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Biomedical subjects

W F Sindelar

Publications and source records attributed to W F Sindelar.

At least 37 records · Page 2Linked to original sources
PubMed1993

Phase I study of debulking surgery and photodynamic therapy for disseminated intraperitoneal tumors.

PURPOSE: Phase I study designed to determine the maximum tolerated dose of intraoperative photodynamic therapy (PDT) at laparotomy/debulking surgery in patients with refractory or recurrent, disseminated intraperitoneal tumors. METHODS AND MATERIALS: Patients received dihematoporphyrin ethers (DHE) 1.5-2.5 mg/kg by i.v. injection prior to surgery. Patients resected to < or = 5 mm of residual disease underwent laser light delivery to all peritoneal surfaces. RESULTS: Fifty-four patients entered the study. Thirty-nine underwent resection and light delivery/PDT. PDT dose was escalated by increasing DHE from 1.5 to 2.5 mg/kg, shortening the interval between DHE injection and surgery from 72 to 48 hr, and increasing the light dose. Initially, 630 nm red light alone was used. In this group, PDT of 2.8-3.0 J/cm2 induced small bowel edema and resulted in 3 small bowel perforations after bowel resection or enterotomy. Further light dose escalation, however, was achieved by switching to less penetrating 514 nm green light to the bowel/mesentery. In later patients, whole peritoneal PDT was supplemented with boost doses of 10-15 J/cm2 red light or 5-7.5 J/cm2 green light to high risk areas. Small bowel complications were not seen after switching to less penetrating green light. Dose limiting toxicities occurred in 2 of 3 patients at the highest light dose of 5.0 J/cm2 green light with boost. These patients had pleural effusions that required thoracentesis and postoperative respiratory support for 7-9 days, while one had a gastric perforation. At potential follow-up times of 3.8-43.1 months (median 22.1 months), 30/39 patients are alive and 9/39 are free of disease. CONCLUSION: The maximum tolerated dose of intraoperative PDT following debulking surgery performed 48 hr after intravenous administration 2.5 mg/kg DHE is 3.75 J/cm2 of 514 nm green light to the entire peritoneal surface with boosts to 5.0-7.5 J/cm2 of 514 nm green light or 10-15 J/cm2 of 630 nm red light to sites of gross disease encountered at surgery.

Adult↗
PubMed1993

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↗
PubMed1993

Tolerance of small bowel anastomoses in rabbits to photodynamic therapy with dihematoporphyrin ethers and 630 nm red light.

Photodynamic therapy (PDT) is being evaluated in experimental clinical trials in patients with peritoneal malignancies. Some patients require partial small bowel resection with re-anastomosis prior to PDT because of bulky tumor or focal involvement of the small bowel by tumor. To assess the safety of PDT in this setting, the tolerance of small bowel anastomoses in New Zealand white rabbits to PDT with dihematoporphyrin ethers (DHE) and 630 nm light was studied. With conventional DHE doses of 1.5-2.5 mg/kg given 24 hours prior to surgery and light doses of 0-20 J/cm2 of 630 nm light, no adverse effects were seen on the healing of small bowel anastomoses. Higher photosensitizer doses of 10 mg/kg and 20 mg/kg in conjunction with 20 J/cm2, however, induced failure and breakdown of fresh anastomoses in 2/3 and 4/4 animals, respectively.

Anastomosis, Surgical↗
PubMed1993

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↗
PubMed1993

Lymph node involvement and pancreatic resection: correlation with prognosis and local disease control in a clinical trial.

In a prospectively randomized trial evaluating pancreatic resection with adjuvant radiotherapy (intraoperative radiotherapy [IORT] vs. external beam radiotherapy [EBRT]), lymph nodal involvement was examined and correlated with outcome. Twenty-six patients underwent pancreatic resection and received either IORT or EBRT (Stages II-IV). Patients who were stage I received surgery alone. Regional nodal metastases were present in 15 of 26 (57%) patients. Seven patients suffered treatment-related mortality. Survival, mortality, and morbidity were unaffected by the type of radiotherapy. The survival of patients with negative nodes (median survival 24 months, range 10 to > 109) appeared superior to the survival of patients with nodal involvement (median survival 11.5 months; range 4-39). Even in patients with locally advanced disease extending into extrapancreatic tissues, two node-negative patients appeared to survive longer (12 and 53 months) than 10 node-positive patients with similarly extensive local disease (median survival 11.5 months; range 4-39). Local disease control, however, appeared to be independent of nodal involvement, with eventual local recurrences in 6 of 8 node-negative patients and in 4 of 7 node-positive patients who were evaluable for local disease control by autopsy or by antemortem laparotomy.

Combined Modality Therapy↗
PubMed1992

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↗
PubMed1991

Technique of photodynamic therapy for disseminated intraperitoneal malignant neoplasms. Phase I study.

Patients with disseminated intraperitoneal malignant neoplasms were given intra-abdominal photodynamic therapy. Patients received dihematoporphyrin ethers intravenously 48 to 72 hours before laparotomy at doses of 1.5 to 3.0 mg/kg. At operation, as much tumor as possible was resected. Red light (630 nm) was delivered to all peritoneal surfaces from an argon-pumped dye laser at doses ranging from 0.2 to 3.0 J/cm2 in an escalating fashion. Viscera and peritoneal surfaces were anatomically isolated and exposed to light for intervals calculated to deliver the prescribed energy. Light was delivered to mesentery and bowel by a flat-cut optical fiber, while other areas, including diaphragm, viscera, omental bursa, gutters, and pelvis, were delivered light through a diffusing wand. Twenty-three patients (13 with ovarian cancer, eight with sarcoma, and two with pseudomyxoma peritoneii) underwent photodynamic therapy. Five of eight patients cleared positive peritoneal cytologies after treatment. Six patients remained clinically free of disease for up to 18 months, and five patients had treatment-related complications. Intraperitoneal phototherapy is technically feasible and deserving of clinical evaluation.

Adrenal Gland Neoplasms↗
PubMed1991

Recurrent or metastatic disease in select patients with adrenocortical carcinoma. Aggressive resection vs chemotherapy.

In a retrospective, nonrandomized comparison of patients with first recurrence of adrenocortical cancer, 18 patients were treated with chemotherapy (primarily mitotane) and 15 patients were treated with surgical resection plus similar chemotherapy. Surgical resection of recurrent adrenocortical cancer was often extensive, with morbidity in 20% of patients and no mortality. Mitotane therapy was ineffective at controlling tumor growth. Median survival from the time of diagnosis for all patients was only 23 months and no patient was cured. Disease-free interval greater than 12 months was associated with prolonged survival, but it only occurred in six patients (18%), with a similar frequency in both treatment groups. Surgical resection of recurrent disease was associated with prolonged survival from the time of first recurrence. The potential benefit of this resection was evident in the 5 patients (33%) who were able to live greater than 5 years from the time of first recurrence with improvement in symptoms and signs of hypercortisolism. Although no patient with recurrent adrenal cancer could be cured, resection of recurrent disease was associated with a slight prolongation of survival and good palliation of Cushing's syndrome.

Adolescent↗
PubMed1991

Threshold dose for peripheral neuropathy following intraoperative radiotherapy (IORT) in a large animal model.

Radiation injury to peripheral nerve is a dose-limiting toxicity in the clinical application of intraoperative radiotherapy, particularly for pelvic and retroperitoneal tumors. Intraoperative radiotherapy-related peripheral neuropathy in humans receiving doses of 20-25 Gy is manifested as a mixed motor-sensory deficit beginning 6-9 months following treatment. In a previous experimental study of intraoperative radiotherapy-related neuropathy of the lumbro-sacral plexus, an approximate inverse linear relationship was reported between the intraoperative dose (20-75 Gy range) and the time to onset of hind limb paresis (1-12 mos following intraoperative radiotherapy). The principal histological lesion in irradiated nerve was loss of large nerve fibers and perineural fibrosis without significant vascular injury. Similar histological changes in irradiated nerves were found in humans. To assess peripheral nerve injury to lower doses of intraoperative radiotherapy in this same large animal model, groups of four adult American Foxhounds (wt 20-25 kg) received doses of 10, 15, or 20 Gy to the right lumbro-sacral plexus and sciatic nerve using 9 MeV electrons. The left lumbro-sacral plexus and sciatic nerve were excluded from the intraoperative field to allow each animal to serve as its own control. Following treatment, a complete neurological exam, electromyogram, and nerve conduction studies were performed monthly for 1 year. Monthly neurological exams were performed in years 2 and 3 whereas electromyogram and nerve conduction studies were performed every 3 months during this follow-up period. With follow-up of greater than or equal to 42 months, no dog receiving 10 or 15 Gy IORT shows any clinical or laboratory evidence of peripheral nerve injury. However, all four dogs receiving 20 Gy developed right hind limb paresis at 8, 9, 9, and 12 mos following intraoperative radiotherapy. These experimental data suggest that intraoperative doses of less than 20 Gy may not result in clinically significant peripheral nerve injury with follow-up of 3.5 years. Longer (5 yrs) follow-up with planned sacrifice of the remaining dogs is scheduled to assess any late peripheral nerve damage.

Animals↗
PubMed1991

A light-diffusing device for intraoperative photodynamic therapy in the peritoneal or pleural cavity.

Light delivery to anatomic areas involved by tumor is critical for effective photodynamic therapy. The authors provide a detailed overview of a light-diffusing device which they have used for intraoperative illumination of the peritoneal and pleural cavities in patients with tumors involving the surfaces of these cavities. Their device represents an inexpensive modification of widely available endotracheal tubes. It has been used to deliver intraoperative photodynamic therapy in over 50 patients without episodes of device failure. When combined with a lipid-based, light-diffusing medium and on-line power/energy density monitoring, it allows homogeneous illumination of these complex surfaces.

Combined Modality Therapy↗
PubMed1989

Clinical experience with regional pancreatectomy for adenocarcinoma of the pancreas.

Twenty patients with adenocarcinoma of the pancreas underwent a regional pancreatectomy, including resection of the pancreas, regional lymphadenectomy, duodenectomy, antrectomy, and sleeve resection of the portal vein. Three patients required mesenteric arterial reconstruction. Adjunctive radiotherapy was administered to 17 patients, with 11 patients receiving intraoperative radiation and six patients receiving postoperative external-beam-radiation. Complications developed in 11 patients (55%), including infectious and septic events (five patients), biliary or enteric fistulas (two patients), mesenteric vascular thrombosis (two patients), and other complications (two patients). Four patients (20%) suffered treatment-related deaths. The overall median survival was 12.0 months. Survival at one year was 50% and, at three years, 10%. Two patients died of causes unrelated to cancer at 18 and 39 months, and one patient remains alive and free of disease 50 months following therapy. Morbidity and survival did not differ among patients who received intraoperative, conventional postoperative, or no radiation therapy. Although occasional patients may benefit with survivals of longer than three years, regional pancreatectomy carries major morbidity and produces little survival benefit for most patients with pancreatic cancer.

Adenocarcinoma↗
PubMed1989

Are complications in intraoperative radiation therapy more frequent than in conventional treatment?

To evaluate whether intraoperative radiation therapy (IORT) results in higher complication rates than conventional radiotherapy, 119 patients were studied who entered four prospectively randomized clinical trials that compared IORT with conventional therapy. Malignant neoplasms included 33 gastric carcinomas, 35 retroperitoneal sarcomas, 22 resectable pancreatic cancers, and 29 unresectable pancreatic cancers. One hundred thirty-six complications developed among 66 patients who received conventional therapy, and 108 complications developed among 53 patients who received IORT. There was no statistical significance between treatment groups with respect to the overall incidence of complications. Analysis of types of complications by tumor type using Fisher's exact test revealed only one significant complication: an increased rate of sepsis among the patients with retroperitoneal sarcoma who received conventional therapy compared with their IORT cohorts. The overall complication rate associated with IORT was equivalent to conventional radiotherapy in the treatment of these malignant neoplasms and supported the use of IORT where clinically indicated.

Abdominal Neoplasms↗
PubMed1989

Bilateral radical neck dissection: report of results in 55 patients.

Between 1952 and 1982, 55 patients underwent bilateral radical neck dissections at the National Cancer Institute. Of these, 17 patients had simultaneous (one-stage) bilateral dissections and 38 had nonsimultaneous (two-stage) dissections. In 37 patients both internal jugular veins were removed, while one vein was preserved in 18 patients. The operative mortality was 11.8% (2/17 patients) for simultaneous bilateral neck dissections and 2.6% (1/38 patients) for nonsimultaneous staged dissections. The overall operative mortality was 5.4%. Of the 18 patients in whom one jugular vein was preserved, six patients (33%) had postoperative facial edema and swelling, while of the 37 patients in which neither jugular vein was saved, 20 patients (54%) developed significant postoperative facial edema. The overall 2-year recurrence rate was 50%. The overall survival rates were 55% at 3 years and 39% at 5 years.

Adolescent↗
PubMed1989

Intraoperative radiation therapy-induced sarcomas in dogs.

In a canine model the tolerance of normal and surgically manipulated tissue to intraoperative radiotherapy (IORT) was investigated to provide guidelines for the clinical use of IORT in human cancer patients. A dose of 20 Gy IORT, with or without external beam radiotherapy, was generally well tolerated without significant increased treatment morbidity. Higher doses of IORT (over 30 Gy) have produced radiation-induced sarcomas in some animals followed over a long period. Therefore IORT should be used only in human cancer patients in well controlled studies, in which complications are well documented, and the possibility of radiation-induced malignancies in long-term survival should be considered.

Animals↗
PubMed1989

Reconstruction of a functional hemidiaphragm with use of omentum and latissimus dorsi flaps.

After ablative surgery that involves the diaphragm, autologous tissue is the material of choice for reconstruction--particularly if adjuvant radiotherapy is planned. Latissimus dorsi muscle and omentum are reliable sources of such tissue. A case is reported describing a method of diaphragm reconstruction after resection by mobilization of the upper latissimus dorsi and passing the free muscle portion over the residual costal margin to form a neodiaphragmatic leaflet. Suture of the transposed latissimus free end to the residual diaphragm tendon and the use of omentum to fill defects residual after muscle transposition were used to complete the reconstruction.

Adult↗
PubMed1988

212Bismuth linked to an antipancreatic carcinoma antibody: model for alpha-particle-emitter radioimmunotherapy.

For comparison of cytotoxicity from alpha-particle irradiation with that from conventional x-irradiation, 212Bi, an alpha-emitting radionuclide, was attached to a monoclonal antibody that recognizes a cell surface antigen on human pancreatic carcinoma cells. For a given level of survival, the 212Bi-antibody complex was found to be approximately 20 times more efficient in cell killing than x-irradiation and 5 times more cytotoxic when compared with the cytotoxicity of an antigen-negative cell line or an isotype-matched control antibody. High linear energy transfer radioimmunotherapy using alpha emitters linked to monoclonal antibodies may be useful in vivo and in vitro for selectively killing target cell populations, especially those resistant to other forms of treatment.

Antibodies, Monoclonal↗