Biomedical subjects

G C Henkelmann

Publications and source records attributed to G C Henkelmann.

3 recordsLinked to original sources

PubMed1990

Locally advanced breast cancer treated with neutron beams: long-term follow-up in 28 patients.

Between 1972 and 1978, 28 patients with locally advanced breast cancer were treated, 15 with neutron beams only and 13 with mixed neutron and photon beams. Half the patients had inflammatory cancer. For neutrons only, doses ranged between 13.35-25.34 nGy. In mixed-beam regimens, the prescribed total dose ranged between 62 and 76 Gy photon equivalent. Nine patients (32%) had a complete response without local recurrence for the duration of their survival ranging from 1 to 14+ years; 18 patients had a partial response (64%); and one patient had no change. Late toxicity was high: of 24 patients who received tangential breast irradiation, 5 (21%) had ulceration of the breast or chest wall, or both. In four patients, mastectomy and skin grafts were necessary for repair. In only one patient did the skin necrosis heal without corrective surgery. Twelve patients received axillary neutron irradiation, resulting in severe edema in four patients, and brachial plexopathy in six patients. Radiation-induced complications progressed steadily for the duration of the patients' survival after the neutron irradiation. The high complication rate encountered is attributed to high doses resulting from an under estimation of the relative biological effect of the neutron beam for late effects, and to the poor physical and geometrical characteristics of the neutron beam.

Adult↗

PubMed1990

An interactive system for point dose optimization.

An interactive system has been developed to aid in determining optimal photon and electron beams and beam weights for radiotherapy treatment planning. Dose constraints at various points are selected and an algorithm searches for a set of beams and weighting factors that satisfy these constraints. In the event that no combination of beam weights satisfies the choice of treatment modalities and dose constraints, the treatment modalities and dose constraints can be modified interactively. The goal of this procedure is different from that of more conventional optimization schemes in which optimal dose values are specified and the optimization algorithm determines the set of beam weights that yields a dose distribution closest to optimal.

Algorithms↗

PubMed1988

Two cycles of MOPP and radiotherapy for stage III1A and stage III1B Hodgkin's disease.

One hundred two adult patients with stage III1A (76 patients) and stage III1B (26 patients) Hodgkin's disease were treated with two cycles of mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) and radiotherapy (XRT) between 1970 and 1984. Sixty-four of the patients were treated between 1970 and 1978 with two cycles of MOPP and XRT to the mantle, upper abdomen, and pelvis. The remaining 38 patients were treated from 1978 to 1984 with a modification of the protocol in which pelvic XRT was omitted and low-dose whole-lung XRT was administered to patients with unfavorable mediastinal disease. The 10-year actuarial freedom-from-progression (FFP) and determinate survival rates at a mean follow-up of 93 months were 84% and 86% for stage III1 disease, 86% and 84% for stage III1A disease, and 78% and 91% for stage III1B disease. Three patients died of treatment-related toxicities without evidence of Hodgkin's disease, two died of complications of myelosuppression and one of acute nonlymphocytic leukemia (ANLL). Neither FFP nor determinate survival rates were significantly influenced by B symptoms, unfavorable mediastinal disease, histologic subtype, extent of abdominal disease, the omission of pelvic XRT, the use of whole-lung XRT, or the number of splenic nodules. Patients 40 years of age or older had a 73% determinate survival rate at 10 years compared with 88% for patients younger than 40 years (P = .01). This survival difference was due to treatment-related toxicity in the older group. This study indicates that two cycles of MOPP and XRT to the mantle and upper abdomen is as effective as more intensive treatment for all patients with stage III1 Hodgkin's disease. This treatment program can preserve fertility and has had only a 1% actuarial incidence of ANLL at 15 years.

Adolescent↗