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Biomedical subjects

H Q Woodard

Publications and source records attributed to H Q Woodard.

At least 19 recordsLinked to original sources
PubMed1991

The composition of body tissues (II). Fetus to young adult.

The composition of body tissues is a function of the age, nutrition, state of health and physical activity of the individual. In this paper, the effects of age on the composition of healthy tissues are reviewed. Eleven soft tissues (adipose tissue, blood--whole, brain--whole, heart, kidney, liver, lung, muscle--skeletal, placenta, skin and spleen) and cortical bone are considered. Elemental compositions, mass and electron densities are tabulated for the tissues, as a function of age, from fetus to young adult. Although the compositions given here are predominantly for healthy tissues, reported changes because of dietary influences are briefly discussed.

Adolescent↗
PubMed1988

Radiation-induced malignant tumors of bone in patients with Hodgkin's disease.

Sixteen cases of radiogenic malignant bone tumors which developed in patients 4 to 31 y after they had received radiation therapy for Hodgkin's disease are compared with 70 similar cases occurring after radiation exposure for other causes. No significant differences in age at irradiation, latent period, histology of tumors or radiographic characteristics were found between the Hodgkin's cases and those of the comparison series. Fourteen of the 16 tumors in Hodgkin's patients, or 87%, were diagnosed in the 15-y period between 1971 and 1985 in contrast to only 34% of the larger non-Hodgkin's series. This difference appears significant and is associated with a doubling of the proportion of Hodgkin's patients who are now living past the minimum latent period for such tumors. The median dose in the Hodgkin's patients, 4000 cGy, is less than the 5100-cGy median in the other patients, and the range and protraction of the total doses are much less. In Hodgkin's patients who have received total nodal irradiation, the volume of osseous tissue which is exposed may reach 25% of the total in the body. This is much greater than in most other treatment plans. Six of the Hodgkin's patients received chemotherapy within a few months of irradiation; only three of 70 non-Hodgkin's patients did so. All of the last factors may have modified the risk of radiation carcinogenesis in the Hodgkin's patients but the data are not yet adequate for quantitation of the effect.

Adolescent↗
PubMed1988

Postradiation sarcomas of bone.

Fifty-nine patients with osteogenic sarcomas arising in bones following exposure to x rays and 20 patients with postradiation malignant fibrous histiocytomas of bone arising as a direct consequence of irradiation were studied. These represent 5.5% of all osteogenic sarcomas and 4.9% of all malignant fibrous histiocytomas of bones. The sarcomas may affect any skeletal site, but most commonly they arose in bones of the pelvic and shoulder girdles or the distal end of the femur. Grounds for irradiation were either nonosseous conditions or preexistent skeletal lesions. Reasons for incidental osseous irradiation included Hodgkin's disease, carcinoma of cervix, breast or lung; bilateral retinoblastoma and others, and giant cell tumor predominated among the irradiated skeletal lesions. The mean and the median radiation doses were 6,040 cGy (rad) and 5,700 cGy (rad), respectively. The period of latency between irradiation and the appearance of the bone sarcoma ranged from 3.5 to 47 y with a mean of 16.5 and median of 14.5, respectively. The cumulative disease-free survival rate for malignant fibrous histiocytoma patients at 3 y was 58%. The cumulative disease-free survival rate at 5 y for patients with osteogenic sarcoma was 17%, with a median survival estimate of 1 y. Although all patients with malignant fibrous histiocytoma who received their radiation therapy for a preexistent bone lesion survived, only 27% of the patients whose bone was normal at the time of irradiation are alive and well at the 3-y mark.

Bone Neoplasms↗
PubMed1988

The effects of adult human tissue composition on the dosimetry of photons and electrons.

A reassessment of the composition of several types of adult human tissues has been completed. Principal findings relating to the compositions of 30 selected tissues will be discussed and comparisons with previously reported data will be highlighted. The effects of tissue composition on the dosimetry of photons and electrons are evaluated by considering attenuation and energy absorption coefficients for photons and the stopping and scattering powers of electrons over the energy interval 0.01-50 MeV. Calculated results for the tissues compared to pure water are presented.

Adult↗
PubMed1987

Average soft-tissue and bone models for use in radiation dosimetry.

Average tissue compositions have been derived for seven groups of soft tissues found in "Reference Man". The analyses took into account some 40 soft tissues comprising the adult human. Different groups of soft tissues were selected to provide average tissue compositions of practical value in radiation dosimetry. In addition, as more reliable skeletal tissue data are now available, an updated tabulation is given of average bone formulations. Elemental compositions and mass and electron densities are tabulated for all of the derived systems.

Bone and Bones↗
PubMed1986

Postradiation malignant fibrous histiocytoma of bone. A clinicopathologic study of 20 patients.

Among the 130 primary or secondary malignant fibrous histiocytomas of bone diagnosed and treated at Memorial Hospital for Cancer and Allied Diseases during the previous half century, 20 (15.4%) arose as a direct consequence of irradiation. This type is the commonest secondary osseous malignant fibrous histiocytoma at this institution. It affects the ilium, the scapula, and the distal end of the femur most frequently, predominantly in patients whose age peaks in the fifth decade of life, when their sarcomas developed. Grounds for the irradiation were either nonosseous conditions (13 patients) or preexistent skeletal lesions (seven patients). Reasons for the incidental bone irradiation included Hodgkin's disease; carcinoma of cervix, breast, or lung; bilateral retinoblastoma, and others; giant cell tumors predominated among the irradiated skeletal lesions. The mean and the median radiation doses were 6,040 and 5,700 rads, respectively. The latent period between irradiation and the appearance of the bone sarcoma ranged from 4 to 47 years with a mean of 16.5 and a median of 14.5 years, respectively. The cumulative disease-free survival rate at 3 years was 58%. Although all patients who received their radiation therapy for a preexistent bone lesion survived, only 27% of patients whose bone was normal at the time of irradiation are alive and well at the 3-year mark.

Adolescent↗
PubMed1986

The composition of body tissues.

A reassessment of the composition data given by ICRP (1975) has been completed, augmented with results from appropriate recent studies. The water, lipid, protein, carbohydrate and ash contents, together with elemental compositions, mass and electron densities are given here for 56 body tissues. Seven tissues (adipose tissue, heart, kidney, liver, mammary gland, muscle--skeletal and skin) had sufficient measured data to enable the spread in the results to be evaluated. All the compositions presented apply to healthy, adult humans, except for some new material on the bones of children.

Body Composition↗
PubMed1985

Postradiation osteogenic sarcoma of bone and soft tissues. A clinicopathologic study of 66 patients.

Sixty-six patients with well-documented osteogenic sarcomas arising in bones and soft tissues after exposure to x-rays, which represent approximately 5.5 percent of all osteogenic sarcomas registered since 1921 at this institution, were studied. These secondary sarcomas occurred in equal proportion in both sexes, with the sixth decade of life being the most common age. In 42 patients, the bone had been normal at the time of irradiation, whereas in 24, the radiation was directed against an osseous tumor or tumor-like lesion. The median latent period was 10.5 years in both groups, ranging from 3.5 to 33 years. The radiation varied from diagnostic quality to 1 MeV x-rays. The dose was variable, but none was less than 2000 rads. Postradiation osteogenic sarcomas most commonly arose in the bones of the pelvic and shoulder regions. Histologically, the sarcomas were mostly of the fibrous type (46%) and radiographically showed a destructive bone lesion with or without signs of radiation osteitis. The cumulative disease-free survival rate at 5 years was 17%, with a median survival estimate of 1 year.

Adult↗
PubMed1984

The relation of weight of haematopoietic marrow to body weight.

Adequate evaluation of the effects of external radiation fields on the haematopoietic system often requires knowledge of the number of grams of active marrow which received specific radiation doses rather than the average dose to the entire active marrow. There are several published reports of the amount of active marrow in different bones expressed as fractions of the total active marrow in the body, but none in which the actual number of grams can be computed for the individual patient. In the present study the number of grams of active marrow in the individual bones of the head and torso of adults has been computed and expressed as percent of body weight. Differences between males and females are not significant. For the major bones of caucasians the standard deviations are less than 25%. Very limited data indicate that there may be a similar range for Japanese adults. Similar computations for children have not been attempted here because of the uncertainties in the necessary data on body proportions.

Adolescent↗
PubMed1982

Bone models for use in radiotherapy dosimetry.

The development of completely artificial, realistic body phantoms for use in radiotherapy dosimetry is hampered by the lack of suitable, definitive elemental data for many skeletal materials. Using published and measured data, the proportions of the tissue components for the important human bones considered in radiotherapy treatments have been derived. Both the tissue proportions and the resulting elementary compositions are listed in tabular form. Simple models of the heads of the humerus and femur are also given. The data are presented in a form such that average bone substitutes can be readily formulated.

Adult↗
PubMed1980

Hodgkin's disease complicated by radiation sarcoma in bone.

Seven patients after treatment of Hodgkin's Disease who developed bone sarcomas in the radiation field were seen at this centre over the past eight years. Radiation-induced sarcoma in bone in patients with Hodgkin's Disease is poorly documented. The large number of cases appeared to be an important new development and led to our review of all the patients with radiation-induced sarcomas (RIS) seen at this centre over the past 40 years. Thirty-seven patients with RIS in previously normal bone were found, and of these, only one patient with underlying Hodgkin's Disease, who was seen here 27 years earlier. Hodgkin's Disease and breast cancer were the most common primary underlying conditions and, as a result, the bones of the shoulder girdle were the commonest site of radiation-induced sarcoma. The clinical histories and radiographic findings of the eight patients with underlying Hodgkin's Disease are discussed in detail.

Adolescent↗
PubMed1979

Absorbed radiation dose in mammography.

Radiation dose from mammographic techniques was determined as a function of surface exposure, beam quality, and depth. Relative exposure vs. depth was measured in tissue-substitute materials by thermoluminescent dosimetry. The f-factors were calculated from elemental compositions of mastectomy specimens. Dose at depth depends on beam quality as well as exposure and tissue composition. Analysis of data from the ACS/NCI Screening Centers shows current average midbreast doses to be 25 times lower (film/screen) and 3 times lower (Xerox) than the 2 rads previously estimated. Quantitative risk indicators other than midbreast dose are also discussed.

Adipose Tissue↗
PubMed1978

Radiation-induced soft-tissue and bone sarcoma.

From the records of Memorial Hospital of the past 50 years, 47 cases with an established diagnosis of radiation-induced sarcoma were identified and divided into two groups: the first included 20 cases of soft-tissue sarcoma arising from irradiated tissues, and the second comprised 27 cases of bone sarcoma arising from normal bones in the irradiated field. Medians for the latent periods from irradiation to diagnosis of bone and soft-tissue sarcoma were 11 and 12, years, respectively. In bone sarcomas, the latent period was longer after larger radiation doses and children appeared to be more susceptible to cancer induction than adults. Criteria for establishing the diagnosis of radiation-induced sarcoma and the magnitude of the risk of bone sarcoma are discussed.

Adolescent↗
PubMed1976

Distribution and retention of 35S-sodium sulfate in man.

Measurements were made of the 35S content of tissues obtained from biopsies and autopsies made during and up to 6 months after treatment of chondrosarcoma or chordoma with carrier-free Na235SO4. Usually 70--90% of an intravenous dose was excreted in the urine during the first 3 days. The major component of the blood concentration had a biologic half-time of 0.4--0.7 days. The initial uptakes in chondrosarcoma, chordoma, and red bone marrow were high and nearly equal, but the rates of loss differed greatly. Uptake in epiphyseal cartilage was comparable to that in chondrosarcoma; uptake in other types of cartilage was lower, but subsequent loss was very slow. For an administered dose of 1 mCi per kilogram of body weight, the integrated radiation doses were 2.4 rads for blood, 33 rads for red bone marrow, 155 rads for chondrosarcoma, 49 rads for chordoma, and 135 rads for normal cartilage. Doses to muscle, skin, and fibrous tissue were 7--15 rads.

Adolescent↗