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Biomedical subjects

K K Fu

Publications and source records attributed to K K Fu.

At least 91 records · Page 5Linked to original sources
PubMed1981

Treatment of carcinoma of the vocal cord. A review of 20 years experience.

At the University of California, San Francisco, 323 patients were treated for carcinoma of the vocal cord between January 1956 and December 1975. Patients with early T1 or T2 lesions were treated with radiotherapy or conservative surgery. Patients with T3 or T4 lesions were treated with total laryngectomy, radiation alone, or combined therapy. Of the 247 patients treated with definitive radiotherapy, initial control of the primary lesion was achieved in 100% of T1S, 80% of T1, 52% of T2, and 50% of T3 and T4 lesions. Surgical salvage of radiation failures was 86%, giving ultimate control rates in this group of 100% for T1S, 97% for T1, 91% for T2 and 64% for T3 and T4. Involvement of the anterior commissure did not significantly affect local control or survival rates of the irradiated patients. Voice quality was satisfactory in 95% of controlled patients. Surgery alone was used as the primary treatment modality in 63 patients, with ultimate local control achieved in 75% of T1S, 83% of T1, 85% of T2, 81% of T3 and T4 lesions. Planned combined therapy was successful in 9/13 patients in whom it was used. The overall 3 and 5 year actuarial survival rates were 84% and 77% respectively corresponding determinate survival rates were 90% and 86%.

Aged↗
PubMed1980

Malignant tumors of salivary glands. A university experience.

The management of salivary gland neoplasms continues to be a challenging clinical problem. Despite recent advances in histopathological classification, agreement among head and neck surgeons concerning optimum treatment is lacking. In attempts to eradicate the more malignant varieties of these tumors, surgeons have performed radical and multilating surgery. Radiation therapy has not been considered efficacious in many centers. A review of 93 maligant salivary gland tumors from 1955 to 1973 at the University of California, San Francisco, suggests that these tumors may be more radiosensitive than once thought. Radiation therapy combined with conservative surgical procedures may be as successful and perhaps more rational treatment than radical surgery alone.

Adenocarcinoma↗
PubMed1980

The effects of misonidazole during continuous low dose rate irradiation.

Hypoxic cell sensitizers have been shown to enhance the radiation effects on tumors for single and multifractionated doses of radiation given in acute exposures. Low dose rate brachytherapy provides an opportunity for short-term high dose drug administration and continuous drug exposure throughout the entire brachytherapy course. To determine the effects of misonidazole during continuous low dose rate irradiation we have exposed the EMT6/SF tumor to continuous irradiation at 4.2 and 1.64 rads/minute with and without misondiazole (at doses of 1 mg/g or 0.2 mg/g), in bilaterally nephrectomized mice, and compared the results to those obtained wih acute exposures. Radiosensitization by misonidazole at a clinically achievable plasma concentration was observed during continuous low dose rate irradiation. The DMF (dose-modifying factor) varied with drug dose and dose rate. At a dose of 1 mg/g the DMF was 2.4 at 221 rads/minute and 1.6 at 4.2 rads/minute; at 0.2 mg/g it was 1.5 at 221 rads/minute and 4.2 rads/minute and 1.4 at 1.64 rads/minute. Cytotoxicity was also observed with drug exposure greater than 6 hours. Our results suggest that it would be advantageous to sue misonidazole during low dose rate brachytherapy.

Animals↗
PubMed1979

Growth kinetics of a rat mammary tumour transplanted into immune-suppressed mice.

The growth kinetics of a transplanted rat mammary tumour and its xenografts in immune-suppressed mice were studied using the technique of labelled mitoses. Growth of the tumour in rats was regular and uniform but when transplanted into mice the growth of the implants was irregular and generally slower. The second passage tumours in mice showed rapid and regular growth with a volume doubling time approximately half that for the tumours in the rat. Values for the G1 phase duration, intermitotic time and growth fraction were greater for the tumours in the mouse although the data for the first passage in mice were difficult to interpret. The kinetic changes between the rat and mouse hosts primarily reflect a large and variable amount of cell loss from the first passage xenografts in the mouse, with adaptation by the second passage towards reduced cell loss.

Animals↗
PubMed1979

Relative biological effectiveness of low- and high-LET radiotherapy beams for jejunal crypt cell survival at low doses per fraction.

In order to determine the relative biological effectiveness (RBE) of various low- and high-LET radiotherapy beams of low coses, LAF1 mice were exposed to one dose and 10 equally fractionated doses of 60Co gamma rays, 137Cs gamma rays, 4-MeV x rays, 300-kVp x rays, helium ions in the plateau and Bragg-peak region, and 15-MeV neutrons; survival of jejunal crypt cells with the microcolony assay of Withers and Elkind was determined using 60Co as the standard. RBE values for the survival of 10 cells/circumference for 10 fractionated exposures (2.4 Gy [240 rad] per fraction of 60Co) were: 1.07 for 137Cs, 1.06 for 4-MeV x rays, 1.16 for 300-kVp x rays, 1.10 for helium ions in the plateau, 1.29 for helium ions in the peak, and 3.02 for 15-MeV neutrons. As LET increased, RBE increased with decrease of dose/fraction.

Animals↗
PubMed1979

Combined radiotherapy and multidrug chemotherapy for advanced head and neck cancer: results of a Radiation Therapy Oncology Group pilot study.

Between February 1976 and June 1977, 15 patients with advanced inoperable squamous cell carcinoma of the head and neck were entered in a pilot study sponsored by the Radiation Therapy Oncology Group using combined radiotherapy and multidrug chemotherapy. Chemotherapy consisted of cyclophosphamide, vincristine, and bleomycin (during radiotherapy) and cyclophosphamide, methotrexate, and bleomycin (after radiotherapy). At the time of last followup or of death, the disease had been controlled at the primary site in eight of the 15 patients (53%), in the neck in 12 patients (80%), and in all sites in seven patients (47%). Followup time ranged from 2 to 24+ months with a median of 7 months. Acute toxic effects of the combined treatment, primarily enhanced radiation mucositis and infection, were severe, and three patients had fatal complications. Although the combination chemotherapy may have enhanced the tumor response to radiotherapy in some of these patients, treatment morbidity and complications were prohibitive for the treatment program to progress to a randomized trial.

Adult↗
PubMed1977

Malignant tumors of the testis: analysis of treatment results and sites and causes of failure.

A total of 150 patients with germinal testicular neoplasms treated at the University of California, San Francisco, were reviewed. The 5-year actuarial survival rate was 95% for 57 patients with seminoma and 56% for 75 patients with carcinoma. Treatment modalities were compared with respect to sites and causes of failure and complications. The most common sites of failure in the carcinoma patients were lung, and supraclavicular or mediastinal lymph nodes. Scrotal orchiectomy, elevated gonadotropins, elements of choriocarcinoma, and bulky abdominal disease were all correlated with high treatment failure rate.

Carcinoma↗
PubMed1977

Acute and late effects of multimodal therapy on normal tissues.

The increasing use of combined radiation, chemotherapy, and surgery had led to an increased incidence of acute and late complications. The complications are, in general, similar to those seen with each modality alone, but occur with increased incidence. Enhanced effects of combined radiation and surgery are modest in number and consist primarily of problems with wound healing and fibrosis, as well as late gastrointestinal damage. Combinations of radiotherapy and chemotherapy have shown a greater degree of enhanced acute and late reactions. Drugs, such as actinomycin-D and Adriamycin, are particularly dangerous if the marked enhancement of radiation effects caused by the drugs in almost all organs is not appreciated and the radiation dose not adjusted accordingly. Proper selection of drugs can lead to enhanced local control by radiotherapy and/or surgery, as well as eradication of microscopic distant metastases, without increased normal tissue injury. Late induction of malignancy can occur with either radiation or chemotherapy alone and, in some cases, this appears to be enhanced when they are combined.

Antineoplastic Agents↗