Cavernous sinus cranial neuropathies: is there a dose-response relationship following radiosurgery?
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Cavernous Sinus↗
Biomedical subjects
T J Kinsella
Publications and source records attributed to T J Kinsella.
Thoracic volume radiation sparing following endobronchial brachytherapy: a quantitative analysis.
A retrospective analysis of patients with inoperable, Stage III non-small cell lung carcinoma presenting with malignant airway occlusion and treated with endobronchial brachytherapy boost prior to radical radiotherapy is reported. Of the 102 patients treated with endobronchial brachytherapy between October 1986 and January 1991, 22 were newly diagnosed, biopsy-proven Stage IIIA (14/22) or IIIB (8/22) non-small cell carcinoma with > 80% endoscopically demonstrated airway occlusion of the carina (1/22), mainstem bronchus (10/22) or lobar bronchus (11/22). Fifteen patients had complete lung or lobar atelectasis. Poor performance status (KPS < 70% in 13/22) and/or weight loss (> 10% in 9/22) rendered these patients ineligible for multi-institutional trials. Endobronchial boost was delivered using low dose rate (20 Gy at 2 cm) or high dose rate brachytherapy (16 Gy in 4 fractions over 2 days at 2 cm). Following a 10-14 day post-endobronchial period to allow for reaeration, patients underwent additional external beam radiotherapy (60 Gy in 30 fractions). Of the 15 patients with atelectasis, 6/15 (40%) reaerated completely, 4/15 (27%) partially, and 5/15 (33%) failed to reaerate. A new method, called "sequential volume integration" was used on the pre- and post-endobronchial films to analyze sparing of thoracic volume from external beam radiation as a consequence of reaeration. Patients with complete reaeration required 47% less and those patients with partial reaeration required 25% less ipsilateral thoracic volume radiation. There was a tend toward improved survival in reaerators (36 weeks) as compared to non-reaerators (24 weeks).
Brachytherapy↗
Modulation of proliferation kinetics in human squamous cell carcinomas of the head and neck.
OBJECTIVE: Proliferation of tumor clonogens during a course of conventional head and neck radiotherapy serves to compromise ultimate tumor control. Biologic strategies that attempt to alter tumor proliferation kinetics using cytostatic or antiproliferative agents may therefore prove valuable by limiting tumor cell repopulation during therapy. DESIGN: Three human squamous cell carcinoma (SCC) cell lines, derived from primary head and neck cancers, have been characterized in vitro via flow cytometric analysis of proliferation kinetics, and in vivo via tumor xenograft growth evaluation in athymic mice. RESULTS: The antiproliferative agent alpha-difluoromethylornithine (DFMO), an inhibitor of polyamine biosynthesis, induced growth inhibition of these SCCs in culture and when administered orally to athymic mice harboring SCC tumor xenografts. Cell cycle kinetic analysis via flow cytometry revealed that DFMO induced a lengthening of in vitro tumor cell potential doubling times. Similarly, DFMO administered continuously via the drinking water to athymic mice harboring human SCC xenografts induced a prolongation of in vivo tumor volume doubling. CONCLUSIONS: These data indicate that biologic agents, such as DFMO, can alter SCC growth kinetics and may prove useful in designing new therapeutic strategies for rapidly proliferating tumors such as those that occur in the head and neck.
Animals↗
Intraoperative radiotherapy in retroperitoneal sarcomas. Final results of a prospective, randomized, clinical trial.
Thirty-five patients with surgically resected sarcomas of the retroperitoneum were enrolled in a prospective, randomized, clinical trial comparing 20-Gy intraoperative radiotherapy in combination with postoperative low-dose (35- to 40-Gy) external-beam radiotherapy with postoperative high-dose (50- to 55-Gy) external-beam radiotherapy alone. Chemotherapy with doxorubicin hydrochloride, cyclophosphamide (anhydrous), and methotrexate sodium was used for a portion of the trial. Fifteen patients who received intraoperative radiotherapy and 20 control patients were followed up for a minimum of 5 years (median follow-up, 8 years). Median survival times were similar for the group that received intraoperative radiotherapy (45 months) and the control group (52 months). There were no indications of benefit from adjunctive chemotherapy. The number of locoregional recurrences was significantly lower among those who received intraoperative radiotherapy (six of 15) than control patients (16 of 20). Patients who received intraoperative radiotherapy had fewer complications of disabling radiation-related enteritis (two of 15) than control patients (10 of 20), but radiation-related peripheral neuropathy was more frequent among those who received intraoperative radiotherapy (nine of 15) than among control patients (one of 20).
Adult↗
Randomized trial of intraoperative radiotherapy in carcinoma of the stomach.
A prospectively randomized controlled clinical trial was performed comparing surgical resection and intraoperative radiotherapy (IORT) with conventional therapy in adenocarcinoma of the stomach. Patients in the experimental group underwent gastrectomy, and IORT was administered to their gastric bed (20 Gy using 11 to 15 MeV electrons). Patients in the control group underwent gastrectomy alone for early-stage lesions confined to the stomach (stages I to II) or resection and postoperative external beam radiotherapy to the upper abdomen (50 Gy using 6 to 10 mV photons) for advanced-stage lesions extending beyond the gastric wall (stages III to IV). One hundred patients were screened for the study, of whom 60 were randomized and underwent exploratory surgery. Nineteen patients were excluded intraoperatively because of unresectability or metastatic disease, leaving 41 patients in the study. Seven patients (17%) died of complications. The median survival for patients with tumors of all stages was 25 months for the IORT group and 21 months for the control group (p = 0.99). Locoregional disease failures occurred in 7 of 16 (44%) IORT patients and in 23 of 25 (92%) control patients (p < 0.001). Complication rates were similar between IORT and control patients. Although IORT failed to afford a significant advantage over conventional therapy in overall survival, IORT did significantly improve control of locoregional disease.
Actuarial Analysis↗
The application of correlated sampling to the computation of electron beam dose distributions in heterogeneous phantoms using the Monte Carlo method.
Although the Monte Carlo method is capable of computing the dose distribution in heterogeneous phantoms directly, there are some advantages to computing a heterogeneity correction factor. If this approach is adopted there are savings in time using correlated sampling. This technique forces histories to have the same energy, position, direction and random number seed as incident on both the heterogeneous and homogeneous water phantom. This ensures that a history that has, by chance, travelled through only water in the heterogeneous phantom will have the same path as it would have through the homogeneous phantom, resulting in a reduced variance when a ratio of heterogeneous dose to homogeneous dose is formed. Metrics to describe the distributions of uncertainty, efficiency, and degree of correlation are defined. EGS4 Monte Carlo calculation of the dose distribution from a 20 MeV electron beam on water phantoms containing aluminum or air slab heterogeneities illustrate that this technique is the most efficient when the heterogeneity is deep within the phantom, but that improved efficiency can be realized even when the heterogeneity is at or near the surface. This is because some correlation between the two histories is retained despite passage through the heterogeneity.
Electrons↗
A retrospective review of nodal treatment for vulvar cancer.
From 1983 to 1990, 42 clinical N0, N1 patients with invasive squamous cell carcinoma of the vulva underwent surgery for the primary cancer, followed by nonrandomized assignment to either surgery or radiation therapy for nodal management. This is a retrospective analysis reviewing treatment outcome and complications of inguinofemoral dissection versus photon irradiation. Group I (N = 24) underwent either bilateral or unilateral inguinofemoral dissection; Group II (N = 18) underwent bilateral groin irradiation. The 3-year disease-free survival was 84.5% and 79.7% for Group I and II (p = 0.74). The nodal failure rate at 3 years was not significantly different. The postoperative complications in the surgically treated nodes were: 17% seromas, 46% wound infection, and 71% wound separation. Of those patients developing either an infection or wound separation, 41% required daily wound care for more than 2 weeks by a visiting nurse after discharge. Only 1 of 18 (6%) irradiated patients developed a clinically significant skin reaction. The median time for complete skin/wound healing was 8 weeks (range 4-24 weeks) in Group I and 2 weeks (range 2-6 weeks) in Group II. Late postoperative complications in the surgically treated patients included meralgia paresthetica (8%) and lymphedema (12%); 1 (6%) Group II patient developed lymphedema. Based on this limited retrospective review, we conclude that inguinofemoral radiation achieves reasonable local control and may represent an alternative to surgery in selected patients. The acute and delayed morbidity of lymphadenectomy exceeds that of irradiation.
Aged↗
Soft tissue sarcoma: combined modality approaches.
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Combined Modality Therapy↗
Total-body irradiation and autologous bone marrow transplant in the treatment of high-risk Ewing's sarcoma and rhabdomyosarcoma.
PURPOSE: In an effort to improve outcome in patients with metastatic or high-risk localized Ewing's sarcoma family of tumors (ESF) and rhabdomyosarcoma (RMS), we explored the role of consolidation therapy with total-body irradiation (TBI) plus autologous bone marrow transplantation (ABMT). PATIENTS AND METHODS: Ninety-one patients were entered onto one of three consecutive protocols from 1981 to 1986. Induction therapy consisted of four or five cycles of vincristine, doxorubicin, and cyclophosphamide (VAdriaC); in the earlier series, patients received one or two cycles with dactinomycin instead of doxorubicin. Irradiation of the primary site was used for local control. Patients who attained a complete response (CR) to induction therapy were eligible for consolidation with 8 Gy TBI plus VAdriaC and ABMT. RESULTS: Nineteen patients were ineligible for consolidation after failing to achieve or maintain a CR following induction therapy; all 19 are dead of disease. Seven eligible patients elected to forgo consolidation; three of seven are long-term event-free survivors. Sixty-five patients received consolidation therapy; 20 of 65 are long-term event-free survivors. A local control rate of 83% was achieved using radiation therapy as the primary modality of local control. Patients with metastatic disease at diagnosis fared substantially worse than did patients with localized tumors (6-year event-free survival [EFS] rate, 14% v 38%; two-sided P [P2] = .008). CONCLUSIONS: Consolidation of patients with metastatic or high-risk localized pediatric sarcomas with 8 Gy TBI plus ABMT has failed to improve the outcome of this group of patients. Metastatic disease at diagnosis continues to confer the poorest prognosis. New therapeutic strategies are needed to consolidate more effectively the remissions that can be achieved in the majority of these patients.
Adolescent↗
Effects of bleomycin with iododeoxyuridine, 5'-amino-5'-deoxythymidine, and radiation in a human bladder cancer cell line.
In vitro bleomycin cytotoxicity in 647V, a human bladder cancer cell line, is enhanced when the cells are preincubated for one cell cycle (24 h) with clinically relevant concentrations (2 microM) of iododeoxyuridine (IdUrd). Bleomycin cytotoxicity after a 1-h exposure is further enhanced by a 24-h preincubation with 2 microM IdUrd plus 30 microM 5'-amino-5'-deoxythymidine (5'-AdThd). Chemosensitization of clinically achievable plasma levels of bleomycin (1-10 mU/ml for 1 h) by IdUrd (+/- 5'-AdThd) is associated with the level of DNA incorporation of IdUrd in 647V cells and with enhanced bleomycin-induced damage in IdUrd-substituted DNA compared to control DNA, as measured by rapid alkaline elution. We also studied the in vitro effects of bleomycin (+/- IdUrd) treatment on the subsequent radiation response of 647V cells. We found that a 1-h preirradiation exposure of 647V cells to low concentrations of bleomycin (1 mU/ml) can radiosensitize the cells with an even greater interaction exhibited by pretreatment with 2 microM IdUrd (24 h) plus bleomycin (1 h) vs control. Since the principal normal tissue toxicities of IdUrd (involving bone marrow and gut) and bleomycin (involving lung) do not overlap, these in vitro data suggest that chemosensitization of bleomycin by IdUrd may provide a new therapeutic regimen for chemotherapy and a significant enhancement for radiotherapy in human bladder cancer and possibly other epithelial cancers.
Bleomycin↗
Global comparison of radiation and chemotherapy dose-response curves with a test for interaction.
In the analysis of the effects of radiation or drugs on clonogenic survival data of mammalian cells, it is often advantageous to compare entire dose-response curves generated under different experimental conditions rather than to conduct single-dose comparisons. We propose a two-stage method for the global comparison of such curves. The first stage consists of individual fits of a flexible model to the dose-response sequences. The second stage treats the fitted coefficients as data and analyzes them jointly using a multivariate analysis of variance. For dose-response models of the type commonly used in the analysis of clonogenic survival data, this method allows the definition of a statistical test for interaction among treatments. That is, a test that the combination of agents produces a dose-response curve which is not what would be expected if the agents were acting multiplicatively (additively in the log cell survival scale). Analyses of cell survival curves by this method for experiments on iododeoxyuridine-mediated radiosensitization and on chemosensitization of bleomycin cytotoxicity in a human bladder cancer cell line (647V) are presented.
Analysis of Variance↗
Radiosensitization by fluorodeoxyuridine: effects of thymidylate synthase inhibition and cell synchronization.
The combination of fluoropyrimidines and radiation has resulted in increased control of colorectal cancer in the clinic, but the basic mechanism of the interaction is not understood clearly. Preliminary work in our laboratory showed that 2-h exposures of HT 29 human colon carcinoma cells to relatively low levels of 5-fluorodeoxyuridine resulted in extended thymidylate synthase inhibition after the drug was removed (up to 30 h after treatment with 0.5 microM 5-fluorodeoxyuridine). The low cytotoxicity associated with this treatment simplified efforts to test the effects of extended thymidylate synthase inhibition on radiosensitivity of HT 29 cells. Although thymidylate synthase was completely inhibited at the end of the 2-h exposure, an increase in the radiosensitivity of the cells was not evident until 16 h after the removal of drug. Flow cytometric analysis showed that cells accumulated in early S phase over time, and the increase in radiation sensitivity of the entire population followed the increase of the proportion of cells in early S, a relatively radiosensitive phase of the cell cycle. This treatment schedule was compared with 24-h continuous exposure, and we found that the same maximum increase in radiosensitivity was achieved by both treatment strategies. However, more cytotoxicity was associated with continuous exposure. This study provides evidence that radiosensitization by 5-fluorodeoxyuridine is in part due to alteration of cell kinetics and redistribution of cells throughout the cycle. This information may be useful in the design of less toxic combined chemo- and radiotherapy treatment strategies by limiting systemic exposure to fluoropyrimidines.
Cell Cycle↗
Single biopsy, tumor kinetic analyses: a comparison of methods and an extension to shorter sampling intervals.
There is emerging and established clinical and laboratory evidence that proliferation of tumor clonogens during radiation therapy can impair local tumor control. The pre-treatment, tumor potential doubling time, T(pot), estimated with in situ bromodeoxyuridine (BrdUrd) labeling, followed by a single biopsy and flow cytometry, may be a predictor of a given tumor's ability to undergo such intra-treatment proliferation. Recent studies have found a strong similarity between T(pot)'s determined in this fashion and the effective doubling times of surviving tumor cells during radiotherapy, as estimated from tumor control versus treatment duration data. Furthermore, several preliminary clinical studies have indicated that T(pot) may be a predictor of outcome, with faster tumors doing worse. Accelerated fractionation might overcome such proliferation, but is more acutely toxic and is unlikely to benefit patients with slowly proliferating tumors. Thus, the BrdUrd/single biopsy method may offer the possibility of selecting between accelerated and conventional or hyperfractionated treatment. Several approaches to the analysis of data generated by this method have been described, but there has been little documentation of the validity of methods in experimental systems, particularly in human experimental tumors. This study explores various analytic methods employed with the BrdUrd, delayed, single-biopsy technique used in determining the potential doubling time, T(pot), of tumors. It compares methods of analysis in three experimental systems and in 40 in situ-labeled human tumors, and proposes a method for shortening the required labeling-biopsy interval to a clinically more convenient range of 3 to 4 hours.
Animals↗
High dose rate intracavitary brachytherapy for carcinoma of the cervix: the Madison system: I. Clinical and radiobiological considerations.
The decision to use five high dose rate intracavitary (HDR-ICR) insertions at weekly intervals for invasive carcinoma of the cervix treated at the University of Wisconsin Comprehensive Cancer Center (UWCCC) was made clinically. It was based on practical considerations and on previous clinical experience worldwide which showed that between 2 and 16 insertions have been used with apparently acceptable results. Although radiobiological considerations favor a large number of small doses, such a large number of HDR-ICR insertions is not clinically practical. Our strategy was to keep the biological effects of external beam and intracavitary insertions in the same ratio as used on a large series of patients treated here with low dose rate (LDR) therapy. This means keeping the same external beam treatment scheme and finding high dose rate (HDR) doses that are biologically equivalent to the previous LDR therapy, as far as possible. External beam and HDR intracavitary dose schedules for the Madison System of treating cervical carcinoma are described in detail. Because there is more repairable damage in late-reacting normal tissues, there is a bigger loss of sparing in these tissues than in tumors when changing from LDR to HDR, so total doses should be reduced more for equal late complications than for equal tumor control. The clinical decision was made to aim at equal tumor control. The possible increase in late complications has to be avoided by reducing the doses to critical normal tissues using extremely careful anatomic positioning of the HDR sources. Critical normal tissues must be kept further away from the radiation sources so that their doses are about 20% lower than with LDR geometry. This requires an extra separation of some millimeters depending on the anatomy and geometry of the individual insertion. The strategy is that the unfavourable radiobiological effects of a few large fractions must be counteracted by better physical dose distributions with HDR-ICR than with the previous LDR insertions. These good distributions are obtainable with the short exposures at HDR.
Brachytherapy↗
High dose rate intracavitary brachytherapy for carcinoma of the cervix: the Madison system: II. Procedural and physical considerations.
The loss in therapeutic ratio accompanying a conversion from low dose-rate (LDR) to high dose-rate (HDR) intracavitary brachytherapy (ICR) requires increased attention to the precision and accuracy of dose distribution calculations and treatment delivery. While the HDR-ICR treatment unit allows better custom-tailored dose distributions compared to LDR, it also requires more attention to detail to achieve the distribution desired. Because the relative biological effectiveness of different isodose levels in a dose distribution varies with the absolute dose (as described in Part 1 of this article), the relative dose distribution used with LDR must be modified for HDR to produce the same expected biological effect. Because of the difference in the radiobiology and physical positioning, simply duplicating applications as performed with LDR misses opportunities for dose distribution improvement as well as opens possibilities for significant complications. Due to differences in positioning the applicator (e.g., retraction of the cervix low in the pelvis instead of packing the applicator high), traditional definitions of points of interest (such as point A) apply poorly with HDR-ICR, compelling new systems of dose specification. With HDR-ICR, irreparable mistakes can happen very quickly, and quality assurance for the treatment plan and calculated dwell times prove much more important than with LDR. Key features of the dose distribution and constant relationships involving doses and dwell times help screen planned treatments for mistakes. This paper details the procedural and physical consideration of the Madison system for HDR-ICR brachytherapy for carcinoma of the cervix.
Brachytherapy↗
Defining the role of radiosurgery in the management of brain metastases.
The role of stereotactic radiosurgery in the management of recurrent and newly diagnosed brain metastases was evaluated prospectively. From December 1988 to March 1991, 58 lesions in 40 patients were treated with accelerator-based stereotactic radiosurgery. All patients were followed for a minimum of 6 months or to death. The primary purpose was to determine the impact of radiosurgery on local control and its subsequent effects on quality of life. An overall tumor control rate of 82% with a complete response rate of 43% were achieved. As anticipated, the response rate for smaller tumors was substantially better than that for larger tumors (78% for lesions < 2 cm3; 50% for lesions > or = 10 cm3). Although the overall in-field progression rate was 18.5%, only 1/23 (4%) complete responders subsequently recurred. The in-field failure rate is highly comparable with recently published surgical data. Progression outside the brain was noted in two-thirds of patients. One quarter of the deaths were neurologic. The median survival for this minimally selected patient population was 6.5 months. Stereotactic radiosurgery was also associated with improved quality of life as measured by Karnofsky score, neurologic function, and steroid dependence. Long-term steroid dependence was encountered in only four patients. We conclude that stereotactic radiosurgery can be used effectively in patients with brain metastases. In this series, a high tumor response rate was achieved which was associated with improved quality of life.
Adult↗
Long term tolerance of thoracic organs to intraoperative radiotherapy.
The tolerance of mediastinal structures to intraoperative radiotherapy (IORT) was investigated in 3 separate animals trials using 49 adult foxhounds and one limited Phase I trial in 4 patients with Stage II or III non-small cell lung cancer (NSCLC). The 1- to 2-year results of these trials have been previously reported with significant toxicity found at dose levels over 20 Gy. We now report the results of five dogs reserved for long term studies and one Stage II NSCLC patient alive at 5 years. Two dogs received 20 Gy IORT and one received 30 Gy IORT to the esophagus, all three to a single 6 cm field with 9 MeV electrons. One control dog underwent surgery without irradiation. One dog received 20 Gy IORT to a single 5 cm mediastinal field with 13 MeV electrons following left pneumonectomy. At 5 years, all five dogs reserved for a long term evaluation were alive and evaluable with minimal endoscopic and radiographic abnormalities. The one patient alive at 5 years for evaluation received 25 Gy IORT to two matched 6 cm fields with 13 MeV electrons. She has stable dyspnea on exertion and there is no evidence of cancer by endoscopy. We conclude, based on these limited data, that IORT in the mediastinum may be safe at dose levels that do not exceed 20 Gy, and further careful evaluation at these lower treatment doses is warranted to determine efficacy.
Animals↗
Prostate-specific antigen as a predictor of radiotherapy response and patterns of failure in localized prostate cancer.
PURPOSE: A study of preradiation and postradiation, serial serum prostate-specific antigen (PSA) levels was performed in patients who had clinically localized prostate cancer. The prognostic value of the PSA in pretreatment evaluation and posttreatment follow-up was assessed. PATIENTS AND METHODS: Sixty-three patients who presented with clinically localized prostate cancer and who were treated with external-beam radiation therapy were followed-up for a median of 25 months. A serum PSA and physical examination were performed at 3-month intervals, and a bone scan was done yearly. An increase in PSA triggered an additional metastatic workup. Prostate rebiopsy was performed for new, palpable nodules or for a serial increase in PSA in the context of a negative metastatic workup. RESULTS: Forty-one patients remained recurrence-free and 22 recurred clinically, 15 distantly and seven locally. The PSA was the strongest, independent, pretreatment prognostic indicator (P = .019) among pretreatment PSA, stage, and grade, but lost significance when the serum prostatic acid phosphatase (PAP) status was included. The initial rate of the PSA decrease after radiation (median half-life, 2.6 months) failed to predict outcome. Recurrence-free patients reached postradiation PSA levels that were equivalent to those reported in disease-free male populations; failure of the PSA to reach such normal levels was a multivariate predictor of subsequent failure (P less than .037). All clinicopathologic documentations of failure were preceded by an increase in PSA levels during follow-up. Delayed versus early PSA increase was associated with clinically localized versus metastatic first recurrence. CONCLUSIONS: The serum PSA is an independent pretreatment and posttreatment predictor of outcome. Additionally, for a median follow-up of 25 months, delayed PSA failure is associated with clinically localized rather than metastatic recurrence, a relationship that may help in selection for local salvage therapy.
Aged↗