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T V Samulski

Publications and source records attributed to T V Samulski.

At least 19 recordsLinked to original sources
PubMed2001

Three-dimensional tumor perfusion reconstruction using fractal interpolation functions.

It has been shown that the perfusion of blood in tumor tissue can be approximated using the relative perfusion index determined from dynamic contrast-enhanced magnetic resonance imaging (DE-MRI) of the tumor blood pool. Also, it was concluded in a previous report that the blood perfusion in a two-dimensional (2-D) tumor vessel network has a fractal structure and that the evolution of the perfusion front can be characterized using invasion percolation. In this paper, the three-dimensional (3-D) tumor perfusion is reconstructed from the 2-D slices using the method of fractal interpolation functions (FIF), i.e., the piecewise self-affine fractal interpolation model (PSAFIM) and the piecewise hidden variable fractal interpolation model (PHVFIM). The fractal models are compared to classical interpolation techniques (linear, spline, polynomial) by means of determining the 2-D fractal dimension of the reconstructed slices. Using FIFs instead of classical interpolation techniques better conserves the fractal-like structure of the perfusion data. Among the two FIF methods, PHVFIM conserves the 3-D fractality better due to the cross correlation that exists between the data in the 2-D slices and the data along the reconstructed direction. The 3-D structures resulting from PHVFIM have a fractal dimension within 3%-5% of the one reported in literature for 3-D percolation. It is, thus, concluded that the reconstructed 3-D perfusion has a percolation-like scaling. As the perfusion term from bio-heat equation is possibly better described by reconstruction via fractal interpolation, a more suitable computation of the temperature field induced during hyperthermia treatments is expected.

Animals↗
PubMed2001

Shape calibration of a conformal ultrasound therapy array.

A conformal ultrasound phased array prototype with 96 elements was recently calibrated for electronic steering and focusing in a water tank. The procedure for calibrating the shape of this 2D therapy array consists of two steps. First, a least squares triangulation algorithm determines the element coordinates from a 21 x 21 grid of time delays. The triangulation algorithm also requires temperature measurements to compensate for variations in the speed of sound. Second, a Rayleigh-Sommerfeld formulation of the acoustic radiation integral is aligned to a second grid of measured pressure amplitudes in a least squares sense. This shape calibration procedure, which is applicable to a wide variety of ultrasound phased arrays, was tested on a square array panel consisting of 7- x 7-mm elements operating at 617 kHz. The simulated fields generated by an array of 96 equivalent elements are consistent with the measured data, even in the fine structure away from the primary focus and sidelobes. These two calibration steps are sufficient for the simulation model to predict successfully the pressure field generated by this conformal ultrasound phased array prototype.

Acoustics↗
PubMed2000

Enhancement of radiotherapy by hyperthermia-regulated gene therapy.

PURPOSE: Interleukin 12 (IL-12) has shown strong antitumoral effects in numerous pre-clinical studies and appears to act synergistically with radiation in murine tumors. The major impediment to its clinical use has been its systemic toxicity. While using intratumorally injected viral gene therapy vectors encoding IL-12 reduces systemic side effects substantially, elevated systemic transgene levels are still observed because adenovirus can reach the circulation. Further restricting IL-12 expression in the tumor is therefore desirable in a combined radiation and adenovirus mediated cancer gene therapy regimen. METHODS AND MATERILAS: Hyperthermia-regulated gene therapy was tested in a nonimmunogenic B16.F10 melanoma line that is syngeneic with C57BL/6 mice. For hyperthermic gene therapy, an adenoviral vector coding for IL-12 under the control of the promoter of the human heat shock protein 70B (hsp70B) was used. One week after transplantation (at a 5-7 mm diameter), tumors were irradiated with 3 x 11 Gy (mo-we-fri). Adenovirus was injected at 3 x 10(8) pfu/tumor 24 h before the last radiation fraction or 3 days afterwards. Hyperthermia was performed 24 h later at 42.5 degrees C. Growth delay to reaching 3 times initial tumor volume was chosen as the biologic endpoint. IL-12 levels in tumor and serum were determined by using the enzyme-linked immunosorbant assay (ELISA). RESULTS: Adenovirus mediated intratumoral expression of IL-12 under the control of a heat inducible promoter in combination with hyperthermia is almost as effective as that under the control of a constitutive cytomegaly virus (CMV) promoter while systemic transgene levels are substantially reduced with the heat inducible promoter. The response to radiotherapy is improved considerably when combined with heat inducible gene therapy without apparent systemic toxicity. When used as a single dose, applying IL-12 gene therapy after completion of radiotherapy appears to be beneficial. CONCLUSIONS: Hyperthermia-regulated gene therapy in combination with radiation is feasible and therapeutically effective in murine tumors with no apparent systemic toxicity.

Adenoviridae↗
PubMed2000

Temperature-dependent changes in physiologic parameters of spontaneous canine soft tissue sarcomas after combined radiotherapy and hyperthermia treatment.

PURPOSE: The objectives of this study were to evaluate effects of hyperthermia on tumor oxygenation, extracellular pH (pHe), and blood flow in 13 dogs with spontaneous soft tissue sarcomas prior to and after local hyperthermia. METHODS AND MATERIALS: Tumor pO2 was measured using an Eppendorf polarographic device, pHe using interstitial electrodes, and blood flow using contrast-enhanced magnetic resonance imaging (MRI). RESULTS: There was an overall improvement in tumor oxygenation observed as an increase in median pO2 and decrease in hypoxic fraction (% of pO2 measurements <5 mm Hg) at 24-h post hyperthermia. These changes were most pronounced when the median temperature (T50) during hyperthermia treatment was less than 44 degrees C. Tumors with T50 > 44 degrees C were characterized by a decrease in median PO2 and an increase in hypoxic fraction. Similar thermal dose-related changes were observed in tumor perfusion. Perfusion was significantly higher after hyperthermia. Increases in perfusion were most evident in tumors with T50 < 44 degrees C. With T50 > 44 degrees C, there was no change in perfusion after hyperthermia. On average, pHe values declined in all animals after hyperthermia, with the greatest reduction seen for larger T50 values. CONCLUSION: This study suggests that hyperthermia has biphasic effects on tumor physiologic parameters. Lower temperatures tend to favor improved perfusion and oxygenation, whereas higher temperatures are more likely to cause vascular damage, thus leading to greater hypoxia. While it has long been recognized that such effects occur in rodent tumors, this is the first report to tie such changes to temperatures achieved during hyperthermia in the clinical setting. Furthermore, it suggests that the thermal threshold for vascular damage is higher in spontaneous tumors than in more rapidly growing rodent tumors.

Animals↗
PubMed2000

Combination treatment of murine tumors by adenovirus-mediated local B7/IL12 immunotherapy and radiotherapy.

Failure of local tumor control still poses a problem for radiotherapy and translates into reduced survival. Combining radiation with chemotherapy or other newer modalities has shown promising results. Immunological approaches to tumor therapy have found renewed interest due to improved insight into mechanisms involved in the immune response to tumors. In this paper, we studied tumor growth delay after various combination regimens of locally injected adenovirus constitutively expressing IL12 and B7.1 (AdIL12/B7.1) and fractionated radiotherapy in two nonimmunogenic murine tumor models, 4T1 and B16.F10. Effects of radiation and virus infection on surface antigen expression in these tumor lines were assessed. Mechanisms of action of AdIL12/B7.1 were studied by conducting additional experiments with and without depletion of NK-cells and/or T-cells, and by cytotoxic T-lymphocyte assays, and immunohistochemical evaluation of tumor blood vessels. Both B7.1 and IL12 were effectively expressed in both irradiated and unirradiated 4T1 and B16.F10 tumor cells but did not add significantly to radiation-induced cell killing in vitro. However, local tumor infection by AdIL12/B7.1 after irradiation significantly increases the effectiveness of radiotherapy when applied after completion of radiotherapy. The mechanism appears to be complicated, involving a host of factors that included the ability of IL12 to activate T-cells and NK-cells and to inhibit angiogenesis and the ability of radiation to induce apoptosis or necrosis among tumor cells. These data support the combination of radiotherapy with adenovirus-mediated immunotherapy and suggest that the concept of adding genetic immunotherapy after radiotherapy in a combined regimen merits further study.

Adenoviridae↗
PubMed2000

Perturbations in hyperthermia temperature distributions associated with counter-current flow: numerical simulations and empirical verification.

Two numerical techniques are used to calculate the effect of large vessel counter-current flow on hyperthermic temperature distributions. One is based on the Navier-Stokes equation for steady-state flow, and the second employs a convective-type boundary condition at the interface of the vessel walls. Steady-state temperature fields were calculated for two energy absorption rate distributions (ARD) in a cylindrical tissue model having two pairs of counter-current vessels (one pair with equal diameter vessels and another pair with unequal diameters). The first assumed a uniform ARD throughout cylinder; the second ARD was calculated for a tissue cylinder inside an existing four antenna Radiofrequency (RF) array. A tissue equivalent phantom was constructed to verify the numerical calculations. Temperatures induced with the RF array were measured using a noninvasive magnetic resonance imaging technique based on the chemical shift of water. Temperatures calculated using the two numerical techniques are in good agreement with the measured data. The results show: 1) the convective-type boundary condition technique reduces computation time by a factor of ten when compared to the fully conjugated method with little quantitative difference (approximately 0.3 degree C) in the numerical accuracy and 2) the use of noninvasive magnetic resonance imaging (thermal imaging) to quantitatively access the temperature perturbations near large vessels is feasible using the chemical shift technique.

Body Temperature Regulation↗
PubMed1999

The treatment of high-grade soft tissue sarcomas with preoperative thermoradiotherapy.

PURPOSE: To explore the use of a novel program of preoperative radiation and hyperthermia in the management of high-grade soft tissue sarcomas (STS). METHODS AND MATERIALS: Eligible patients were adults over 18 with Grade 2 or 3 STS, surgically resectable without a local excision prior to referral to Duke University Medical Center and without distant metastases. Patients were staged generally with CT and/or MR imaging. The diagnosis was established with fine needle aspiration or incisional biopsy. Patients were then treated with 5000 to 5040 cGy, 180-200 cGy per fraction. Chemotherapy was usually not employed. Generally two hyperthermia treatments per week were given with a planned thermal dose of 10-100 CEM 43 degrees T90. Invasive thermometry and thermal mapping were done in all patients. Surgical resection was planned 4-6 weeks after the completion of radiation and hyperthermia. RESULTS: Ninety-seven patients were treated on study between 1984 and 1996. Follow-up ranged from 12 to 155 months (median 32). All tumors were high-grade in nature, 44 greater than 10 cm in size (maximum tumor diameter), 43 5-10 cm in size, 10 less than 5 cm. Seventy-eight of the 97 tumors were located in an extremity. Of the 97 patients, 48 remain alive and continually free of disease following initial therapy. Of the remaining 49 patients, 44 have relapsed (34 dead, 10 living with disease), 3 have died secondary to complications of therapy, and 2 have died of unrelated causes. Ten-year actuarial overall survival, cause-specific survival, and relapse-free survival are 50, 47, and 47% respectively. The predominant pattern of failure has been distant metastases with only 2 patients developing local failure alone. Ten-year actuarial local control for extremity tumors is 94%, 63% for the 19 patients with tumors at sites other than the extremity. Of the 78 patients with extremity lesions, 63 have had limb preservation and remain locally controlled. Overall 38 patients experienced 57 major complications. There were 3 deaths, one due to adriamycin cardiomyopathy and two secondary to wound infections. Four patients required amputation secondary to postoperative wound healing problems. Complications directly attributable to hyperthermia occurred in 15 patients with 11 instances of second- or third-degree burns and two instances of subcutaneous fat necrosis. The hyperthermia complications were generally not severe and either healed readily or were excised at the time of surgical resection of the primary tumor. CONCLUSIONS: For these aggressive high-grade soft tissue sarcomas, this treatment program of preoperative thermoradiotherapy provided excellent local regional control for extremity lesions (95%) and satisfactory local regional control (63%) of nonextremity sarcomas, but did not appear to influence the rate of distant metastases or survival. Complications were frequent but apart from the direct thermal burns, not too different from those reported for preoperative radiotherapy alone. More effective adjuvant systemic therapy is necessary to impact favorably on survival.

Adult↗
PubMed1999

Computational techniques for fast hyperthermia temperature optimization.

Hyperthermia temperature optimization involves arriving at a temperature distribution which minimizes a stated goal function, the goal function having a biological basis in maximizing tumor cell kill while not exceeding normal tissue toxicity. This involves the computationally intensive process of multiple evaluations of the temperature goal function, requiring repeated evaluations of the power deposition and its corresponding temperature distribution. Two computational schemes are proposed to expedite the temperature optimization process: (1) temperature distribution evaluation by superpositioning precomputed distributions, and (2) using representative tissue groups (rather than every point in the domain) to evaluate the goal function. The application of these schemes is illustrated with a typical optimization problem, as applied to symmetric and asymmetric, heterogeneous models. Application of these schemes reduced the optimization time on a DEC Alpha 1000 4/266 (Alpha is a registered trademark of Digital Equipment Corporation.) from several h to min, with little difference in results. The computational schemes, though demonstrated in the context of electromagnetic hyperthermia, are generally applicable to other forms of nonionizing radiation employed in hyperthermia therapy.

Humans↗
PubMed1998

Magnetic resonance thermometry during hyperthermia for human high-grade sarcoma.

PURPOSE: To determine the feasibility of measuring temperature noninvasively with magnetic resonance imaging during hyperthermia treatment of human tumors. METHODS: The proton chemical shift detected using phase-difference magnetic resonance imaging (MRI) was used to measure temperature in phantoms and human tumors during treatment with hyperthermia. Four adult patients having high-grade primary sarcoma tumors of the lower leg received 5 hyperthermia treatments in the MR scanner using an MRI-compatible radiofrequency heating applicator. Prior to each treatment, an average of 3 fiberoptic temperature probes were invasively placed into the tumor (or phantom). Hyperthermia was applied concurrent with MR thermometry. Following completion of the treatment, regions of interest (ROI) were defined on MR phase images at each temperature probe location, in bone marrow, and in gel standards placed outside the heated region. The median phase difference (compared to pretreatment baseline images) was calculated for each ROI. This phase difference was corrected for phase drift observed in standards and bone marrow. The observed phase difference, with and without corrections, was correlated with the fiberoptic temperature measurements. RESULTS: The phase difference observed with MRI was found to correlate with temperature. Phantom measurements demonstrated a linear regression coefficient of 4.70 degrees phase difference per degree Celsius, with an R2 = 0.998. After human images with artifact were excluded, the linear regression demonstrated a correlation coefficient of 5.5 degrees phase difference per degree Celsius, with an R2 = 0.84. In both phantom and human treatments, temperature measured via corrected phase difference closely tracked measurements obtained with fiberoptic probes during the hyperthermia treatments. CONCLUSIONS: Proton chemical shift imaging with current MRI and hyperthermia technology can be used to monitor and control temperature during treatment of large tumors in the distal lower extremity.

Adult↗
PubMed1997

Combined external beam irradiation and external regional hyperthermia for locally advanced adenocarcinoma of the prostate.

PURPOSE: To determine the safety and efficacy of combined external beam irradiation and external regional hyperthermia in the treatment of adenocarcinoma of the prostate. METHODS AND MATERIALS: From 1987 to 1994, 30 patients received combined external beam irradiation and external regional hyperthermia for locally advanced prostate cancer. The results of the 21 patients with newly diagnosed (n = 18) or locally recurrent (n = 3) adenocarcinoma are reported herein. No patient had evidence of distant metastases. Total radiotherapy doses of 65-70 Gy to the prostate were planned using a four-field box technique. Hyperthermia treatments were delivered using an annular phased array microwave device. The treatment goal was to achieve temperatures > or = 42 degrees C in all measured points within the prostate. RESULTS: Of the newly diagnosed patients, 16 out of 18 (89%) had T3 or T4 tumors, 11 out of 18 (61%) had Gleason scores of 7-9, and the mean pretreatment Prostate Specific Antigen (PSA) was 69 ng/ml. The median follow-up of all 21 patients was 36 months. None of the patients achieved the treatment goal of all intratumoral temperatures > or = 42 degrees C. The mean CEM 43 T90 was 2.34 min. The disease-free survival at 36 months is 25%; 12 out of 18 (67%) of the patients have relapsed. The only significant predictor of relapse was pretreatment PSA. There were no complications > Grade 3. CONCLUSIONS: In spite of the inability to achieve high tumor temperatures, the relapse-free survival rate in this population of patients with very advanced localized prostate cancer treated with radiation therapy plus hyperthermia compares favorably with most series using radiation therapy alone. Further studies aimed at improving the ability to deliver hyperthermia to the prostate are warranted.

Adenocarcinoma↗
PubMed1996

Radiation therapy and hyperthermia improve the oxygenation of human soft tissue sarcomas.

The adverse prognostic impact of tumor hypoxia has been demonstrated in human malignancy. We report the effects of radiotherapy and hyperthermia (HT) on soft tissue sarcoma oxygenation and the relationship between treatment-induced changes in oxygenation and clinical treatment outcome. Patients receiving preoperative radiotherapy and HT underwent tumor oxygenation measurement pretreatment after the start of radiation/pre-HT and one day after the first HT treatment. The magnitude of improvement in tumor oxygenation after the first HT fraction relative to pretreatment baseline was positively correlated with the amount of necrosis seen in the resection specimen. Patients with <90% resection specimen necrosis experienced longer disease-free survival than those with > or = 90% necrosis. Increasing levels of tumor hypoxia were also correlated with diminished metabolic status as measured by P-31 magnetic resonance spectroscopy.

Cell Hypoxia↗
PubMed1996

Radiation plus local hyperthermia versus radiation plus the combination of local and whole-body hyperthermia in canine sarcomas.

PURPOSE: The purpose of this study was to assess the effect of increasing intratumoral temperatures by the combination of local hyperthermia (LH) and whole body hyperthermia (WBH) on the radiation response of canine sarcomas. METHODS AND MATERIALS: Dogs with spontaneous soft tissue sarcomas and no evidence of metastasis were randomized to be treated with radiation combined with either LH alone or LH + WBH. Dogs were accessioned for treatment at two institutions. The radiation dose was 56.25 Gy, given in 25 2.25 Gy daily fractions. Two hyperthermia treatments were given; one during the first and one during the last week of treatment. Dogs were evaluated after treatment for local recurrence, metastasis, and complications. RESULTS: Sixty-four dogs were treated between 1989 and 1993. The use of LH+WBH resulted in statistically significant increases in the low and middle regions of the temperature distributions. The largest increase was in the low temperatures with median CEM 43 T90 values of 4 vs. 49 min for LH vs. LH + WBH, respectively (p<0.001). There was no difference in duration of local tumor control between hyperthermia groups (p = 0.59). The time to metastasis was shorter for dogs receiving LH + WBH (p = 0.02); the hazard ratio for metastatic disease for dogs in the LH + WBH group was 2.4 (95% confidence interval, 1.2-5.4) with respect to dogs in the LH group. Complications were greater in larger tumors and in tumors treated with LH + WBH, CONCLUSION: The combination of LH + WBH with radiation therapy, as described herein, was not associated with an increase in local tumor control in comparison to use of LH with radiation therapy. The combination of LH + WBH also appeared to alter the biology of the metastatic process and was associated with more complications than LH. We identified no rationale for further study of LH + WBH in combination with radiation for treatment of solid tumors.

Animals↗
PubMed1996

1H MRI phase thermometry in vivo in canine brain, muscle, and tumor tissue.

The temperature sensitivity of the chemical shift of water (approximately 0.01 ppm/degree C) provides a potential method to monitor temperature changes in vivo or in vitro through the changes in phase of a gradient-echo magnetic resonance (MR) image. This relation was studied at 1.5 T in gel materials and in vivo in canine brain and muscle tissue, heated with a radio frequency (rf) annular phased array hyperthermia antenna. The rf fields associated with heating (130 MHz) and imaging (64 MHz) were decoupled using bandpass filters providing isolation in excess of 100 dB, thus allowing simultaneous imaging and rf heating without deterioration of the MR image signal-to-noise ratio. In a gel, temperature sensitivity of the MR image phase was observed to be (4.41 +/- 0.02) phase degrees/degree C for Te = 20 ms, which allowed temperature changes of 0.22 degree C to be resolved for a 50-mm3 region in less than 10 s of data acquisition. In vivo, for Te = 20 ms, the temperature sensitivity was (3.2 +/- 0.1) phase degrees/degree C for brain tissue, (3.1 +/- 0.1) phase degrees/degree C for muscle, and (3.0 +/- 0.2) phase degrees/degree C for a muscle tumor (sarcoma), allowing temperature changes of 0.6 degree C to be resolved in a 16-mm3 volume in less than 10 s of data acquisition. We conclude that, while the technique is very sensitive to magnetic field inhomogeneity, stability, and subject motion, it appears to be useful for in vivo temperature change measurement.

Animals↗
PubMed1994

Clinical outcome after neoadjuvant thermoradiotherapy in high grade soft tissue sarcomas.

In the treatment of soft tissue sarcomas, hyperthermia has been demonstrated to enhance tumor necrosis from radiation therapy. The current study reports the clinical course of patients treated with this neoadjuvant therapy regimen. Forty-four patients with deep, undisturbed, nonmetastatic, high grade soft tissue sarcomas completed a neoadjuvant treatment protocol with combined hyperthermia and radiation therapy followed by wide surgical resection. Negative surgical margins were obtained in 40 patients. There was one local recurrence, thus yielding a local control rate of 97.5%. All other failures were either through regional lymphatic spread or pulmonary metastasis. As a group, the patients at 36 months had a 72% overall and a 58% disease-free survival. The most common pathologic diagnosis was malignant fibrous histiocytoma (MFH), which demonstrated a 36-month survival of 52% vs. 82% for others (P = 0.02). Tumor size was not prognostically significant for disease free or overall survival (P = 0.13). Those patients with surgical margins < 1 cm had a significantly lower disease-free survival and overall survival in a multivariate analysis (P = 0.02 and P = 0.006, respectively). Overall survival did not correlate with either the number of hyperthermia treatments received or the amount of tumor necrosis. Although this neoadjuvant protocol results in excellent local control rates, overall survival rates are comparable to adjuvant therapy employing radiation alone.

Adult↗
PubMed1994

Inverse techniques in hyperthermia: a sensitivity study.

Numerical modeling methods and hyperthermia treatment temperature measurements have been used together to reconstruct steady-state tumor temperature distributions. However, model errors will exist which may in turn produce errors in the reconstructed temperature distributions. A series of computer experiments was conducted to study the sensitivity of reconstructed two-dimensional temperature distributions to perfusion distribution modeling errors. Temperature distributions were simulated using a finite element approximation of Pennes' bioheat transfer equation. Relevant variables such as tumor shape, perfusion distribution, and power deposition were modeled. An optimization method and the temperatures "measured" from the simulated temperature distributions were used to reconstruct the tumor temperature distribution. Using this procedure, the sensitivity of the reconstructed tumor temperature distribution to model-related errors, such as the perfusion function, was studied. It was found that: 1) if the problem is conduction dominated, large errors in the perfusion distribution produce only small errors in the reconstructed temperature distribution (maximum error < 1.0 degrees C), and 2) when the actual perfusion distribution contains a small random variation (+/- 15%) which is neglected by the model, the reconstructed temperature distribution will be in good agreement with the actual temperature distribution (maximum error < or = 0.3 degrees.

Algorithms↗
PubMed1993

Intraperitoneal cisplatin and regional hyperthermia for ovarian carcinoma.

PURPOSE: To review the theoretical basis and results of a Phase I study of concurrent intraperitoneal cisplatin and hyperthermia in the treatment of ovarian carcinoma. METHODS AND MATERIALS: Previously treated patients with epithelial ovarian carcinoma received intraperitoneal instillation of cisplatin and 60 minutes of regional hyperthermia, with a goal temperature of 41.5 degrees C. Cisplatin dose started at 20 mg/m2 with escalation to the maximally tolerated dose. Six such cycles given every 3 weeks were planned. Pharmacokinetic studies with and without hyperthermia were performed. RESULTS: Fifteen patients receiving 17 courses of treatment were evaluable. The maximally tolerated dose of cisplatin was between 80 and 120 mg/m2. The dose limiting toxicity was nephrotoxicity in all but one course. The median intraperitoneal temperature was 40.7 degrees C; the majority of treatments in which the goal temperature was not reached had power limited by patient discomfort. No major toxicities attributable to hyperthermia were noted. Pharmacokinetic studies noted no significant differences between treatments with vs. without hyperthermia, with intraperitoneal to plasma area under the curve ratios being 30-35. Ten patients had a decline in their CA-125 count during treatment, although in only two patients did this response persist beyond their course of treatment. CONCLUSION: Intraperitoneal cisplatin and regional hyperthermia can be performed with reasonable toxicity. The maximally tolerated dose of 80-120 mg/m2 in pretreated patients (which is similar to those reported with cisplatin alone) and median intraperitoneal temperatures of 40.7 degrees C, however, are felt to be too low to be efficacious in a significant percentage of women with bulky recurrent disease. Further study using intravenous thiosulfate and controlled analgesia is being performed.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

Cumulative minutes with T90 greater than Tempindex is predictive of response of superficial malignancies to hyperthermia and radiation.

PURPOSE: To better define thermal parameters related to tumor response in superficial malignancies treated with combined hyperthermia and radiation therapy. METHODS AND MATERIALS: Patients were randomized to receive one or two hyperthermia treatments per week with hyperthermia given during each week of irradiation. Hyperthermia was given for 60 min with treatments begun within 1 hr following irradiation. Power was increased to patient tolerance or normal tissue temperature of 43.0 degrees C. Irradiation was generally given 5 times per week with doses prescribed to normal tissue tolerance (generally 24-70 Gy at 1.8-2.5 Gy per fraction). Multipoint thermometry was used with temperatures obtained every 5 min. RESULTS: One hundred eleven individual treatment fields containing 1 or more tumor nodules were completely evaluable. The complete and overall response rates were 46% and 80%, respectively. Forty-one percent of all treatment fields (51% of responding lesions) remained controlled at 2 years. Multivariate analysis revealed that the cumulative minutes that the temperature achieved by 90% of the measured tumor sites (T90) was > or = 40.0 degrees C, tumor histology, tumor volume, and radiation dose were significantly associated with complete tumor response. The complete response rate was not significantly affected by the number of hyperthermia treatments given per week. The incidence of clinically significant complications was low. CONCLUSIONS: These results support the usefulness of the cumulative minute system in describing time-temperature relationships. The significance of thermal variables with regard to tumor response strongly supports the contention that hyperthermia can be a useful adjunct to irradiation for the local control of cancer.

Adult↗