Laser therapy of colorectal tumors

Between Jan. 1, 1986 and March 31, 1988 a total of 128 patients with tumours of the colon and rectum were treated by Nd-Yag laser at Nürnberg City Hospital. There were 36 benign and 92 malignant lesions. The indications for laser therapy were stenosis, bleeding, spasms of the pelvic floor and increased mucous production. Initial control of these problems could be achieved in 105 patients (82%), however, the symptoms recurred in 50% of the malignant and 47% of the benign tumours. Complications of laser treatment were encountered in 13 patients necessitating an operative intervention in 6. In all, 34 patients underwent additional surgery after laser treatment. Most frequently, a diverting colostomy had to be provided (n = 18) while 12 patients underwent anterior resection; in three an abdomino-perineal resection was performed and in one patient a Hartman procedure was necessary. The median observation time of patients with benign tumours is, at present, 16 months with 72% being free of disease. In malignant tumours the median survival time of patients with laser therapy only is 4.5 months; those with additional surgical treatment survived a median of 17.5 months.     

Laser therapy of gastrointestinal tumors

Surgical resection remains the therapy of choice for the treatment of potentially curable gastrointestinal tract (GI) malignancies. Many of these tumors are incurable at the time of diagnosis and therapy should be directed towards palliation with the intent of minimizing pain, bleeding, obstruction, and potential morbidity. Endoscopic laser therapy is uniquely applicable for the palliation of GI tumors and in selective instances may be appropriate for the treatment of early lesions. Eighty-six patients with GI malignancy have been treated at our institution since 1985. Thirty-one patients had advanced upper GI lesions (esophagus: 26, gastric: 3, duodenal: 1, and pancreatic: 1) and 55 patients had lower GI tumors (colon: 37 and rectal: 18). Pre-resectional recanalization for obstructing colorectal carcinomas obviating initial operative diversion was performed in 31 (56%) of 55 patients. Twenty-four patients had palliative laser therapy (obstruction: 17 and hemorrhage: 7) with resolution of their symptoms. There was 1 laser related perforation in the pre-resectional group and the overall complication rate was 1.2%. Endoscopic Nd:YAG and currently photodynamic laser therapy for GI tumors has proven to be an effective mode of therapy for advanced GI neoplasms with minimal morbidity. The utility of photodynamic therapy for the treatment of early stage esophageal and gastric cancers remains controversial.

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Resumen La resección quirúrgica sigue siendo la terapía de escogencia para las neoplasias malignas potencialmente curables del tracto gastrointestinal. Muchos de estos tumores ya son incurables en el momento del diagnóstico y el tratamiento debe ser dirigido hacia la paliación con miras a mínimizar el dolor, la hemorragia, la obstrucción y la morbilidad potencial. La terapia endoscópica con laser es especialmente aplicable a la paliación de tumores GI y en casos seleccionados puede representar el tratamiento apropiado de lesiones tempranas. Ochenta y seis pacientes con neoplasias malignas GI han sido tratados en nuestra institución desde 1985. Treinta y un pacientes presentaban lesiones GI altas avanzadas (26 esófagicas, 3 gástricas, 1 duodenal y 1 pancreática) y cincuenta y cinco pacientes presentaban tumores GI bajos (colon 37, rectal 18). La recanalización pre-resección de carcinomas colorrectales obstructivos para evitar una derivación operatoria fue efectuada en 31/55 (56%) pacientes. Veinticuatro pacientes fueron sometidos a terapia paliativa con laser (obstrucción 17, hemorragia 7) con resolución de sus síntomas. Se presentó una perforación relacionada con el laser en el grupo pre-reseccional y la tasa global de complicaciones fue 1.2%. La terapia endoscópica con laser Nd: YAG, y la actual terapia fotodinámica de tumores GI, han probado ser modalidades terapéuticas efectivas en el manejo de neoplasmas GI avanzados, con mínima morbilidad. La utilidad de la terapia fotodinámica de cánceres esofágicos y gástricos tempranos sigue siendo motivo de controversion.

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Résumé La résection chirurgicale reste le traitement de choix des tumeurs malignes du tube digestif (TD) potentiellement curables. Malheureusement, beaucoup de tumeurs ne sont pas curables au moment du diagnostic et la thérapeutique se dirige vers une attitude palliative que ce soit pour réduire la douleur, arrêter une hémorragie ou lever une occlusion, ou en un mot, pour réduire la morbidité. Le traitement par laser est destiné le plus souvent au traitement palliatif des tumeurs avancées mais il peut aussi servir à traiter des lésions du début. Quatre-vingt patients ayant une tumeur maligne du TD one été traités dans notre unité depuis 1985. Trente et un patients avaient des lésions avancées du TD supérieur (oesophage = 26, estomac = 3, duodénum = 1, pancréas = 1) et cinquante cinq patients avaient des tumeurs du TD inférieur (côlon = 37 et rectum = 18). La reperméation avant résection pour des cancers obstructifs a été réalisée dans 31/55 patients, évitant ainsi une colostomie de décompression. Vingt-quatre patients ont eu un traitement palliatif par laser avec résolution complète de leur symptomatologie (occlusion = 17, hémorragie = 7). Il y a eu une perforation en rapport avec l'utilisation du laser dans le groupe de patients reperméabilisés en préopératoire, pour un taux global de complications de 1.2%. Le laser Nd:YAG et, actuellement, le laser photodynamique sont utilisées et ont fait la preuve de leur efficacité pour les lésions avancées avec une morbidité minime. L'utilité du laser photodynamique reste discutée dans le traitement de lésions de l'oesophage ou de l'estomac à leur début.

     

Permanent iodine-125 implant and external beam radiation therapy for the treatment of malignant brain tumors.

Survival data of 114 patients treated for malignant brain tumors with 125I interstitial radiation therapy at Henry Ford Hospital, Detroit, Mich. (1986-1990), are presented. The first 64 patients were treated with temporary 125I implants with a total prescribed dose of 60 Gy at a dose rate of 40 cGy/h. In order to reduce the risk of injury to the surrounding normal tissue associated with high-dose brachytherapy, a new approach was initiated using permanent implants with a lower dose rate; 50 patients were treated after surgical resection with permanent implantation of 125I seeds at a lower dose rate of 4-7 cGy/h, with a total dose of 10,000-12,000 cGy, and concurrent external radiation therapy of 5,000 cGy. The rationale of this protocol was to increase the effectiveness of the low-dose-rate implant by a concurrent 'daily' boost of external radiation, thus inhibiting the proliferation of tumor cells during the protracted low-dose radiation treatment. Survival was compared between groups with permanent and temporary implants in terms of effectiveness in tumor control as well as impact on clinical condition. Low-dose-rate implant with concurrent external radiation therapy seems to offer the best chance for long-term survival without deterioration in the clinical condition.     

Long-term effects of treatment for childhood brain tumors.

Recent studies have recognized brain tumor to be the most important solid malignancy in childhood. Improved diagnostic methods and advances in surgical technology and instrumentation have significantly lowered operative mortality, facilitating more precise and radical surgical resections.     

Gene therapy for brain tumors: the fundamentals

BACKGROUND: Over the past two decades, significant advances have been made in the fields of virology and molecular biology, and in understanding the genetic alterations present in brain tumors. The knowledge gained has been exploited for use in gene therapy. OBJECTIVE: The purpose of this article is to present an introduction to the field of brain tumor gene therapy for the practicing clinician. RESULTS: A variety of gene therapy strategies have now been used in the laboratory and in clinical trials for brain tumors. They can be divided into five categories: 1) gene-directed enzyme prodrug ("suicide gene") therapy (GDEPT); 2) gene therapy designed to boost the activity of the immune system against cancer cells; 3) oncolytic virus therapy; 4) transfer of potentially therapeutic genes--such as tumor suppressor genes--into cancer cells; and 5) antisense therapy. GDEPT is the strategy that has been most extensively studied. CONCLUSIONS: To date, gene therapy has been found to be reasonably safe and concerns related to adverse events such as insertional mutagenesis have not been realized. Although patients have not been cured, the development of this therapy could still be considered to be at an early stage. Current research is addressing factors that could be limiting the successful clinical application of gene therapy, which remains an intriguing experimental option for patients with malignant brain tumors.     

New three-dimensional moving field radiation therapy for brain tumors.

A new modified rotation radiation method called "three-dimensional moving field radiation therapy" is described. The new method uses rotation in many planes while maintaining the the same isocenter to achieve a good spatial dose distribution. This delivers a high dose to tumors and spares the surrounding normal structures. This easy method can be carried out using the equipment for conventional rotation radiation therapy. The new method was superior to the one plane rotation radiation therapy using a physical phantom with film, a chemical phantom using the iodine-starch reaction, and a new biological model using tumor cells. Treatment of six brain tumors irradiated with total air doses of 50-60 Gy caused no hair loss or radiation necrosis.     

Stereotactic intratumoral photodynamic therapy for recurrent malignant brain tumors.

Photodynamic therapy (PDT) using purified hematoporphyrin derivative and stereotactic intratumorally implanted optical laser fiber(s) was used to treat patients with recurrent malignant gliomas and metastatic melanoma of the brain. Tumor response to PDT was evaluated by recording changes in the volume and pattern of tumor enhancement between computed tomographic and magnetic resonance imaging scans done before and after PDT, metabolic changes in tumor tissue by 31P magnetic resonance spectroscopy, and patient outcome. Toxicity of PDT to brain was evaluated on the basis of changes in the patients' neurological examinations and correlated with changes in brain adjacent to tumor seen on postoperative imaging studies. Dramatic tumor responses to PDT were seen in all gliomas, but no response of tumor to treatment was seen with melanoma. Transient signs and symptoms of increased peritumoral cerebral edema caused by PDT were seen in all patients. Two patients suffered permanent neurological sequelae, monocular blindness and a partial visual field defect, as a result of treatment. Two patients with recurrent anaplastic astrocytomas remain in remission at 45 and 35 weeks after PDT. We conclude that intratumoral photoradiation therapy of hematoporphyrin derivative-photosensitized malignant gliomas effectively produces necrosis of the solid component of malignant gliomas; however, intratumoral photoradiation may not reach the portion of tumor that invades normal brain.     

Optimal light dose for interstitial photodynamic therapy in treatment for malignant brain tumors

BACKGROUND AND OBJECTIVE:The primary goal was to determine the maximal tolerable light dose that can be administered to patients undergoing multifiber interstitial photodynamic therapy (PDT) of malignant brain tumors at a fixed dose of photosensitizer. STUDY DESIGN/MATERIALS AND METHODS: Eighteen patients (12 glioblastomas, 5 anaplastic astrocytoma, and 1 malignant ependymoma) were included in this study. The total light dose delivered to the tumor was divided into three groups of six patients each: 1,500-3,700 J, 3,700-4,400 J, and 4,400-5,900 J. RESULTS: Five patients (all glioblastomas) demonstrated postoperative permanent neurologic deficits. None of the patients in 1,500-3,700 J, two patients in 3,700-4,400 J, and three patients in 4,400-5,900 J had neurologic deficits. Glioblastomas recurred more often than anaplastic astrocytomas. Increasing the light dose did not make a difference in local/regional control of glioblastomas. Patients with anaplastic astrocytomas survived (mean, 493 days) longer than patients with glioblastomas (mean, 116.5 days) after PDT. Four patients had prolonged survival (more than a year) after PDT. CONCLUSIONS: Increasing the total light dose delivered to the tumor increases the odds of having a permanent neurologic deficit but does not increase survival or time to tumor progression. There was no difference in local or marginal recurrence with increasing light dose. Recurrent anaplastic astrocytomas tend to do better than recurrent glioblastomas with PDT.     

Laser treatment of ureteral tumors

Ureteroscopic laser coagulation was performed in 20 patients. In 4 of these patients endoscopic treatment was judged to be incomplete and biopsy demonstrated a muscle invasive tumor in 3 and a poorly differentiated tumor in 1. Therefore, segmental resection or nephroureterectomy followed. In the other 16 patients laser treatment alone (8) or in conjunction with electroresection (8) eradicated the tumor successfully. All of these were stage Ta or T1 and grade 1 or 2 tumors. Three recurrences (after 12, 24 and 49 months) were detected within a medium observation period of 13.8 months and could be eradicated easily with the laser, since these tumors were small. A ureteral stricture developed at the treatment site once in the "laser only" group and 3 times in the group with laser treatment and electroresection. Endoscopic laser coagulation seems to be a promising treatment modality for selected small ureteral tumors. Electroresection has a high risk for development of a ureteral stricture. Regular retrograde ureteropyelography is mandatory for follow-up.     

CT-guided stereotactic injection of radionuclide for treatment of brain tumors.

The authors report on 40 brain tumor patients treated with CT-guided stereotactic injection of 198Au and 32P. Among the 40 cases were astrocytoma in 23 cases, craniopharyngioma in 9, meningioma in 4, pituitary adenoma in 2, and pinealoma and metastatic carcinoma each in 1 case. The tumors were all located in deep or important areas of the brain which were difficult to deal with by conventional operation. 62 injections of colloidal isotopes were performed, and all were successful. No major adverse effects or complications occurred on follow-up of 6-12 months, 28 patients were improved in their clinical symptoms, and CT scanning showed that the tumor sizes were diminished. The effective rate is 70%.     

Photoradiation therapy: current status and applications in the treatment of brain tumors

Photoradiation therapy is achieved when a photosensitizing drug is activated by light to form products that are lethal to tumor cells. The most commonly used drug is hematoporphyrin derivative, which is preferentially taken up and retained by malignant tissue. Photoactivation is usually produced by using a dye laser tuned at 630 nm (red light). The primary mechanism of neoplastic cell damage in photoradiation therapy involves the production of free radicals formed during illumination of hematoporphyrin derivative by light of this wavelength. The treatment would seem to damage first the tumor cell membrane, then the cytoplasmic inclusions, and finally the nucleus. Photoradiation therapy has been quite effective in the treatment of superficial malignancies, especially in skin, breast, eye, bladder, bronchus, and stomach. Experience with brain tumors is still limited. Important unresolved problems in the application of photoradiation therapy to gliomas include relative uptake of hematoporphyrin derivative into the tumor, limited light penetration of the tissue, local heating, and damage induced in normal brain by photoradiation therapy.     

Transparent microballoon dissection in the surgical treatment of brain tumors.

In spite of maximal microsurgical efforts, perilesional neural tissue can be injured by surgical instruments in the process of the separation and dissection of tumors. We hypothesized that transparent microballoon dissection could be helpful in the gentle separation of brain tissue from tumor by minimizing cerebral damage, and in separating sulcal and cisternal walls during surgical interventions on brain masses. We used the transparent microballoon dissection technique in 3 primary cases and 4 metastatic brain tumors that were verified with computed tomography (CT) and magnetic resonance imaging (MRI). Gentle separation of tumor from surrounding brain, reduction of cerebral damage, and separation of sulcal and cisternal walls were feasible in all patients. Postoperative CT and MRI showed satisfactory results in reducing perilesional cerebral damage. The transparent microballoon inflation technique is a useful microsurgical method for the gentle separation of tumors from surrounding brain tissue, minimizing cerebral damage, and separating sulcal and cisternal walls during surgical interventions for brain masses. Our conclusion is that using the microballoon dissection method may be suitable in microneurosurgical practice.     

The role of radiosurgery in the treatment of malignant brain tumors.

Most studies describing the results of radiosurgery have concentrated on the definitive treatment of small, histologically benign lesions such as vascular malformations, acoustic neurinomas, and pituitary adenomas. More recently, the role of radiosurgery using the gamma knife or LINAC-based systems to treat malignant neoplasms has become better defined. Most solitary metastases, ependymomas, well-circumscribed (on imaging studies) AAs, and a few glioblastomas (and other tumors) have responded dramatically to radiosurgery. Provided that the tumor volume was small (less than or equal to 14 cm3; 30-mm diameter), radiosurgery safely has caused tumor disappearance, shrinkage, or stabilization, regardless of prior surgery, conventional fractionated irradiation, or tumor radioresistance. For patients with recurrent or persistent, small, malignant intracranial tumors, radiosurgical treatment has obviated the need for prolonged hospitalization and has eliminated the risks associated with general anesthesia and open craniotomy.     

Combined treatment of brain stem tumors

During the two recent decades the introduction of new technologies to neurosurgery resulted in certain progress in diagnosis and combined treatment of brain stem tumors which still remain the most complex problems of neurooncology. Using the present-day diagnostic complex including a thorough dynamic neurological examination, neurophysiological investigations, and visualization methods allowed not only to detect the primary forms of brain stem tumors and their sizes but also to reveal the topographoanatomical interrelationships with the stem structures that allowed to determine the chances of surgical, combined treatment or the radiation and chemotherapy treatment only. The article gives an analysis and the clinical course of the diagnosis and combined treatment of 333 children and adult patients with primary, secondary and peri-trunkal tumors of the brain stem.     

脑干肿瘤的显微手术治疗

目的：总结１５例脑干肿瘤进行１６次显微手术的经验。方法：根据肿瘤生长部位及方向不同选择不同的入路。肿瘤位于延脑突向ＩＶ脑室取后颅窝枕下中线开颅，切开小脑蚓部；突向桥小脑血者选择单侧乳突后入路，切除部分小脑。手术在显微镜下直视瘤内分小块切除。结果：１０例获得较好的疗效。随访５个月至２年半。３例恢复工作、学习，３例生活自理，４例需人照料，恢复过程良好。结论：选择手术入路是成功的关键，ＭＲＩ是脑干肿瘤首