Effect of divalent versus monovalent cations on the MS2 retention capacity of amino-functionalized ceramic filters

Ceramic capillary membranes conditioned for virus filtration via functionalization with n-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA) are analyzed with respect to their virus retention capacity when using feed solutions based on monovalent and divalent salts (NaCl, MgCl2). The log reduction value (LRV) by operating in dead-end mode using the model bacteriophage MS2 with a diameter of 25 nm and an IEP of 3.9 is as high as 9.6 when using feeds containing MgCl2. In contrast, a lesser LRV of 6.4 is observed for feed solutions based on NaCl. The TPDA functionalized surface is simulated at the atomistic scale using explicit-solvent molecular dynamics in the presence of either Na+ or Mg2+ ions. Computational prediction of the binding free energy reveals that the Mg2+ ions remain preferentially adsorbed at the surface, whereas Na+ ions form a weakly bound dissolved ionic layer. The charge shielding between surface and amino groups by the adsorbed Mg2+ ions leads to an upright orientation of the TPDA molecules as opposed to a more tilted orientation in the presence of Na+ ions. The resulting better accessibility of the TPDA molecules is very likely responsible for the enhanced virus retention capacity using a feed solution with Mg2+ ions.

Global sensitivity analysis of an in-sewer process model for the study of sulfide-induced corrosion of concrete

The presence of high concentrations of hydrogen sulfide in the sewer system can result in corrosion of the concrete sewer pipes. The formation and fate of hydrogen sulfide in the sewer system is governed by a complex system of biological, chemical and physical processes. Therefore, mechanistic models have been developed to describe the underlying processes. In this work, global sensitivity analysis was applied to an in-sewer process model (aqua3S) to determine the most important model input factors with regard to sulfide formation in rising mains and the concrete corrosion rate downstream of a rising main. The results of the sensitivity analysis revealed the most influential model parameters, but also the importance of the characteristics of the organic matter, the alkalinity of the concrete and the movement of the sewer gas phase.

An adaptive framework to differentiate receiving water quality impacts on a multi-scale level

The paradigm shift in recent years towards sustainable and coherent water resources management on a river basin scale has changed the subject of investigations to a multi-scale problem representing a great challenge for all actors participating in the management process. In this regard, planning engineers often face an inherent conflict to provide reliable decision support for complex questions with a minimum of effort. This trend inevitably increases the risk to base decisions upon uncertain and unverified conclusions. This paper proposes an adaptive framework for integral planning that combines several concepts (flow balancing, water quality monitoring, process modelling, multi-objective assessment) to systematically evaluate management strategies for water quality improvement. As key element, an S/P matrix is introduced to structure the differentiation of relevant 'pressures' in affected regions, i.e. 'spatial units', which helps in handling complexity. The framework is applied to a small, but typical, catchment in Flanders, Belgium. The application to the real-life case shows: (1) the proposed approach is adaptive, covers problems of different spatial and temporal scale, efficiently reduces complexity and finally leads to a transparent solution; and (2) water quality and emission-based performance evaluation must be done jointly as an emission-based performance improvement does not necessarily lead to an improved water quality status, and an assessment solely focusing on water quality criteria may mask non-compliance with emission-based standards. Recommendations derived from the theoretical analysis have been put into practice.

Final results of a phase I study of TH-302, a hypoxia-activated cytotoxic prodrug (HAP)

2573

Background: TH-302 is a 2-nitroimidazole prodrug of the DNA alkylator, bromo-isophosphoramide mustard (Br-IPM). TH-302 is essentially inactive under normoxia but in severe hypoxia and in the presence of certain reductases, it is reduced and Br-IPM is released. Methods: Eligible patients (pts) had ECOG ≤1, advanced or metastatic solid tumors, evaluable by RECIST, and acceptable hematologic, liver and renal function. A modified accelerated titration design was used. TH-302 was administered intravenously over 30–60 minutes on Day 1, 8 and 15 of a 28-day cycle. CT scans were obtained after every 2 cycles. Detailed pharmacokinetic sampling was performed on Days 1 and 15. The primary objectives of this study were to determine the dose limiting toxicity (DLT) and the maximum tolerated dose (MTD). Results: Twenty-nine pts enrolled at 3 sites at 9 dose levels from 7.5–670 mg/m2. Median age: 64y. 20 male/9 female. ECOG 0/1: 16/13. Primary tumor: prostate (8), colorectal (8), lung (5) other (8). Two of 5 pts at 670 mg/m2 had DLT: Herpes simplex perianal/rectal ulcers and dehydration due to mucositis. Reversible skin and mucosal adverse events (AE) occurred in 12 of 15 (80%) pts at ≥480 mg/m2 including grade 3 events in 3 pts. The most common TH-302-related AEs were nausea, skin lesions, vomiting and fatigue. Hematologic toxicity was mild and limited: two pts with grade 1 and one pt with grade 2 neutropenia and five pts with grade 1 thrombocytopenia. Five pts had grade 3 and one grade 4 lymphopenia. Four pts have enrolled at an intermediate dose of 575 mg/m2 with no DLT so this is likely the MTD and is well above the predicted biologic effective dose of 100 mg/m2. One pt with SCLC treated at 480 mg/m2 and one with melanoma treated at 670 mg/m2 had unconfirmed partial responses; 12 pts had stable disease (6 continuing after 4 or more cycles), 7 had PD, 4 were unevaluable and 4 are too early to assess. Cmax and AUC for TH-302 and Br-IPM increased linearly with no accumulation at Day 15. Conclusions: Weekly TH-302 has remarkably little hematologic toxicity. Skin and mucosal AEs have developed at the higher dose levels. Skin/mucosa are known to have hypoxic regions. TH-302 is the first HAP to demonstrate tumor responses in Phase I. The MTD is likely 575 mg/m2. Studies in combination with chemotherapy are ongoing.

[Table: see text]

Responses to the combination of the glycolytic inhibitor 2-deoxy-glucose (2DG) and docetaxel (DC) in patients with lung and head and neck (H/N) carcinomas

14025

Background: We demonstrated in mouse xenografts that the combination of docetaxel chemotherapy with 2DG is feasible and increases responses against tumors (CancerRes; 2004 64:31–4). Methods: To determine the maximum tolerated dose (MTD) of daily oral doses of 2DG given alone and in combination with weekly docetaxel (DC) in patients (pts) with advanced malignancies who had relapsed after chemotherapy, and to evaluate the pharmacokinetics (PK) of 2DG alone and in combination with weekly DC. 2DG was initially administered orally once daily for 7 days every other week starting at a dose of 2 mg/kg, and DC was administered at 30mg/m2 for 3 of every 4 weeks. A modified accelerated titration design was used. Following completion of the every other week (EOW) 2DG dosing regimen, 3 weeks on and 1 week off (3–1W) dosing; and then continuous (CW) 2DG dosing were investigated. Results: 21 pts were enrolled in the EOW dosing at 2DG doses up to 88 mg/kg/day; another 10 pts were enrolled in the other dosing regimens. 5 pts had lung cancer (4 NSCLC + 1 SCLC); and another 6 pts had H/N cancers. One pt discontinued for DC-related sensory neuropathy. Single cases of DLT occurred - asymptomatic (64mg/kg) and symptomatic (88 mg/kg) Grade 3 hyperglycemia. The MTD was not reached with the EOW regimen. 2DG is rapidly absorbed (Tmax 0.5–1h) with a half-life of 5–10h. 2DG exhibits linear PK following single and multiple doses with minimal accumulation after multiple doses at 63 and 88 mg/kg. 2DG PK and DC PK do not alter each other. One of 18 evaluable pts in the EOW dosing with breast cancer had a partial response (PR). Another 8 pts achieved disease stabilization (SD) among them: 2 of 4 pts with NSCLC, 2 of 6 pts with H/N cancers, 1 pt with thyroid cancer, and 1 of 3 pts with adenoidcystic carcinoma. The others were unknown primary and a breast lymphoma. Also the MTD was not reached at 63mg/kg (3–1W) dosing where one patient with H/N cancer achieved stabilization of his disease. Enrollment of pts in the CW regimen is ongoing now. Conclusions: The combination of 2DG and DC appears to be feasible and safe with no evidence of PK interactions. Evidence of anti-tumor activity was observed in patients with NSCLC and H/N cancers.

No significant financial relationships to disclose.

Glufosfamide (GLU) plus gemcitabine (GEM) in pancreatic adenocarcinoma: Preliminary results of a phase 2 trial

15005

Background: Glufosfamide is glucose linked to isophosphoramide mustard, the active metabolite of ifosfamide. Cancer cells use glucose at a higher rate than normal cells, which may lead to preferential metabolic targeting by GLU. The Phase 1 study established a GLU dose of 4500 mg/m2 for the GLU + GEM regimen. The objectives of the Phase 2 part of this study are to evaluate the safety and efficacy of GLU+GEM in pts with pancreatic adenocarcinoma. Methods: Eligible pts had metastatic and/or locally advanced pancreatic adenocarcinoma previously untreated with chemotherapy, Karnofsky Performance Status =70, creatinine clearance (CrCL) =60 mL/min and acceptable hematologic and liver function. Pts received GLU 4500 mg/m2 iv over 4 hours on Day 1 and GEM 1000 mg/m2 iv over 30 minutes on Days 1, 8 and 15 of every 28-day cycle. CT scans were obtained every 8 weeks. Primary endpoint was response rate. Results: Twenty-nine pts were enrolled. One patient with ineligible histology was excluded from efficacy analyses. The 14 male/15 female pts had a median age of 59 years. Median cycles on treatment was 4 (range 1–10+) and 9 pts completed all 6 cycles. Six of 28 (21%; 95% CI: 8- 41%) pts had a partial response (duration 1.0+ to 5.8+ months), one unconfirmed. Ten of 28 (36%) pts had stable disease (median duration 5.3 months). Median progression-free survival was 3.7 months. Six-month survival was 54% (95% CI: 38–78%). Grade 3/4 neutropenia and thrombocytopenia occurred in 21/29 (72%) and 8/29 (28%) pts. Five pts (18%) had a GLU-related serious adverse event (SAE). Two pts died due to SAE unrelated to GLU. Three pts developed renal failure; two were GLU-related with evidence of renal tubular acidosis (RTA). One pt developed GLU-related SAE of RTA without renal failure. The CrCL fell below 60 mL/min in 7 of 27 (26%) pts with CrCL =60 at baseline. Conclusions: Preliminary data indicate that GLU + GEM may benefit pts with chemotherapy naïve pancreatic adenocarcinoma.

[Table: see text]

Glufosfamide (GLU) plus gemcitabine (GEM) in advanced solid tumors: Phase 1 results

14022

Background: Glufosfamide is glucose linked to isophosphoramide mustard, the active metabolite of ifosfamide. Cancer cells use glucose at a higher rate than normal cells, which may lead to preferential metabolic targeting by GLU. GLU has shown activity in patients (pts) with pancreatic cancer in Phase 1/2 studies with the dose-limiting toxicities (DLT) being nephrotoxicity and neutropenia. The MTD was 4500 mg/m2. In preclinical studies, GLU has shown additive activity when combined with GEM. The objectives of this study are to establish the maximum tolerated dose (MTD) and to evaluate the safety, efficacy and PK of GLU + GEM in advanced solid tumors. Methods: Eligible pts had Karnofsky Performance Status ≥70, no prior GEM, at least one lesion by RECIST, creatinine clearance (CrCL) ≥60 mL/min and acceptable hematologic and liver function. Cohorts of 3–6 patients were treated with GLU 1500–4500 mg/m2 IV over 4 hours on Day 1 and GEM 1000 mg/m2 IV over 30 minutes on Days 1, 8 and 15 of every 28-day cycle for up to 6 cycles. CT scans were obtained every 8 weeks. Detailed PK sampling was performed. Results: Nineteen pts with pancreatic (8), gall bladder (4) and other (7) cancers were enrolled. Two DLTs have occurred: Grade 3 fatigue at 2500 mg/m2 and Grade 4 thrombocytopenia at 4500 mg/m2. Both cohorts were expanded. No DLTs occurred in the 1500 or 3500 mg/m2 cohorts. Three pts completed all 6 cycles and 3 pts continue on study. Reasons for early discontinuation were progressive disease (10), clinical deterioration (1), AE (1) and death (1). Grade 3/4 neutropenia occurred in 7 pts (5 during Cycle 1) and Grade 3/4 thrombocytopenia in 5 pts (2 during Cycle 1). The CrCL fell below 60 mL/min in one patient. No objective tumor responses have been reported; 10 of 18 (56%) evaluable pts had stable disease (SD) at 8 weeks, including 1 pt with heavily pretreated ovarian cancer with ongoing SD after 8 months on therapy. PK analyses suggest no interaction between GLU and GEM. Conclusions: Phase 1 data indicate that full dose GLU (4500 mg/m2) can be given safely in combination with GEM. Both early and delayed Grade 3/4 thrombocytopenia and neutropenia have been observed. A Phase 2 cohort of 28 pts with pancreatic adenocarcinoma is currently enrolling. Studies with GEM/GLU in other tumor types are planned.

[Table: see text]

Monitoring of hematological, inflammatory and oxidative reactions to acute oral iron exposure in human volunteers: preliminary screening for selection of potentially-responsive biomarkers

BACKGROUND

Iron is an essential micronutrient but also a major catalyst of oxidative and inflammatory reactions.

OBJECTIVE

To evaluate the potential utility of selected biomarkers in blood or urine to indicate in vivo oxidative or inflammatory response to oral iron intake at pharmacological doses.

METHODS

Three healthy volunteers provided morning, fasting samples of blood and urine on up to 13 study days--3 before, 7 during and 3 following a 7-consecutive-day period of receiving 120 mg of iron per day as ferrous sulfate in commercially available syrup. A series of 23 biomarkers were measured on each collection of biological fluids to monitor iron-responsive changes in biomarkers related to hematological or iron status, inflammation and in vivo oxidation.

RESULTS

Among the inflammatory biomarkers measured, white blood cells, serum CRP and urinary neopterin showed no response to iron dosing. Only circulating interleukin-4 (IL-4) and TNF-alpha had abnormal responses with a time association to the oral iron intake. Among the oxidative biomarkers, expression of blood superoxide dismutase (SOD), hemoxygenase-1, catalase as well as circulating thiobarbituric acid reactive substances (TBARS), total oxidative capacity and carbonyl proteins were stable in response to iron exposure. Only urinary TBARS, 8-hydroxy-2-desoxyguanosine and isoprostanes evidenced consistent or suggestive responses to ingestion of the iron challenge. Serum hepcidin concentration increased dramatically in all three subjects after only the first 120 mg dose of iron, and remained elevated even 9 days after cessation of the iron intervention.

CONCLUSIONS

Most of the candidate biomarkers show very limited promise as response-indicators to oral iron dosing at the 120 mg dosages or lower, but circulating IL-4, TNF-alpha as well as urinary TBARS, 8-hydroxy-2-desoxyguanosine and isoprostanes showed potential utility as reliable indicators of oxidative and inflammatory response to oral ferrous sulfate.

Tositumomab and Iodine I 131 Tositumomab for Recurrent Indolent and Transformed B-Cell Non-Hodgkin’s Lymphoma

Purpose

An open-label phase II study was conducted at two centers to establish the efficacy and safety of tositumomab and iodine I 131 tositumomab at first or second recurrence of indolent or transformed indolent B-cell lymphoma.

Patients and Methods

A single dosimetric dose was followed at 7 to 14 days by the patient-specific administered radioactivity required to deliver a total body dose of 0.75 Gy (reduced to 0.65 Gy for patients with platelets counts of 100 to 149 × 109/L). Forty of 41 patients received both infusions.

Results

Thirty-one of 41 patients (76%) responded, with 20 patients (49%) achieving either a complete (CR) or unconfirmed complete remission [CR(u)] and 11 patients (27%) achieving a partial remission. Response rates were similar in both indolent (76%) and transformed disease (71%). The overall median duration of remission was 1.3 years. The median duration of remission has not yet been reached for those patients who achieved a CR or CR(u). Eleven patients continue in CR or CR(u) between 2.6+ and 5.2+ years after therapy. Therapy was well tolerated; hematologic toxicity was the principal adverse event. Grade 3 or 4 anemia, neutropenia, and thrombocytopenia were observed in 5%, 45%, and 32% of patients, respectively. Secondary myelodysplasia has occurred in one patient. Four patients developed human antimouse antibodies after therapy. Five of 38 assessable patients have developed an elevated thyroid-stimulating hormone; treatment with thyroxine has been initiated in one patient.

Conclusion

High overall and CR rates were observed after a single dose of tositumomab and iodine I 131 tositumomab in this patient group. Toxicity was modest and easily managed.

Pivotal study of iodine I 131 tositumomab for chemotherapy-refractory low-grade or transformed low-grade B-cell non-Hodgkin's lymphomas

PURPOSE

To evaluate the efficacy and safety of tositumomab and iodine I 131 tositumomab (Bexxar; Corixa Corp, Seattle, WA, and GlaxoSmithKline, Philadelphia, PA) in patients with chemotherapy-refractory low-grade or transformed low-grade non-Hodgkin's lymphoma (NHL) and to compare its efficacy to the patients' last qualifying chemotherapy (LQC) regimens.

PATIENTS AND METHODS

Sixty patients who had been treated with at least two protocol-specified qualifying chemotherapy regimens and had not responded or progressed within 6 months after their LQC were treated with a single course of iodine I 131 tositumomab.

RESULTS

Patients had received a median of four prior chemotherapy regimens. A partial or complete response (CR) was observed in 39 patients (65%) after iodine I 131 tositumomab, compared with 17 patients (28%) after their LQC (P <.001). The median duration of response (MDR) was 6.5 months after iodine I 131 tositumomab, compared with 3.4 months after the LQC (P <.001). Two patients (3%) had a CR after their LQC, compared with 12 (20%) after iodine I 131 tositumomab (P <.001). The MDR for CR was 6.1 months after the LQC and had not been reached with follow-up of more than 47 months after iodine I 131 tositumomab. An independent review panel verified that 32 (74%) of the 43 patients with nonequivalent durations of response (> 30 days difference) had a longer duration of response after iodine I 131 tositumomab (P <.001). Only one patient was hospitalized for neutropenic fever. Five patients (8%) developed human antimurine antibodies, and one (2%) developed an elevated TSH level after treatment. Myelodysplasia was diagnosed in four patients in follow-up.

CONCLUSION

A single course of iodine I 131 tositumomab was significantly more efficacious than the LQC received by extensively pretreated patients with chemotherapy-refractory, low-grade, or transformed low-grade NHL and had an acceptable safety profile.

Health care, information needs, and outreach: reaching Ohio's rural citizens

As a rural state, Ohio has a vital interest in addressing rural health and information needs. NetWellness is a Web-based consumer health information service that focuses on the needs of the residents of Ohio. Health sciences faculty from the state's three Carnegie Research I universities--University of Cincinnati, Case Western Reserve University, and The Ohio State University--create and evaluate content and provide Ask an Expert service to all visitors. Through partnerships at the state and local levels, involving public, private, commercial, and noncommercial organizations, NetWellness has grown from a regional demonstration project in 1995 to a key statewide service. Collaboration with public libraries, complemented by alliances with kindergarten through twelfth grade agencies, makes NetWellness Ohio's essential health information resource.

Radioimmunotherapy with iodine (131)I tositumomab for relapsed or refractory B-cell non-Hodgkin lymphoma: updated results and long-term follow-up of the University of Michigan experience

CD20-targeted radioimmunotherapy is a promising new treatment for B-cell non-Hodgkin lymphoma (NHL). We now provide updated and long-term data on 59 chemotherapy-relapsed/refractory patients treated with iodine (131)I tositumomab in a phase I/II single-center study. Fifty-three patients received individualized therapeutic doses, delivering a specified total-body radiation dose (TBD) based on the clearance rate of a preceding dosimetric dose. Six patients received dosimetric doses only. Dose-escalations of TBD were conducted separately in patients who had or had not undergone a prior autologous stem cell transplant (ASCT) until a nonmyeloablative maximally tolerated TBD was established (non-ASCT = 75 cGy, post-ASCT = 45 cGy). Fourteen additional non-ASCT patients were treated with 75 cGy. Unlabeled antibody was given prior to labeled dosimetric and therapeutic doses to improve biodistribution. Forty-two (71%) of 59 patients responded; 20 (34%) had complete responses (CR). Thirty-five (83%) of 42 with low-grade or transformed NHL responded versus 7 (41%) of 17 with de novo intermediate-grade NHL (P =.005). For all 42 responders, the median progression-free survival was 12 months, 20.3 for those with CR. Seven patients remain in CR 3 to 5.7 years. Sixteen patients were re-treated after progression; 9 responded and 5 had a CR. Reversible hematologic toxicity was dose limiting. Only 10 patients (17%) had human anti-mouse antibodies detected. Long-term, 5 patients developed elevated thyroid-stimulating hormone levels, 5 were diagnosed with myelodysplasia and 3 with solid tumors. A single, well-tolerated treatment with iodine (131)I tositumomab can, therefore, produce frequent and durable responses in NHL, especially low-grade or transformed NHL. (Blood. 2000;96:1259-1266)

Pasteurella multocida meningitis in infancy - (a lick may be as bad as a bite)

Pasteurella multocida is the commonest cause of local infection after an animal bite, but is an unusual cause of meningitis. We report a case of P. multocida meningitis occurring in a 7-week-old infant which was contracted after non-traumatic contact with a household pet, that is, without any animal bite or scratch. The organism may be easily confused with more common Gram-negative pathogens. In this case, it was initially incorrectly diagnosed as Haemophilus influenzae type b (Hib); a possibility which has important implications in the era of routine use of Hib vaccine in infant immunisation programs.

CONCLUSION

Pasteurella multocida is an unusual, but serious cause of meningitis in infancy. It is potentially preventable by the avoidance of contact between young infants and the saliva of household pets, in particular by assiduous hand hygiene.

Randomized trial of radiation for age-related macular degeneration

PURPOSE

To assess external beam radiation efficacy for subfoveal neovascularization associated with age-related macular degeneration.

METHODS

All patients were evaluated in the same institution. In this prospective trial, 27 eyes (27 patients) with subfoveal neovascularization associated with age-related macular degeneration were randomized to either single fraction radiation (750 centigray) or observation. Endpoints were assessed by fluorescein angiography and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity. Examiners were masked to patient treatment status. Parametric and nonparametric statistical analyses were performed.

RESULTS

Twenty-seven patients were entered into the trial with a mean age of 76 years (range, 64 to 89) and a mean follow-up of 17 months (range, 7 to 32). The visual acuity loss was slightly less in the irradiated group, a finding of borderline significance (P < .046). There was no significant difference in fluorescein angiographic evidence of subretinal neovascular membrane change in the control group vs the irradiated group.

CONCLUSIONS

External beam radiation, at this dose and fractionation, did not appear harmful. There was slightly less visual loss in irradiated eyes. No difference in fluorescein angiographic characteristics of subfoveal neovascularization size or progression in eyes with age-related macular degeneration was noted.

A comparison of cause-specific melanoma mortality and all-cause mortality in survival analyses after radiation treatment for uveal melanoma

OBJECTIVE

To determine the causes and patterns of mortality after uveal melanoma radiation.

DESIGN

A cohort study from a single institution was performed. Mortality was modeled using semiparametric survival techniques. All cause and cause-specific mortality analyses were performed. Mortality was compared with expected mortality from the U.S. census data.

PARTICIPANTS

A total of 731 patients were studied, and 710 (97%) of these had medium or large melanomas. The mean tumor diameter was 11.3 mm, and the mean tumor thickness was 5.8 mm. Ciliary body was involved in 122 (17%) of patients. Complete follow-up was available on 99.6% (728 of 731) of patients.

MAIN OUTCOME MEASURES

The authors analyzed the distribution and causes of post-treatment mortality.

RESULTS

The 5- and 10-year all-cause Kaplan-Meier survival rates were 75.6% and 62.3%, respectively. Both melanoma risk factors (older age, ciliary body involvement, and larger tumor diameter) and nonmelanoma risk factors (older age and medical condition) were significant prognostic factors of all-cause mortality. Deaths from nonmelanoma causes accounted for 91 (42.3%) of 215 deaths. The 5-year and 10-year estimates of nonmelanoma deaths were 8.3% and 15.9%, respectively. Nonmelanoma mortality was similar to that observed in the general U.S. population (91 observed, 98.1 expected). Melanoma metastases accounted for 124 (57.7%) of 215 deaths. The 5- and 10-year estimates for probability of metastatic death were 16.1% and 21.8%, respectively. The largest tumor diameter was the best predictor for melanoma mortality; ciliary body involvement, older age, and distance from the fovea also were significant in multivariate analyses.

CONCLUSION

A significant proportion of patients with uveal melanoma die of nonmelanoma causes after radiation. In analyzing prognostic factors, considerable information may be lost if analyses are based on all-cause mortality rather than cause-specific mortality.

Patient-specific whole-body dosimetry: principles and a simplified method for clinical implementation

The purpose of this article is to describe the methods used to determine the precise, patient-specific dose (in mCi) of 131I anti-B1 antibody needed to deliver a specified whole-body radiation dose (generally 75 cGy) to patients being treated for non-Hodgkin's lymphoma.

METHODS

The general principles, as well as simplified methods for dosimetry calculation, are described, and a "worked" example is provided. The approach described involves administration of a tracer dose that is used to determine the patient-specific whole-body residence time. The total-body radiation dose per unit of cumulated activity is calculated using an ellipsoid model of the human body, with an assumption of uniform distribution of radioactivity. Together, they determine the appropriate patient-specific therapeutic dose of radiolabeled antibody needed to deliver a specified total-body dose of radiation.

RESULTS

Because a monoexponential whole-body effective half-time adequately describes the total-body kinetics, the patient's whole-body residence time is estimated from three whole-body radioactivity observations obtained over 6-7 days. Whole-body counts can be collected using either a thyroid probe system or a whole-body gamma camera. The residence time, in conjunction with the patient's weight, determines the desired therapeutic activity. Dose attenuations are instituted for obesity and reduced blood platelet counts.

CONCLUSION

Methods for determining total-body dose of radiation, including a simplified dosimetric method based on just three data points, are described. Tables and graphs to allow such calculations are presented for radioimmunotherapy with 131I anti-B1 antibody, although they are likely to be useful in other forms of radiopharmaceutical therapy as well.

Iodine-131 anti-B1 antibody for B-cell lymphoma: an update on the Michigan Phase I experience

Iodine-131 anti-B1 antibody radioimmunotherapy for B-cell lymphoma was previously reported to have substantial antitumor activity in B-cell non-Hodgkin's lymphoma (NHL) after failures of standard and salvage chemotherapy. In this article, the University of Michigan Phase I clinical experience is updated, with follow-up of up to 6 yr since initial treatment reported.

METHODS

Thirty-four patients with CD20-expressing NHL were first studied with one or more dosimetric doses of approximately 5 mCi of 1311 anti-B1 antibody (after varying predoses of unlabeled anti-B1 antibody). They were then treated with a patient-specific radioimmunotherapeutic dose designed to deliver a specified radiation dose to the whole body of between 25 and 85 cGy. Patients were observed for toxicity and tumor response.

RESULTS

Seventeen (50%) patients had low-grade NHL, 9 (26%) had low-grade transformed NHL and 8 (24%) had de novo intermediate-grade NHL. At study entry, 17 (50%) had an elevated lactate dehydrogenase level, 12 (35%) had high tumor burden and 18 (53%) had not responded to their last chemotherapy. The median number of prior NHL therapies was 4.1. Twenty-eight of 34 patients completed treatment, with 22 of 28 (79%) achieving a response and 14 of 28 (50%) achieving a complete response (CR). The median duration of response was 357 days. The median duration of response for CRs was 471 days, with 4 CRs having a duration of > 1000 days (maximum = > 1460 days). Bone marrow toxicity was dose-limiting and dependent on the total-body dose (TBD) of radiation. Thrombocytopenia appeared to be more marked in patients with prior bone marrow transplantation. The TBD of 75 cGy was established as the maximum tolerated dose in patients who had not had prior bone marrow transplantation. Duration of CR was significantly longer (p < 0.04) in patients who received a TBD of 65-75 cGy (1109 days) than it was in those who received a lower TBD of 25-60 cGy (385 days). Four of 34 (12%) patients developed detectable human antimouse antibody levels. The median survival from study entry for all patients was 1508 days (range = 63 to >2226 days). Sixteen of 17 patients who achieved a response of > or = 6 mo duration remain alive.

CONCLUSION

This update of the Phase I results after 1311 anti-B1 antibody treatment for NHL indicates that CRs can be durable and that survival can be of long duration. This form of therapy for NHL should have increasing application in clinical practice after confirmation of these results in larger multicenter studies.

Candidates for prostate radioactive seed implantation treated by external beam radiotherapy

PURPOSE

We report the prostate-specific antigen-based freedom from biochemical failure after conventional and three-dimensional conformal external beam radiotherapy for patients who would have been candidates for 125I implantation monotherapy.

MATERIALS AND METHODS

Patients included in the study were required to have prostate-specific antigen values < or = 20, T stage < or = 2b, and Gleason score sum of 2 to 6. All patients underwent external beam irradiation with curative intent and a minimum follow-up from completion of treatment of at least 1 year. In addition, all patients had to have pretreatment and follow-up prostate-specific antigen measurements and no history of hormonal manipulation, orchiectomy, or radical prostatectomy. A total of 187 patients meeting these criteria were treated between March 1988 and June 1995, and they form the study group for this analysis. Freedom from biochemical failure was defined as prostate-specific antigen value that failed to be maintained at 1 ng/mL or less or an increase in prostate-specific antigen value of 0.5 ng/mL or more in 1 year even if prostate-specific antigen value was less than 1 ng/mL.

RESULTS

Among the 187 patients, the median pretreatment prostate-specific antigen value was 7.4 ng/mL (0.3-19.9 ng/mL). The median follow-up was 34 months. Twenty-three percent of patients had a Gleason score sum of 2 to 4, and 77% had a Gleason score sum of 5 to 6. Clinical stages were T1 in 33% and T2 in 67%. One hundred twenty-five patients were treated by conventional external beam radiotherapy with a median dose of 69.5 Gy (60-71 Gy), and 62 patients were treated by three-dimensional conformal external beam radiotherapy with a median dose of 76.4 Gy (71.6-87 Gy). The overall freedom from biochemical failure was 75% at 4 years. Rates of freedom from biochemical failure by pretreatment prostate-specific antigen levels were 91% for prostate-specific antigen value < or = 4 ng/mL, 65% for prostate-specific antigen value > 4 but < or = 10 ng/mL, and 30% for prostate-specific antigen value > 10 ng/mL. Pretreatment prostate-specific antigen value was a statistically significant prognosticator, with lower values associated with favorable freedom from biochemical failure outcome in univariate and multivariate analyses. Conventional versus three-dimensional treatment, T1 versus T2 stage, and Gleason score sum 2 to 4 versus 5 to 6 did not show statistically significant difference in freedom from biochemical failure.

CONCLUSIONS

Although our overall results after external beam radiotherapy for early-stage prostate cancer patients are less favorable than the best results published for 125I implantation monotherapy, our results are comparable to those in most other studies with implantation monotherapy. This most likely results from selection bias as well as our stricter definition of freedom from biochemical failure. In addition, for our subset of patients, there was no statistically significant improvement in the 4-year freedom from biochemical failure with the use of higher doses.

Anterior segment sparing to reduce charged particle radiotherapy complications in uveal melanoma

PURPOSE

The purpose of this investigation is to delineate the risk factors in the development of neovascular glaucoma (NVG) after helium-ion irradiation of uveal melanoma patients and to propose treatment technique that may reduce this risk.

METHODS AND MATERIALS

347 uveal melanoma patients were treated with helium-ions using a single-port treatment technique. Using univariate and multivariate statistics, the NVG complication rate was analyzed according to the percent of anterior chamber in the radiation field, tumor size, tumor location, sex, age, dose, and other risk factors. Several University of California San Francisco-Lawrence Berkeley National Laboratory (LBNL) patients in each size category (medium, large, and extralarge) were retrospectively replanned using two ports instead of a single port. By using appropriate polar and azimuthal gaze angles or by treating patients with two ports, the maximum dose to the anterior segment of the eye can often be reduced. Although a larger volume of anterior chamber may receive a lower dose by using two ports than a single port treatment. We hypothesize that this could reduce the level of complications that result from the irradiation of the anterior chamber of the eye. Dose-volume histograms were calculated for the lens, and compared for the single and two-port techniques.

RESULTS

NVG developed in 121 (35%) patients. The risk of NVG peaked between 1 and 2.5 years posttreatment. By univariate and multivariate analysis, the percent of lens in the field was strongly correlated with the development of NVG. Other contributing factors were tumor height, history of diabetes, and vitreous hemorrhage. Dose-volume histogram analysis of single-port vs. two-port techniques demonstrate that for some patients in the medium and large category tumor groups, a significant decrease in dose to the structures in the anterior segment of the eye could have been achieved with the use of two ports.

CONCLUSION

The development of NVG after helium-ion irradiation is correlated to the amount of lens, anterior chamber in the treatment field, tumor height, proximity to the fovea, history of diabetes, and the development of vitreous hemorrhage. Although the influence of the higher LET deposition of helium-ions is unclear, this study suggests that by reducing the dose to the anterior segment of the eye may reduce the NVG complications. Based on this retrospective analysis of LBNL patients, we have implemented techniques to reduce the amount of the anterior segment receiving a high dose in our new series of patients treated with protons using the cyclotron at the UC Davis Crocker Nuclear Laboratory (CNL).

Metastatic risk for distinct patterns of postirradiation local recurrence of posterior uveal melanoma

OBJECTIVE

The purpose of the study is to compare the prognostic significance of horizontal/marginal versus vertical/diffuse patterns of postirradiation local recurrence of posterior uveal melanoma.

DESIGN

The study design was a nonrandomized, retrospective clinical study. Semiparametric and nonparametric statistical techniques were used.

PARTICIPANTS

Seven hundred sixty-six posterior uveal melanoma patients were studied.

INTERVENTION

Either iodine-125 plaque or helium ion radiation therapy was performed.

MAIN OUTCOME MEASURES

Local tumor recurrence and systemic metastasis were measured.

RESULTS

Local tumor recurrence was detected in 66 (8.6%) of 766 irradiated tumors. The 5-year actuarial rate of local recurrence was 10%. The recurrence pattem was horizontal/marginal in 27 patients (41%) and vertical/diffuse in 39 patients (59%). Systemic metastasis was detected in 5 patients (19%) with horizontal/marginal recurrence and in 19 patients (49%) with vertical/diffuse recurrence. After known metastatic risk factors were controlled, the relative risk for metastasis was 2.2 for horizontal/marginal recurrence and 5.1 for vertical/diffuse recurrence (P = 0.05). The actuarial rate of systemic metastasis was 2.9% per year for all patients, 6.3% per year for patients with horizontal/marginal recurrence, and 15.5% per year for patients with vertical/diffuse recurrence.

CONCLUSIONS

Postirradiation local recurrence of posterior uveal melanoma is a risk factor for systemic metastasis. Vertical/diffuse recurrences may be associated more strongly with metastatic disease than horizontal/marginal recurrences.

Influence of fraction size, total dose, and overall time on local control of T1-T2 glottic carcinoma

PURPOSE

To evaluate the influence of fraction size, overall time, total dose, and other prognostic factors on local control of T1 and T2 glottic carcinomas.

METHODS AND MATERIALS

Between 1956 and 1995, 398 consecutive patients with early glottic carcinoma (315 T1 and 83 T2) were treated with once-a-day definitive radiotherapy at the University of California, San Francisco, and associated institutions. Treatment was delivered 5 days per week. Minimum tumor dose ranged from 46.6 to 77.6 Gy (median: 63 Gy). The fraction size was < 1.8 Gy in 146; 1.8-1.99 Gy in 128; 2.0-2.24 Gy in 62, and > or = 2.25 Gy in 62 patients. Overall time ranged from 34 to 75 days (median: 50 days). The majority of patients treated with a fraction size of 2.25 Gy completed therapy within 43 days. Median follow-up of all alive patients was 116 months (range 3-436 months).

RESULTS

Five-year local control was 85% for T1 and 70% for T2 glottic carcinomas (p = 0.0004). For T1 lesions, within the dose and time range evaluated, there was no apparent relationship between fraction size, overall time, total dose, and local control on multivariate analysis. Treatment era was the only significant prognostic factor (p = 0.02), and anterior commissure (AC) involvement was of borderline significance (p = 0.056). Five-year local control was 77% for patients treated between 1956-1970, 89% for between 1971-1980, and 91% for between 1981-1995; 80% for patients with AC involvement and 88% for those without. For T2 lesions, prognostic factors for local control on multivariate analysis were: overall time (p = 0.003), fraction size (p = 0.003), total dose (p = 0.01), impaired vocal cord mobility (p = 0.02), and subglottic extension (p = 0.04). Five-year local control was 100% for T2 lesions treated with overall time < or = 43 days vs. 84% for overall time > 43 days; 100% for fraction size > or = 2.25 Gy vs. 44% for fraction size < 1.8 Gy; 78% for total dose > 65 Gy vs. 60% for total dose < or = 65 Gy; 79% for normal cord mobility vs. 45% for impaired cord mobility, and 58% for lesions with subglottic extension vs. 77% for those without. The severe complication rate for the entire group was low: 1.8%.

CONCLUSIONS

Total dose, fraction size, and overall time were significant factors for local control of T2 but not T1 glottic carcinomas. Anterior commissure involvement was associated with decreased local control for T1 but not T2 lesions. For T1 lesions, local control improved over the treatment era. For T2 lesions, local control decreased with impaired cord mobility and subglottic extension.

Uveal melanoma. Growth rate and prognosis

OBJECTIVE

To study in vivo tumor growth rates, doubling times, and the association of these parameters with local tumor control and melanoma-related mortality.

METHODS

We retrospectively reviewed uveal melanomas with documented growth on serial evaluations before treatment. The tumor dimensions were based on clinical measurements for tumor diameters and quantitative echography to determine tumor thickness. One hundred forty-five patients met study criteria. All tumors were initially measured by the same observer with the same techniques, and, in 133 cases, serial observations and treatment were performed at our institution.

RESULTS

Tumor-doubling time estimates were log normally distributed, with a median of 1.4 years. Those 13 patients in whom metastases developed tended to have more rapid tumor growth rates. Iodine 125 brachytherapy failed in 8 patients with more rapidly growing tumors.

CONCLUSIONS

Faster growing tumors appear to be more likely to develop early metastases and have failure of local radiation control.

Orbital metastases: diagnosis and course

AIMS

Three issues were investigated in adult outpatients with orbital metastases. One, how accurate are current diagnostic methods? Two, what is the survival associated with orbital metastases? Three, did any clinical factors correlate with prognosis in this patient cohort?

METHODS

Retrospective analysis of patients with orbital metastases managed in an ocular oncology unit.

RESULTS

11 of 31 (35%) patients had no known primary malignancy at the time of orbital diagnosis. In eight of 31 (26%) computed tomography and/or magnetic resonance imaging data did not yield the diagnosis of metastases. In 15 of 17 (88%) cases a fine needle aspiration biopsy was diagnostic. Several types of therapy were used. The median survival was 1.3 years.

CONCLUSION

Orbital metastases, even with newer diagnostic techniques can be difficult to diagnose. Management was based on location and extent of both orbital and systemic disease as well as vision. In most cases, orbital symptoms were palliated; however, survival was dismal. No clinical factor correlated with prognosis.