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Biomedical subjects

H D Suit

Publications and source records attributed to H D Suit.

At least 55 records · Page 3Linked to original sources
PubMed1993

Gorham's massive osteolysis: the role of radiation therapy and a review of the literature.

PURPOSE: This paper reviews the natural history and management of patients with Gorham's disease and presents four cases treated at The Massachusetts General Hospital since 1965. Gorham's disease is characterized by localized endothelial proliferation which results in destruction and resorption of bone. The etiology is undefined. There is no evidence of a malignant, neuropathic, or infectious component. This disease is progressive in most patients, but in occasional instances the process has been noted to be self-limited. The principal treatment modalities are surgery and radiation therapy. METHODS AND MATERIAL: Since 1965, four patients with Gorham's Disease have been treated at the Massachusetts General Hospital. Three received definitive radiation therapy in doses ranging from 31.5 to 45 Gy. The fourth patient underwent surgery primarily. RESULTS: Three patients are currently alive and fully functional with no evidence of disease at last follow-up. The fourth patient died of progressive disease despite treatment with both radiation therapy and surgery. CONCLUSION: The prognosis for patients with Gorham's disease is generally good unless vital structures are involved. Due to the rarity of this entity, there is no standard therapy. Definitive radiation therapy in moderate doses (40-45 Gy in 2 Gy fractions) appears to result in a good outcome and few long-term complications.

Adult↗
PubMed1993

Preoperative radiation, surgical margins, and local control of extremity sarcomas of soft tissues.

The relationship between status of the surgical margin and local control of soft tissue sarcoma of the extremities by preoperative radiation therapy has been assessed in 132 consecutive patients from 1974 to 1988. The 5-year actuarial local control rate was 94% for all patients; the rates were 97% and 82% for the 104 tumors with negative margins and the 28 tumors with positive margins, respectively. The local control rate was independent of the extent of the negative margin. For primary sarcomas, the local control rates were 96%, 97%, and 100%, respectively, for margins that were negative at < or = 1 mm or > 1 mm, or the specimens were negative for tumor; for positive margins the result was 83%. The overall local control rate was lower (not significant) for recurrent than for primary sarcomas: 88% vs. 94%. On the other hand, when stratifying by margin status, no difference was observed in local control results, i.e.: (1) 97% and 91% for primary and recurrent tumors with negative margins, respectively, and (2) 83% and 80% for primary and recurrent tumors with positive margins, respectively. Local control was not significantly higher in those patients who were treated by surgical resection (S), radiation (RT), and re-excision of the previous tumor bed than in those whose radiation therapy was started after the biopsy and followed by one surgical resection. For primary sarcomas that were resected with negative margins the results were: 100% of 15 patients treated by S-RT-S and 96% of 75 patients treated by RT-S.

Actuarial Analysis↗
PubMed1993

Radiosensitivity in vitro of human soft tissue sarcoma cell lines and skin fibroblasts derived from the same patients.

Skin fibroblast cell strains and tumour cell lines were established from 12 patients with various types of soft tissue neoplasms, and radiation survival curve parameters were measured in vitro. Soft tissue sarcoma cells were consistently more sensitive to X-irradiation than fibroblasts isolated from the same patient, and were also more sensitive as a group than cell lines derived from 34 other human tumours. There was a general correlation in radiosensitivity between fibroblasts and tumour cells derived from the same patient, indicating that some component of tumour cell sensitivity may relate to genetic factors in the host. Such genetic factors, however, do not explain all of the heterogeneity in tumour cell response. The response of soft tissue sarcoma in vivo may be dependent on complex radiomodifying factors other than inherent radiation sensitivity, thus making it difficult to predict clinical outcome by use of assays which use survival of irradiated tumour cell lines in vitro as an endpoint.

Adult↗
PubMed1993

Operative treatment of sacrococcygeal chordoma. A review of twenty-one cases.

Between 1972 and 1992, twenty-one patients had a primary operation for the treatment of a sacrococcygeal chordoma; seventeen had had a diagnostic biopsy elsewhere. The average age at the time of the operation was fifty-five years (range, six to seventy-eight years); fourteen patients were male and seven were female. In all patients, a posterior approach was used, even for resections at the cephalic levels of the sacrum. In addition, sixteen of the twenty-one patients were treated with adjuvant radiation therapy. Four patients died; three died of metastatic chordoma. Of the remaining seventeen patients, fifteen were apparently free of disease and had not had a local recurrence at the time of the latest follow-up examination. The average duration of follow-up for these fifteen patients was four and one-half years. Of the nine patients who were followed for at least five years, seven were disease-free at the latest follow-up evaluation. Of the seven patients in whom both second sacral roots were the most caudad nerve-roots spared, four had normal bladder control and five had normal bowel control. Of the four patients in whom the most caudad nerve-roots spared were the first sacral or more cephalic roots, all had impaired bladder control, one had impaired bowel control, and three had a colostomy.

Adult↗
PubMed1993

Wound healing after preoperative radiation for sarcoma of soft tissues.

Morbidity from wound healing was retrospectively analyzed in a series of 202 consecutive patients with tumors of the soft tissue of the extremities, torso and head and neck region who were treated with preoperative irradiation and conservative operation at the Massachusetts General Hospital between January 1971 and June 1989. A radiation boost dose was given to 143 patients (71 percent) postoperatively. The overall wound complication rate was 37 percent. One patient died because of necrotizing fasciitis. In 33 instances (16.5 percent), secondary operation was necessary, including six patients (3 percent) who required amputation. The wounds in the remaining 40 patients (20 percent) were treated without operation. Multivariate analyses of the data showed the factors that were significantly associated with wound morbidity: tumor in the lower extremity (p < 0.001), increasing age (p = 0.004) and postoperative boost with interstitial implant (p = 0.016). Accelerated fractionation (BID, two fractions per day) reached borderline statistical significance (p = 0.074). Two other factors showed association with wound morbidity by univariate analysis, but not in multivariate model: high pathologic grade (p = 0.02) and estimated volume of resected specimen > or = 200 milliliters (p = 0.065). Patient gender, intercurrent disease (diabetes or hypertension), obesity, maximal tumor size, primary versus recurrent tumor, duration of bed rest postoperatively, dose of postoperative boost radiation, the use of postoperative boost, the use of adjuvant chemotherapy and year of treatment did not show significant importance for wound morbidity. When the severe wound complications (defined as requiring secondary operation and including the patient who died because of necrotizing fasciitis) were considered, among all analyzed variables, only localization of tumor in the lower extremity as a single factor was significant (p < 0.001). Techniques for managing the wound are considered which are judged likely to contribute to a decrease of the incidence of wound healing delays.

Adolescent↗
PubMed1992

Tumors arising in SCID mice share enhanced radiation sensitivity of SCID normal tissues.

We addressed the question of whether cancers arising in an abnormally radiation sensitive normal tissue are also abnormally sensitive to ionizing irradiation. Germ line mutation-carrying mice with an enhanced radiation sensitivity of the normal tissue, the severe combined immunodeficient (SCID), and normally radiation sensitive mice (C3H) were used to study the sensitivity of normal and tumor tissues in vivo and in vitro. The lethal dose for 50% of the irradiated animals after single dose whole body irradiation was 2.6-fold higher in C3H compared to SCID mice. The dose for an isoeffective acute skin reaction after single dose irradiation was end point dependent 1.7 to 3.7 times higher in C3H than in SCID mice. Embryonic fibroblast and methylcholanthrene induced soft tissue sarcomas derived from C3H and SCID mice were established in vitro and colony-forming assays after single dose irradiation were carried out. Choosing mean inactivation dose as the end point, SCID fibroblast lines were 3.0-fold and SCID tumor cell lines 2.7-fold more radiation sensitive than C3H fibroblast lines and C3H tumor cell lines. Tumor control and growth delay assays for 110-mm3 tumors were used to compare the radiation sensitivity of SCID and C3H tumors in vivo. The doses for 50% local tumor control and a growth delay of 40 days were 2.6 times higher in C3H tumors compared to SCID tumors. Tumors arising in an abnormally radiation sensitive normal tissue are also sensitive to irradiation. The difference in radiation sensitivity of normal tissues predicted the difference in tumor tissues in these two murine systems.

Animals↗
PubMed1992

Therapeutic gain of local and radical resection combined with postoperative radiation for murine fibrosarcomas.

Resection of 8-mm fibrosarcomas (FSaII) growing in the right leg of syngeneic C3H/Sed mice was performed under a dissecting (x8) microscope. Local and radical resection achieved 20% (5/25) and 48% (12/25) tumor control, respectively. TCD80s (average dose expected to control 80% of irradiated tumors) for radiation alone given as one fraction per day for 5 consecutive days were 73.1 and 118.0 Gy for the microscopic and 8-mm tumors, respectively. Radiation therapy started at 4 or 7 days following local or radical resection enhanced both the local tumor control and the treatment-related morbidity represented by leg shortening. From enhancement ratios (ERs) for tumor control (TCD80 for radiation alone/TCD80 for postoperative radiation) and for leg shortening (dose for 5-mm leg shortening for radiation alone/postoperative radiation) values, therapeutic gain factors (TGFs) were derived as ER tumor/ER leg shortening. These were 1.3 and 1.4 for local and radical resection followed by radiation started on the 7th postoperative day, respectively. Corresponding figures for radiation started on the 4th postoperative day resulted in 1.2 for both resection procedures.

Animals↗
PubMed1992

Local control and patient survival.

Consideration is given to the concern that future improvements in radiation therapy which achieve increases of local control probabilities will fail to yield gains in survival, in that the new local control patients will ultimately fail because of the development of distant metastasis. The concept is that the local failure merely represents a marker of the exceptionally malignant nature of the tumor; hence, elimination of the local tumor will not affect the ultimate outcome, viz distant failure. This would mean that all tumors which fail locally after the current best radiation therapy will have established distant metastasis (subclinical) at the time of treatment of the primary tumor in stage M0 patients. Thus, a more effective local treatment would not impact on the ultimate fate of the patient. Several lines of evidence are discussed which document that tumor free survival is greater after treatment which yields higher local control probabilities than those achieved by conventional external beam radiation therapy. That is, not all of the new local control patients develop distant metastasis.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Potential improvement of three dimension treatment planning and proton therapy in the outcome of maxillary sinus cancer.

Carcinomas arising in the maxillary sinus are challenging technical problems for radiotherapists due to the complexity of the regional anatomy and the close relations of the tumor to dose-limiting critical structures (eyes, optic nerves, optic chiasm, and brain stem). This study shows that an improvement in the dose distribution can be achieved with the use of three dimensional treatment planning and a combination of x-ray and proton beam arrangements. Although tumor coverage was identical when comparing dose distributions of X rays alone to X rays plus proton beam boost, the critical structures received less dose in the X rays plus proton beam plan. Because a superior dose distribution should yield an improved local control and reduced morbidity, a benefit in survival could be expected.

Carcinoma, Squamous Cell↗
PubMed1992

A dose response analysis of injury to cranial nerves and/or nuclei following proton beam radiation therapy.

The low tolerance of the central nervous system (CNS) limits the radiation dose which can be delivered in the treatment of many patients with brain and head and neck tumors. Although there are many reports concerning the tolerance of the CNS, few have examined individual substructures of the brain and fewer still have had detailed dose information. This study has both. A three dimensional planning system was used to develop the combined proton beam/photon beam treatments for 27 patients with skull-base tumors. The cranial nerves and their related nuclei were delineated on the planning CT scans and the radiation dose to each was determined from three dimensional dose distributions. In the 594 CNS structures (22 structures/patient in 27 patients), there have been 17 structures (in 5 patients) with clinically manifest radiation injury, after a mean follow-up time of 74 months (range 40-110 months). From statistical analyses, dose is found to be a significant predictor of injury. Using logistic regression analysis, we find that, for each cranial nerve, at 60 Cobalt Gray Equivalent (CGE) the complication rate is 1% (0.5-3% with 95% confidence) and that the 5% complication rate occurs at 70 CGE (64-81 CGE with 95% confidence). The slope of the dose response curve (at 50%) is 3.2 (2.2-5.4 with 95% confidence). No significant relationship between dose and latency period for nerve injury was found.

Adolescent↗
PubMed1992

Response of xenografts of human malignant gliomas and squamous cell carcinomas to fractionated irradiation.

The response of xenografts of five human malignant glioma cell lines and two human squamous cell carcinomas to fractionated irradiation was studied. For this, the tumors were transplanted into nude mice which had been further immunosuppressed by 6 Gy whole-body irradiation. Radiation was given as 30 fractions applied under normal blood flow conditions in two sessions per day over 15 days. Absolute and specific tumor growth delay after 48 Gy, and tumor control dose 50% (TCD50) were evaluated. Using local tumor control as experimental endpoint, four out of five malignant gliomas were more resistant to fractionated radiation therapy than the two squamous cell carcinomas. The TCD50s of these four gliomas ranged from 73 Gy to more than 120 Gy, whereas the TCD50s of the squamous cell carcinomas were 51 and 60 Gy. Absolute tumor growth delay correlated well with TCD50, but no correlation was obtained between specific growth delay and TCD50. The response of the human tumor xenografts in vivo did not correlate with the surviving fractions at 2 Gy of the same cell lines in vitro which have been previously obtained in our laboratory. The results suggest that the unique radioresistance observed in malignant gliomas in patients is at least in part reflected in human tumor xenografts. The lack of correlation between the surviving fraction at 2 Gy in vitro and the tumor response in vivo could be a consequence of an immune response by the host, a difference in cell radiation sensitivity between cell lines and xenografted tumors, or of differences of parameters such as hypoxic fraction, rate of repopulation, and cell cycle effects between the different tumor lines studied. It illustrates the difficulties which might be involved in the prediction of the response of individual tumors to radiation therapy based solely on the intrinsic radiosensitivity of the tumor cells as assayed by in vitro assays of colony formation.

Animals↗
PubMed1991

Intraoperative electron beam radiation therapy for retroperitoneal soft tissue sarcoma.

From December 1981 to December 1989, 20 patients with primary or recurrent retroperitoneal sarcoma received 4000 to 5000 cGy of external beam radiation therapy (EBRT) in conjunction with surgical resection and intraoperative radiation therapy (IORT). Seventeen of 20 patients underwent complete (14 patients) or partial (3 patients) resection. Three patients had shown evidence of metastases after EBRT by the time of surgery. The 4-year actuarial local control and disease-free survival rates of the 17 patients undergoing resection were 81% and 64%, respectively. Twelve patients received IORT at the time of resection for microscopic disease (10 patients) or gross residual sarcoma (2 patients). Of the ten patients receiving IORT for microscopic tumor, one patient has died of local failure and peritoneal sarcomatosis and two patients have died of distant metastases only. The remaining seven patients are disease-free. One patient treated for gross residual sarcoma has experienced a local failure 1 year after IORT and is without disease 7 years after salvage chemotherapy. The other patient treated for gross residual sarcoma has died of local failure. Five patients did not receive IORT at the time of resection because of the extensive size of the tumor bed. Three of these patients are disease-free with one patient alive with lung metastases and one patient dying of hepatic metastases. Aggressive radiation and surgical procedures appear to provide satisfactory resectability and local control with acceptable tolerance.

Adolescent↗
PubMed1991

A comparative study on the xenotransplantability of human solid tumors into mice with different genetic immune deficiencies.

These experiments set out to assess the role of NK and B cells in the resistance of nude mice to human tumor xenotransplantation. The transplantability of 9 fresh and 8 cultured human tumors was compared in 2 strains of mice with different genetic immune deficiencies: athymic NCr/Sed (nu/nu) nude mice, and nude-beige-xid (N:NIH-nu-bg-xid/Sed mice). Flow cytometric studies showed both strains to be deficient in Thy. 1.2 (T) cells and unresponsive to stimulation by Concanavalin A (Con A) or direct T-cell-receptor triggering with anti-CD3. The number of B cells was similar in the 2 strains, but the response to lipopolysaccharide (LPS) was markedly reduced in the nude-beige-xid animals. The number of asialoGM1-positive cells (predominantly NK) detected by flow cytometry was also reduced in the nude-beige-xid mice. The transplantability of the human tumors was found to be equivalent in the 2 strains. Quantitative cell-transplantation assays performed for 2 of the tumor cell lines did not reveal any subtle transplantation advantage for the more broadly immune-deficient animals. No evidence could, therefore, be found to suggest that NK or B cells were major determinants of human tumor xenotransplantability in these strains of mice.

Animals↗
PubMed1991

The life shortening effects of treatment with doxorubicin and/or local irradiation on a cohort of young C3Hf/Sed mice.

The long-term consequences of treating a cohort of C3Hf/Sed mice in early life with either local-field single dose radiation, systemic doxorubicin, or both, are reported in this study. Significant life shortening was observed in all treatment groups. Median survival times (days) from time of treatment were: control, 690; 35 Gy, 560; 70 Gy, 460; 5 mg/kg doxorubicin, 580; 10 mg/kg doxorubicin, 350; 35 Gy + 5 mg/kg doxorubicin, 510; 70 Gy + 10 mg/kg doxorubicin, 310. Mice receiving hind limb irradiation died principally from induced sarcomas in a dose dependent fashion (80% after 70 Gy and 55% after 35 Gy). Those treated with doxorubicin alone showed an increase in the actuarial incidence of spontaneous malignancies but died mainly from non-malignant causes. Histological examination did not reveal any characteristic cardiac, renal or pulmonary lesions. Doxorubicin did not increase the rate of development of radiation induced sarcomas in mice treated with combined modality.

Animals↗
PubMed1991

Blood flow of human soft tissue sarcomas measured by thallium-201 scanning: prediction of tumor response to radiation.

Thallium-201 chloride (201T1) has been used to determine regional perfusion in the myocardium and in tumors. This study was done to determine the potential prognostic importance of lesion tracer uptake to regression, local control, and rate of distant metastasis in 14 patients with neoplasms of soft tissue. Most patients had planned resections following preoperative radiation therapy. Minimum follow-up was 4 years. The ratio of nuclide uptake in the tumor to surrounding normal tissue was used as an estimate of relative blood flow. Tumors with acute volume responses (greater than or equal to 50% at the completion of X irradiation) had lower 201T1 uptake indicating lower relative blood flow than tumors that failed to have a volume reduction [1.63 +/- 0.30 (n = 9) vs 3.49 +/- 0.41 (n = 5) 201T1]. All patients had local tumor control. Patients with high uptake tumors tended to develop metastases at a higher frequency, although this was not statistically significant (p = 0.10). We conclude that 201T1 scans are a safe, non-invasive method of estimating tumor perfusion which can be useful to predict acute response to radiation, and may help to identify patients who will ultimately develop distant metastases.

Adolescent↗