 
depending upon the particular location of the temperature probe in the 
esophagus rendering the results different depending upon the particular 
location where use actually takes place. First, where the temperature 
probe has a position adjacent the right main bronchus, the temperature 
tends to depend too much on the temperature of the air with which the 
patient is ventilated. Where the esophageal probe temperature element has 
a position adjacent the left atrium of the heart, the humidity of the air 
with which the patient is ventilated can cause somewhat artifically 
deviant temperature readouts. For example, where the air is too dry, the 
tendency was to obtain temperature readouts which are slightly too cool. 
On the other hand, where the air humidity is wet, the temperature sensed 
appeared to be artifically elevated somewhat. These two locations compared 
with the remaining locations in the esophagus indicate a difference in the 
temperature sensed to be between .+-.0.2 to 0.6.degree. C. in utilizing an 
esophageal probe. 
Likewise various inaccuracies could be introduced by the utilization of a 
rectal probe. For example, the position of the probe could be altered by 
the normal peristalsis. Moreover, the tip can be encased by stool so as to 
present an insulation resulting in lower artificial temperature readings. 
The other traditional locale of the tympanic membrane presents 
inaccuracies because of the tendency of the accuracy of the readout to be 
dependent upon actual contact with the very delicate tympanic membrane. 
Thus, with this location there is a tendency toward light and intermittent 
contact resulting in artificially lower temperature readings. 
It is an object of the present invention to obviate the inaccuracies noted 
above in sensing patient core body temperature in the traditional locales 
by utilizing instead a temperature readout of the bladder of the patient. 
It has been found that a temperature readout in the bladder achieves a 
consistency of accuracy which is superior to that provided by sensing 
temperature in the usual three traditional locales because of its central 
visceral location and also because urine draining from a core organ, the 
kidney, constantly flows into the bladder. These two factors insure that a 
thermistor tipped catheter placed into the bladder will enable accurate 
determination of true body core temperature. In addition urinary catheters 
are relatively sanitary and comfortable and may readily be retained in 
position. Inasmuch as a bladder catheter will always be placed in a 
seriously ill patient, the incorporation of a temperature sensing device 
such as a thermistor or thermocouple in its tip not only poses no 
additional discomfort to the patient, but relieves him of the necessity of 
having another probe inserted into still another orifice. 
It is recognized that it has been proposed to provide a thermistor in the 
tip of a conventional bladder catheter. Such a proposal is contained in an 
IBM technical disclosure bulletin entitled "Central Body Temperature 
Apparatus" by E. R. Ellinwood and G. C. Rastelli, Vol. 11, No. 11, dated 
April of 1969. This disclosure, however, does not suggest the utilization 
of such a device in systemic hyperthermia nor has the proposed device, to 
applicant's knowledge, ever been actually produced and utilized in any 
medical procedure, much less whole body hyperthermia. 
It will be understood that whole body or systemic hyperthermia has been 
induced by others by means other than an extracorporeal heat circuit as 
described in my prior patent. For example, others have proposed the 
utilization of hot wax baths or externally applied hot water controlled 
blankets. As far as applicant is aware none of these methods of inducing 
systemic hyperthermia has heretofore been controlled by sensing the core 
body temperature by a bladder temperature sensing probe. Indeed, it may be 
that the accuracies of induced core body temperature which can be achieved 
by these procedures is equal to the temperature sensing accuracies that 
can be achieved by sensing temperature at one or more of the traditional 
locations. Thus, while the improvements relating to the control of 
systemic hyperthermia by sensing bladder temperature of the present 
invention has particular efficacy when utilized to control systemic 
hyperthermia induced by an extracorporeal blood circuit, such improvement 
would have equal applicability to systemic hyperthermia induced by any 
other method capable of achieving accuracies similar to that achieved by 
the extracorporeal blood circuit method. 
Another object of the present invention is the provision of improvements in 
the apparatus used in inducing hyperthermia through an extracorporeal 
circuit, such improvements embodying the utilization of a temperature 
sensing probe in the tip of a bladder catheter. 
These and other objects of the present invention will become more apparent 
during the course of the following detailed description and appended 
claims.

Referring now more particularly to the drawings, there is shown therein a 
preferred apparatus 10 to which the principles of the present invention 
are applied for practicing the improved method of the present invention. 
Except for the improvements, the apparatus 10 is similar to the apparatus 
disclosed in my prior patent, hence, the disclosure of the patent is 
hereby incorporated by reference into the present specification. 
As set forth in my prior patent, the apparatus 10 includes sterile tubing, 
generally indicated at 12, which defines an extracorporeal blood flow 
path. A pump mechanism preferably in the form of a peristaltic roller 
pump, generally indicated at 14, is provided for pumping blood along the 
extracorporeal flow path at a controlled rate from the inlet tubing end to 
the outlet tubing end. In addition, there is provided a temperature 
control zone preferably in the form of a heat exchanger assembly 16 
through which the blood flowing along the extracorporeal flow path has its 
temperature controlled, preferably both by heating and cooling, through a 
control device, generally indicated at 18, for the liquid circuit of the 
heat exchanger assembly 16. Finally, the apparatus 10 includes means, 
generally indicated at 20, for communicating the inlet end of the tubing 
12 defining the extracorporeal flow path with the bloodstream of a patient 
and the outlet end of the tubing 12 defining the extracorporeal flow path 
with the bloodstream of the patient, so that the returning blood is 
systemically distributed without adversely affecting the blood depleted 
areas from which the blood is withdrawn. 
The tubing 12 may be formed of any suitable plastic material, as, for 
examle, vinyl polymer (e.g. Tygon.RTM.), polytetraflouroethylene (e.g. 
Teflon.RTM.), or other plastic materials having known uses in medical 
applications (e.g. Silastic.RTM.). An exemplary tubing size is 1/4" i.d., 
with a convenient length being from 3-5'. The pump assembly 16, as 
previously indicated, preferably embodies a peristaltic roller type pump 
driven by a variable speed electric motor. A peristaltic pump is preferred 
because it can utilize the replaceable sterile tubing 12 for blood contact 
and does not provide pump parts which must be maintained in a sterile 
condition. An exemplary pump is manufactured by Sarns, having a 1-2 liter 
per minute capacity. 
A preferred embodiment of the heat exchanger assembly 16 is available 
commercially under the tradename Travenol Mini-Prime, 5MO 337, which has a 
57 cc capacity and rated flow of 1-3 liters per minute. See also U.S. Pat. 
No. 3,640,340, the disclosure of which is hereby incorporated by reference 
into the present specification. In addition, the heat exchanger disclosed 
in commonly assigned U.S. Patent Application Ser. No. 79,955 filed Sept. 
28, 1979 may also be used and hence this disclosure is also hereby 
incorporated by reference into the present specification. 
With reference to FIG. 2, the control device 18 is made up of individually 
known components. As shown, there is provided a cooled liquid reservoir 22 
and a heated liquid reservoir 24 each containing a body of liquid. While 
any liquid may be utilized a preferred embodiment is water. Each reservoir 
is provided with a stirring or agitating means 26 for purposes of mixing 
the liquid contained therein so as to render the temperature thereof more 
uniform throughout. The cool liquid reservoir 22 is provided with a 
cooling unit, schematically indicated at 28, while the heated liquid 
reservoir 24 is provided with a heating unit 30. A liquid circulating 
system is provided in cooperating relation between the cooled liquid 
reservoir 22 and heated liquid reservoir 24 and the liquid side of the 
heat exchanger 16. Such circulating system includes the utilization of two 
pump assemblies, schematically indicated in the drawings at 32 and 34. 
As shown in FIG. 2, the pump assembly 32 is associated with the cooling 
liquid reservoir 22 and includes an inlet or suction pipe 36 extending 
from the reservoir 22 to one side of the pump 32 and an outlet pipe 38 
extending therefrom. Similarly, an inlet pipe 40 extends from the heated 
liquid reservoir 24 to one side of the pump 34 which side has an outlet 
pipe 42 extending therefrom. Outlet pipes 38 and 42 are interconnected by 
a T-connector 44 which has a pipe 46 extending therefrom to the liquid 
inlet side of the heat exchanger 16. A pipe 48 extends from the outlet of 
the liquid side of the heat exchanger 16 which by means of a Y-connection 
50 communicates with two branch conduits 52 and 54 extending respectively 
to the opposite sides of the pumps 32 and 34. The circuit is completed by 
pipes 56 and 58 connected respectively to the outlet of the opposite sides 
of pumps 32 and 34 and the cooled liquid reservoir 22 and heated liquid 
reservoir 24 respectively. As shown, an overflow pipe 59 is connected 
between the reservoirs. 
The cooling unit 28 is of conventional nature and is adapted to maintain 
the liquid in the reservoir 22 at a substantially constant temperature as, 
for example, 30.degree. C. Likewise, the heating unit 30 is of 
conventional construction and is adapted to maintain the liquid within the 
heated liquid reservoir 24 at a substantially constant temperature as, for 
example, 45.degree. C. Pump 32, when operated, serves to meter from the 
reservoir 22 through pipe 36 an amount of liquid which is equal to the 
amount of liquid returned through pipe 56. In a similar manner, pump 34 
when operated serves to meter an amount of flow from the reservoir 24 
which is always equal to the amount returned through return pipe 58. A 
control, schematically indicated at 60, for varying the rate of movement 
of the pumps 32 and 34, e.g. electrical controls for the variable speed 
electrical motors driving the same which form a part of the pump 
assemblies schematically illustrated is operable so that the total output 
of the two pumps is adjusted to and maintained at a substantially constant 
rate, as for example, approximately 10 liters per minute. The control 60 
is also operable to effect a proportional variation in the rate which each 
of the two pumps assume of this total output from 0-10 to 10-0. 
Control of the pump assemblies 32 and 34 is undertaken in accordance with 
the readout of three temperature recording devices 62, 64 and 66 placed 
respectively to sense the core temperature of the patient's body, the 
temperature of the blood leaving the heat exchanger 16 being returned to 
the patient and the temperature of the liquid entering the heat exchanger. 
A pressure sensing device 68 is also provided in the liquid inlet line 46. 
It will be understood that the temperature sensing devices and pressure 
sensing devices are of any conventional design, preferably of the type 
providing a remote readout, as schematically indicated by corresponding 
primed numerals. 
For illustrative purposes it is sufficient to note that control 60 can be 
manually operated to determine the proportion of the total liquid flow 
through the heat exchanger which is provided by the cooled liquid at 
30.degree. C. and the heated liquid at 45.degree. C. Control 60 thus 
serves to directly vary the liquid temperature sensed by device 66 between 
the low limit of 30.degree. C. and upper limit of 45.degree. C., which in 
turn will vary the temperature of the blood sensed by device 64 which in 
turn will affect the patient's systemic blood temperature and hence the 
temperature sensed by device 62. It will be understood that while the 
operation of control 60 is set forth for illustrative purposes as being 
manual, the control 60 may be rendered automatic and programmable if 
desired. 
Referring again more particularly to FIG. 1 the communicating means 20 
preferably comprises a totally subcutaneous inplant device, generally 
indicated at 70, which serves as the means communicating with the 
patient's bloodstream and a pair of percutaneous cannula assemblies, 
generally indicated at 72 and 74, which serve as the means for operatively 
communicating the implant device 70 with tubing 12 defining the 
extracorporeal flow path. As best shown in FIG. 1, the implant device 
includes a body 76 of elastomeric material such as Silastic .RTM., molded 
so as to provide an arterial passage 78, a spaced venous passage 80 and a 
by-pass conduit 82 connected between the inner end of the passage 78 and 
the inner end of the passage 80. As best shown in FIG. 1, the passages 78 
and 80, together with the by-pass conduit 82, are of generally U-shaped 
configuration. 
Each of the passages 78 and 80 has a peripheral cross-sectional 
configuration which is elongated in one direction; namely the direction in 
which they are spaced apart, with sharp points defining opposite ends in 
the direction of elongation. The preferred configuration shown is further 
characterized by a pair of convexly curved lines extending between the 
sharp points, the distance between the central portions of the convex 
lines being approximately one-half the distance between the two end 
points. While the by-pass conduit may be of other cross-sectional 
configuration, as shown, it too is of similar cross-sectional 
configuration. This preferred cross-sectional configuration for the 
passages 78 and 80 is provided for the purpose of cooperatively receiving 
the correspondingly shaped exterior peripheries of the cannula assemblies 
72 and 74, which assemblies are so shaped for the purpose of cooperating 
with a pair of slits 84 and 86 formed in the body 76 in operative 
association with the passages 78 and 80 respectively. 
As shown, each slit 84 and 86 extends from a position exterior of the body 
76 to a position of communication with the inner end of the associated 
passage 78 or 80. The width of each slit is generally equal to the 
distance between the end points of the associated passage and is oriented 
in its closed condition, as best shown in FIG. 1, in longitudinal 
alignment with a plane passing between the end points of the associated 
passage. 
In a closed condition wherein the cannula assemblies are removed, the two 
planar interior surfaces of the body 76 which define the respective slit 
84 or 86 are resiliently urged into engagement by the elastomeric 
characteristics of the body material. The engagement of the surfaces 
serves to exclude any spaces which could contain fluid such as blood 
between the two positions of extent of the slit, as aforesaid. 
The resiliency of the elastomeric material of the body 76 also permits each 
slit 84 and 86 to be moved by its respective cannula assembly 72 and 74 
with a trocar (not shown) mounted therein with a protruding sharp end into 
an open condition where the planar body surfaces defining the slit are 
spread arcuately so that the profile thereof coincides with the peripheral 
configuration of the associated passage 78 or 80. 
To aid the entry and insertion of each cannula-trocar assembly through its 
associated slit, there is molded in embedded relation within the body 76 a 
pair of metallic guide structures 88 and 90. Each guide structure is 
preferably made of medically acceptable interior use metal, such as 
stainless steel (e.g. Vitallium Metal manufactured by Howmedica). The 
implant device 70 also includes a pair of tubes 100 and 102 made of 
vascular prosthesis material. A preferred vascular prothesis material is 
woven Dacron .RTM. marketed commercially by Meadox Medicals although any 
other acceptable vascular prosthesis material may be utilized. As best 
shown in FIG. 1, the tube 100 has one end thereof fixed in communicating 
relation with the outer end portion of the arterial passage 78, as by 
being molded in embedded relation. The opposite end of the tube 100 is 
adapted to be connected, as by suture, to a surgical opening formed in the 
side wall of a femoral artery so that the interior of the tube 100 is in 
communicating relation with the interior of the femoral artery. In a like 
manner, one end of the tube 102 is embedded in communicating relation with 
the outer end portion of the venous passage 80 and its opposite end is 
adapted to be sutured to a surgical side wall opening in the associated 
femoral vein so that its interior is in communicating relation with the 
femoral vein. 
The implant device 70 also includes a layer of fabric 104 which is fixed to 
the inner side wall of the elastomeric body as by Silastic .RTM. glue or 
the like. The fabric 104 includes marginal portions extending laterally 
outwardly from the operative inner side wall of the body 76 to which it is 
fixed. The fabric layer 104 and particularly the marginal portions thereof 
provide for initial fixation by suture of the body 76 during implant and 
for subsequent semipermanent fixation by tissue ingrowth. A preferred 
fabric material in Dacron .RTM. double velour which is marketed 
commercially by Meadox Medicals. 
For identification purposes directly from the implant device itself, 
radiopaque identification (not shown) is provided on the operative outer 
side wall of the elastomeric body 76. Such identification insures that the 
proper cooperating cannula assemblies 72 and 74 will always be used since 
such assemblies can be ascertained from the implant itself after total 
implantation has been effected through X-ray identification. 
It will be understood that since the assemblies 72 and 74 are left and 
right hand mirror images of one another, a description of one of the 
assemblies will suffice to give an understanding of both. Each assembly 
includes a percutaneous cannula 106 comprising a tubular body which 
includes a straight section defining the subcutaneous end portion of the 
cannula and an angular section 112 which, together with an adjacent part 
of the straight section, defines the extracorporeal end portion of the 
cannula. The cannula 106 is preferably molded of radiopaque plastic 
material having sufficient rigidity to prevent interior collapse when in 
operative position within the implant device 70. Thermoset plastics are 
preferred although thermoplastic materials with sufficient functional 
rigidity and heat stability for sterilization can be used. An exemplary 
material is ethylene-propylene-terpolymer (e.g. where the third monomer is 
nonbornadiene) impregnated with a radiopaque material such as barium 
sulfate. 
As shown, the entire straight section of the cannula 106 has its exterior 
periphery formed with a cross-sectional configuration which conforms with 
and engages within the interior periphery of the body 76 defining the 
artery passage 78 or venous passage 80. Such configuration, however, is 
required only in the extent of the subcutaneous end portion which is 
disposed within the passage and associated slit of the implant body during 
operation. 
The cannula 106 includes an interior passage which extends through the 
angular section 112 into the straight section 110 and out of the extremity 
thereof. In order to maximize the interior passage cross-sectional area 
for an optimum exterior cross-sectional size, the cross-sectional 
configuration of the interior passage at least in the straight section, 
conforms to the exterior cross-sectional configuration. 
In this regard it will be noted that the cooperating trocar (not shown) 
preferably consists essentially of a molded body of plastic material, 
similar to the plastic material of the cannula 106, which provides a blade 
part and a handle part. The blade part is of a longitudinal extent 
generally equal to the longitudinal extent of the straight section of the 
cannula 106. The main extent of the blade part has an exterior peripheral 
cross-sectional configuration conforming with the interior cross-sectional 
configuration of the portion of the interior passage extending through the 
straight cannula section. The blade part includes a sharpened tip portion 
which tapers gradually in cross-sectional configuration outwardly from the 
aforesaid configuration to a point. 
It will be noted that the extracorporeal end of the straight section of 
each cannula 106 is closed as by a diaphragm or plug of elastomeric 
material 122 which preferably is preslit (although may be imperforate) to 
permit the passage of the trocar, pointed end first, therethrough. 
The exterior periphery of the outer end of the angular section 112 is 
provided with gripping flanges operable to effect a fluid-tight connection 
with the interior of the tubing 12. When the trocar is withdrawn as shown, 
the elastomeric plug slit, which has expanded to receive the trocar, 
contracts to close the end of the straight section of the cannula and 
insure that all of the blood will flow outwardly through the angular 
section 112 and into the tubing 12. 
Formed on the exterior periphery of the straight section of the cannula is 
an annular shoulder which forms a stop surface facing in a direction 
toward the open extremity of the straight cannula section operable to 
engage the guide part of the implant device when the cannula is in its 
fully inserted operative position, as shown in FIG. 1. The straight 
cannula section is formed with an opening which extends inwardly from one 
exterior end point into communication with the interior passage at a 
position to register with the by-pass conduit 82 of the implant body 76 
when the cannula is fully inserted, as aforesaid. 
A preferred procedure is to coat all of the blood contacting surfaces of 
the cannulas 106, tubing 12 and elastomeric body 76 (passages 78 and 80, 
conduit 82 and slits 84 and 86) with an anticoagulant coating. A suitable 
coating material for this purpose is marketed commercially under the 
generic tradename TDMAC. 
The manner in which the device 70 is surgically implanted is in accordance 
with usual implant procedures well known to those skilled in the art. For 
present purposes suffice it to say that the elastomeric body 76 is 
implanted in an anterior femoral region spaced downwardly from the 
position of bending at the hip approximately the distance of the width of 
a normal-sized palm (approximately 4") as is clearly shown in FIG. 1. The 
large area faces of the body 76 are preferably disposed parallel with the 
skin with the face having the fabric 104 fixed thereto innermost. The 
arterial and venous tubes 100 and 102 extend upwardly and free ends are 
tapered and sutured to surgical openings in the side walls of the femoral 
artery and vein respectively so as to extend therefrom at an angle of 
approximately 45.degree. C. This procedure is accomplished in accordance 
with usual practices relating to the use of vascular prosthesis material. 
The marginal edge portions of the fabric 104 is sutured to the adjacent 
tissue to provide initial body 76 fixation, as aforesaid. All of the 
exterior surfaces of the implant device 76 are contacted with tissue (with 
fat). 
As previously indicated, it is possible to use known shunt devices (e.g. 
U.S. Pat. No. 3,713,441) in lieu of the device 70 so long as they provide 
the necessary capacity which is ordinarily not the case without 
modification. 
The manner in which each cannula assembly 72 or 74 is inserted into 
cooperating relation to the implanted device 70 should be apparent from 
the above. It is of significance to note the advantages of the utilization 
of a main implant body 76 which provides increase palpation facility 
during cannulation. Moreover, cannulation is effected in a straight line 
relationship resulting in a straight line percutaneous communication with 
the extracorporeal flow path. The preferred cross-sectional configuration 
of the cannula enables simple but effective alignment to be accomplished 
during insertion. Such cross-sectional configuration also provides optimal 
cooperation with the slits 84 and 86 of the elastomeric body 76 both in 
expanding the slits during insertion and in contracting the peripheral 
portion of the cannula extending therethrough to insure a good fluid-tight 
connection. The extension of this cannular cross-sectional configuration 
with the elastomeric body passages 78 and 80 also insures non-distortion 
of these passages and a ful flow area of 4 mm or larger. 
It will be understood that one the inlet and outlet ends of the tubing 12 
are connected over the flanges of the cannula of the assemblies 72 and 74 
and the associated trocars of the assemblies are withdrawn, pump 14 can be 
started to commence the flow of blood along the extracorporeal flow path 
at the approximate 1 liter per minute as aforesaid and through the 
temperature control zone thereof. Initially, control 60 is set to pass 
100% 45.degree. C. water through the heat exchanger 16. During this 
initial treatment phase withdrawn blood temperatures measured at 62 will 
show a gradual increase from the initial normal reading of approximately 
37.degree. C. 
In accordance with the principles of the present invention the improvement 
thereof consists essentially in utilizing a combined temperature probe and 
bladder catheter assembly, generally indicated at 124, for accomplishing 
the aforesaid temperature measurement 62 which corresponds with the 
patient's body core temperature. As shown, assembly 124 includes a 
thermistor 126 imbedded in an outer catheter wall 128 in close proximity 
of a balloon chamber 130 therein. The thermistor includes electrical leads 
which extend therefrom in imbedded relation along the length of the 128 
wall to exit from the opposite end in such a way as not to alter the 
exterior physical characteristics of the catheter body formed by the outer 
wall. The external leads for the thermistor are illustrated at 132 in FIG. 
3. The catheter itself is of conventional bladder type construction having 
a side opening conduit 134 for carrying urine from a patient's bladder and 
a retention balloon conduit 136 which terminates in balloon chamber 130. 
The assembly 124 is used in a manner similar to a conventional bladder 
catheter with the thermistor providing a temperature measurement which is 
routed through instrumentalities interconnected by electrical leads, all 
of which is in accordance with known technology. It will be understood 
that the assembly 124 is inserted into operative relation with the patient 
at the start of the hyperthermic treatment or method to be performed. 
Thus, as previously indicated, the temperature measurement provided by the 
assembly 124 during the initial treatment phase will show a gradual 
increase from the initial normal reading of approximately 37.degree. C. 
The capacity and effectiveness of the heat exchanger 16 is such that 
readings of the returning blood taken at 64 closely approximate the 
45.degree. C. maximum water temperature utilized. As the heated blood is 
returned to the femoral vein through the blood receiving percutaneous 
cannula 106, venous passage 80 and tube 102, it is distributed 
systemically which, in turn, has the effect of increasing the total 
systemic temperature. As the patient's core body temperature increases 
toward the 41.5.degree. C. level, control 60 must be operated to lower the 
liquid reading at 66 to a value below 45.degree. C. as, for example, 
42.5.degree. C. The liquid temperature level stabilized at 42.5.degree. 
C., the patient core body temperature readings at 62 by the thermistor 126 
of the assembly 124, and returning blood readings will stabilize at a 
desired level of approximately 41.5.degree. C. and 40.0.degree. C. 
respectively. This critical phase wherein the patient's systemic 
temperature is increased and stabilized should, as aforesaid, normally be 
completed within one hour, although here again, variation because of 
patient size will occur. 
Once temperature stabilization is achieved as aforesaid, treatment is 
continued for a time period effective for the particular cancer which the 
patient has. A preferred minimum time for all types including simple 
carcinomas in six hours although treatment times of 20 hours and longer 
will be required for more complex cancer situations. 
Preferably, a third phase of the present method involves utilizing the 
continued blood flow through the temperature control zone of the 
extracorporeal flow path to reduce the blood temperature to normal and, 
hence, the patient's systemic temperature to normal. This phase is 
initiated by turning control 60 to pass predominantly 30.degree. C. water 
through the heat exchanger 16. This has the effect of substantially 
lowering the readings of the returning blood taken at 64. Again, this 
cooler blood is distributed systemically, causing the systemic temperature 
to lower until a normal of 37.degree. C. is reached. The decreasing 
temperature phase normally will require a time period approximately the 
same as the initial increasing temperature phase although usually somewhat 
less. 
Preferably, the patient is maintained during treatment in a skin contacting 
environment approximating that of an intensive care room. While it is 
within the contemplation of the invention to provide a skin insulating 
environment and even comparable elevated temperatures to inhaled gases, 
the intensive care like environment is preferred because the temperature 
level of the skin and respiratory system does not vary significantly from 
the induced hyperthermia systemic level and access to the patient is much 
more readily obtained. Moreover, the application of radiation or 
chemotherapy treatments can be carried on simultaneously if desired. 
It thus will be seen that the objects of the invention have been fully and 
effectively accomplished. It will be realized, however, that the foregoing 
preferred specific embodiment has been shown and described for the purpose 
of illustrating the functional and structural principles of this invention 
and is subject to change without departure from such principles. 
Therefore, this invention includes all modifications encompassed within 
the spirit and scope of the following claims.