Dose coefficients for intakes of radionuclides via contaminated wounds.

The NCRP Wound Model, which describes the retention of selected radionuclides at the site of a contaminated wound and their uptake into the transfer compartment, has been combined with the ICRP element-specific systemic models for those radionuclides to derive dose coefficients for intakes via contaminated wounds. These coefficients can be used to generate derived regulatory guidance (i.e., the activity in a wound that would result in an effective dose of 20 or 50 mSv, or in some cases, a organ-equivalent dose of 500 mSv) and clinical decision guidance (i.e., activity levels that would indicate the need for consideration of medical intervention to remove activity from the wound site, administration of decorporation therapy or both). Data are provided for 38 radionuclides commonly encountered in various activities such as nuclear weapons, fuel fabrication or recycling, waste disposal, medicine, research, and nuclear power. These include 3H, 14C, 32P, 35S, 59Fe, 57,58,60Co, 85,89,90Sr, 99mTc, 106Ru, 125,129,131I, 134,137Cs, 192Ir, 201Tl, 210Po, 226,228Ra, 228,230,232Th, 234,235,238U, 237Np, 238,239,240,241Pu, 241Am, 242,244Cm, and 252Cf.

IGF-II promoter methylation and ovarian cancer prognosis.

PURPOSE: The insulin-like growth factor-II (IGF-II) gene has four promoters that produce distinct transcripts which vary by tissue type and developmental stage. Dysregulation of normal promoter usage has been shown to occur in cancer; DNA methylation regulates promoter use. Thus, we sought to examine if DNA methylation varies among IGF-II promoters in ovarian cancer and if methylation patterns are related to clinical features of the disease. STUDY DESIGN: Tumor tissue, clinical data, and follow-up information were collected from 215 patients diagnosed with primary epithelial ovarian cancer. DNA extracted from tumor tissues was analyzed for IGF-II promoter methylation with seven methylation specific PCR (MSP) assays: three for promoter 2 (P2) and two assays each for promoters 3 and 4 (P3 and P4). RESULTS: Methylation was found to vary among the seven assays: 19.3% in P2A, 45.6% in P2B, 50.9% in P2C, 48.4% in P3A, 13.1% in P3B, 5.1% in P4A, and 6.1% in P4B. Methylation in any of the three P2 assays was associated with high tumor grade (P = 0.043), suboptimal debulking (P = 0.036), and disease progression [hazards ratio (HR) = 1.73, 95% confidence interval (CI) 1.09-2.74]. When comparing promoter methylation patterns, differential methylation of P2 and P3 was found to be associated with disease prognosis; patients with P3 but not P2 methylation were less likely to have disease progression (HR = 0.39, 95% CI 0.17-0.91) compared to patients with P2 but not P3 methylation. CONCLUSIONS: This study shows that methylation varies among three IGF-II promoters in ovarian cancer and that this variation seems to have biologic implications as it relates to clinical features and prognosis of the disease.

Medical management of radiation injuries: current approaches.

The current approach to medical management of irradiated patients begins with early diagnosis of radiation injury. Medical assessment of radiation dose is based on event history, symptomatology and laboratory results, with emphasis on time to emesis and lymphocyte depletion kinetics. Dose assessment provides a basis for early use of haematopoietic growth factors that can shorten the period of neutropaenia for patients with acute radiation syndrome. Assessments of haematopoietic, gastrointestinal and cutaneous syndromes have improved in recent years, but treatment options remain limited. Selected examples of current developments are presented.

Neoadjuvant chemoradiation therapy in patients with surgically treated esophageal cancer.

Over the past 10 years, 232 patients were treated at the East Carolina School of Medicine for cancer of the esophagus. Of these, 73 received neoadjuvant chemoradiation therapy and subsequent surgical resection. The results in this group suggest improved cancer control, with 18 patients (25%) remaining free of recurrence 3 years after treatment, compared with 11 out of 159 patients (7%) in the group that was not treated with neoadjuvant therapy (p < 0.0001). The 5-year recurrence-free survival with neoadjuvant chemoradiotherapy and surgery was 16% (12/73) compared with 3% (5/159) with other types of therapy. Two protocols of neoadjuvant chemoradiotherapy with subsequent surgery were compared: I: Split-course, once-a-day radiotherapy and concomitant cisplatinum/5-fluorouracil followed by esophagectomy. II: Accelerated, twice-a-day radiotherapy with concomitant triple chemotherapy using cisplatinum/5-fluorouracil/vinblastine followed by transhiatal extrathoracic esophagectomy. The survival rate was similar in the two groups of patients but the complication rate was higher in group II. Neoadjuvant chemoradiation therapy and the techniques of transhiatal esophagectomy may have contributed to the improved results in the treatment of esophageal carcinoma. Accelerated radiotherapy with triple chemotherapy was more toxic and did not give better survival rates than split-course, once-a-day, conventional, fractionated-protracted radiotherapy combined with two drugs.

Micronuclei in lymphocytes of prostate cancer patients undergoing radiation therapy.

To further verify the applicability of the micronucleus (MN) assay in biodosimetry, we measured the MN yield in cytokinesis-blocked (CB) peripheral blood lymphocytes (PBL) of eight prostate cancer (PC) patients. These patients had no previous chemotherapy or radiotherapy (xRT). They were treated with standardized schemes of fractionated pelvic xRT. Before xRT, and at one random time-point during the course of xRT, blood samples were collected from each patient for the following purposes: (1) to verify the relationship between the MN yield in PBL and the estimated equivalent (EQ) total-body absorbed dose; and (2) to evaluate the individual differences of ex vivo radiation dose-response (1-4 Gy) relationship of MN yield in PBL before xRT. The number of xRT fractions, cumulative tumor dose, and EQ total-body absorbed doses of these patients represented a wide range. We found in PBL of these patients that (1) MN yield (Y) increased linearly with the estimated EQ total-body absorbed dose as Y=14.6+9.2D (R(2)=0.7, p=0.007); the distributions of MN yield were overdispersed; the ratio of relative increment of MN yield per 1000 binucleated (BN) PBL ranged from 0.9 to 8.2 (median: 4.1) folds above that of the respective baseline levels; and (2) before xRT, the MN yields also increased linearly with the ex vivo radiation dose; at each radiation dose level, the distributions of MN yield were overdispersed in most patients. In two of the three patients with xRT-induced early side effects (cystitis, diarrhea), the MN yield in PBL induced by ex vivo irradiation before xRT was significantly higher than in the other patients without xRT-induced side effects. These findings suggest that MN yields in CB PBL can be used as an in vivo biodosimeter. Since the differences in individual ex vivo radiation dose-response relationship of MN yield in PBL before xRT appeared to be significant, our preliminary results also suggest that it may be possible to identify individual intrinsic radiosensitivity before the start of xRT.

Survival of patients with squamous cell carcinoma of the supraglottic larynx--thirty-five-year experience with radiotherapy.

A retrospective comparison of treatment policies in two institutions revealed a change in the reliance on radiotherapy. Since 1978, high-energy, high-dosage radiotherapy has played a prominent role in the primary therapy of squamous cell carcinoma of the supraglottic larynx. Statistically, the overall determinate survival rate has improved compared with results during the preceding period, but the death rate from intercurrent disease and second primary cancers has remained unchanged. Improved cancer control and patient survival were restricted to clinical tumor stages III, T4N0, and T4N1. The choice of primary therapy and the radiation dose and fractionation pattern were important variables influencing the survival. A description of the data is followed by a critical analysis of the significance of the findings, in view of the fact that the treatments were performed in two different institutions at different time periods.

Effect of ex vivo hyperthermia on radiation-induced micronuclei in lymphocytes of cancer patients before and during radiotherapy.

To investigate the effect of ex vivo hyperthermia (HT) and 137Cs-irradiation on micronucleus (MN) production in cytokinesis-blocked lymphocytes, we obtained the peripheral blood samples from the same cancer patients (n=6) before and during fractionated partial-body radiotherapy (xRT). The whole blood cultures were heated at 43.5 degrees C for 60 min, followed by 137Cs irradiation (0-4 Gy). The control cultures from the same patients were incubated at 37 degreesC after being exposed to radiation. The lymphocytes were then stimulated with PHA. Cytochalasin B was applied at 44 h, and lymphocytes were harvested at 72 h. MN frequency was determined on Giemsa-stained slides. We found that in patients before xRT, HT (43.5 degrees C) significantly increased the MN yield (mean+/-SEM) in unirradiated lymphocytes from 15.6+/-2.8 (37 degrees C) to 39.7+/-10.9. Further, in patients either before or during xRT, when the lymphocytes were treated with HT (43.5 degrees C) and combined with ex vivo irradiation, the MN yield (Y) could be estimated by a linear equation Y=C+alphaD. Our findings indicate that as measured by the MN production in cytokinesis-blocked lymphocytes, HT alone at 43.5 degrees C++ induced DNA damage. Moreover, it enhanced the radiation-induced cytogenetic damage. Therefore, the application of HT may impair the T-cell function in cancer patients who are receiving radiotherapy. 1998 Elsevier Science B.V.

Recurrence after different primary treatment for cancer of the supraglottic larynx.

Retrospective analysis of patient records at two hospitals was performed with the principal goal of clarifying the role of primary radiotherapy ill patients with squamous cell carcinoma of the supraglottic larynx. Primary surgery was frequently performed during the first period from 1958 to 1978. Primary radiotherapy with surgery in reserve was the prevailing therapy during the second period from 1978 to 1993. Fewer recurrences were observed during the second period. The improved results were apparent mainly in patients with the more advanced stages (III, T4N0 and T4N1). Analysis of many factors suggest that the more frequent choice of primary radiotherapy with surgery in reserve, or applied as preoperative treatment, with optimal dosage and technique, might have contributed to the improved results.

Reliability of finger stick capillary blood for the lymphocyte micronucleus assay.

Compared with peripheral blood sampling, capillary blood collecting by finger stick is less traumatic and more convenient. To assess the sensitivity and reliability of capillary blood for the lymphocyte micronucleus (MN) assay, this study was performed in three sample groups, i.e. healthy donors (n = 3), cancer patients before treatment (n = 7), and cancer patients who were undergoing fractionated partial-body radiotherapy (n = 9). For each group, we measured three intra-individual variables, i.e. micronucleus (MN) frequency, binucleate (BN) index, and micronucleated BN index of lymphocytes obtained from capillary blood and the corresponding peripheral blood. Our results indicated that in all three sample groups, the differences in these variables between capillary blood and peripheral blood either before or after ex vivo 137Cs irradiation (2 Gy) were insignificant. Since capillary blood is more accessible than peripheral blood, we believe that it is a reliable source for the lymphocyte MN assay especially when venipuncture is not convenient.

Current techniques in three-dimensional CT simulation and radiation treatment planning.

The modern CT simulator is capable of interactive three-dimensional (3D) volumetric treatment planning; this allows radiation oncology departments to operate without conventional X-ray simulators. Treatment planning is performed at the time of virtual simulation by contouring the organs or volumes of interest and determining the isocenter. A digitally reconstructed radiograph (DRR) provides a beam's-eye-view display of the treatment field anatomy and contoured areas of interest. Conformal and noncoplanar teletherapy is facilitated for patients with prostate cancer, lung cancer, and brain tumors. Ongoing developments include 3D dose calculation, dose-volume histogram analysis, and tumor dose escalation.

Assessment of two protocols for the human lymphocyte cytokinesis-blocked micronucleus assay.

This study indicated that by adding cytochalasin B (6 micrograms/ml) at 24 h, the lymphocyte culture time for micronucleus (MN) assay could be shortened to 64 h. In both unirradiated and ex-vivo irradiated (2 Gy) lymphocytes from three populations, we found that the differences in MN yield obtained by our modified cytokinesis-blocked time frame and that recommended by Fenech and Morley (1985) were insignificant (P = 0.66-0.87). We believe that the shorter assay time may enhance the applicability of MN assay for the rapid assessment of ionizing radiation overexposures.

Preservation of cytoplasm in the human lymphocyte micronucleus assay.

A major limitation in the quantitative accuracy of the human lymphocyte micronucleus (MN) assay is preservation of the cytoplasm during the cell harvesting. In this short communication, an improved method for cytoplasm preservation in a cytokinesis-blocked, whole-blood microculture (0.3 ml) technique is described. We believe that the timing of the hypotonic treatment, speed of centrifugation, handling of the cell suspension and proper Giemsa staining are important variables in the human peripheral lymphocyte MN assay.

Radiation dose-dependent variations of micronuclei production in cytochalasin B-blocked human lymphocytes.

Using the cytokinesis-block technique, lymphocytes from healthy volunteers (n = 9) were evaluated for 1) the radiation dose-response curve for micronuclei (MN) expression; 2) technique variables on the yield of MN; and 3) the shortest lymphocyte incubation time required for the MN assay. We found that the best fitting of relationships between increasing MN production and increasing irradiation dose (0-4.0 Gy) was the linear-quadratic model as expressed by the yield equation Y = C+alpha D+beta D2 (P = 0.0003). When lymphocytes were irradiated in vitro with 2.0 Gy and harvested at various time intervals, MN increased during the entire 84 hr culture time. The radiation caused a division delay in lymphocyte as indicated by an increased frequency of mononucleated cells and a decreased number of mitotic indices. The data showed that a shortened culture time (60 hr) for the MN assay is possible and that binucleated cells with > or = 3 MN were found only in cells irradiated at > or = 2.0 Gy. These findings suggest that scoring of MN in lymphocytes may be a practical biological dosimeter for the rapid screening of accidental radiation exposure victims, especially when their clinical manifestations are not obvious.

Variations associated with disaggregation methods in DNA flow cytometry.

We investigated the variations in DNA ploidy by flow cytometry (FC) among cell suspensions acquired by different disaggregation methods from the same tumor specimens. Cell suspensions (n = 121) of 40 solid tumors were obtained by mechanical mincing (n = 33), enzymatic digestion (n = 19), in vitro fine needle aspiration (FNA) (n = 34) or scraping (n = 35) of the tumor tissues. Mechanical disaggregation gave the highest cell yield, whereas enzymatic digestion provided the best cell viability. The mean values for the G0/G1 coefficient of variation, DNA indices and percent S phase were not significantly different in cell suspensions obtained with the four methods. However, the yield of malignant cells ranged from 60.4 +/- 5.3% (SEM) (enzymatic) to 82.3 +/- 3.1% (scraping). Tissue aliquots of 32 tumors were disaggregated by three to four methods, and the combined results of DNA ploidy obtained from different cell preparations showed that 22 tumors were nondiploid, but concordance with an abnormal DNA peak was found in only 27.3% (6/22) of the DNA nondiploid tumors. Our results indicate that scraping tumor tissue appears to be the best method for DNA FC since it has the highest percentage (61.3) of DNA nondiploid clones. Also, we believe the multiple samplings may provide comprehensive information on the DNA ploidy of solid tumors.

The effect of tissue disaggregation methods on the clonogenicity of solid human tumor cells.

The effect of mechanical, enzymatic and combined disaggregations on the same tumor tissue (n = 154) to define variables related to clonogenic efficiency (CE) of human tumor clonogenic assay (HTCA) was examined. Overall, CE was highly associated with the percentage of malignant cells in the inoculative suspensions (P less than 0.001) and the total cell concentration plated (P = 0.03). However, there was no significant correlation between CE and the disaggregation method, type of tumor, cell viability, proportion of macrophages in the inoculum, or length of incubation (10 or 20 days). In addition, a higher CE was found in some nonadherent fractions when comparing the CE of the original plating suspensions to that of their nonadherent fractions. It is concluded that mechanical disaggregation is the simplest technique for obtaining the highest yield of malignant cells, which is a decisive factor for colony growth, and that an incubation time of 10 days and 1 x 10(6) cells per plate is the best condition for the human tumor clonogenic assay.

Intraarterial iododeoxyuridine infusion combined with irradiation. A pilot study.

The halogenated pyrimidine, iododeoxyuridine (IUdR), enhances cytotoxicity of ionizing irradiation experimentally. Continuous intraarterial infusion of IUdR was combined with irradiation to maximize drug concentration in tumor and reduce potential systemic toxicity. Percutaneous tumor-specific artery catheterization was utilized in five patients, with delivery of IUdR (20 mg/kg/day) by continuous infusion 5 days prior to irradiation treatments and continued for 10-14 days. Infusion vessels included the internal mammary, the internal iliac, the renal, the common femoral, and the bronchial arteries. Conventional radiotherapy fields, fractionation, and total doses were utilized, and therapy was well tolerated. Low-grade leukopenia and thrombocytopenia was observed several weeks following infusion. A clinically nonsignificant skin reaction was observed within the irradiation fields 2-3 weeks after initiation of irradiation in several patients. No alopecia or stomatitis was observed. This study minimizes initial hepatic dehalogenation of IUdR when given by intraarterial administration. Two patients have been free of disease for over 20 years, with no long-term toxicity from IUdR therapy.

Primary irradiation, surgery or combined therapy in squamous cell carcinoma of the larynx. A comparison of treatment results from two centers.

We compared two groups of patients with squamous cell carcinoma of the larynx. Group 1 consisted of 483 patients treated from 1958 through 1978. Primary surgery was selected in 41% pre- or postoperative radiation therapy in 16% and primary radiation therapy in 43%. Group 2 consisted of 247 patients treated from 1978 through 1983. Primary surgery was selected in only 1.6%, pre- or postoperative radiation therapy in 23%, and primary radiation therapy, with surgery in reserve for residual or recurrent carcinoma, in 76%. Although the results were comparable for patients with early stage tumors in the two groups, significantly higher local-regional tumor control rates and corrected survival rates were recorded for patients with advanced tumors in group 2. More patients survived with a cancer-free functional larynx, the surgical salvage rates were higher, the complication rates and the death rates lower in group 2 compared to group 1.

Combined hepatic artery 5-fluorouracil and irradiation of liver metastases. A randomized study.

The effect of hepatic irradiation (RT) after intraarterial 5-fluorouracil (5-FU) was evaluated in 37 randomized patients with colorectal adenocarcinoma hepatic metastases. Patients underwent percutaneous transbrachial artery catheterization of the hepatic artery followed by 21-day continuous 5-FU infusion (CT). Hepatic irradiation of 25.5 Gy was delivered to 19 patients 14 days after completion of infusion (CT + RT). All patients received subsequent weekly maintenance 5-FU. A 37% (seven of 19) response rate was observed in CT + RT, and a 50% response rate (nine of 18) in CT: median survival was 6 months for CT + RT, and 8 months for CT, (P = 0.106). Improved survival was observed in two subsets of patients. Tumor vascularity was graded angiographically from 0 to 4+; those patients with highest vascularity (4+) had a 20-month median survival (P = 0.0009). Patients with Grade 1, well-differentiated, histologic type had a median survival of 20 months (P = 0.0001). Four patients with both 4+ vascularity and Grade 1 histologic type had 27.5 months' median survival (P = 0.0019). Age, performance status, elevated liver function tests, previous systemic therapy, and time interval between diagnosis and entry on this study did not impact on survival (P greater than 0.05), nor did these variables eliminate the significance of vascularity and grade (P less than 0.05). Survival after intraarterial 5-FU infusion was not improved by this regimen of sequential external irradiation. Regional therapy may benefit those patients with 4+ vascular tumors and/or well-differentiated tumor grade. Future trials are needed to explore the interaction of halogenated pyrimidines with irradiation and determine whether these prognostic factors can aid in patient selection for regional therapy of hepatic metastases.