Harmonin homology domain-mediated interaction of RTEL1 helicase with RPA and DNA provides insights into its recruitment to DNA repair sites

The regulator of telomere elongation helicase 1 (RTEL1) plays roles in telomere DNA maintenance, DNA repair, and genome stability by dismantling D-loops and unwinding G-quadruplex structures. RTEL1 comprises a helicase domain, two tandem harmonin homology domains 1&2 (HHD1 and HHD2), and a Zn2+-binding RING domain. In vitro D-loop disassembly by RTEL1 is enhanced in the presence of replication protein A (RPA). However, the mechanism of RTEL1 recruitment at non-telomeric D-loops remains unknown. In this study, we have unravelled a direct physical interaction between RTEL1 and RPA. Under DNA damage conditions, we showed that RTEL1 and RPA colocalise in the cell. Coimmunoprecipitation showed that RTEL1 and RPA interact, and the deletion of HHDs of RTEL1 significantly reduced this interaction. NMR chemical shift perturbations (CSPs) showed that RPA uses its 32C domain to interact with the HHD2 of RTEL1. Interestingly, HHD2 also interacted with DNA in the in vitro experiments. HHD2 structure was determined using X-ray crystallography, and NMR CSPs mapping revealed that both RPA 32C and DNA competitively bind to HHD2 on an overlapping surface. These results establish novel roles of accessory HHDs in RTEL1's functions and provide mechanistic insights into the RPA-mediated recruitment of RTEL1 to DNA repair sites.

Hamiltonian Engineering with Multicolor Drives for Fast Entangling Gates and Quantum Crosstalk Cancellation

Quantum computers built with superconducting artificial atoms already stretch the limits of their classical counterparts. While the lowest energy states of these artificial atoms serve as the qubit basis, the higher levels are responsible for both a host of attractive gate schemes as well as generating undesired interactions. In particular, when coupling these atoms to generate entanglement, the higher levels cause shifts in the computational levels that lead to unwanted ZZ quantum crosstalk. Here, we present a novel technique to manipulate the energy levels and mitigate this crosstalk with simultaneous off-resonant drives on coupled qubits. This breaks a fundamental deadlock between qubit-qubit coupling and crosstalk. In a fixed-frequency transmon architecture with strong coupling and crosstalk cancellation, additional cross-resonance drives enable a 90 ns CNOT with a gate error of (0.19±0.02)%, while a second set of off-resonant drives enables a novel CZ gate. Furthermore, we show a definitive improvement in circuit performance with crosstalk cancellation over seven qubits, demonstrating the scalability of the technique. This Letter paves the way for superconducting hardware with faster gates and greatly improved multiqubit circuit fidelities.

Performance evaluation of various aerobic biological systems for the treatment of domestic wastewater at low temperatures

Studies were undertaken on the performance evaluation of three different types of aerobic reactors, namely, activated sludge process, fluidized bed reactor and submerged bed reactor. Initially synthetic wastewater was used for stabilizing the system and later domestic wastewater of IIT Madras was used as the feed for the biological systems. The hydraulic retention time was maintained as 24 h. The seed sludge was collected from IIT Madras sewage treatment plant. The inlet COD to the reactors with synthetic wastewater was 1,000 +/- 20 mg/L and with real wastewater, it was 150 to 350 mg/L. The performance of the reactors was evaluated based on the soluble COD and nitrogen removal efficiency. The pH, temperature, dissolved oxygen (DO) and mixed liquid suspended solid (MLSS) concentration were measured periodically. The reactors were acclimatized at 35 degrees C in batch mode and changed to continuous mode at 30 degrees C. After the systems attained its steady state at a particular temperature, the temperature was reduced from 35 degrees C to 5 degrees C stepwise, with each step of 5 degrees C. The start-up time for submerged bed reactor was slightly more than fluidized and conventional activated sludge process.The COD removal efficiency of the three reactors was higher with synthetic wastewaters as compared to actual domestic wastewater. Submerged bed reactor was more robust and efficient as compared to activated sludge and fluidized bed reactors. The COD removal efficiency of the reactors was relatively good until the operating temperature was maintained at 15 degrees C or above. At 10 degrees C, submerged bed reactor was able to achieve 40% COD removal efficiency whereas; the fluidized bed and conventional ASP reactors were showing only 20% COD removal efficiency. At 5 degrees C, almost all the systems failed. Submerged bed reactor showed around 20% COD removal efficiency. However, this reactor was able to regain its 90% of original efficiency, once the temperature was raised to 10 degrees C. At higher temperatures, the nitrification efficiency of the reactors was above 80-90%. As the temperature reduced the nitrification efficiency has reduced drastically. In summary, submerged bed reactors seems to be a better option for treating domestic wastewaters at low temperature regions.

Management of tumors of the thoracolumbar spine

Current improvements in radiologic imaging and surgical instrumentation have greatly expanded the role of surgery in management of tumors of the thoracolumbar junction. For primary malignant tumors, the aim of surgery should be curative, with eradiction of all gross disease. For metastatic tumors, indications for surgery include cancer therapy, stabilization, neurologic palliation, tissue diagnosis, and pain relief. Because the thoracolumbar region is a transitional zone, surgical stabilization may require anterior-posterior approaches and instrumentation.

Indications and results of combined anterior-posterior approaches for spine tumor surgery

Spinal instrumentation currently allows gross-total resection and reconstruction in cases of malignancies at all levels of the spine. The authors analyzed the results in 110 patients who underwent surgery for primary and metastatic spinal tumors over a 5-year period (1989-1993) at a single institution. Major primary sites of tumor included breast (14 cases), chordoma (14 cases), lung (12 cases), kidney (11 cases), sarcoma (13 cases), plasmacytoma (10 cases), and others (36 cases). Prior to surgery, 55 patients (50%) had received prior treatment. Forty-eight patients (44%) were nonambulatory, and severe paraparesis was present in 20 patients. Fifty-three patients (48%) underwent combined anterior-posterior resection and instrumentation. 33 (30%) underwent anterior resection with instrumentation, 18 (16%) underwent anterior or posterior resection alone, and the remaining six patients (5%) underwent posterior resection and instrumentation. Major indications for anterior-posterior resection included three-column involvement, high-grade instability, involvement of contiguous vertebral bodies, and solitary metastases. Postoperatively, 90 patients improved neurologically. The overall median survival was 16 months, with 46% of patients surviving 2 years. Fifty-three patients (48%) suffered postoperative complications. Despite the high incidence of complications, the majority of patients reported improvement in their quality of life at follow-up review. Our findings suggest that half of all patients with spinal malignancies require combined anterior-posterior surgery for adequate tumor removal and stabilization.

Surgical treatment of spinal cord compression from epidural metastasis

PURPOSE

A retrospective study of the results of neoplastic cord compression was undertaken to determine the effectiveness of surgical treatment and to assess quality of life in patients undergoing extensive procedures with potential morbidity.

PATIENTS AND METHODS

Over a 5-year period (1989 to 1993), a total of 110 patients underwent surgery. Fifty-five patients (50%) had undergone prior treatment, including 47 (43%) who had failed to respond to prior irradiation (RT). Before surgery, 48 patients (44%) were nonambulatory, with severe paresis being present in 20. Surgery included staged anterior-posterior resections in 53 patients (48%), anterior resections in 33 (30%), and posterior resection in six (5%), all of whom required spinal instrumentation for reconstruction; only 18 patients underwent resection without instrumentation.

RESULTS

Postoperatively, 90 patients (82%) were improved, both in terms of pain relief and ambulatory status. Fifty-three patients (48%) experienced postoperative complications, related statistically to the following three factors: age over 65 years, prior treatment, and presence of paraparesis. The overall median survival duration was 16 months, with 46% alive at 2 years. Apart from primary tumor, the presence of preoperative paraparesis had the most significant impact on survival.

CONCLUSION

Our data suggest that the effective surgical treatment of neoplastic compression requires anterior-posterior resection in most patients to achieve the goal of total tumor resection, with the majority requiring instrumentation. Long-term survival is feasible in a subset of patients with this aggressive surgical approach.

Management of the vertebral artery in excision of extradural tumors of the cervical spine

Extradural tumors of the cervical spine may involve the vertebral artery on one or both sides, posing one of the limiting factors toward the radical resection of such neoplasms. A standard anterior approach may be inadequate for the management of such tumors. An anterolateral approach allows the dissection and mobilization of the vessel, which can then be preserved, resected, or reconstructed with a vein graft. An anterior approach can be supplemented with this for tumor resection and stabilization. This management strategy is described in 10 patients with a variety of tumors.

Use of instrumentation in degenerative disease of the cervical spine

Degenerative diseases of the cervical spine (including cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament) occur predominantly in elderly persons. Decompressive laminectomy has been the standard of surgical treatment in the United States for several decades. Postlaminectomy kyphosis and instability and inadequate decompression of anterior compressing forces can fail to halt and may even contribute to progression of neurologic deterioration. Instrumentation of the cervical spine provides a means of stabilization and allows safer multilevel anterior decompression. The biomechanics of degenerative disease of the cervical spine as well as surgical treatment options are discussed. Atlantoaxial transarticular screw fixation and other modalities of instrumentation are described.

Pediatric spinal axis tumors

Pediatric spinal cord tumors occur in the intramedullary or extramedullary spaces. The extramedullary tumors are further divided into those in intradural-extramedullary or extradural locations. Tumors in the intradural-extramedullary region include nerve sheath tumors, meningiomas, and "embryonal" tumors. In the extradural space are neuroblastomas, sarcomas, and other primary tumors of bone. The radiographic findings, histology, and management of each type of tumor are included in this article, which focuses on extramedullary tumors.

Treatment of neoplastic spinal cord compression: results of a prospective study

Currently, external radiation and steroid therapy are used in most patients with neoplastic spinal cord compression. Surgery is generally used to treat those who do not respond to radiation therapy. To determine the role of de novo surgery in patients with spinal metastases, a prospective study was undertaken. Over a 4 1/2-year period, the cases of 54 patients with radiologically documented spinal metastases were studied. The sites of tumor origin included soft tissue sarcoma (8 patients), kidney (6 patients), lung (5 patients), breast (5 patients), spine (6 patients), unknown primary site (6 patients), and others (18 patients). Sites of compression included the cervical spine segments in 15 patients, thoracic segments in 23, lumbar in 14, and sacral in 2. Before surgery, 24 patients (44%) were nonambulatory. Three surgical approaches were used: anterior vertebral body resection in 45 patients, laminectomy in 7, and lateral osteotomy in 2. After surgery, 37 patients received external radiation therapy. All patients improved (became ambulatory) after surgery, with 23 of 25 patients surviving at 2 years continuing to be ambulatory. The 30-day mortality rate was 6% (three patients); eight patients (15%) sustained various surgical complications. These results are superior to those reported after external radiation therapy and steroids alone, and they support the concept that de novo surgery be considered in selected patients with spinal metastases.

Spinal instrumentation for degenerative disease of the lumbar spine

Instrumentation for spinal implant is currently changing more rapidly than at any previous period in its 100-year history. At present, the most common indication for spinal instrumentation is degenerative disease of the lumbar spine, which can be roughly categorized as of three kinds: herniated lumbar disks, spondylolisthesis, and spinal stenosis. The literature on indications for arthrodesis is reviewed. A brief summary of the approach and type of instrumentation available for the lumbar spine is presented.

Treatment of spinal metastases from kidney cancer by presurgical embolization and resection

Surgical treatment of bone metastases from kidney cancer is often complicated by profuse blood loss. The authors report the results of a retrospective review of 30 consecutive patients who underwent surgery for spinal metastases from kidney cancer. Seventeen patients (57%) were operated on after failing radiation therapy. Prior to operation, selective spinal angiography and embolization were performed in 17 patients with no permanent neurological deficits resulting. Gross total resection of the tumor and stabilization of the spine were then accomplished with acceptable blood loss. Twenty-seven (90%) of the 30 patients improved neurologically following surgery. There was a median survival time of 16 months, a 2-year survival rate of 33%, and a 5-year survival rate of 15%. Major surgical complications in this series were related to excessive blood loss in patients without embolization. These data suggest that patients with spinal metastases from kidney cancer should undergo spinal angiography and embolization prior to resection of the tumor. To improve upon current results, such treatment should be carried out prior to external radiation therapy.

Chemotherapy of recurrent esthesioneuroblastoma. Case report and review of the literature

Esthesioneuroblastoma is a rare epithelial tumor of the nasal olfactory mucosa. Its clinical course is characterized by indolent growth and persistent local recurrence and occasional distant metastases despite attempts at cure. Our report documents the response of a patient to a cisplatin-based drug combination and reviews the English-language literature of 25 patients treated with chemotherapy. We conclude that this tumor is sensitive to several different combinations and suggest guidelines for the use of chemotherapy in advanced or metastatic esthesioneuroblastoma.

Optimal use of the Ommaya reservoir in clinical oncology

A major obstacle to the effective systemic therapy of intracranial malignancies and infections, the bloodbrain barrier was overcome by the development of the Ommaya reservoir in 1963. Initially used in treating cryptococcal meningitis, this closed system for continued access to the ventricular spaces has a variety of applications. They include treatment of cancer pain, chronic or recurrent CNS infection, prophylaxis of CNS involvement in acute lymphoblastic leukemia, and treatment of leptomeningeal malignancy. The authors outline the rationale, latest indications, surgical technique, and potential complications arising from the use of the Ommaya reservoir and other such subcutaneous reservoirs.

Spondylectomy for malignant tumors of the spine

Spondylectomy is the complete surgical removal of all parts of one or more vertebrae above the sacrum. We report our initial experience with spondylectomy in eight patients with malignant tumors of the spine operated on over a 7-year period (1980 to 1986). Four patients had primary neoplasms of the spine, and four others had solitary metastases to the vertebrae. Following surgery, five patients underwent radiation therapy (RT) and chemotherapy depending on histology of the tumor. Radiographic confirmation of tumor resection was obtained on all patients. Pain relief was noted in all patients, and six patients with preoperative neurological deficits improved. There was no surgical mortality, and one patient developed wound dehiscence following surgery. Six of the eight patients are alive with a median follow-up of 36 months, and local control was achieved in six of the eight patients. These preliminary data suggest that malignant tumors of the spine can be completely resected using a staged approach. In potentially responsive tumors, systemic chemotherapy is recommended between the two operations to reduce the risk of systemic dissemination.

Neurosurgery in the treatment of cancer pain

Patients with pain syndromes resulting from recurrent or metastatic cancer should be evaluated carefully to determine the cause of their pain and the need for appropriate antitumor treatment. Currently, opioid analgesics are the mainstay of pain control, but side effects limit their use in some patients. When pharmacologic pain control is inadequate or associated with intolerable side effects, neurosurgery should be considered. Currently the implantation of a pump for the intraspinal infusion of opioid analgesics is the most popular procedure, but its usefulness may be limited by the development of opioid tolerance. The most effective ablative pain control procedure at the current time is cordotomy, which is indicated in patients with unilateral pain. Although the place of neurostimulatory procedures in controlling cancer pain is not well established, they are attractive because of their nondestructive nature and potential usefulness in the treatment of bilateral pain syndromes. Specific antitumor surgical procedures should be considered in patients with certain spinal and plexopathy syndromes, because such intervention offers the prospect of both pain relief and tumor control. In this article, the neurosurgical procedures used in the management of cancer pain are reviewed.

Combined treatment of osteosarcoma of the spine

We reviewed the clinical features and results of treatment in 24 patients with osteogenic sarcoma of the spine treated over a 35-year period. There were 14 male and 10 female patients 13 to 71 years old. The tumor arose de novo in 13 patients and was secondary to other conditions in 11. All patients presented with pain, and 16 (67%) had neurological deficits. Patients were divided into two treatment groups. Thirteen patients treated from 1949 to 1977 usually underwent limited tumor resection and external radiation therapy. The second group, 11 patients treated from 1978 to 1984, underwent more aggressive surgical resection and received combination chemotherapy as well as local radiation to the tumor bed. In the second group, there were 5 long term survivors, and only 1 patient developed metastatic disease while on therapy. Failure to obtain local control was the major cause of treatment failure. Complete surgical resection of the tumor by spondylectomy and combination chemotherapy offer the best prospect for cure of osteogenic sarcoma of the spine.

Reoperation for brain metastases

We report the results of reoperation for brain metastases in 21 patients with recurrent tumors following initial successful resection. The tumor recurrences were local (original site) in 14 patients, and occurred at other sites in the brain in the remaining seven. Time to CNS recurrence ranged from 3 to 30 months. At time of repeat craniotomy, disease was limited to the CNS in 12 (57%) of the patients. Median survival following second craniotomy was 9 months, and the actuarial 2-year survival was 25%. Neurological improvement was seen in two thirds of the patients; the median duration of neurological improvement was 6 months. There was no mortality, and only one patient developed increased deficit following surgery. We conclude that repeat resection of brain metastases is an important therapeutic option in selected patients, and should be considered in symptomatic patients with accessible mass lesions before the use of other experimental treatment.

Craniofacial resection for anterior skull base tumors

We present the results of treatment of 30 patients with anterior skull base tumors operated on over an 11-year period. At the time of surgery, intracranial invasion was present in 10 patients. Histology revealed epithelial tumors in 18 patients, sarcoma in 6, esthesioneuroblastoma in 4, and 2 miscellaneous histologies. The overall median survival was 5 years and varied according to histology and grade of tumor. Currently malignancies involving the skull base can be successfully resected using a craniofacial approach, with minimum operative mortality. Limited intracranial invasion need not necessarily represent a major contraindication of this procedure if morbidity can be kept to a minimum.

Surgical treatment of spinal chordomas

The clinical features and results of 34 patients with chordomas treated over a seven-year period were analyzed. Surgical treatment consisted of wide local excision (n = 6), marginal resection (n = 5), intralesional resection (n = 20), and biopsy (n = 3). Eighteen patients received postoperative radiotherapy. The local recurrence rate was 65%, with 30% of patients developing distant metastases. With the introduction of computed tomography, smaller tumors are currently being diagnosed; as a result, 35% of the patients in this series are disease free, compared with 10% described previously.

The combined neurosurgical-thoracic management of superior sulcus tumors

Thirty patients with superior sulcus carcinoma were prospectively evaluated over an 18-month period. All patients underwent complete neuroradiological evaluation by computed tomography (CT) and myelography. Prior to operation, brachial plexopathy was noted in 20 patients (67%), and invasion of the spine in eight (27%). Using a team approach, gross total resection of tumor was achieved in 17 of 26 patients (65%) undergoing thoracotomy. There was no operative mortality. The use of a team approach allows extended surgical resection, especially when the spine is involved. In patients presenting with brachial plexopathy or cord compression, de novo surgery before radiation may provide better long-term palliation and pain relief.

Craniofacial resections for tumors involving the base of the skull

Over a 10 year period, 42 patients with tumors involving the base of the skull underwent operation at our institution. Twenty-six patients had tumors involving the anterior fossa and cribriform plate, 3 patients had tumors involving the anterior fossa and orbit, 3 patients had invasion of the middle fossa, 5 patients had invasion of the temporal bone, and 5 patients had invasion of the clivus. A detailed analysis of the 26 patients who underwent craniofacial resection for tumors invading the anterior fossa cribriform plate region has been presented. Histologic studies revealed epithelial tumors in 18 patients, sarcoma in 6 patients, melanoma in one patient, and ossifying fibroma in one patient. The median survival in this group of patients was 60 months. Survival was influenced by histologic diagnosis. Malignant tumors involving the base of the skull can be successfully resected using a craniofacial approach with minimum morbidity and acceptable operative mortality as demonstrated in this experience. Unfavorable prognostic factors included massive intracranial extension, high grade tumor, and previous treatment failure.

Antitumor and antinociceptive approaches to control cancer pain

Patients with cancer pain often present with specific clinical syndromes that allow specific anti-tumor approaches. If these approaches are not feasible, neurosurgical procedures for pain relief should be considered. The major advantage of neurosurgical procedures is freedom from the excessive side effects of narcotic therapy. The most durable pain procedure is cordotomy, while intraspinal narcotics offer a rational treatment alternative in selected patients. Spinal and plexopathy syndromes that are amenable to more specific anti-tumor therapy should be looked for, since newer surgical approaches offer the prospect of both pain relief and tumor control.

Surgical treatment of spinal cord compression in kidney cancer

Forty-three patients with renal-cell carcinoma underwent treatment for spinal cord compression over a 7-year period. Of these, 32 patients underwent surgery, while 11 patients underwent radiation alone. Before operation, 25 patients had relapsed following prior radiation, while seven others received postoperative radiation. A more aggressive surgical approach, tailored to the site of compression within the spinal canal, was used with the majority undergoing gross total tumor resection by an anterior approach. Immediate stability of the spine was achieved with methyl-methacrylate reconstruction of the resected segments. Preoperative spinal angiography with embolization of hypervascular tumors was carried out in eight patients. Patient parameters in the surgical and irradiated groups were comparable, except that a greater proportion of the radiation alone group had more than one organ system involved (64% v 44%). The median survival of the surgically treated patients was 13 months, compared with 3 months for those treated by radiation alone. In addition, a greater proportion of the surgically treated patients were benefitted neurologically (70%) compared with those treated by radiation (45%). With the development of effective surgical treatment for spinal metastases, early consideration for surgical treatment (before radiation) should be considered in selected patients. Preoperative spinal angiography and embolization are recommended whenever feasible to minimize intraoperative blood loss.

The treatment of single brain metastasis from non-oat cell lung carcinoma. Surgery and radiation versus radiation therapy alone

Between 1978-1980, 104 patients with single brain metastases (SBM) from non-small cell lung carcinoma (NSCLC) were treated at Memorial Sloan-Kettering Cancer Center (MSKCC). These included 35 patients treated with surgical resection and radiation (S + ERT) and 69 patients treated with conventional external beam radiation therapy alone (ERT). Surgical resection was combined with whole brain (WBRT) and focal radiation in 83% and 17% of patients, respectively. In the ERT group, all patients received WBRT. Both treatment groups were similar with regard to age, sex, stage distribution, location and size of SBM, and time to relapse from initial diagnosis of NSCLC. The histologic examination, however, revealed adenocarcinoma predominating in those patients receiving S + ERT and epidermoid carcinoma in those receiving ERT. Follow-up treatment, symptomatic, and CTT response rates were evaluated. With S + ERT, the overall subjective and objective responses were 80% and 87%, respectively, and with ERT, 83% and 72% (of the 47 patients available for follow-up CT scans), respectively. Survival data indicate a significant advantage of S + ERT over ERT with a median survival of 16 months versus 4 months (P less than 0.0001). Three major factors, however, may have contributed to this difference: (1) patients in the S + ERT group generally received more aggressive initial treatment to the primary disease in the lung (72%) compared to the ERT group (36%); (2) in the S + ERT group, extracranial disease was absent at the time of SBM diagnosis in 49% of the S + ERT group compared to 26% in the ERT group; and (3) distant metastases were present in only 6% of the surgical patients yet, they were present in 49% of those treated with radiation alone. In one subset of patients, however--those with a radically treated primary and no extracranial disease--S + ERT resulted in a median survival of 33 months with 33% of the population still alive with no evidence of disease compared to 12 months and 0%, respectively, with ERT alone. Moreover, intracranial relapse was the cause of death in only one S + ERT patient (9%), yet it accounted for 50% of the ERT deaths. These data suggest that an aggressive approach to SBM in such favorable prognostic patients may indeed improve survival.

Postradiation sarcoma involving the spine

Postradiation sarcomas arising many years after treatment of cancer are long term sequelae of therapy. We describe the clinical features, radiographic findings, and results of treatment in 13 patients with such sarcomas encountered over a 6-year period. Of these patients, 9 had bone sarcomas and the remaining 4 had paraspinal tumors arising from adjacent soft tissue and nerve. The primary cancer for which radiation was given included Hodgkin's disease (4 patients), breast cancer (2 patients), cervix cancer (2 patients), and a variety of others (5 patients). The latent interval to the occurrence of the second neoplasm varied from 6 to 30 years (median, 10 years) after treatment of the original tumor. Despite aggressive treatment, the overall prognosis was poor. The median survival was 8 months, with only 3 surviving more than 2 years. Although rare, postradiation sarcoma should be considered in the differential diagnosis of patients presenting with late onset of spinal pain or neurological symptoms after clinical remission of an original cancer.

Chordomas

Chordomas constitute between 1% and 4% of primary malignant bone tumors. Approximately 50% originate in the sacrum, 35% at the base of the skull, and 15% in the true vertebrae. The majority of tumors are encountered from the fifth through seventh decades, with a male preponderance. The clinical symptoms and signs are nonspecific and lead to frequent errors in clinical diagnosis. Radiographic findings include nonspecific destruction of the vertebral body, with reactive sclerosis; calcification is more often seen in sacral tumors. Computed tomography (CT) frequently reveals an anterolateral soft-tissue mass, which is often more extensive than the osseous involvement. The optimal treatment for sacral tumors should be en bloc resection of the tumor performed through intact bone a level above (wide local excision); for vertebral lesions, an anterior surgical approach with resection of the vertebral body should be performed. While conventional radiation has little efficacy in this tumor, a variety of innovative newer approaches may prove more effective in the future. Conventional chemotherapy has not proved effective in this tumor. With early diagnosis, and more effective surgical therapy, the current disease-free survival at five years should be between 30% and 50%.

Treatment of neoplastic epidural cord compression by vertebral body resection and stabilization

The results of treatment of neoplastic spinal cord compression by vertebral body resection and immediate stabilization in 101 consecutive patients over a 5-year period have been analyzed. Sites of primary cancer included the lung (25 patients), kidney (15 patients), breast (14 patients), connective tissue (12 patients), and a variety of others (35 patients). Of the 101 patients, 23 received surgery de novo; the remaining 78 patients had undergone previous therapy. Sites of involvement included the cervical region in 13 patients, the thoracic region in 68 patients, and the lumbar region in 20 patients. Prior to surgery, severe pain was noted in 90% of the patients, and 45% were non-ambulatory. Using an anterolateral surgical exposure, the vertebral body was resected along with all epidural tumor. Immediate stabilization was achieved with methyl methacrylate and Steinmann pins. Following surgery, the overall ambulation rate was 78%, and 85% of patients experienced pain relief. Of the 23 patients who had received no prior therapy, 90% continued to be ambulatory at their last follow-up examination or until death. The authors believe that surgery prior to irradiation is indicated in selected patients with neoplastic cord compression. In patients with solitary osseous metastasis to the spine, potentially curative resection can be undertaken if surgery is performed when the tumor is still confined to the vertebral body.

Combined-modality treatment of osteogenic sarcoma of the skull

The authors present the results of combined-modality treatment in eight patients with osteosarcoma of the skull. Six patients had de novo tumors, and two others had secondary sarcomas resulting from malignant transformation in Paget's disease. Wide surgical excision and combination chemotherapy were used in seven patients, and surgery and radiation therapy were employed in one case. Following chemotherapy, six patients underwent additional surgery. This aggressive approach resulted in four long-term survivors among the patients with de novo tumors. These data suggest that surgery in combination with chemotherapy provides the best potential for long-term disease control in patients with osteosarcoma of the skull.

Osteogenic sarcoma of the skull. A clinicopathologic study of 19 patients

The authors studied 19 patients with well documented osteogenic sarcomas arising in the skull, which represent 1.6% of all osteogenic sarcomas registered during a 60-year period (1921-1981). Ten sarcomas were primary, de novo tumors. Nine others developed secondary osteogenic sarcomas; among these, six arose as a complication of Paget's disease, two followed irradiation, and one was associated with pre-existent fibrous dysplasia. The sarcomas arose in equal proportion in both sexes with the men being much older (mean age, 44 years) as compared to the women (mean age, 31 years). Patients with de novo osteogenic sarcomas were considerably younger than those with secondary lesions. Osteoblastic osteogenic sarcoma was by far the most common histologic variant in both the primary and the Paget's sarcomas. None of the patients with Paget's sarcoma lived longer than 1 year; the median survival here was 4 months. Patients with de novo osteogenic sarcomas fared much better and there are four long-term survivors (longer than 3 years) who are currently disease-free.

Surgical treatment of brain metastases. Clinical and computerized tomography evaluation of the results of treatment

The results of treatment of brain metastases in a series of 125 patients who underwent surgery with or without postoperative radiation from 1978 through 1982 were analyzed. The major sites of primary tumor included the lung (40%), melanoma-skin (11%), kidney (11%), colon (8%), soft tissue sarcoma (8%), breast (6%), and a variety of others (15%). At the time of craniotomy, disease was considered limited to the central nervous system in 63 patients (50%). After surgery, 83 patients (66%) were neurologically improved, and 26 (21%) had their deficits stabilized. The overall median survival was 12 months, and 25% lived 2 years. Eight patients (12%) are alive 5 years or more following surgery. Survival varied with site of primary tumor, location of brain metastasis, extent of systemic disease, and neurologic deficit at time of craniotomy. Over a follow-up period ranging from 18 months to 6 years, 42 patients (34%) developed either local recurrences or other sites of brain metastases. These data suggest that although craniotomy followed by radiation is highly effective in the initial treatment of selected patients with brain metastases, alternate therapies require investigation in view of the high central nervous system relapse rate in long-term survivors.

Surgical treatment of spinal cord compression in patients with lung cancer

We analyzed the clinical features, radiological findings, and results of surgical treatment in a series of 25 patients with lung cancer and invasion of the spine. In 12 of the 25 (40%) patients, involvement of the spine was present at the time of initial presentation of malignancy. Computed tomography revealed the presence of a large paravertebral soft tissue mass with destruction of adjacent ribs in the majority. The surgical approach consisted of an anterolateral exposure through a formal thoracotomy in 22 patients and a thoracoabdominal flank approach in the 3 patients with lumbar lesions. All gross tumor was resected from the involved paravertebral tissues, vertebral body, and epidural space. Immediate stabilization of the spine was then achieved with methyl methacrylate. Local brachytherapy (iridium-192 implants) was used in 19 patients. After treatment, 87% were ambulatory, and 67% maintained ambulation for more than 6 months. Our data suggest that compression of the spinal cord in many patients with lung cancer results from direct extension of tumor through the chest wall. Because the majority of such patients often have localized disease involving the spine, aggressive surgical treatment is indicated.

Surgical treatment of single brain metastases from non-small-cell lung cancer

We analyzed the results of surgical treatment of 50 patients with brain metastases from non-small-cell lung cancer who underwent craniotomy between the years 1978 through 1983. The onset of brain metastases was synchronous in 14 patients, occurred within 1 year of treatment of the primary tumor in 21 patients, and after 1 year in 15 patients. A total of 28 patients had undergone curative resection of the lung tumor; 15 patients had undergone palliative resection with or without radioactive implants, and 7 patients did not undergo surgical treatment of their primary tumor. At time of craniotomy, 31 patients were considered to have disease limited to the central nervous system. Following surgery, 34 patients received radiation therapy (30 whole brain radiation, 4 focal radiation); 15 patients had previously undergone whole brain radiation ("radiation failures"), and there was 1 postoperative death. The overall median survival in this series was 18 months. Favorable prognostic variables included (a) curative resection of the primary tumor (median 28 months), (b) disease limited to the central nervous system (median 24 months), and (c) negative mediastinal nodes at time of thoracotomy (median 28 months). The incidence of local recurrence of intracranial tumor at the original site was higher in those patients who had failed previous radiation (53%) compared to those who received postoperative radiation (12%). Although the overall degree of neurological palliation was 75%, patients who had failed radiation were less successfully palliated, and the majority continued to require steroid therapy following tumor resection. These results suggest that patients with single brain metastases from non-small-cell lung cancer who have undergone curative resection of their primary tumor have considerable potential for long-term survival, and surgical resection prior to radiation should be considered. Even in symptomatic patients with controlled or limited extracranial disease, such treatment provides rapid effective neurological palliation and can be accomplished currently with minimal mortality and morbidity.

An anterior surgical approach to the upper thoracic vertebrae

Of the various anterior surgical approaches to the spine, exposure of the upper two thoracic vertebrae remains the most challenging. An operative approach to this region is described. The major features include resection of a portion of the clavicle and the manubrium sterni. Following resection of the tumor and involved vertebra, anterior fusion is performed using the clavicle as a strut graft. Immediate stabilization may also be achieved with methyl methacrylate replacement of the vertebral bodies. The operation is well tolerated, and requires minimal postoperative immobilization. The clinical presentation, radiological features, and results of treatment in a series of seven patients operated on during a 2-year period are presented.

A transsternal approach to the upper thoracic vertebrae

An anterior surgical approach to the upper thoracic vertebrae has been described. A T-shaped skin incision is used, with the horizontal limb 1 cm above the clavicle, and the vertical limb extending in the midline over the body of the sternum. A portion of the manubrium sterni, as well as the medial third of the clavicle, is resected; the avacular tissue plane between the carotid sheath laterally and the trachea and esophagus medially is developed to reach the prevertebral space. After surgery, immediate fusion is performed using the clavicle and manubrium. This procedure is well tolerated, and was associated with minimal morbidity and no mortality in a series of seven patients.

Acute nonlymphocytic leukemia following treatment of malignant glioma. Report of two cases

Two patients with malignant brain tumors who developed acute nonlymphocytic leukemia after treatment with radiation and chemotherapy are described. Both patients survived more than 2 years after diagnosis of the brain tumor. Survival following the diagnosis of leukemia was short, and both patients died of hemorrhage secondary to thrombocytopenia. A review of the literature reveals that leukemia after combined-modality treatment of malignant brain tumors is rare. A prolonged survival period from diagnosis of the primary tumor, treatment with nitrosoureas and radiation, plus the development of a preleukemic myelodysplastic syndrome are all important features of therapy-related nonlymphocytic leukemia.

Vertebral body resection in the treatment of cancer involving the spine

Results of radical spinal surgery with vertebral body resection in of 51 patients with primary and metastatic cancer of the spine were analyzed. Seven patients had primary spine tumors, 16 had paravertebral tumors that involved the spine by direct extension, and 28 had blood-borne metastases to the spine. Thirty-five patients (68%) had prior therapy directed to the spine: 4 had undergone previous surgery, 9 had surgery and radiation, and 22 had radiation alone. Forty-five patients (90%) had intractable pain, and 25 patients (48%) were nonambulatory. Myelography revealed high-grade or complete block in 39 patients (76%). Following surgery, 38 of 45 (84%) had pain relief, and 40/58 (78%) were ambulatory at discharge. Of the 25 patients who were unable to walk prior to surgery, 15 (60%) improved to fully ambulatory status. The surgical mortality was low (4%), and complications were few (10%). These results are superior to those reported following treatment by radiation and steroid therapy. In selected patients who have actual or potential neural compression resulting from tumor within the vertebral body, such surgery should be considered as initial therapy.

Harrington rod stabilization for pathological fractures of the spine

Nineteen patients with tumors involving the thoracolumbar spine were treated by Harrington rod stabilization following laminectomy. Sixteen patients had metastatic neoplasms, and three had primary tumors of the vertebral column. In five patients, extensive decompressive laminectomy and Harrington distraction rods to provide immediate stability were used as initial treatment; postoperative irradiation was then given. All five patients were ambulatory, and the four patients with preoperative pain all noted relief of pain following treatment. The remaining 14 patients had received radiation therapy to the spine prior to surgery; in these 14, indications for surgery included a combination of pain and weakness (10 patients), pain alone (two patients), or weakness alone (two patients). Of 12 patients with preoperative pain, after surgery pain relief was noted in nine patients, and eight were ambulatory. Major wound breakdowns occurred in two of the 14 patients who had received radiation prior to surgery. These results suggest that Harrington rod instrumentation is useful in providing postoperative stability and restoring alignment following laminectomy for tumors involving the spine, but carries an increased risk of wound-related complications if used in a previously irradiated region.

Surgical treatment of brain metastases from lung cancer

Thirty-five patients underwent surgical resection of brain metastases from non-oat-cell lung cancer between 1978 and 1981. Twenty-nine patients received postoperative radiation therapy to the brain. Twenty-three patients were male and 12 were female. Intracranial metastases occurred as the initial symptom of malignancy in 14 patients, and at varying periods following treatment of the primary tumor in 21 patients. The primary tumor and involved nodes were treated by definitive surgery in 18 patients, palliative resection and interstitial radiation in 10 patients, and by radiation therapy or chemotherapy alone in seven patients. The overall median survival time was 14 months. Favorable prognostic variables included: 1) absence of local or systemic disease at time of craniotomy (median 23 months survival time); 2) aggressive treatment of the primary tumor (median 18 months survival time); and 3) metachronous onset of brain metastases (median 15 months survival time). These survival data represent a considerable improvement over the historical 6 months median period of survival in such patients.