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Biomedical subjects

E Glatstein

Publications and source records attributed to E Glatstein.

At least 19 recordsLinked to original sources
PubMed2000

Comparison between isotropic and nonisotropic dosimetry systems during intraperitoneal photodynamic therapy.

BACKGROUND AND OBJECTIVE: On-line monitoring of light fluence during intraperitoneal photodynamic therapy (IP PDT) is crucial for safe light delivery. A flat photodiode-based dosimetry system is compared with an isotropic detector-based system in patients undergoing IP PDT. STUDY DESIGN/MATERIALS AND METHODS: Flat photodiodes and spherical detectors were placed side by side in the abdomen, for simultaneous light dosimetry in 19 patients. Tissue phantom experiments were performed to provide a preliminary estimate of the tissue optical properties of the peritoneum. RESULTS: The conversion factor between systems for 630-nm light was found to be 1.7 +/- 0.12. The mu(eff) of the tissues in the abdomen is estimated to vary between 0.5 cm(-1) to 1.4 cm(-1) assuming a mu(s)' = 7 cm(-1). CONCLUSIONS: The measured conversion factor should allow for comparison of light fluences with future clinical protocols that use an isotropic-based detector system. Differences in the optical properties of the underlying tissues may contribute to the variability in light measurements.

Clinical Protocols↗
PubMed1999

Autologous stem-cell transplant after conventional dose adjuvant chemotherapy for high-risk breast cancer: impact on the delivery of local-regional radiation therapy.

BACKGROUND: High-dose chemotherapy with autologous stem-cell transplantation is used increasingly in the treatment of poor-prognosis primary breast cancer. Because these patients may be cured with standard multimodality therapy, it is important to address both the efficacy of transplantation, and its effect on the delivery of standard treatments including local radiation therapy. PATIENTS AND METHODS: Patients with high risk primary breast cancer were treated with high-dose cyclophosphamide and thiotepa and stem-cell transplant following surgery and conventional-dose adjuvant chemotherapy. Outcome, including sites of failure and delivery of local radiation therapy, was assessed for 103 patients. RESULTS: Overall and disease-free survival rates at 18 months were 83% (+/- 4%) and 77% (+/- 4%) respectively. Twenty patients (19.4%) received radiation therapy prior to transplant. Of the remaining 83, 77 received radiation therapy after transplant. Overall, 5 (19.2%) of 26 first sites of recurrence were local alone. For patients receiving radiation prior to transplant, 3 of 7 (43%, 95% CI: 6%-80%) sites of first recurrence were local, while 2 of 19 (10.5%, 95% CI: 0%-24.5%) sites of first recurrence were local alone in patients receiving post-transplant radiation or no radiation. CONCLUSION: Transplantation does not appear to significantly compromise the delivery or outcome of local radiation therapy for primary breast cancer.

Adult↗
PubMed1999

Photodynamic therapy in the treatment of cancer: current state of the art.

Photodynamic therapy (PDT) is a treatment modality using a photosensitising drug and light to kill cells. The clinical use of PDT requires the presence of a photosensitising agent, oxygen and light of a specific wavelength which matches the absorption characteristics of the photosensitiser. When the photosensitiser is activated by the appropriate wavelength of light, it interacts with molecular oxygen to form a toxic, short-lived species known as singlet oxygen, which is thought to mediate cellular death. The appeal of PDT in oncology is that the photosensitiser tends to be retained in tumour tissues for a longer period of time as compared with normal tissues resulting in a large therapeutic index. This potential for minimal normal tissue toxicity has prompted an interest in studying PDT as a cancer treatment. Furthermore, the use of PDT is not precluded by prior radiotherapy, chemotherapy or surgery. The development of PDT has been hampered by the limitations of the older photosensitisers, namely limited depth of tissue penetration, and extended skin phototoxicity which limits the number of applications during a course of treatment. However, newer photosensitisers are being developed which allow greater depth of tissue penetration and have minimal skin phototoxicity allowing for multiple fractionated treatments. With such advancements, PDT has great potential to become an integral part of cancer treatment in the future.

Humans↗
PubMed1998

Hodgkin disease?

Explore the source record for details and available documents.

Adolescent↗
PubMed1998

Randomized prospective study of the benefit of adjuvant radiation therapy in the treatment of soft tissue sarcomas of the extremity.

PURPOSE: This randomized, prospective study assesses the impact of postoperative external-beam radiation therapy on local recurrence (LR), overall survival (OS), and quality of life after limb-sparing resection of extremity sarcomas. PATIENTS AND METHODS: Patients with extremity tumors and a limb-sparing surgical option were randomized to receive or not receive postoperative adjuvant external-beam radiotherapy. Patients with high-grade sarcomas received postoperative adjuvant chemotherapy whereas patients with low-grade sarcomas or locally aggressive nonmalignant tumors were randomized after surgery alone. RESULTS: Ninety-one patients with high-grade lesions were randomized; 47 to receive radiotherapy (XRT) and 44 to not receive XRT. With a median follow-up of 9.6 years, a highly significant decrease (P2 = .0028) in the probability of LR was seen with radiation, but no difference in OS was shown. Of 50 patients with low-grade lesions (24 randomized to resection alone and 26 to resection and postoperative XRT), there was also a lower probability of LR (P2 = .016) in patients receiving XRT, again, without a difference in OS. A concurrent quality-of-life study showed that extremity radiotherapy resulted in significantly worse limb strength, edema, and range of motion, but these deficits were often transient and had few measurable effects on activities of daily life or global quality of life. CONCLUSION: This study indicates that although postoperative external-beam radiotherapy is highly effective in preventing LRs, selected patients with extremity soft tissue sarcoma who have a low risk of LR may not require adjuvant XRT after limb-sparing surgery (LSS).

Extremities↗
PubMed1998

Primary cardiac sarcoma: a novel treatment approach.

Primary cardiac sarcomas carry a dismal prognosis with no known curative therapy using standard treatment approaches. By its very location, the possibility of a radical complete resection--the underlying principle in the management of any soft-tissue sarcoma--is precluded. While literally in a continuous "blood bath," cardiac sarcomas are associated with a very high rate of hematogenous metastases. This report describes the management of a case in a 51-year-old white man with a high-grade unresectable cardiac sarcoma who was treated with hyperfractionated (twice daily) radiotherapy to a total dose of 7,050 cGy along with a radiosensitizer, (5'-iododeoxyuridine. The patient currently is disease-free and functioning well more than 5 years following this novel treatment approach.

Antineoplastic Agents↗
PubMed1998

"Just Another Statistic"

On returning from a medical meeting, we learned that sadly a patient, "Mr. B.," had passed away. His death was a completely unexpected surprise. He had been doing well nine months after a course of intensive radiotherapy for a locally advanced head and neck cancer; in his most recent follow-up notes, he was described as a "complete remission." Nonetheless, he apparently died peacefully in his sleep from a cardiac arrest one night and was found the next day by a concerned neighbor. In our absence, after Mr. B. expired, his death certificate was filled out by a physician who didn't know him in detail, but did know why he recently was treated in our department. The cause of death was listed as head and neck cancer. It wasn't long after his death before we began to receive those notorious "requests for additional information," letters from the statistical office of a well-known cooperative group. Mr. B., as it turns out, was on a clinical trial, and it was "vital" to know further details of the circumstances of his passing. Perhaps this very large cancer had been controlled and Mr. B. succumbed to old age (helped along by the tobacco industry). On the other hand, maybe the residual "fibrosis" in his neck was actually packed with active tumor and his left carotid artery was finally 100% pinched off, or maybe he suffered a massive pulmonary embolism from cancer-related hypercoagulability. The forms and requests were completed with a succinct "cause of death uncertain," adding, "please have the Study Chairs call to discuss this difficult case." Often clinical reports of outcomes utilize and emphasize the endpoint "disease specific survival" (DSS). Like overall survival (OS), the DSS can be calculated by actuarial methods, with patients who have incomplete follow-up "censored" at the time of last follow-up pending further information. In the DSS, however, deaths unrelated to the index cancer of interest are censored at the time of death; thus, a death from intercurrent disease is considered a "success" (to the investigator, that is; obviously, not to the patient and his or her family). The DSS rate will always be superior to the OS rate. Obviously, for any OS curve, if one waits long enough it will ultimately come to zero. There is thus a very logical rationale for reporting the DSS separately, particularly in diseases where death from intercurrent disease is expected to be common. Analyzing the DSS allows researchers to better compare the biologic efficacy of two or more cancer treatments, since it does not necessarily come to zero. Unlike some other endpoints, including local-regional control or freedom from progression, it takes into account the possibility of salvage therapy. DSS also focuses on an endpoint of interest to the public-death from cancer. In a recent popular media survey in which people were asked how they would choose to die if they could, 0% selected cancer. However, there are two serious potential problems with heavy dependence on the DSS. First, since patients who die from intercurrent disease are considered "cured," it seriously inflates the apparent effectiveness of a cancer treatment. Given the same biologic disease and the same treatment, the DSS as calculated in an old, sick population at high risk of intercurrent death will be better than the DSS in a younger, healthier population whose major risk is from their cancer. This problem has been discussed with respect to early stage prostate cancer, in which the conservative approach of observation has been criticized. The studies at issue rely heavily on the DSS, suggesting a comparable DSS (90% at 10 years) with "watchful waiting" to other researchers' results with aggressive therapy. The problem is that these series of conservative management focus on a patient population (as opposed to individuals) with a high risk of competing causes of mortality, which is very different from the population of patients generally treated with aggressive therapy (in which some have shown overall survivals superior to age-matched controls). It is fallacious and illogical to compare nonrandomized series of observation to those of aggressive therapy. In addition to the above problem, the use of DSS introduces another potential issue which we will call the bias of cause-of-death-interpretation. All statistical endpoints (e.g., response rates, local-regional control, freedom from brain metastases), except OS, are known to depend heavily on the methods used to define the endpoint and are often subject to significant interobserver variability. There is no reason to believe that this problem does not occasionally occur with respect to defining a death as due to the index cancer or to intercurrent disease, even though this issue has been poorly studied. In many oncologic situations-for example, metastatic lung cancer-this form of bias does not exist. In some situations, such as head and neck cancer, this could be an intermediate problem (Was that lethal chest tumor a second primary or a metastasis?.Would the fatal aspiration pneumonia have occurred if he still had a tongue?.And what about Mr. B. described above?). In some situations, particularly relatively "good prognosis" neoplasms, this could be a substantial problem, particularly if the adjudication of whether or not a death is cancer-related is performed solely by researchers who have an "interest" in demonstrating a good DSS. What we are most concerned about with this form of bias relates to recent series on observation, such as in early prostate cancer. It is interesting to note that although only 10% of the "observed" patients die from prostate cancer, many develop distant metastases by 10 years (approximately 40% among patients with intermediate grade tumors). Thus, it is implied that many prostate cancer metastases are usually not of themselves lethal, which is a misconception to anyone experienced in taking care of prostate cancer patients. This is inconsistent with U.S. studies of metastatic prostate cancer in which the median survival is two to three years. It is possible that many deaths attributed to intercurrent disease in "watchful waiting" series were in fact prostate cancer-related, perhaps related to failure to thrive, urosepsis, or pulmonary emboli. We will not know without an independent review of the medical records of individual patients; in some cases, even the most detailed review, sometimes even an autopsy, will not be conclusive. There are only a few data available describing the problems created by cause-of-death-interpretation bias. One small study, presented only in abstract form, assessed the cause of death in 50 randomly selected prostate cancer patients who died. Five experts in prostate cancer were asked to assign the cause of death as due to or not due to prostate cancer. The DSS varied from 21% to 35% among the five reviewers, a relative difference of 66%. Studies of autopsies, which are now rarely done in the U.S., have shown that fatal malignant tumors were occasionally missed by clinicians and-even more sobering-an occasional patient thought to have died from metastatic cancer is found to have no tumor but to have died from a "benign" cause such as TB. One study suggested an error rate of approximately 8%. Clearly the use of DSS is here to stay and is a useful adjunct to OS in analyzing randomized trials. There needs to be more research on the validity and interobserver reproducibility of the DSS. In the meantime, researchers should not report DSS without reporting OS and the reasons for intercurrent deaths should be described-peer reviewers should enforce this. As with so many other problems with statistics in the medical literature, it is the job of the reader to remain skeptical. The rate of intercurrent deaths in a study should reflect the age and demographics of the study population. If the DSS is far superior to the OS, the population being studied may be unusually sick (and thus unrealistic), or there may be a bias in classifying the causes of death. Similarly, if the DSS and OS are identical (unless a highly virulent malignancy is being studied), it may suggest the researchers have only included an unusually healthy (and thus unrealistic) patient population. Finally, we would also be a bit suspicious of a sizeable series that did not have any deaths that were considered of "uncertain" cause, unless the researchers specifically included them as being due to the cancer. We honestly think that everybody has a few patients like Mr. B.

Journal Article↗
PubMed1997

Phase I trial of photodynamic therapy in the treatment of recurrent superficial transitional cell carcinoma of the bladder.

OBJECTIVES: A Phase I trial of photodynamic therapy (PDT) in the treatment of superficial transitional cell carcinoma (TCC) of the bladder was performed. METHODS: Twenty patients with recurrent superficial TCC of the bladder after receiving a mean of 2.6 (range 1 to 6) courses of intravesical therapy were treated with PDT. The photosensitizer Photofrin II dose was 1.5 or 2.0 mg/kg. A 630-nm intravesical red laser was used to activate the photosensitizer 2 days after administration of Photofrin II. A 0.01% intralipid solution was used as a bladder-filling medium to scatter light and achieve more homogeneous light distribution. Light doses from 5.1 to 25.6 J/cm2 (total dosage 1500 to 5032 J) were used to illuminate the bladder. RESULTS: Twenty patients underwent 21 treatments with PDT. Complications included asymptomatic reflux in 4 patients. One other patient, treated at the highest total light dose, experienced bladder contraction and fibrosis. Nine patients (45%) had no tumor evident at cystoscopy, on random biopsies, or in urinary cytology at the 3-month evaluation after treatment. Four patients remained without recurrent disease for 23 to 56 months. Sixteen of 20 (80%) patients experienced recurrence, and 8 of the 16 underwent cystectomy. CONCLUSIONS: An intravenous photosensitizer dose of 1.5 mg/kg Photofrin II followed by light energy in the range of 13 J/cm2 (total light dose 2500 to 3250 J) was defined as a safe treatment parameter and resulted in tumor responses. With present technologies, administration of PDT requires careful dosimetry.

Adult↗
PubMed1997

Alternating MOPP and ABVD chemotherapy plus mantle-field radiation therapy in patients with massive mediastinal Hodgkin's disease.

PURPOSE: To evaluate the efficacy and toxicity of mechlorethamine, vincristine, procarbazine, and prednisone (MOPP)/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy plus mantle-field radiation therapy in the treatment of patients with massive mediastinal Hodgkin's disease of any stage. PATIENTS AND METHODS: Eighty patients presented with Hodgkin's disease and a mediastinal mass greater than one third the greatest chest diameter on chest radiograph. Patients were staged and treated with MOPP alternated with ABVD chemotherapy for a total of six cycles. Patients then received 10 Gy mantle-field radiation therapy delivered to the original extent of disease followed by 25 to 35 Gy to the residual abnormalities. RESULTS: The complete response (CR) rate was 89%. With a median follow-up duration of 10 years, disease-free survival of the complete responders is 78% at 15 years and overall survival is 75% at 15 years. For patients with stage I or II disease, disease-free survival was 76% at 15 years and overall survival was 79%; for those with stage III or IV disease, disease-free survival was 82% at 15 years and overall survival was 64%. Age, stage, sex, B symptoms, number of extranodal sites, lactate dehydrogenase (LDH) levels, erythrocyte sedimentation rate, and platelet count did not influence treatment outcome. Treatment-related pneumonitis was noted in 16% of patients (fatal in one), mainly in those older than age 35 years who received total doses of radiation therapy greater than 42 Gy. Fertility is more often preserved with MOPP/ABVD therapy than with MOPP chemotherapy and there appears to be less pulmonary and cardiac disease than with ABVD chemotherapy. Two patients have developed second solid tumors within radiation ports and one relapsed patient developed acute leukemia after MOPP salvage therapy. CONCLUSION: MOPP/ABVD followed by mantle-field radiation therapy is an effective treatment for all stages of Hodgkin's disease that present with a large mediastinal mass. Our data suggest that the large mediastinal mass is a more dominant determinant of prognosis than Ann Arbor stage or other clinical prognostic factors.

Adolescent↗
PubMed1997

Classification of Non-Hodgkin's Lymphoma: A Proposal.

The pathology community has traditionally classified the non-Hodgkin's lymphomas (NHL) according to their histogenetic characteristics, an approach that has fostered the proliferation of multiple, often conflicting, lymphoma classification schemes with limited clinical relevance. The scientific acceptance of these histogenetically pure schemes is based on an implicit belief that all that is scientifically sound must adhere to linear dynamic theory; that is, that the elemental components of a system in a linear and direct fashion control the behavior of the whole. Non-linear dynamic theory, however, which has recently acquired acceptance within the scientific community, offers another equally valid approach to the classification of the NHL by acknowledging the inherent indeterminacy of nature. In other words, rather than classifying the NHL according to their cell of origin in the hopes that the elemental unit will predict the clinical outcome, we propose that pathologists accept the premise that nature is inherently unpredictable and define the NHL according to their clinical characteristics, such as natural history and response to therapy. Using these criteria, a proposed classification is discussed containing two major subtypes of lymphomas (indolent and aggressive) which can be further subdivided into five groups: the low-grade, or indolent, group includes the small lymphocytic and the follicular cleaved cell (small, and small, mixed) categories, while the high-grade, or aggressive, group includes the large-cell, the Burkitt's lymphoma, and the lymphoblastic lymphomas. Each of these groups is discussed in detail, with comparisons to the Revised European American Lymphoma classification to demonstrate clinical relevance. Although it is clear to us that the proposed scheme presented in this manuscript is not the only clinically valid one that can be constructed, it is equally clear that any scheme that is developed-in order to be considered valid-must be guided principally by its clinical relevance.

Journal Article↗
PubMed1996

Radiation biology of lung cancer.

The enormous problem that is lung cancer still defies satisfactory therapeutic strategy. This article summarizes some of the more important laboratory efforts directed at understanding the biology of this complex disease. The radiation sensitivities of established lung cancer cell lines are outlined. The effect of radiation dose rate and chemotherapy is explored. The emerging biology of oncogenetic alterations is explored as it relates to radiation sensitivity in general, and lung cancer in particular. Finally, novel therapeutic approaches including photodynamic therapy are introduced.

Antineoplastic Agents↗