A unique phenotype of acquired Glanzmann thrombasthenia due to non-function-blocking anti-αIIbβ3 autoantibodies

Essentials Acquired Glanzmann thrombasthenia (aGT) is generally caused by function-blocking antibodies (Abs). We demonstrated a unique aGT case due to marked reduction of αIIbβ3 with anti-αIIbβ3 Abs. The anti-αIIbβ3 Abs of the patient did not inhibit platelet function but reduced surface αIIbβ3. Internalization of αIIbβ3 induced by the Abs binding may be responsible for the phenotype. SUMMARY: Background Acquired Glanzmann thrombasthenia (aGT) is a bleeding disorder generally caused by function-blocking anti-αIIbβ3 autoantibodies. Aim We characterize an unusual case of aGT caused by marked reduction of surface αIIbβ3 with non-function-blocking anti-αIIbβ3 antibodies (Abs). Methods A 72-year-old male suffering from immune thrombocytopenia since his 50s showed exacerbation of bleeding symptom despite mild thrombocytopenia. Platelet aggregation was absent with all agonists but ristocetin. Analysis of αIIbβ3 expression and genetic analysis were performed. We also analyzed effects of anti-αIIbβ3 Abs of the patient on platelet function and αIIbβ3 expression. Results Surface αIIbβ3 expression was markedly reduced to around 5% of normal, whereas his platelets contained αIIbβ3 to the amount of 40-50% of normal. A substantial amount of fibrinogen was also detected in his platelets. There were no abnormalities in ITGA2B and ITGB3 cDNA. These results indicated that reduced surface αIIbβ3 expression caused a GT phenotype, and active internalization of αIIbβ3 was suggested. Anti-αIIbβ3 IgG Abs were detected in platelet eluate and plasma. These Abs did not inhibit PAC-1 binding, indicating that the Abs were non-function-blocking. Surface αIIbβ3 expression of a megakaryocytic cell line and cultured megakaryocytes tended to be impaired by incubation with the patient's Abs. After 2 years of aGT diagnosis, his bleeding symptom improved and surface αIIbβ3 expression was recovered to 20% of normal with reduction of anti-αIIbβ3 Abs. Conclusion We demonstrated a unique aGT phenotype due to marked reduction of surface αIIbβ3. Internalization induced by anti-αIIbβ3 Abs may be responsible in part for the phenotype.

Hepatocyte Response to Continuous Low Dose-rate Radiation in Radioimmunotherapy Assessed by Micronucleus Assay

The response of hepatocytes to low dose-rate irradiation was examined in mice following the injection of radiolabelled monoclonal antibody. Mice were injected intravenously with an 131I-labelled monoclonal antibody 196-14 which recognizes CA125 antigen, and the effect of continuous low dose-rate irradiation on hepatocytes was assessed using the micronucleus assay. The frequency of micronuclei increased in a dose-dependent fashion, but it was lower than the frequency induced by conventional external X-rays which was determined immediately after the irradiation. A linear quadratic model (micronucleus frequency = aD+bD2+c) showed that the value of b decreased with low dose-rate irradiation from the radiolabelled antibody. It is concluded that the micronucleus assay is useful for the evaluation of the response of hepatocytes to irradiation in radioimmunotherapy.

Primary splenic malignant lymphoma associated with hepatitis C virus infection

We present two cases of primary splenic malignant lymphoma associated with chronic hepatitis C virus infection detected early by routine follow-up imaging studies. Septumlike structures were seen on postcontrast computed tomography or magnetic resonance imaging, which presented characteristic gross findings. These findings may suggest primary splenic malignant lymphoma during the course of chronic hepatitis C.

The inhaled administration of KF19514, a phosphodiesterase 4 and 1 inhibitor, prevents antigen-induced lung inflammation in guinea pigs

We examined in this study the effect of KF19514, a phosphodiesterase 4 and 1 inhibitor, on antigen-induced lung inflammation by inhaled administration in guinea-pigs. It was previously reported that inhaled KF19514 prevented antigen-induced bronchoconstriction and platelet-activating factor (PAF)-induced lung inflammation. In fact, a variety of factors other than PAF are related to lung inflammation in real subjects with asthma. Guinea-pigs were actively sensitized by exposure to ovalbumin (OA). Fifteen to 20 days later, the guinea pigs were challenged by exposure to aerosols of five successively increasing concentrations of OA (0.01, 0.1, 0.5, 1 and 5 mg/ml). Bronchoalveolar lavages (BALs) were performed 24 h after the antigen challenge, and airway hyperresponsiveness to acetylcholine (ACh) was studied 24 h after the challenge by measuring lung resistance and dynamic compliance. Ovalbumin antigen challenge produced a marked and significant eosinophil accumulation in the BAL fluids and airway hyperresponsiveness to ACh 24 h after the challenge. Inhaled KF19514 (0.01-0.1%) inhibited the eosinophil accumulation significantly and dose-dependently but inhaled rolipram (0.01-0.1%) and aminophylline (0.1-1%) did not. In addition, the development of airway hyperresponsiveness was prevented by inhaled KF19514 (0.01%) but not by inhaled rolipram (0.01%) and aminophylline (0.1%). Based on these data, KF19514 was suggested to be a promising drug in the treatment of asthma by local administration to the lung.

Acute histological effects of interstitial hyperthermia on normal rat brain

Histological changes in the brains of Fischer rats at different times after interstitial heating with various thermal doses were studied. The brains, subjected to sham-heating, and heating at 39 and 40 degrees C for 30 min showed mild capillary congestion and minimal vacuolation at 4, 24 and 72 h. In the brains heated to 41, 42 and 43 degrees C for 30 min, there was local vascular congestion, petechiae, vacuolation and cellular shrinkage with nuclear pyknosis at 4 h; enhanced congestion and petechiae, acute cellular necrosis, infiltration of polymorphonuclear leukocytes and marked vacuolation at the margin at 24h; total coagulative necrosis of all parenchymal and vascular elements, early liquefaction necrosis and vascular hyperplasia at the margin at 72 h; enhanced vascular hyperplasia at the margin at 120 h and 168 h. The threshold thermal dose for the histopathological damage in the rat brain was heating at 41 degrees C for 30 min.

The effect of erdosteine and its active metabolite on reactive oxygen species production by inflammatory cells

OBJECTIVE

We examined the effect of erdosteine (KW-9144), an expectorant, and related compounds on inflammatory cell-derived reactive oxygen species which are involved in airway inflammation.

METHODS

Neutrophils were isolated from peritoneal lavages of casein-injected rats and from peripheral blood of healthy human donors. Eosinophils were isolated from peritoneal lavages of horse serum-injected guinea pigs. These cells were stimulated with phorbol 12-myristate 13-acetate (PMA) and the production of reactive oxygen species was measured with luminol-dependent chemiluminescence (LDCL).

RESULTS

M1, an active metabolite of erdosteine, significantly inhibited PMA-induced LDCL of the all cell populations with treatment before stimulation. The effects of S-carboxymethylcysteine (S-CMC), ambroxol and N-acetylcysteine (NAC) on the LDCL response were weaker than those of M1. Furthermore, PMA-induced LDCL was decreased by posttreatment with M1.

CONCLUSION

These results suggest that M (an active metabolite of erdosteine) may exert an antiinflammatory effect by scavenging inflammatory cells-derived reactive oxygen species.

KF19514, a phosphodieterase 4 and 1 inhibitor, inhibits PAF-induced lung inflammatory responses by inhaled administration in guinea pigs

Phosphodiesterase (PDE) 4 inhibitors are well known for their inhibitory effect on bronchoconstriction and inflammation and may be promising anti-asthma drugs. Platelet-activating factor (PAF) has been proposed as an inflammatory mediator to be relevant to asthma. It causes bronchoconstriction, airway microvascular leakage, inflammatory cell accumulation in the lung and hyperresponsiveness. In this study, we therefore have investigated the anti-asthmatic effects of the inhaled KF19514 [5-phenyl-3'-(3-pyridyl)methyl-3H-imidazo(4,5-c)(1,8) naphthyridin-4(5H)-one], a PDE 4 and 1 inhibitor, on PAF-induced lung inflammatory responses in guinea pigs. The inhaled KF19514 (0.0001-0.01%) significantly inhibited PAF-induced eosinophil and neutrophil accumulation into the airway and hyperresponsiveness in guinea pigs. The IC50 value of KF19514 against eosinophil accumulation was 14.8 microM (0.00063%). Moreover, the effect of KF19514 on the electrical field stimulation-induced bronchial contraction was examined using the main bronchi of guinea pigs in vitro. KF19514 inhibited both cholinergic and tachykininergic contraction and, in particular, produced a potent inhibitory effect on tachykininergic contraction (IC50 = 0.49 microM). The mechanism by which KF19514 inhibited the PAF-induced hyperresponsiveness may in part be the suppression of the tachykinin release. Based on these results, it was demonstrated that the inhaled KF19514 might have a significant potential effect on the inflammatory cell accumulation and hyperresponsiveness induced by PAF.

Anti-inflammatory and bronchodilator properties of KF19514, a phosphodiesterase 4 and 1 inhibitor

We investigated the effects of KF19514 (5-phenyl-3-(3-pyridyl)methyl-3H-imidazo[4,5-c][1,8]naphthyridin-4 (5H)-one) on bronchoconstriction and allergic inflammation in guinea pigs and on tumor necrosis factor-alpha production in mice. KF19514 inhibited phosphodiesterase 4 (IC50 = 0.40 microM) and phosphodiesterase 1 (IC50 = 0.27 microM) derived from canine tracheal smooth muscles. KF19514 relaxed contracted tracheal smooth muscle and had a potent inhibitory effect on antigen-induced bronchoconstriction (EC50 = 0.058 microM) in vitro. Intravenous administration of KF19514 inhibited histamine-induced bronchoconstriction (ID50 = 2.8 microg/kg i.v.). Moreover, oral administration of KF19514 inhibited anaphylactic bronchoconstriction (ID50 = 0.2 mg/kg p.o.), and eosinophil infiltration in airway stimulated with platelet-activating factor (PAF) or antigen. KF19514 also produced a significant inhibition of tumor necrosis factor-alpha production in mice (ID50 = 0.023 mg/kg p.o.). Finally, KF19514 completely inhibited antigen-induced hyperreactivity at 0.1 mg/kg p.o. These results demonstrate that KF19514 may have efficacy in the treatment of asthma.

Clinical results of radiofrequency hyperthermia for malignant liver tumors

PURPOSE

To evaluate thermometry and the clinical results of radiofrequency (RF) hyperthermia for advanced malignant liver tumors.

METHODS AND MATERIALS

One hundred seventy-three patients with malignant liver tumors treated between 1983 and 1995 underwent hyperthermia. The 173 tumors consisted of 114 hepatocellular carcinomas (HCCs) and 59 non-HCCs (47 metastatic liver tumors and 12 cholangiocarcinomas). Eight-megahertz RF capacitive heating equipment was used for the hyperthermia. Two opposing 25-cm electrodes were generally used for heating the liver tumors. Our standard protocol was to administer hyperthermia 40-50 min twice a week for a total of eight sessions. The liver tumor temperature was measured by microthermocouples when possible. Transcatheter arterial embolization, radiotherapy, immunotherapy, and chemotherapy were combined with hyperthermia treatment in accordance with each patient's liver function.

RESULTS

One hundred forty (81%) of the 173 patients who underwent more than four sessions of hyperthermia were evaluated in this study. Thermometry was performed in 77 (55%) of these 140 patients. The maximum tumor temperature, average tumor temperature, and minimum tumor temperature in the HCC were (mean +/- standard error) 41.2 +/- 0.2 degrees C, 40.3 +/- 1.3 degrees C, and 40.1 +/- 0.2 degrees C, respectively. The same thermometry results for non-HCC were 42.3 +/- 0.2 degrees C, 41.2 +/- 0.2 degrees C, and 40.9 +/- 0.2 degrees C, respectively. The maximum and minimum temperatures (41.8 +/- 0.2 degrees C and 40.3 +/- 0.4 degrees C) in the patients with a complete or partial response (CR or PR) were higher than those in the patients with no response or progressive disease (NR or PD) (41.3 +/- 0.5 degrees C and 39.8 +/- 0.4 degrees C), but the difference was not significant. Of the 73 cases with HCC who were evaluated by computed tomography (CT), CR was achieved in 7 (10%), PR in 15 (21%), NR in 37 (51%), and PD in 14 (19%). Of the 45 cases involving liver metastases evaluated by CT, CR was achieved in 3 (7%), PR in 17 (38%), NR in 12 (27%), and PD in 13 (29%). The 1-year cumulative survival rate for HCC patients was 30.0%, and the 5-year survival rate was 17.5%. The 1-year survival of non-HCC patients was 32.5%, and the longest survival was 30 months. The sequelae of hyperthermia included focal fat necrosis in 20 patients (12%), gastric ulceration in 4 (2%), and liver necrosis in 1 (1%). The sequelae of thermometry were severe peritoneal pain in seven patients (11%), intraperitoneal hematoma in one (1%), and pneumothorax in one (1%).

CONCLUSION

Even though the thermometry results for liver tumors were not satisfactory, the treatment results are promising. Further clinical trials of RF capacitive hyperthermia for the treatment of advanced liver tumors should be encouraged.

Modification of the response of a quiescent cell population within a murine solid tumour to boron neutron capture irradiation: studies with nicotinamide and hyperthermia

C3H/He mice bearing SCC VII tumours received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps, to label all proliferating (P) cells. 20 min after intraperitoneal injection of sodium borocaptate-10B (BSH), or 3 h after oral administration of dl-p-boronophenylalanine-10B (BPA), the tumours were irradiated with thermal neutrons. To modify the uptake dose of 10B, nicotinamide (NA) was intraperitoneally injected 60 min before the administration of 10B-compounds and/or the tumours were heated to 41.5 degrees C for 20 min immediately before irradiation. After irradiation, the tumours were excised, minced and trypsinized. The tumour cell suspensions were then incubated with cytochalasin-B (a cytokinesis-blocker). The micronucleus (MN) frequency in cells not BrdU-labelled (quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. With or without the administration of 10B-compounds, the sensitivity of Q cells was lower than that of total (P + Q) tumour cells. With thermal neutron irradiation in the presence of either BPA or BSH, the MN frequency in each cell population was increased. A greater increase in the MN frequency of total tumour cells was observed after thermal neutron irradiation in the presence of BPA than in the presence of BSH. The distribution of 10B from BPA into tumour cells was thought to be more dependent on the uptake ability of the tumour cells than that from BSH. Sufficient quantity of 10B from these two 10B-compounds to cause a highly lethal event inside the cancer cell with thermal neutron irradiation could not be delivered to Q cells. When NA and/or heat treatment were combined with 10B-compound administration, NA increased MN frequency in the BSH treated total cells, and heat treatment elevated MN frequency in Q cells. From the viewpoint of cell kill effect, the combined treatment with nicotinamide and heat treatment was more useful than treatment with either nicotinamide or heat treatment alone, not only in the total tumour cells but also in the Q cells.

Clinical usefulness of determining the rate of thermal clearance within heated tumors

Between June 1987 and June 1988, 28 patients (28 tumors) with liver, retroperitoneal, intrapelvic, or superficial tumors were treated with hyperthermia combined with radiotherapy and/or chemotherapy. Hyperthermia was administered once or twice a week for 30-60 min per session, up to a total of 2-11 sessions, with an 8-MHz RF capacitive heating device. Blood flow in the tumors was evaluated from the rate of thermal clearance (TCR) using the bio-heat transfer equation. The TCR was measured in the middle of the first heating session and at the end of the last heating session by turning off the output power of the heating device. For 9 patients, contrast-enhanced CT scans were taken and CT numbers at the centers of tumors were measured before and after the entire course of hyperthermia. Changes in TCR were closely related to average tumor center temperature, changes in CT number, and tumor response. When smaller and more superficial tumors were treated by hyperthermia combined with radiotherapy and/or chemotherapy that consisted of many heating sessions and during which a high average tumor center temperature was achieved, a better tumor response was obtained. The better the tumor response, the higher the local control rate became. The cause-specific survival rate of patients who achieved good tumor responses was higher than that of patients who showed poor tumor responses. Changes in TCR and CT number in heated tumors were useful and important indicators of tumor response to hyperthermia.

An attempt to enhance chemosensitivity of quiescent cell populations in solid tumors by combined treatment with nicotinamide and carbogen

cis-Diamminedichloroplatinum(II) (cisplatin) was intraperitoneally injected into mice bearing SCC VII or EMT6/KU tumors after ten administrations of 5-bromo-2'-deoxyuridine (BrdU) to label all the proliferating tumor cells. The tumors were excised 1 h after the cisplatin injection, minced, and trypsinized. The tumor cell suspensions were then incubated with cytochalasin-B (a cytokinesis blocker). The micronucleus frequency was determined, using immunofluorescence staining for BrdU. Cells that were not labeled with BrdU were regarded as quiescent. The micronucleus frequency in the total number of tumor cells was determined in tumors that had not been pretreated with BrdU. To modify the sensitivity to cisplatin, nicotinamide was intraperitoneally injected before the administration of cisplatin or mice were placed in a circulating carbogen (95% O2, 5% CO2) chamber for 30 min after cisplatin administration. In both tumor systems, the micronucleus frequency in quiescent cells was lower than that in the total cells. Nicotinamide pretreatment increased the micronucleus frequency in total and in quiescent cells in both tumor systems, and to a higher extent in total cells. The combination of nicotinamide and carbogen increased the micronucleus frequency more markedly than treatment with either nicotinamide or carbogen alone. In total cells of both tumors, the nicotinamide injection increased the uptake of [195mPt]cisplatin. The combined treatment raised the uptake more markedly than did treatment with either agent alone. In total cells of the SCC VII tumor, these increases in micronucleus frequency and the [195mPt]cisplatin uptake following nicotinamide or combined pretreatment were significant. In both tumors, carbogen breathing also elevated the micronucleus frequency to some degree in total and quiescent cells and the [195mPt]cisplatin uptake in total cells. The combined nicotinamide and carbogen treatment was considered to be useful for sensitizing tumor cells to chemotherapy with cisplatin in vivo.

Radiobiological evidence suggesting heterogeneous microdistribution of boron compounds in tumors: its relation to quiescent cell population and tumor cure in neutron capture therapy

PURPOSE

The heterogeneous microdistribution of boron compounds in tumors and its significance on tumor cure were examined by a radiobiological procedure. The role of quiescent (Q) cells in tumor was especially investigated.

METHODS AND MATERIALS

10B-enriched paraboronophenylalanine (BPA) and mercaptoundecahydrododecaborate (BSH) were administered to SCCVII tumor bearing C3H/He mice by intragastric and i.v. injections, respectively. The continued effects of these boron compounds with thermal irradiations were studied by using colony formation and tumor control assays. Their effects on Q cells were also analyzed by the combined method of micronucleus frequency assay and an identification of proliferating (P) cells by BUdR and anti-BUdR monoclonal antibody.

RESULTS

10B-concentration after BPA (1,500 mg/kg) and BSH (75 mg/kg) administration were 11 ppm at 3 h and 10.5 ppm at 30 min, respectively. Cell survival decreased exponentially with an increment of neutron fluence (phi). The exponential parts of the curves were: -InSF = -0.052+ 13.0x10(13)phi, -InSF = -0.032+7.68X10(-13)phi, and -InSF = -0.0005+2.68x10(-13)phi for BPA-BNCT, BSH-BNCT, and NCT alone, respectively. Fifty percent tumor control was obtained at the influence of 10.2 x 10(12) n/cm2 in BPA-BNCT. On the other hand, 11.4 x 10(12) n/cm2 of neutrons had to be delivered in BSH-BNCT. The normal nuclear division fraction defined as the cell fraction that did not express micronuclei at first mitosis after treatment was investigated. The surviving cell fraction and the normal nuclear division fraction were regarded as equal in NCT alone. However, the normal nuclear division factor following BPA-BNCT was greater than the surviving cell fraction, and the difference increased with an increase in neutron fluence. In Q cells, BSH-BNCT yielded higher micronucleus frequency than BPA-BNCT and NCT alone. The frequencies in Q cells following BPA-BNCT and NCT alone were almost same as that in total cell population after NCT alone.

CONCLUSIONS

Our data suggested that BPA distributed in tumors hetergeneously. Q cells especially might not accumulate BPA. To decrease the possible disadvantage of BPA-BNCT, the combination of BPA and BSH or other neutron capture element that emit particles with longer ranges, for example, gadolinium, would have to be investigated.

Thermoradiotherapy of superficial and subsurface tumours: analysis of thermal parameters and tumour response

Between 1988 and 1993, 57 superficial and subsurface tumours of various tumour type were treated with a 430-MHz microwave heating device. Mean (range) tumour depth of the 57 tumours was 3.0 (0.5-6.5) cm. Fifty-four tumours were treated with thermoradiotherapy. Total radiation dose ranged from 20 to 70 Gy with a mean of 53 Gy. For the remaining three tumours, thermochemotherapy was performed. Hyperthermia was given once a week, and a total of 207 heat sessions was administered. Our goal of hyperthermia treatment was to elevate all monitored tumour points > 41 degrees C for > 30 min. The mean (range) number of intratumoral thermometry points was 3.7 (2-6). The goal of hyperthermia treatment was achieved in 49% of the sessions. At the time of maximum tumour regression, complete response was noted in 53% of the tumours treated with thermoradiotherapy. Univariate analysis demonstrated that parameters including tumour type (breast cancer versus others), tumour depth, minimum tumour temperature, average tumour temperature, minimum equivalent time at 43 degrees C, and number of heat sessions achieving the treatment goal significantly affected the tumour response of the combined treatment, while total radiation dose and number of heat sessions were not significant factors for tumour response. Multivariate logistic analysis revealed that only tumour depth (< 3 versus > or = 3 cm) was a significant prognostic factor for tumour response (p = 0.029). Tumour type (breast cancer versus others) and a number of heat sessions achieving the treatment goal (0-1 versus 2-5) were found to be of borderline significance in the multivariate analysis (p = 0.075 and 0.097 respectively). The number of heat sessions achieving a minimum tumour temperature of > 41 degrees C for > 30 min seems a practical thermal parameter that influences tumour response. The present study indicates the importance of quality and quantity of heat session on the treatment outcome of thermoradiotherapy.

Clinical experiences in the thermoradiotherapy for advanced gastric cancer

Recurrent and/or inoperable gastric cancer has been treated by thermoradiotherapy at Kyoto University Hospital since 1983. In the present study, the efficacy of hyperthermia (using radiofrequency capacitive heating) plus radiotherapy for gastric cancer was evaluated in 21 patients with local recurrence, abdominal wall metastases, peritonitis carcinomatosis or paraaortic node metastases. The intratumour temperature was measured using a microthermocouple thermometer. The means of the maximum, average, and minimum intratumour temperature were 43.5, 42.1, and 41.1 degrees C respectively. The local tumour response was evaluated using computed tomography (CT). The local response rate (complete regression plus partial regression/all tumours) was 88.9%, which seemed to be higher than that of other reports using thermochemotherapy or radiotherapy alone. The one-year cumulative survival rate was 39.1%.

Clinical results of thermoradiotherapy for soft tissue tumours

Thirty-one unresectable and/or recurrent soft tissue tumours in 27 patients underwent hyperthermia in combination with radiation therapy. Locoregional hyperthermia was administered once or twice a week for 40-60 min to a total of 2-14 sessions using RF capacitive or microwave heating equipment. Radiation therapy was given 10-20 min before hyperthermia at doses of 20.8 to 70 Gy. The mean +/- SD of the maximum, average, and minimum intratumour temperatures was 44.0 +/- 2.9 degrees C, 42.3 +/- 1.6 degrees C, 40.1 +/- 1.1 degree C respectively, and that of the percentage of the intratumour points that exceeded 41 and 43 degrees C was 66.0 +/- 33.6, and 31.0 +/- 26.1 respectively. Of the 31 tumours treated, 13 (42%) showed CR (complete regression), 10 (32%) PR (> 50 and < 100% regression) and 8 (26%) NC (< 50% regression). Since intratumour low density areas on post-treatment CT scans have been demonstrated to be a useful parameter for assessing tumour response to thermoradiotherapy, the presence of low density areas was also assessed. Low density areas were classified into the following three categories according to the percent area occupied in the maximal cross-section of the tumour: type I, < 50%, type II, 50-80%; type III, > 80%. Of 20 tumours evaluable, 6 (30%) exhibited type III change, 11 (55%) type II and 3 (15%) type I. All of the type III tumours demonstrated a marked response on follow-up or histopathological examination. The major complication associated with treatment was skin ulcer in two patients. The five-year survival of the total 27 patients and 18 patients who had no distant metastases at the start of treatment was 32 and 48% respectively. These results indicate the clinical benefit of thermoradiotherapy using RF capacitive or microwave equipment for locally advanced and/or recurrent soft tissue tumours.

Clinical evaluation of 430 MHz microwave hyperthermia system with lens applicator for cancer therapy

The clinical efficacy of a microwave (MW) hyperthermia system using an electric-field converging (lens) applicator is evaluated for 42 malignant tumours with a maximum tumour depth of less than 7 cm. The mean of the maximum, average and minimum tumour temperature of the 42 tumours are 44.5, 42.5 and 40.7 C, respectively. The thermal parameters are higher for tumours in the chest, abdominal walls and hip than for those in the neck, groin and extremities. No apparent difference in thermal parameters according to the depth of tumour is shown. Of 40 tumours treated by hyperthermia in combination with radiotherapy, 20 (50%) showed complete regression, 14 (35%) showed partial regression, and six (15%) showed no change. This phase I and II study indicates clinical feasibility of the newly developed MW heating apparatus, and strongly suggests the usefulness of thermoradiotherapy in the treatment of localised superficial and subsurface malignancies.

Effect of hyperthermia on the number of platinum atoms binding to DNA of HeLa cells treated with 195mPt-radiolabelled cis-diaminedichloroplatinum(II)

HeLa S-3 cells were treated with 195mPt-radiolabelled cis-diaminedichloroplatinum II) (CDDP) for 60 min at various temperatures to examine the relationship between the lethal effect and the number of Pt atoms binding to DNA, RNA and protein molecules. The mean lethal concentration (Do) of CDDP for 60-min treatment at 0, 25, 37, 40, 42 and 44 degrees C was 233, 69.9, 15.9, 11.7, 8.3 and 4.7 microM respectively. By using identically treated cells, the number of Pt atoms combined with DNA, RNA and protein molecules was determined in the subcellular fractions prepared by the method of Schneider (1961). Thus, the Do's given as the drug concentrations were substituted for the number of Pt atoms combined with each fraction. Then the efficiency of the Pt atom to kill the cells was expressed as the reciprocal of the number of Pt atoms combined and was calculated for each molecule. The efficiency for DNA was 2.47, 2.75, 9.49, 9.66, 10.53 and 15.00 x 10(4) nucleotides respectively for the conditions described above. A detailed comparison of the Do's and efficiencies suggested that the supra-additive effect of the combination treatment could be explained by two mechanisms, i.e. the increased drug level in DNA (from 37 to 42 degrees C) and the increased efficiency of the Pt atoms to kill the cells (> 42 degrees C).

The radiosensitivity of quiescent cell populations in murine solid tumors in irradiation with fast neutrons

PURPOSE

We analyzed the characteristics of radiosensitivity and potentially lethal damage repair in the quiescent cell populations of murine SCC VII solid tumors irradiated with fast neutrons, in comparison with those irradiated with 10 MV X rays.

METHODS AND MATERIALS

SCC VII tumor-bearing C3H/He mice were irradiated with 30 MeV fast neutrons or 10 MV X rays after receiving 10 injections of 5-bromo-2'-deoxyuridine (BUdR) to label all proliferating tumor cells. Immediately or 24 h after irradiation, the tumors were excised and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus frequency in cells without BUdR labeling was determined using immunofluorescence staining to BUdR. This micronucleus frequency was then used to calculate the surviving fraction of unlabeled cells from the regression line for the relation between micronucleus frequency and the surviving fraction of all tumor cells. Thus, a cell survival curve could be determined for the cells not labeled by BUdR, which can be regarded as the quiescent cells for all practical purposes.

RESULTS

The difference in intrinsic radiosensitivity between all tumor and quiescent cells became smaller by using fast neutrons, compared with X rays, especially when large radiation doses were given. Potentially lethal damage repair by quiescent cells was less evident following irradiation with fast neutrons than with X rays, especially when large doses were delivered.

CONCLUSION

By using fast neutrons in clinical radiotherapy, the radiosensitivity of solid tumors is thought to depend on their heterogeneity less critically than for X rays.

Site-specific phase I, II trials of hyperthermia at Kyoto University

Site-specific phase I, II trials of locoregional hyperthermia undertaken at Kyoto University are briefly reviewed. Thermometry analysis demonstrated the usefulness of RF (radiofrequency) capacitive heating equipment in the treatment of various subsurface or deep-seated tumours including locally advanced breast cancers, soft tissue tumours, lung cancers involving the chest wall, liver tumours, unresectable or recurrent colorectal cancers, and invasive urinary bladder cancers. The difficulty in heating whole tumour volume or hypervascular tumours to therapeutic temperatures was also shown. Non-randomized trials for locally advanced breast cancers, unresectable or recurrent colorectal cancers and invasive urinary bladder cancers demonstrated a higher response rate in thermoradiotherapy than in radiotherapy alone. The complications associated with treatment were not generally serious except for chronic bowel damages in a trial for colorectal cancers. These promising phase I, II trials encourage the future phase III trials.

Middle dose rate irradiation in combination with carbogen inhalation selectively and more markedly increases the responses of SCCVII tumors

PURPOSE

Carbogen increases the radiation response of tumors and reduced dose rate irradiation spares the damage of normal tissues. The purpose in this paper is to investigate the possibility of selective radiosensitization of tumors by reduced dose rate irradiation in combination with carbogen inhalation.

METHODS AND MATERIALS

SCCVII tumors in C3H/He mice were irradiated at middle dose rate (0.1 Gy/min) or high dose rate irradiation (3.0 Gy/min) in combination with carbogen inhalation. The mice were enclosed in a box with carbogen flushing at 1.01/min. The tumor response was measured by a cytokinesis block micronucleus assay. The effects on intestinal crypt cells and bone marrow cells were investigated by microcolony assay or Hendry's method, respectively.

RESULTS

The anti-tumor effect of middle dose rate irradiation was equal to that of a high dose rate irradiation. Carbogen inhalation, more efficiently, increased the antitumor effect when combined with middle and high dose rate irradiation, and yielded enhancement ratios of 1.6 at around 2 Gy. Middle dose rate irradiation produced less damage on intestinal crypt cells and bone marrow cells in comparison with high dose rate irradiation, and carbogen inhalation never enhanced the responses of these normal tissues in combination with middle dose rate irradiation. Dose modifying factors were 1.3-2.0.

CONCLUSION

Since middle dose rate irradiation in combination with carbogen inhalation gave the therapeutic gain factors of 2.0-3.2, which were much larger than those obtained with any other radiosensitizers, this combination has a potential as a new modality for improving the results of cancer radiotherapy.

Estimation of the initial slope of the cell survival curve after irradiation from micronucleus frequency in cytokinesis-blocked cells

We have already reported that the alpha/beta ratio of the cell survival curve could be estimated from the micronucleus frequency in cytokinesis-blocked cells treated with cytochalasin-B after irradiation. In this paper, we investigate the direct relationship between the alpha value and the appearance of micronuclei. Cells of the SCCVII, RIF-1, EMT6, V-79, CHO, HeLa and human esophageal cancer cell lines were used for the study. Low-dose-rate irradiation was used to determine the alpha component of the relationship between dose and micronucleus frequency according to the linear-quadratic (LQ) model. A reduction of the dose rate from 3.09 to 0.0142 Gy/min correspondingly decreased the micronucleus frequency; however, the fraction of binucleate cells without micronuclei was not affected in SCCVII and RIF-1 cells. When this fraction was defined as the normal nuclear division fraction, it decreased exponentially as a function of radiation dose. Then dose vs normal nuclear division fraction (NNDF) was fitted as follows: -ln NNDF = aD + C, where D is radiation dose in grays and C is constant. The slope of the dose vs normal nuclear division fraction was not affected by dose rate. The correlation was also explored between the slope (a) and the alpha value of the cell survival curve determined by the colony formation assay in cells of eight cell lines. These two values showed extremely high agreement: alpha = 1.01 a + 0.00795 (r = 0.99, P < 0.01). This assay was applied to estimate the alpha value of the cell survival curve of human esophageal cancer cell lines established from surgical specimens.

The response of quiescent cell populations in murine solid tumors to irradiation with fast neutrons

5-bromo-2'-deoxyuridine (BUdR) was injected into SCC VII tumor-bearing mice intraperitoneally to label all proliferating tumor cells. The mice were irradiated with fast neutrons or x-rays. Immediately, or 24 h after irradiation, the tumors were excised, minced and trypsinized. The tumor cell suspensions were incubated with cytochalasin-B (a cytokinesis blocker). The micronucleus frequency was determined using immunofluorescence staining to BUdR. The cells that were not labeled with BUdR could be regarded as the quiescent cells. The micronucleus frequency in total tumor cells was determined from the irradiated tumors that were not pretreated with BUdR. The difference in radiosensitivity between total and quiescent cells was markedly reduced with fast neutrons, especially at higher doses of radiation. Potentially lethal damage repair by total and quiescent cells was inhibited more strongly with neutrons than with x-rays. When using fast neutrons, the radiosensitivity of solid tumors depends on their heterogeneity less critically than for x-rays.

Phase I/II trial of preoperative thermoradiotherapy in the treatment of urinary bladder cancer

Between April 1984 and September 1988, preoperative radiotherapy or thermoradiotherapy was administered to 49 patients with bladder cancer (T1-4N0M0; UICC classification, 1987). Twenty-one patients were preoperatively treated by radiotherapy alone, with 4 Gy per fraction and three fractions per week to a total dose of 24 Gy (TDF = 53, group 1). The other 28 patients were treated by the same radiotherapy regimen in combination with hyperthermia (group 2). Regional hyperthermia was administered for 35-60 min immediately after irradiation (two sessions per week to a total of four sessions) using an 8 MHz RF capacitive heating device. Group 2 was divided into group 2 (high), in which the average intravesical temperature (T(av)) was > 41.5 degrees C, which was the mean value, and group 2 (low) with a T(av) < 41 x 5 degrees C. Group 2 (high) showed a significantly higher incidence of down-staging and tumour degeneration than both group 1 and group 2 (low). In addition, the local recurrence rate was lower and survival time was longer in group 2 than in group 1, although not significantly so. In particular, the patients with T3-4 or grade 3 bladder cancer in group 2 had a longer average survival than those in group 1, although the difference was not significant. The toxicity associated with hyperthermia was pain during treatment, and complications were not serious.

Enhancement of chemosensitivity of quiescent cell populations in murine solid tumors using nicotinamide

Cis-diamminedichloroplatinum(II) (CDDP) was intraperitoneally injected into mice bearing SCC VII or EMT6/KU tumors after 10 administrations of 5-bromo-2'-deoxyuridine (BUdR) to label all the proliferating tumor cells. One hour later, the tumors were excised, minced and trypsinized. The tumor cell suspensions were incubated with cytochalasin B (a cytokinesis blocker). The micronucleus (MN) frequency was determined using immunofluorescence staining to BUdR. The cells that were not labeled with BUdR could be regarded as the quiescent cells. The MN frequency in total tumor cells was determined from the tumors that were not pretreated with BUdR. To modify the sensitivity to CDDP, nicotinamide was intraperitoneally injected before CDDP administration. In both tumor system, the MN frequency in quiescent cells was lower than in total cells. Nicotinamide pretreatment increased the MN frequency in total and quiescent cells in both tumor systems, especially in total cells of the SCC VII tumor. The nicotinamide injection increased the uptake of 195mPt-CDDP into the total cells, especially in the SCC VII tumor. Nicotinamide administration before chemotherapy using CDDP was considered to be effective for tumor control, especially in tumors including large acutely hypoxic fractions such as the SCC VII murine tumor.

Scintigraphic study on the distribution of radiolabeled cis-diamminedichloroplatinum (II) in the tumor-bearing rabbit: a comparison between intra-arterial injection with lipiodol and intravenous injection

To compare the distribution of cis-diamminedichloroplatinum (II) (CDDP) on scintigraphic images between intra-arterial injection with lipiodol and intravenous injection, we obtained serial scintigraphic images using radiolabeled CDDP (Pt-195m CDDP), which had a high specific activity (7.4 x 10(6) Bq [200 microCi]/mg-CDDP), in the rabbit VX-2 tumor system. A dose of 9.25 x 10(6) Bq (250 microCi) of Pt-195m CDDP was injected at one shot via an ear vein, while 7.4 x 10(6) Bq (200 microCi of Pt-195m CDDP mixed with 1 ml of lipiodol was injected at one shot via a saphenous artery. Mean pixel count, which was corrected for the total dose injected, in the arterially injected tumor always exceeded than that in the intravenously injected tumor. Pt-195m CDDP uptake by the rabbit tumor at 2 hr was 7.8% of the total injected dose with intravenous injection and 16.0% with intra-arterial injection. These data suggest that intra-arterial injection with lipiodol is a more useful method to increase CDDP uptake by tumors than intra-venous injection.

Radiosensitization of SCCVII tumours and normal tissues by nicotinamide and carbogen: analysis by micronucleus assay

The radiosensitizing effect on SCCVII tumours of carbogen (95% O2 + 5% CO2) combined with nicotinamide was investigated using the micronucleus assay and an in vivo/in vitro colony formation assay following single irradiation. The effects on intestinal crypt cells and bone marrow cells were also examined in mice. The frequency of micronuclei in tumours increased with an increase in the nicotinamide dose (administered 1 h before the irradiation of 5 Gy) from 0.1 to 1.0 mg/g, and showed a 1.3-fold increase at 1.0 mg/g when compared with radiation alone. The micronucleus frequency showed a more marked increase following irradiation combined with nicotinamide and carbogen inhalation starting 15 min before irradiation. The radiosensitizing effect reached a plateau at a nicotinamide dose of 0.1 mg/g in combination with carbogen, giving an enhancement ratio (ER) of 1.8 relative to radiation alone at 2 Gy. In the radiation dose range of 5-20 Gy, ERs of 1.8-1.9 and 1.5 (at a 10% cell-survival level) were obtained for the combination of 0.1 or 1.0 mg/g nicotinamide and carbogen and for carbogen alone, respectively. A slight increase in the regeneration response of the jejunum and the bone marrow was observed following irradiation combined with 0.1 mg/g nicotinamide and carbogen, yielding ERs of 1.07 for the jejunum and 1.15 for the bone marrow. Thus, the nicotinamide/carbogen combination, with its large therapeutic gain factor at low doses and proven low toxicity in humans, seems to improve the response of cancer to radiotherapy.

Distribution of radiolabeled cis-diamminedichloroplatinum (II) on scintigraphic images in the tumor-bearing rabbit

To evaluate the feasibility of using scintigraphic images to assess the distribution of cis-diamminedichloroplatinum (II) (CDDP), we obtained serial scintigraphic images using radiolabeled CDDP (Pt-195m CDDP), which had high specific activity (7.4 x 10(6) Bq [200 microCi]/mg-CDDP) in the rabbit VX-2 tumor system. Radioactivity at the heart decreased in a biexponential manner, with an initial half-time of 15.3 min and secondary phase of 4.5 days. Time-activity curves revealed that the tumor/heart ratio was greater than 1.0 (1.0-1.1) between 30 min and 4 hr after intravenous injection. The scintigraphic study clearly depicted the tumor. Pt-195m CDDP uptake by the rabbit tumor at 2 hr was 7.8% of the total injected dose. These data suggest that scintigraphic imaging using Pt-195m CDDP is a promising method for imaging tumors and evaluating their CDDP uptake.

Determination of the target volume of HeLa cells treated with platinum-195m radiolabeled trans-diaminedichloroplatinum(II): a comparison with cis-diaminedichloroplatinum(II)

HeLa S-3 cells were treated with 195mPt-radiolabeled trans-diaminedichloroplatinum(II) (TDDP) under various conditions, and the relationship between lethal effect and the number of Pt atoms binding to DNA, RNA and proteins was examined. The mean lethal concentrations for the cells treated with TDDP at 37 degrees C for 1, 2 and 3 h were 163.7, 65.8 and 24.9 microM, respectively. By using identically treated cells, the number of Pt atoms combined with DNA, RNA and protein molecules was determined after the cells were fractionated using the method of Schneider. In this way, the D0 values given as the drug concentration were substituted for the number of Pt atoms combined with each fraction, then the target volumes, expressed as the reciprocals of the D0 values, were calculated for each fraction. The results suggested that DNA and high molecular weight RNAs (except t-RNA), under some limited condition, could be the target molecules for cell killing by TDDP. The target volumes for DNA were 1.31 x 10(3), 3.01 x 10(3) and 6.26 x 10(3) nucleotides for 1, 2 and 3 h treated cells, respectively. Cell killing effects of TDDP were lower than CDDP by a factor of 39.5, 19.0 and 16.5 for 1, 2 and 3 h treatments at 37 degrees C, respectively, when viewed from the stand point of the target volume, while those from the mean lethal dose (D0) were 17.6, 9.8 and 6.7, respectively.

The number of platinum atoms binding to DNA, RNA and protein molecules of HeLa cells treated with cisplatin at its mean lethal concentration

HeLa S-3 cells were treated with 195mPt-radiolabeled cis-diamminedichloroplatinum(II) (CDDP) under various conditions, and the relationship between lethal effect and the number of Pt atoms binding to DNA, RNA and proteins was examined. The mean lethal concentrations for the cells treated with CDDP at 37 degrees C for 1, 2 and 3 h were 2.8, 2.0 and 1.1 microgram/ml, respectively. By using identically treated cells, the number of Pt atoms combined with DNA, RNA and protein molecules were determined after fractionation of the cells using the method of Schneider. In this way, the D0 values given as the drug concentration were substituted for the number of Pt atoms combined with each fraction, then the target volumes expressed as the reciprocals of D0 values were calculated for each fraction. The results provide strong support for the idea that DNA is the primary target for cell killing by CDDP, and the target volumes were 5.17 x 10(4), 5.71 x 10(4) and 1.03 x 10(5) nucleotides for 1, 2 and 3 h treated cells, respectively.

Regional hyperthermia combined with radiotherapy in the treatment of lung cancers

Twenty locally advanced lung cancers were treated by hyperthermia in combination with radiotherapy between November 1980 and January 1990. All tumors selected had invaded or were in contact with the chest wall, so that transcutaneous insertion of thermal probes into the tumor was possible. Using an 8 or 13.56 MHZ RF capacitive heating device, hyperthermia was given once or twice a week after irradiation for 30-60 min per session (1-12 sessions in total). Radiotherapy was delivered at dose of 13.6-70 Gy. The thermal parameters analyzed were a) maximum, average, and minimum intratumor temperatures (Tmax, Tav, and Tmin), which were recorded at the termination of each treatment, and b) the percentages of the intratumor points that exceeded 41 C (%T greater than or equal to 41 C). The mean +/- SD for Tmax, Tav, Tmin, and %T greater than or equal to 41 C was 42.9 +/- 1.7 C, 41.6 +/- 1.2 C, 39.7 +/- 1.1 C, and 56.2 +/- 25.8, respectively. Larger tumors showed higher thermal parameters than the smaller tumors. Of the 12 tumors treated by definitive therapy, 2 (17%) achieved CR, 7 (58%) PR, and 3 (25%) NR. Four of 10 tumors that did not achieve CR showed large intratumor low density areas on post-treatment CT, reflecting massive coagulation necrosis. Higher thermal parameters were closely related to the appearance of low-density areas but not to changes in tumor size. Four tumors treated preoperatively were successfully resected 2 weeks after thermoradiotherapy, whereas four palliatively-treated tumors showed no regression. The side effects associated with hyperthermia were pain in 12 patients (60%) and dyspnea in 3 (15%), all of which resolved after termination of treatment. A skin abscess and a pneumothorax attributed to thermal probe insertion were observed in one patient each. These results indicate that regional RF capacitive hyperthermia is clinically feasible for local treatment of selected lung cancers.

Hyperthermia combined with radiation therapy for primarily unresectable and recurrent colorectal cancer

The value of adjuvant hyperthermia to radiotherapy in the treatment of locally advanced colorectal cancers was investigated. Between 1981 and 1989, 71 primarily unresectable or recurrent colorectal tumors were treated with radiotherapy at the Department of Radiology, Kyoto University Hospital. Of the 71 tumors, 35 were treated with radiotherapy plus hyperthermia (group I), while 36 tumors (group II) were unsuitable for hyperthermia mainly because of difficulties with the insertion of temperature probes or the thickness of the patient's subcutaneous fat (greater than 2 cm). The mean total radiation dose was 58 Gy and 57 Gy for groups I and II, respectively. Thirty deep-seated pelvic tumors were treated with an 8 MHz radiofrequency capacitive heating device, and five subsurface tumors were treated with a 430 MHz microwave hyperthermia system. Hyperthermia was given following radiotherapy for 30-60 min for a total of 2-14 sessions (mean 5.7). In 32 of the 35 tumors heated, direct measurement of tumor temperature was performed. For the five tumors treated with the microwave heating device, the means of the mean maximum, average, and minimum measured intratumoral temperatures were 45.4 degrees C, 43.3 degrees C, and 40.6 degrees C, respectively. The corresponding values were 42.2 degrees C, 41.3 degrees C, and 40.3 degrees C for the 27 tumors treated with the capacitive heating device. Effective heating of deep-seated pelvic tumors was more difficult than heating of abdominal wall or perineal tumors. The local control rate at 6 months after the treatment, which was defined as absence of local progression of the tumors, was 59% (17/29) and 37% (11/30) for groups I and II, respectively. The objective tumor response rate (complete regression plus partial response) evaluated by computed tomography was 54% (19/35) in group I, whereas it was 36% (10/28) in group II. A better response rate of 67% was obtained in the 15 tumors with a mean average tumor temperature of greater than 42 degrees C. Although limitation of our current heating devices exist, the combination of hyperthermia with radiotherapy is a promising treatment modality in the treatment of locally advanced colorectal cancer.

Clinical research into hyperthermia treatment of cancer using a 430 MHz microwave heating system with a lens applicator

Tokyo Metropolitan Komagome Hospital, Kyoto University Hospital, and Aichi Cancer Center used a lens applicator microwave equipment, the HTS-100, to treat 90 patients with a total of 96 tumours. The results were analysed, and the following conclusions reached. Three clinical cases have been presented to illustrate the features of the HTS-100. (1) The results of 383 heating sessions using the HTS-100 were analysed. Even tumours larger and deeper than 5 cm could be heated above 42 degrees C. The heating area is much wider than that of the other 2450, 915, 430 MHz microwave heating equipments. (2) Hyperthermia treatment using the HTS-100 was combined with radiotherapy. The percentage effectiveness in terms of CR+PRa was 66.3% for the 89 cases which could be evaluated. Even for tumours larger than 5 cm, and deeper than 4 cm, local control was achieved in 60.7%. Thus, the indications for microwave heating have been significantly expanded. (3) Combination of microwave heating and RF heating is a new protocol which also expands the indications for hyperthermia therapy. (4) The percentage of patients experiencing the side-effects of pain, a sensation of heat, and burns was 15.6%, 6.3%, and 3.6%, respectively. Most of these side-effects were mild and temporary. The percentage of patients experiencing pain was higher than in conventional microwave heating, probably because the area of heating was wider. (5) In the future, the HTS-100 can be expected to play an important role in clinical cancer hyperthermia.

Combined effects of hepatic arterial embolization using degradable starch microspheres (DSM) in hyperthermia for liver cancer

Regional hyperthermia with a radiofrequency capacitive heating apparatus in combination with hepatic arterial embolization with degradable starch microspheres (DSM) was performed in 20 primary and six metastatic liver cancer patients. Efficacy was assessed primarily with regard to the improvement in heating efficiency. An angiocatheter was inserted into the hepatic artery in order to determine the DSM dosage adequate to arrest blood flow. The temperature rise in the tumours after heating alone and after heating combined with DSM embolization was compared. The maximum temperature and initial temperature rise within tumours were significantly improved by the combination therapy. Local tumour response could be evaluated in 10 primary and three metastatic liver cancer patients and tumour reduction over 50% was obtained in 40% and 33% respectively. Abdominal pain, nausea and vomiting, presumably due to reflux of the DSM, were experienced by several patients. In three patients heating could not be continued. However, all the symptoms were transient and responsive to symptomatic treatment, and no significant late complications were observed. Hepatic arterial embolization with DSM for liver tumours is considered effective and safe when combined with regional hyperthermia.

[Clinical assessment of thermoradiotherapy of breast cancer and cancer of the urinary bladder]

Non-randomized clinical trials of thermoradiotherapy for breast cancer and carcinoma of the urinary bladder were reported. Thermoradiotherapy was useful for breast cancer treatment in term of (1) increased local control for locally advanced tumors and (2) possibility of reducing dose of irradiation for recurrent tumors following radiotherapy. Tumor response to thermoradiotherapy was dependent on tumor volume and maximum or minimum tumor temperature. Thermoradiotherapy was also effective as a preoperative-treatment for urinary bladder cancer. The incidence of down-staging and degeneration of tumors was significantly higher in thermoradiotherapy than in radiotherapy. These effects were temperature dependent. Patients with T 3-4 NOMO or Grade 3 tumors treated with thermoradiotherapy showed a tendency of increased survival compared with those treated with radiotherapy alone.

Frequency of micronuclei in hepatocytes following X and fast-neutron irradiations--an analysis by a linear-quadratic model

The usefulness of the micronucleus assay for investigating the radiation response of hepatocytes was examined. The frequency was defined as the ratio of the total number of micronuclei to the number of hepatocytes examined. The dose-response curves were curvilinear after X rays and linear after neutrons. These dose-response curves were analyzed by a linear-quadratic model, frequency = aD + bD2 + c. The a/b ratio was 3.03 +/- 1.26 Gy following X irradiation. This value is within the range of the alpha/beta ratios reported by others using the clonogenic assay of hepatocytes. While the a/b value for neutrons was 24.3 +/- 11.7 Gy, the maximum relative biological effectiveness of neutrons was 6.30 +/- 2.53. Since the micronucleus assay is simple and rapid, it may be a good tool for evaluating the radiation response of hepatocytes in vivo.

Radiofrequency thermotherapy for malignant liver tumors

Inoperable malignant liver tumors have been treated by radiofrequency hyperthermia at Kyoto University Hospital since 1983. In this study, clinical hyperthermia for malignant liver tumor was evaluated for 67 tumors in which we could measure intratumor temperatures. Of the 67 tumors, 41 were hepatocellular carcinomas (HCC), six cholangiocarcinomas, and 20 metastatic tumors. Cholangiocarcinoma and metastatic tumors were more susceptible to this treatment than HCC. Of the three types of HCC, higher intratumor temperatures were achieved in the diffuse type than in the nodular or massive types. The minimum tumor temperature of HCC stayed below 40 degrees C in 46% of cases, especially in larger tumors. The local response rates (complete remission plus partial remission/all) were 28% and 11% for HCC and non-HCC, respectively, for thermochemotherapy; 86% and 33%, for thermoradiotherapy; and 33% and 89%, for thermotherapy with embolization. No apparent relationship was observed between the intratumor temperatures and local response rate.

Monitoring liver tumor therapy with [18F]FDG positron emission tomography

Positron emission tomography (PET) with [18F]-2-flurodeoxy-glucose (FDG) can be utilized as a functional imaging modality for monitoring liver tumor therapy. We report three cases in which PET-FDG was more useful for this purpose than other imaging methods and tumor markers.

Clinical results of thermoradiotherapy for locally advanced and/or recurrent breast cancer--comparison of results with radiotherapy alone

From August 1979 until 1988, 26 breast cancer patients with 30 tumours were treated by hyperthermia in combination with radiotherapy. Of the 30 tumours, 11 were locally advanced primary tumours (group 1), six were locally advanced recurrent tumours after operation (group 2) and 13 were locally recurrent tumours after radiotherapy (group 3). The thermal profiles showed that the capability of an RF capacitive heating device is comparatively high for large breast tumours with a volume of more than 100 cm3, and that of a 430 MHz microwave device with a single-lens applicator is excellent for localized tumours. The response rate of group 1 and 2 tumours was excellent, and superior to that of historically controlled tumours that were treated by radiotherapy alone from July 1962 until August 1979. In group 3 the tumour response to thermoradiotherapy was not different from that to radiotherapy, but the possibility of significantly reducing total irradiation dose was indicated. More than one good heating session led to a significantly high local response, and factors having a tendency to influence local response were average minimum tumour temperature, tumour volume, and number of effective heat treatments.

Radiofrequency thermotherapy for malignant liver tumors

Inoperable malignant liver tumors have been treated by radiofrequency hyperthermia at Kyoto University Hospital since 1983. In this study, clinical hyperthermia for malignant liver tumor was evaluated for 67 tumors in which we could measure intratumor temperatures. Of the 67 tumors, 41 were hepatocellular carcinomas (HCC), six cholangiocarcinomas, and 20 metastatic tumors. Cholangiocarcinoma and metastatic tumors were more susceptible to this treatment than HCC. Of the three types of HCC, higher intratumor temperatures were achieved in the diffuse type than in the nodular or massive types. The minimum tumor temperature of HCC stayed below 40 degrees C in 46% of cases, especially in larger tumors. The local response rates (complete remission plus partial remission/all) were 28% and 11% for HCC and non-HCC, respectively, for thermochemotherapy; 86% and 33%, for thermoradiotherapy; and 33% and 89%, for thermotherapy with embolization. No apparent relationship was observed between the intratumor temperatures and local response rate.

Initial clinical results of a 430 MHz microwave hyperthermia system using a lens applicator

The applicability of a 430 MHz microwave (MW) hyperthermia system using an electric field converging (lens) applicator was evaluated. Twenty-two tumors with a maximum tumor depth of less than 7 cm (10 chest wall tumors, 8 abdominal and pelvic tumors, 2 extremity tumors, and 2 neck tumors) were treated with the lens applicator heating system for a total of 72 sessions in conjunction with irradiation or chemotherapy. Of the 72 heat sessions, our treatment goal of 30 min of hyperthermia with all monitored tumor temperatures above 42 degrees C was achieved in 31 sessions (43%). The average tumor temperature was 42.5, 43.1, 42.0, and 42.0 degrees C for chest wall, abdominal and pelvic, extremity, and neck tumors, respectively; similarly 88, 83, 64 and 50% of monitored points exceeded 41 degrees C. A lens applicator heating system increased the penetration depth of MW, and tumor temperature of 41 degrees C at 5 cm from the surface was easily achieved with a four-aperture lens applicator. Of the 22 tumors, 10 tumors exhibited complete response (CR), 7 partial response (PR) and 5 no response (NR). These results suggest that the lens applicator heating system is useful for heating localized subsurface tumors with a maximum tumor depth of 5-6 cm.

[Clinical results of loco-regional hyperthermia combined with chemotherapy in the treatment of malignant tumors]

From December 1982 through January 1989, 22 patients with 25 tumors were treated by thermochemotherapy. Of the 25 tumors, 13 were locally recurrent tumors after radiotherapy, 10 distant metastases, and 2 peritoneal disseminations. Employing two types of heating devices (8MHz capacitive RF, 430MHz microwave), hyperthermia was administered once or twice weekly, for 30-60 minutes per session, up to total sessions of 2-15 (mean = 6.9). In some sessions, anticancer drugs were administered intravenously or intraarterially immediately before or simultaneously with hyperthermia. Of the 25 tumors treated, 2 (8%) showed CR, 11 (44%) PR, 7 (28%) NC, and 5 (20%) PD. The better the tumor response was, the higher local control rate was achieved. The survival rate of patients who achieved CR or PR was higher than that of patients who showed NC or PD. Tumor volume, depth of tumor, averaged maximum intratumor temperature, the number of effective heat sessions and the number of anticancer drugs used were shown to affect the tumor response by multivariate analysis. On the other hand, averaged minimum intratumor temperature and history of previous treatment did not affect the tumor response. As almost all the tumors treated were considered to be refractory to radiotherapy or chemotherapy, the tumor responses obtained with thermochemotherapy seemed very encouraging. The expanded trials are warranted to reveal the effectiveness of thermochemotherapy.

Histopathological changes of human tumors following thermoradiotherapy

Twenty human malignant tumors treated with thermoradiotherapy were examined histopathologically. Hyperthermia was administered regionally with a 13.56-MHz or 8-MHz RF heating device, once or twice a week after irradiation, 2 to 12 sessions in total. Fifteen tumors received a total radiation dose of 26 to 70 Gy in fractions of 1.8 Gy to 2.0 Gy a day, 5 days a week, whereas five tumors received a total dose of 20 to 60 Gy in fractions of 4 Gy each, twice a week. Microscopic examination of 4 of the 20 tumors revealed complete necrosis throughout the cross-section of the entire tumor. All the four tumors had received a total dose of over 60 Gy and a tumor center temperature of over 42 degrees C. In 10 tumors, more than 50% but less than 99% of the cross-section of the entire tumor had massive coagulation necrosis. The remaining six tumors showed relatively little change; the area of intratumor necrosis was less than 50%. The grade of tumor necrosis was dependent on both the temperatures of tumor center and periphery, and a total radiation dose. The small blood vessels and capillaries in the tumor parenchyma were markedly damaged in 16 of the 20 tumors, while the blood vessels in the tumor stroma were damaged in only 2 tumors. Condensation of the destroyed nucleus observed in 15 tumors was considered to be a typical change induced by thermoradiotherapy. Viable tumor cells remained in the tumor central area in only four tumors and around the blood vessels in only three tumors. However, in the tumor peripheral area, viable tumor cells were observed in 16 out of the 20 tumors. These results indicate that histopathological changes induced by thermoradiotherapy are greater in the tumor central area than in the tumor peripheral area, and provide strong rationale for utilizing full dose radiation therapy in combination with hyperthermia as opposed to lower doses for cancer therapy.

Radiofrequency (RF) capacitive hyperthermia combined with radiotherapy in the treatment of abdominal and pelvic deep-seated tumors

Thermal parameters and tumor response were determined in 33 abdominal and pelvic deep-seated tumors which were treated with hyperthermia in combination with radiation therapy. Hyperthermia was applied regionally for a total of 3-14 sessions (mean; 6.4 sessions), using an 8 MHz radiofrequency (RF) capacitive heating device. An average tumor temperature (Tav) of more than 42 degrees C was achieved in 17 (52%) tumors, and intratumor temperatures above 42 degrees C could be maintained for more than 20 min (effective heat session) in 103 (52%) of the 198 heat sessions. Of the 33 tumors, 4 tumors exhibited complete regression (CR), 7 PRa (80-99% regression), 7 PRb (50-79% regression) and 15 NR (less than 50% regression). Tumor response (CR + PRa) was apparently dependent on the thermal parameters. Tumors with Tav of more than 42 degrees C or those receiving more than three effective heat sessions showed a significantly higher response rate than those heated less effectively. This trend was also noted in minimum tumor temperature. As to radiation dose, most of the responders received a total of 60-70 Gy irradiation. The two characteristic features in tumor response in effectively heated tumors, were slow tumor regression and appearance of an intratumor low density area on post-treatment computed tomography.

Histological analysis of the effect of hyperthermia on normal rabbit hepatic vasculature

The effects of hyperthermia on rabbit hepatic vasculature were studied histologically. To investigate heat-induced vascular damage in the central veins, portal veins, and hepatic arterioles, the left lobes of rabbit liver were heated locally for 30 min in the range of 40-46 degrees C. Hyperthermia was induced by an 8-MHz radiofrequency current heating device using a needle type interstitial applicator. This device allowed application of heat to a central area of 10 x 10 mm no more than 1 degree C below the preset temperature. Within the area of 1 cm2, the percentage of damaged (ruptured or thrombosed) vessels was estimated for each type of hepatic vasculature. Vascular damage following hyperthermia continued up to 24 h after heating for the three types of hepatic vasculature. Central veins were the most thermosensitive followed by portal veins, whereas hepatic arterioles were the most thermoresistant. The temperature causing 50% vascular damage 24 h after heating was 41.5-42.5 degrees C, 42.5-43.5 degrees C, and 44-45 degrees C for central veins, portal veins, and arterioles, respectively. This differential thermal responsiveness of hepatic vasculature may be attributed to the histological structure of the vessels.

[Clinical results of thermoradiotherapy of locally advanced and recurrent breast cancers--comparison of results with radiotherapy alone]

From August 1979 through January 1988, 23 breast cancer patients with 25 tumors supposed to be refractory to conventional treatment were treated by thermoradiotherapy. Of the 25 tumors, 10 were locally advanced primary tumors [Group 1], 4 locally advanced recurrent tumors after operation more than 5 cm in maximum diameter [Group 2], and 11 locally recurrent tumors after radiotherapy [Group 3]. The present study was not a formal randomised-trial, but a historical-controlled study. The results were compared with tumors which were treated by radiation therapy alone between July 1962 and August 1979. The historical control groups comprised 11 tumors for Group 1, 17 for Group 2 and 19 for Group 3. Employing 4 types of heating devices (8, 13.56 MHz capacitive RF, 430, 2450 MHz microwave), hyperthermia was administered once or twice a week after irradiation, for 30-60 minutes per session, up to a total sessions of 2-9. Radiotherapy was delivered in fractions of 180 to 200 cGy per day, 5 days per week, up to 28-74.4 Gy in total, or in fraction of 400 cGy, two times per week, up to 28-60 Gy. Tumor temperatures were measured by inserting thermocouples into the tumors. The tumors that did not recur during follow-up of more than 3 months were regarded as locally controlled tumors, and the local control rate was calculated. The local control rate in Group 2 and the local response rate (CR + PRa) in Group 1 were higher than those of the historically controlled tumors. In Group 3, hyperthermia combined with lower total doses of irradiation showed a high local response rate similar to that by radiation therapy alone. Thus local hyperthermia in combination with radiation therapy seems to be more effective than radiotherapy alone for locally advanced and recurrent breast cancers.

Effect of misonidazole in preoperative irradiation for bladder cancer followed by total cystectomy

Between 1980 and 1984, 44 patients were treated for bladder cancer by preoperative irradiation of 40 Gy to the pelvic region followed by total cystectomy. These patients were prospectively divided into two groups at random. In 23 cases, 500 mg of misonidazole (MISO) was administered four hours prior to irradiation. Twenty-one patients were preoperatively treated by radiation alone. Most patients had histopathological grading of G3-4, and the distribution of T-factors in the two groups was comparable. Thirty-seven patients out of 44 underwent total cystectomy within three weeks after irradiation. pT-factors were carefully examined in resected specimens. Survival rates were calculated by the Kaplan-Meier method. The 5 year survival rate for T3 patients in the group treated by MISO combined with radiotherapy was 59%, while that for T3 patients in the radiation only group was 43%. A reduction in T-factors was observed in 9 of 17 T3 cases treated by MISO combined with radiation, and in one of 14 T3 cases treated by radiation alone. This finding was significant on chi-square test (p = 0.02). Since the survival rate of T3 patients with a reduction in T-factors by preoperative irradiation was superior to that of cases without reduction (70% vs. 43%), the combined use of MISO in preoperative irradiation seems to be useful for the treatment of T3 bladder cancer.