A 2450 Mhz Slab-Loaded Direct Contact Applicator with Choke
A Teflon-slab-loaded, direct contact microwave diathermy applicator has been developed. It produces minimal leakage radiation during effective heating of simulated planar tissue models. Because of TEM mode excitation, heating patterns are relatively uniform.
Dual‐beam TEM applicator for direct‐contact heating of dielectrically encapsulated malignant mouse tumor
A microwave heating technique, a direct parallel to the parallel-opposed treatment field that is used in therapeutic ionizing radiation, has been developed. The sources of radiation are two oppositely directed TEM applicators that operate at 2450 MHz. The applicator's design consists of an open-ended rectangular waveguide that is partially loaded with low-loss dielectric slabs. Such a structure can support a TEM mode of propagation. On direct contact with a tissue-equivalent slab, the TEM applicator heats uniformly in the transverse plane. Exposed C3H mouse tumors, 1 cm in diameter and transplanted to grow on the flank of mice, were encapsulated within simulated phantom materials with dielectric properties that are similar to that of the tumor to form a rectangular slab. The TEM applicators were used to heat from opposite sides at alternating intervals of 5 to 50 seconds. The technique is capable of producing a uniform temperature of 42 (±0.25) °C over the entire tumor.
Antitumor activities of (2"R)-4'-O-tetrahydropyranyl-adriamycin (THP) and its combination with other antitumor agents on murine tumors.
(2''R)-4'-O-Tetrahydropyranyladriamycin (THP) is a new derivative of doxorubicin (adriamycin, ADM). The concentrations of THP and ADM required to inhibit by 50% the growth of a cultured L1210 cells was 0.003 microgram/ml and 0.016 microgram/ml, respectively. Various therapeutic designs of combinations of THP with other antitumor agents were investigated in vivo using the L1210 murine leukemia. The combination of THP with cytosine arabinoside (Ara-C), cyclocytidine hydrochloride (Cyclo-C), 6-mercaptopurine (6-MP) and cyclophosphamide (EX) showed a great effectiveness following daily intraperitoneal treatment from days 1 to 10. High therapeutic effects were also obtained with the combinations of THP with Ara-C, Cyclo-C, vincristine (VCR) and EX following intravenous combination therapy one day following implantation of L1210 leukemia. Schedule dependency and its therapeutic efficacy of THP were examined. THP showed almost the same antitumor activity on the solid-type sarcoma-180 or solid-type Ehrlich carcinoma as ADM by intraperitoneal or intravenous treatment. THP showed some superior activity to ADM in the advanced stage of L1210 leukemia. High antitumor activity of THP on murine leukemia L1210 has been reported by Tsuruo et al. (Cancer Res. 42: 1462-1467, 1982) and was also confirmed. THP gave many mice cures, especially in the intravenous treatment.