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Biomedical subjects

C Fryer

Publications and source records attributed to C Fryer.

21 records · Page 2Linked to original sources

Intergroup Hodgkin's disease in children study of stages I and II: a preliminary report.

The intergroup study of involved-field (IF) radiotherapy, IF radiotherapy plus MOPP chemotherapy, and extended-field (EF) radiotherapy for treatment of Hodgkin's disease in children has assessed 305 patients. Of these, 279 were "not ineligible" (no mediate cause for disqualification). Among 223 randomized patients, 144 were evaluable, 131 had documentation of complete or partial remission, 20 of the remitters relapsed, and two died. Among 62 nonrandomized patients with favorable presentations (unilateral upper neck, unilateral inguinal, or massive mediastinal disease), 29 had documented remission, two relapsed, and none died. Length of initial disease control (LIDC) was used to measure duration of response. LIDC was best in patients given IF plus MOPP, and 95% are disease free. EF was better than IF radiotherapy (P = 0.004). Of the disease characteristics prognostic for response (stage, histologic subtype, and presence of symptoms), only the last factor had a statistically significant effect on LIDC (P = 0.004). Ninety-six percent of the patients survive. Using criteria developed by the committee, 23% of the staging procedures reviewed were nonevaluable and 28% of the radiotherapy treatments were nonevaluable. The necessity for criteria for evaluation of staging and treatment is certain. Length of followup is too short for correlations of treatment with significant late effects and for relevant therapeutic recommendations.

Antineoplastic Agents↗

Radiation and high-dose metronidazole in supratentorial glioblastomas.

We used "high-dose" metronidazole, an "in vitro" and "in vivo" specific radiosensitizer of hypoxic cells, in a controlled trial to evaluate possible enhancement of radiation effect in patients with supratentorial glioblastomas. Thirty-six patients were stratified according to functional level and randomly allocated within two weeks of operation to one of two therapeutic groups: Group 1, radiation alone; and Group 2, radiation as in Group 1 but with high-dose metronidazole. We examined survival with the Kaplan-Meier probability plot and non-parametric tests. Patients in Group 2 had a 4 1/2-month delay between relapse and subsequent death (P = 0.02). This shift of the survival curves suggests a delay in the time of tumor regrowth consistent with the ability of metronidazole to make the hypoxic tumor cells less radioresistant. Nitroimidazole derivatives may be useful radiosensitizers in human solid tumors.

Administration, Oral↗

Radiosensitizing effect of nicotinamide and carbogen combined in fractionated pions or x-rays in SCCVII tumors.

Well-known radiotherapeutic strategies for hypoxic cells include hypoxic radiosensitizers, heavy particles, and fractionated irradiation. This study attempted to obtain the ultimate effectiveness of these strategies by combining nicotinamide plus carbogen (N + C) as a hypoxic radiosensitizer with fractionated pions. In addition, the influence on the N + C effect of X-ray dose rate used as a reference radiation was evaluated. When SCCVII tumors in the dorsum of feet reached 50 mm3 in volume, they were irradiated with pions (0.2 Gy/min), the same dose rate (LDR; 0.2 Gy/min) X-rays, or high dose rate (HDR; 1.5 Gy/min) X-rays in 10 fractions over 11 days. Nicotinamide (0.5 mg/g) was administered i.p. one hour before irradiation, and normobaric carbogen (95% oxygen and 5% carbon dioxide) was breathed from 10 min before irradiation. The effect was evaluated by tumor growth time (TGT50) assay. The combination of N + C significantly enhanced the effect of 30 Gy LDR and 28 Gy HDR X-rays, with the effect corresponding to that of 39 Gy HDR X-rays: the enhancement ratios were 1.2 and 1.4, respectively. The effect of 20 Gy pions was equivalent to the effect of 33 Gy HDR X-rays (ratio of 1.65), or the effect of N + C combined with 28 Gy HDR X-rays. However, N + C did not enhance the effect of 20 Gy pions. This suggested that the fractionated pions had great biological effectiveness against hypoxic cells. In conclusion, N + C afforded no additional benefit with fractionated pions, but it was thought to be of value for fractionated X-rays, even in a dose rate of 0.2 Gy/min.

Administration, Inhalation↗