Biomedical subjects
Publications and source records attributed to T J Kinsella.
Explore the source record for details and available documents.
PURPOSE: Recent randomized trials of selected patients with single brain metastasis comparing resection followed by whole-brain radiotherapy (WBRT) to WBRT alone have shown a statistically significant survival advantage for surgery and WBRT. A multiinstitutional retrospective study was performed, which identified comparable patients who were treated with stereotactic radiosurgery (RS) and WBRT. METHODS AND MATERIALS: The RS databases of four institutions were reviewed to identify patients who met the following criteria: single-brain metastasis; no prior cranial surgery or WBRT; age > 18 years; surgically resectable lesion; Karnofsky Performance Status (KPS) > or = 70 at time of RS; nonradiosensitive histology. One hundred twenty-two patients were identified who met these criteria. Patients were categorized by: (a) status of the primary, (b) status of non-CNS metastasis, (c) age, (d) baseline KPS (from 70-100), (e) histology, (f) time from diagnosis of primary to the detection of the brain metastasis, (g) gender, and (h) tumor volume. RS was performed with a linear accelerator based technique (peripheral dose range was 10-27 Gy, median was 17 Gy). WBRT was performed in all but five patients who refused WBRT (dose range was 25-40 Gy, median was 37.5 Gy). RESULTS: The median follow-up for all patients was 123 weeks. The overall local control rate (defined as lack of progression in the RS volume) was 86%. Intracranial recurrence outside of the RS volume was seen in 27 patients (22%). The actuarial median survival from date of RS is 56 weeks, and the 1-year and 2-year actuarial survival rates are 53% and 30%. The median duration of functional independence (sustained KPS > or = 70) is 44 weeks. Nineteen of 77 deaths were attributed to CNS progression (25% of all deaths). Multivariate analysis revealed the following factors to be statistically significant predictors of survival: baseline KPS (p < .0001) and absence of other sites of metastasis (p = 0.008). CONCLUSION: The RS in conjunction with WBRT for single brain metastasis can produce substantial functional survival, especially in patients with good performance status and without extracranial metastasis. These results are comparable to recent randomized trials of resection and WBRT. The advantages of RS over surgery in terms of cost, hospitalization, morbidity, and wider applicability strongly suggest that a randomized trial to compare RS with surgery is warranted.
PURPOSE: To determine the response rate and kidney graft survival following local irradiation to the transplanted renal graft undergoing persistent rejection after medical management including pulse steroids and OKT3. The role of radiation for renal transplant rejection after failure of OKT3 has not been previously reported. METHODS AND MATERIALS: From July 1, 1988 to July 1, 1994, 72 consecutive patients with kidney graft rejection were treated with local irradiation to the transplanted renal graft following failure of medical management. All patients received pulse steroids and OKT3, an anti-CD3 immunosuppressant. Patients who failed to respond to methylprednisolone and OKT3 therapy were referred for radiation therapy. The median time from the diagnosis of rejection to irradiation was 8 days. All kidney grafts received local graft irradiation to a total of 8 Gy delivered in four daily fractions. RESULTS: Sixty (83%) patients initially responded to radiotherapy at 7 days after completion of radiotherapy, as defined by a decrease in serum creatinine. Thirty-five responding patients have not experienced a second episode of graft rejection. Overall, 43 (60%) patients have renal graft survival, with a median follow-up of 16 months (range of 6-73 months)> CONCLUSION: It is concluded that there is a subgroup of kidney graft patients undergoing graft rejection who are refractory to pulse steroids and OKT3 therapy where irradiation may be an effective modality with high rates of response and a moderate rate of graft survival. However, a prospective, randomized trial in these medically refractory patients is needed to ascertain whether these results are clinically significant.
PURPOSE: The frequency of radiation-induced neoplasms was determined in dogs enrolled in the National Cancer Institute canine trials of intraoperative radiotherapy (IORT). METHODS AND MATERIALS: Twelve protocols assessing normal tissue response to IORT involved 238 dogs in a 15-year trial. Eighty-one dogs were followed for > 24 months postoperatively and were assessed for tumor development; 59 of these animals received IORT. RESULTS: Twelve tumors occurred in the 59 dogs receiving IORT. Nine were in the IORT portals and were considered to be radiation induced. No tumors occurred in 13 sham animals or in 9 animals treated with external beam radiotherapy alone. The frequency of radiation-induced malignancies in dogs receiving IORT was 15%, and was 25% in animals receiving > or = 25 Gy IORT. Frequency of all tumors, including spontaneous lesions, was 20%. CONCLUSIONS: Intraoperative radiotherapy contributed to a high frequency of sarcoma induction in these dogs. Unknown to date in humans involved in clinical trials of IORT, this potential complication should be looked for as long-term survivors are followed.
Explore the source record for details and available documents.
PURPOSE: This study was designed to compare costs of adjuvant radiation versus observation in the management of early-stage testicular seminoma after inguinal orchiectomy. MATERIALS AND METHODS: A line-by-line inspection of the charges generated during a course of adjuvant pelvic and paraaortic radiotherapy and of three cycles of bleomycin, etoposide, and platinum salvage chemotherapy was performed for five patients who received irradiation and five patients who received salvage chemotherapy. The average charge for either treatment was then calculated. Only those charges directly associated with the diagnosis of seminoma were included in the analysis. Follow-up charges were also generated from the patients' billing records. The optimum follow-up regimen for either management option was derived from a synthesis of the international literature. A 5% rate of failure was assumed if adjuvant irradiation was administered, and a 15% rate of failure was assumed if observation was the option chosen. Charges were truncated at 5 years. RESULTS: The total charge generated over 5 years based on following a policy of observation is $27,223 per patient versus $19,557 if the option of adjuvant irradiation in chosen. Using University of Wisconsin institutional reimbursement rates, the estimated costs were $20,487 and $14,722 for the option of observation and adjuvant radiation, respectively. The cost equivalence point between the two options occurs at 2.5 years, when the initial cost of adjuvant radiotherapy is matched by the cost generated during the period of observation. The maximum cost difference is achieved by 5 years. CONCLUSION: Following a policy of observation postorchiectomy for early-stage testicular seminoma generates 39% more medical costs per patient over a 5-year follow-up period than does following the standard policy of adjuvant irradiation to the pelvic and paraaortic regions, with no reported difference in outcome.
The aim of this study was to improve local control and survival of patients with radioresistant tumours by sensitising proliferating cells using halogenated analogues of thymidine, with emphasis on increasing the proportion of tumour cells that incorporate the sensitiser. It has been found clinically that 2 weeks of continuous infusion of IUdR at 1000 mg m-2 per day can be tolerated, followed after a gap by a third week of the same. The sensitising compound is taken up only into those cells which are in S-phase at the time of administration. It is assumed that if the same total dose of 3 g m-2 were administered spread evenly over a longer period, it would be tolerated at least as well, and a higher proportion of tumour cells would become sensitised (labelled with IUdR). The question then arises: is the reduced concentration of IUdR enough to cause significant radiosensitisation? This question was investigated in two contrasting lines of human colon cancer in vitro. It is essential that at least 90% of all clonogenic tumour cells should be labelled with the IUdR (that is 1 log), or else the sensitiser enhancement ratio (SER) cannot be expected to exceed 1.1. Similarly, to reach an SER of 1.2, we should label 99% of cells (2 logs labelled). To achieve such proportions labelled, infusions would have to be 5 or 10 times longer than the population doubling time of clonogenic cells Tpot that is of several weeks duration. The infusion should be either continuous or perhaps better-by repeated small boluses at intervals of less than T (duration of DNA synthesis), so that no proliferating cells escape being exposed to the IUdR. It is shown that LIs (labelling indices) of 94% can be obtained with SERs ranging from 1.5 to 3.0 and 99% with SERs from 1.2 to 2.4, in the two most contrasting human colon cancer cell lines for which data are available. Longer, lower dose infusions than previously used should be considered so as to emphasise the importance of not allowing any potentially clonogenic tumour cells to pass through S-phase without labelling.
This in vivo study examines the ability of 5'-amino-5'-deoxythymidine (5'-AdThd) to modulate 5-iododeoxyuridine (IdUrd) cellular metabolism in two human colon cancer xenografts (HT 29 and HCT-116), two actively proliferating normal mouse tissues (bone marrow and intestine), and a quiescent normal mouse tissue (liver). 5'-AdThd is a thymidine analogue that at low concentrations (<30 micrometer) can increase thymidine kinase activity, which is the rate-limiting enzyme for activation of IdUrd. We reported recently that the in vitro incubation of HT 29 and HCT-116 cells in 5'-AdThd + IdUrd resulted in an enhancement of 5-iodo-2'-dUTP pools, IdUrd DNA incorporation, and subsequent radiosensitization compared with incubation with IdUrd alone (Clin. Cancer Res., 1: 407-416, 1995). These in vitro effects were more significant in the radioresistant cell line HT 29. Using a 6-day continuous infusion of IdUrd (50 or 100 mg/kg/day) and/or 5'-AdThd (200 mg/kg/day), no increase in systemic toxicity (percentage of body weight loss) was observed in athymic nude mice with 5'-AdThd alone or when combined with IdUrd. There was significant dose-dependent, systemic toxicity with IdUrd, which was reversible within 3 days of completing the lower-dose IdUrd infusion. However, a comparison of plasma levels during the 6-day continuous infusion of IdUrd +/- 5'-AdThd showed a significant interaction of IdUrd and 5'-AdThd, resulting in higher plasma levels by day 6 of both compounds and the principal metabolites, iodouracil and deoxyuridine, which is consistent with nonlinear saturating effects on dihydrouracil dehydrogenase. Coadministration of IdUrd and 5'-AdThd resulted in an increase in the percentage of IdUrd DNA incorporation in the two proliferating normal tissues, which was significant only with the lower IdUrd dose. No effect on IdUrd DNA incorporation was found in normal liver at either IdUrd dose +/- 5'-AdThd. Similar to our in vitro data, the continuous infusion of IdUrd and 5'-AdThd showed a significant effect by increasing the percentage of IdUrd DNA incorporation in HT-29 xenografts at both IdUrd doses, whereas coadministration of 5'-AdThd had no such effect in HCT-116 xenografts.
Evidence for clinically significant radiosensitization by the halogenated pyrimidine 5-iododeoxyuridine (IdUrd) continues to accumulate. In vitro radiosensitization has been demonstrated in human colon tumor cell lines following exposure to 1-10 micrometer. Coadministration of leucovorin (LV) increases radiosensitization, which correlates directly with increased IdUrd DNA incorporation. Clinical data regarding proliferation rates and thymidine kinase levels in tumors versus normal tissues suggest selective incorporation of IdUrd into gastrointestinal tumors may occur. The objectives of this Phase I study were: (a) to assess the feasibility of LV modulation of IdUrd radiosensitization by determining the maximum tolerated dose (MTD) of IdUrd plus LV; and (b) to perform correlative laboratory studies to investigate the potential of IdUrd plus LV to increase radiosensitization in vivo. Seventeen patients with unresectable or recurrent gastrointestinal adenocarcinomas received a 14-day course of continuous i.v. infusion of IdUrd prior to initiation of radiotherapy. Two additional 14-day infusions of IdUrd with LV were given during the course of radiotherapy (60 Gy in 6 weeks). The initial dose of IdUrd was 250 mg/m2/day and was escalated in subsequent patients to 400 and 600 mg/m2/day. The LV dose remained fixed at 250 mg/m2/day. Leukopenia was the dose-limiting toxicity, and 400 mg/m2/day was the MTD for this trial. At the MTD, the mean +/- SD steady-state plasma concentration of IdUrd during the infusion, measured by high-performance liquid chromatography, was 0.66 +/- 0.23 micrometer. There was no significant influence of LV on IdUrd DNA incorporation in peripheral blood granulocytes as measured by high-performance liquid chromatography. Based on toxicity data and correlative laboratory studies, a meaningful increase in radiosensitization would not be achieved with the IdUrd infusion schedule and dose of LV investigated compared with IdUrd alone.
PURPOSE: Proliferation of surviving tumor clonogens during a course of protracted radiation therapy may be a cause of local failure in cervical carcinoma. The effect of total treatment time was analyzed retrospectively in relation to pelvic control and overall survival for squamous cell carcinomas of the uterine cervix. METHODS AND MATERIALS: Two hundred and nine patients (Stage IB-IIIB) treated with a combination of external beam and low dose rate intracavitary irradiation were evaluable for study. Multivariate analysis and Kaplan-Meier statistical methods were used to determine the effect of treatment time on pelvic control and survival at 5 years. RESULTS: The median treatment duration was 55 days. For all stages combined, the 5-year survival and pelvic control rates were significantly different with treatment times < 55 days vs. > or = 55 days: 65 and 54% (p = 0.03), 87 and 72% (p = 0.006), respectively. By stage, a shorter treatment duration (i.e., < 55 days vs. > or = 55 days) was significant for 5-year overall survival and pelvic control for Stages IB/IIA and III, but not for Stage IIB: Stage IB/IIA (81 and 67%, 96 and 84%), Stage III disease (52 and 42%, 76 and 55%) and Stage IIB (43 and 50%, 74 and 80%, respectively). Survival decreased 0.6%/day and pelvic control decreased 0.7%/day for each additional day of treatment beyond 55 days for all stages of disease. Additionally, significant late complications were not influenced by treatment time. CONCLUSION: These results suggest that prolongation of treatment time is associated with decreased local control and survival in patients with cervical carcinoma. This is consistent with emerging data from other institutions. Therapeutic implications include avoidance of unnecessary treatment breaks, the design of fractionation schemes that decrease treatment duration, and possibly the use of tumor cytostatic drugs during conventional radiation.
PURPOSE: In September 1989, a postoperative Phase II high dose rate (HDR) brachytherapy protocol was started for International Federation of Gynecology and Obstetrics (FIGO) Stage I endometrial adenocarcinoma. This review reports the overall survival, local control, and complication rates for the initial 63 patients treated in this Phase II study. METHODS AND MATERIALS: High dose rate brachytherapy was delivered using an Iridium-192 HDR remote afterloader. Sixty-three patients were entered into the Phase II protocol, each receiving two vaginal cuff treatments 1 week apart (range 4-12 days) with vaginal ovoids (diameter 2.0-3.0 cm). No patient received adjuvant external beam radiation. A dose of 32.4 Gy in two fractions was prescribed to the ovoid surface in 63 patients. The first three patients treated at our institution received 15, 16.2, and 29 Gy, respectively, to determine acute effects. RESULTS: At a median follow-up of 1.6 years (range 0.75-4.3 years) no patient has developed a vaginal cuff recurrence. One regional recurrence (1.6%) occurred at 1.2 years at the pelvic side wall. This patient is alive and without evidence of disease 7 months after completion of salvage irradiation, which resulted in the only vaginal stenosis (1.6%). Fourteen patients (22%) experienced vaginal apex fibrosis by physical exam, which was clinically symptomatic in four patients. Two patients reported stress incontinence; however, these symptoms were noted prior to their HDR therapy. One patient died 2.4 years after HDR therapy due to cardiovascular disease without evidence of cancer at autopsy. CONCLUSION: Preliminary results of our phase II HDR vaginal cuff protocol for postoperative FIGO Stage IA, Grade 3 or Stage IB, Grade 1-2 patients demonstrate that 32.4 Gy in two fractions is well tolerated by the vaginal cuff mucosa. Local control appears comparable to our prior experience and others with low dose rate (LDR) brachytherapy. Additional patient accrual and further follow-up will better determine the late morbidity, local control, and overall survival of these patients.
PURPOSE: To evaluate the impact of stereotactic radiosurgery on the survival of patients treated with malignant gliomas. METHODS AND MATERIALS: A total of 115 patients from three institutions (75 from the Joint Center for Radiation Therapy, 30 from the University of Wisconsin, and 10 from the University of Florida) were treated with a combination of surgery, external beam radiation therapy, and linac-based radiosurgery as part of similar institutional protocols from March 1988 through July 1993. Patients were stratified into six prognostic classes (classes 1-6) based on the recursive partitioning analysis of multiple prognostic factors previously reported by the Radiation Therapy Oncology Group. RESULTS: The actuarial 2-year and median survival for all patients analyzed was 45% and 96 weeks, respectively. In comparison to the results from a previously published analysis of 1578 patients entered on three Radiation Therapy Oncology Group external beam radiotherapy protocols from 1974 to 1989, those patients treated with radiosurgery had a significantly improved 2-year and median survival (p = 0.01) corresponding with a standardized mortality risk ratio of 0.51 [95% confidence interval (CI): 0.31, 0.85]. This improvement in survival was seen predominantly for the worse prognostic classes (classes 3-6). The 2-year survival for the radiosurgical patients compared with the previously reported patients was 81% vs. 76% for classes 1/2, 75% vs. 35% for class 3, 34% vs. 15% for class 4, and 21% vs. 6% for classes 5/6, respectively. Although Karnofsky performance status and prognostic class were significant on univariate analysis, only the Karnofsky score was a significant predictor of outcome on multivariate analysis. Median and 2-year survival for patients with a Karnofsky score > or = 70 was 106 weeks and 51%, respectively, as compared to 38 weeks and 0% for patients with a Karnofsky score < 70% (p = 0.001). CONCLUSIONS: The addition of radiosurgery to conventional treatment (surgery and external beam radiotherapy) of malignant gliomas appears to improve survival when compared to historical reports. These results should be interpreted with caution because the recursive partitioning model does not completely predict the prognosis of the patients treated in the present study. Although this study suggests that radiosurgery may prolong survival in patients with malignant gliomas, the role of radiosurgery in the management of these patients remains to be defined by a prospective randomized trial.
PURPOSE: The clinical late effects of intraoperative radiotherapy (IORT) on peripheral nerve were investigated in a foxhound model. METHODS AND MATERIALS: Between 1982 and 1987, 40 animals underwent laparotomy with intraoperative radiotherapy of doses from 0-75 Gy administered to the right lumbosacral plexus. Subsequently, all animals were monitored closely and sacrificed to assess clinical effects to peripheral nerve. This analysis reports final clinical results of all animals, with follow-up to 5 years. RESULTS: All animals treated with > or = 25 Gy developed ipsilateral neuropathy. An inverse relationship was noted between intraoperative radiotherapy dose and time to neuropathy, with an effective dose for 50% paralysis (ED50) of 17.2 Gy. One of the animals treated with 15 Gy IORT developed paralysis, after a much longer latency than the other animals. CONCLUSIONS: Doses of 15 Gy delivered intraoperatively may be accompanied by peripheral neuropathy with long-term follow-up. This threshold is less than that reported with shorter follow-up. The value of ED50 determined here is in keeping with data from other animal trials, and from clinical trials in humans.
Biochemical modulation of iododeoxyuridine (IdUrd) incorporation into the DNA of tumor cells is a potential clinical strategy to enhance radiosensitivity and to simultaneously differentiate the sensitivity of rapidly proliferating tumor cells and more slowly proliferating adjacent normal tissues to radiation. The interactions of hydroxyurea (HU) and IdUrd were studied in a human bladder cancer cell line, 647V. Exposure of exponentially growing 647V cells to HU concentrations of 10-100 microM for one cell population doubling (24 h) resulted in no cytotoxicity as assessed by clonogenic survival. Flow cytometric analysis showed a significant increase in an early S-phase population after a 12-h exposure but a return to a normal cell cycle distribution after a 24-h exposure to 100 microM HU. Incorporation of IdUrd into DNA was increased 2-fold by coincubation with HU (100 microM) and a clinically achievable concentration of IdUrd (2 microM) for 24 h. To elucidate the mechanism of modulation, IdUTP pools were compared in 647V cells treated with 2 microM IdUrd with or without 100 microM HU. A 2-fold increase in IdUTP pools was evident within 2 h when this drug combination was used. With the use of multivariate statistical analysis, the radiosensitivity of 647V cells was compared after a 24-h exposure to various concentrations of IdUrd (0 and 2 microM) and HU (0, 10, and 100 microM). A 24-h exposure to 100 microM HU alone or to 2 microM IdUrd alone before irradiation resulted in significant (P < 0.02) radiosensitization with sensitizer enhancement ratios of 1.15 and 1.27, respectively. A 24-h exposure to 100 microM HU + 2 microM IdUrd resulted in even more significant (P = 0.001) radiosensitization, which was found to be a greater than additive response (sensitizer enhancement ratio, 1.76 observed compared with 1.37 expected). No radiosensitization was found with a 12-h exposure to 100 microM HU alone. The mechanism of biochemical modulation of IdUrd by a noncytotoxic dose of HU is proposed as increasing the IdUTP pools by stimulating enzymes in the thymidine salvage pathway and subsequently enhancing IdUrd incorporation and radiosensitization.
Explore the source record for details and available documents.
PURPOSE: Different treatment techniques are used in high dose rate (HDR) remote afterloading intracavitary brachytherapy for uterine cervical cancer. We have investigated the differences between "optimized" and "nonoptimized" therapy using both a tandem and ring (T/R) applicator, and a tandem and ovoids (T/O), applicator. METHODS AND MATERIALS: HDR afterloading brachytherapy using the Madison System for Stage IB cervical cancer was simulated for 10 different patients using both a T/R applicator and a T/O applicator. A treatment course consists of external beam irradiation and five insertions of HDR afterloading brachytherapy. Full dosimetry calculations were performed at the initial insertion for both applicators and used as a reference for the following four insertions of the appropriate applicator. Forty dosimetry calculations were performed to determine the dose delivered to Point M (similar to Point A), Point E (obturator lymph nodes), vaginal surface, bladder, and rectum. "Optimized" doses were specified to Point M and to the vaginal surface. "Nonoptimized" doses were specified to Point M only. Using the linear-quadratic equation, calculations have been performed to convert the delivered dose using HDR to the biologically equivalent doses at the conventional low dose rate (LDR) at 0.60 Gy/h. RESULTS: Major differences between "optimized" and "nonoptimized" LDR equivalent doses were found at the vaginal surface, bladder, and rectum. Overdoses at the vaginal surface, bladder, and rectum were calculated to be 208%, nil, and 42%, respectively, for the T/R applicator with "nonoptimization." However, for the T/O applicator, the overdoses were smaller, being nil, 32%, and 27%, respectively, with "nonoptimization." CONCLUSION: Doses given in high dose rate intracavitary brachytherapy border on tissue tolerance. "Optimization" of either applicator decreases the risk of a dose that may have potential for complications. Optimization of a tandem and ovoids best ensures that the doses are not diminished at the treatment sites, and that the potential for overdose is reduced.
Current treatment of locally advanced bone and soft tissue sarcomas of the pelvic girdle are associated with a high local and distant failure rate, and local tumor control after hemipelvectomy can be a significant problem. IORT has been used in conjunction with hemipelvectomy, both conventional (seven patients) and limb-sparing internal hemipelvectomy (one patient), in seven males and one female, median age 27 (range 24-57) years with locally extensive high grade bone (seven patients) or soft tissue (one patient) sarcomas. IORT (15-30 Gy, 8-16 MeV) was delivered to sacral resection margins and surrounding soft tissues considered likely to harbor microscopically residual disease. Four patients received 46-54 Gy postoperative radiotherapy in addition to IORT. During a median follow-up of 33 months (range 6-131 months) two patients developed a local recurrence (25%), and five patients distant metastases (62%). Three patients with pelvic girdle sarcomas remained free of tumor (37%) with a mean follow-up of 100 (range 49-131) months. There was no treatment-related mortality. Two patients developed radiation-induced necrosis of the coccyx (25%). On the basis of this preliminary experience, it appears that IORT may substantially help to control local recurrence and survival in patients with marginally resectable sarcomas of the pelvic girdle after hemipelvectomy. Since the majority of the patients die from metastatic disease, there is a need for adjuvant systemic treatment.
Among Ewing's sarcoma (ES) of bone and related entities are tumours with neuro-ectodermal features that could represent a biologically distinct type. In order to assess the prognostic significance of the various forms of ES, a retrospective joint study involving three cancer centres in Europe and the U.S.A. was initiated. The material from 315 primary ES was reviewed by a panel of five pathologists and classified as typical ES (220 cases), atypical ES (48 cases) or ES with neuro-ectodermal features (47 cases). Prognostic factor analysis on treatment failure-free survival was performed using the Cox model. It included histopathological classification, initial patient characteristics, clinical presentation and treatment type. After multivariate analysis, in addition to treatment type (P < 0.001), metastases (P = 0.003) and proximal tumour location (P = 0.006), two histopathological parameters correlated with poor treatment failure-free survival, the presence of filigree pattern (P = 0.044) and dark cells (P = 0.043). We conclude that ES with neuro-ectodermal features does not appear to have a different outcome to the other subtypes.