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Biomedical subjects

D J Keys

Publications and source records attributed to D J Keys.

6 recordsLinked to original sources
PubMed1980

Analysis of failures after definitive irradiation for epidermoid carcinoma of the nasopharynx.

From 1955 to 1976, 111 patients were treated with definitive radiotherapy for epidermoid carcinoma of the nasopharynx. There was a definite correlation between recurrence at the primary site and T-stage; 9.5% of T1-2 patients, 38.1% of T3 patients and 54.1% of T4 patients had local recurrences. Similarly, failure in the neck correlated with N-stage, being negligible for N0 and N1 but 28.6% for N2 and 36.1% for N3. The incidence of distant metastases had no correlation with T-stage but correlated very closely with N-stage. The patients were grouped into four T and N categories, T1-2 N0-1, T1-2 N2-3, T3-4 N0-1, and T3-4 2-3. The five year relapse-free survival for the T1-2 N0-1 category was 69% but was only about 20% for each of the other three categories. The major cause of poor survival for the T3-4 N0-1 category was recurrence at the primary site, whereas for the T1-2 N2-3 and T3-4 N2-3 categories, it was the high incidence of distant metastases, approximately 50%. Recommendations are to increase dose at the primary site for T3-4 N0-1 patients and to institute clinical trials testing adjuvant chemotherapy for patients with neck stages N2 and N3.

Actuarial Analysis↗
PubMed1979

An iridium-192 mold for use in treating carcinoma of the soft palate.

A Lucite sandwich mold containing Iridium-192 wire for use in the treatment of soft palate carcinoma is described. This mold is very simple to use, produces a homogeneous (+/- 10%) radiation field across the midplane of the tumor, and requires minimal machinist time.

Brachytherapy↗
PubMedDate not supplied

Thin-walled parallel plate ionization chamber for use with photon and electron beam dosimetry.

The design and construction of a thin-walled parallel plate ionization chamber is described. The chamber makes use of a sputtered collecting electrode. The characteristics of this chamber include low leakage (less than 10(-13) A), no stem effect, and reproducibility within 1%. No polarization effects have been seen for electron beams over an energy range 7-25 MeV while for cobalt 60-25 MV photon beams, it is only 10%-15%.

Radiometry↗