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Biomedical subjects

M Chadha

Publications and source records attributed to M Chadha.

At least 19 recordsLinked to original sources
PubMed2005

Spinal tuberculosis with concomitant spondylolisthesis: coexisting entities or 'cause and effect'?

STUDY DESIGN: Report of three unusual cases of coexisting spondylolisthesis and tuberculosis in the same patient. OBJECTIVES: To document the rare occurrence and attempt to postulate the probable reasons for such an association. SETTING: Tertiary care teaching hospital in a developing country. METHODS: This communication reports the outcome of three cases where there was spondylolisthesis and spinal tuberculosis in the same patient. The probable reason for such an occurrence is discussed along with a literature review relevant to this topic. RESULTS: The cases responded favorably to conservative treatment with multidrug antitubercular chemotherapy and spinal braces. CONCLUSIONS: Association of spondylolisthesis and spinal tuberculosis is extremely rare. If the tubercular process is fulminant, spondylolisthesis secondary to destruction of posterior elements by the infective process can occur. Gross destruction of anterior elements secondary to tuberculosis in some patients may place excessive stresses on the posterior elements and may precipitate a spondylolisthesis even if there was no active infection in the posterior elements. However, there remains a distinct possibility that pars defect may have existed prior to infective pathology.

Adult↗
PubMed2004

Fluorosis-induced hyperparathyroidism mimicking a giant-cell tumour of the femur.

We report the case of a young woman who, over a period of five years was diagnosed and treated for a giant-cell tumour of bone, osteomalacia and fluorosis. A review of the literature revealed a correlation between these three diagnoses, the primary pathology being fluorosis and the remaining symptoms being secondary manifestations. It is important to be aware of this association, especially in regions with endemic skeletal fluorosis.

Adult↗
PubMed2001

Encounters with pseudoaneurysms in orthopaedic practice.

Thirteen pseudoaneurysms are presented of which five were caused as a complication of pin/wire placement of external fixators (one conventional and four Ilizarov frames). The most common symptom was the presence of profuse persistent bleeding from either the wound or the pin/wire site. In nine patients the pseudoaneurysm was directly caused by a fracture or subsequent fracture stabilisation. Pre-operative evaluation included radiography, arteriography, Doppler and computed tomography (CT) angiography. Depending on the site and size of the pseudoaneurysm management consisted of either ligation, resection and end-to-end anastamosis/vein grafting, lateral suture, endoaneurysmorrhaphy or selective embolisation.A high index of suspicion needs to be maintained following penetrating injury in the vicinity of a major vessel, particularly in the presence of persisting symptoms. External fixators are widely used to treat complex orthopaedic problems. The procedure is technically demanding, requiring a sound knowledge of cross-sectional limb anatomy. Injudicious use may result in potentially life/limb threatening complication of pseudoaneurysm.

Adolescent↗
PubMed2001

Life-threatening respiratory failure following accidental infusion of polyethylene glycol electrolyte solution into the lung.

Functional fecal retention is the most common cause of encopresis in children. Hospitalization may be required to clear the bowel following failure of outpatient management. Although the safety and efficacy of polyethylene glycol electrolyte solution is well established in children older than 6 months (1), its use should be carefully monitored in patients with altered mental status or impaired airway protective reflexes. We report the accidental infusion of NuLytely into the lungs of an 11-year-old female patient who consequently developed life-threatening acute lung injury. She rapidly developed respiratory failure requiring emergent tracheal intubation and suctioning, followed by mechanical ventilation. Careful monitoring is needed to avoid this potential complication if polyethylene glycol solution is infused via a nasogastric tube.

Child↗
PubMed2000

The Ilizarov method in infected nonunion of fractures.

Thirty patients with infected non-union of long bones were treated with radical resection of the necrotic bone and bone transport or compression/distraction osteosynthesis. Non-union, infection, deformity, bone gap and shortening were all addressed simultaneously using the Ilizarov principles. There were 15 cases with bone loss ranging from 4 to 12 cm (median bone gap of 7 cm), 10 cases of stiff non-union (six of which had an associated deformity) and five cases of mobile non-union. The median time in the Ilizarov frame was 150 days. Median follow up time after frame removal was 23.5 months. Bone grafting at the docking site was only required in three cases (10%). There were three cases of refracture (10%) and three cases of recurrence of infection (10%). The bone result was excellent in 21 patients (70%), good in three (10%), fair in none (0%) and poor in six (20%). The functional results were excellent in eight patients (26.7%), good in 12 (40.0%), fair in three (10%) and poor in seven (23.3%). It is difficult to precisely define the indications for preservation and reconstruction of severe injuries. The surgical team has to take into account the length, disability, complications and cost of treatment. Patients must be aware of the limitations of functional results and the possible difficulty of return to work despite the reconstructive attempt.

Adolescent↗
PubMed1999

Patterns of failure in endometrial carcinoma stage IB grade 3 and IC patients treated with postoperative vaginal vault brachytherapy.

OBJECTIVE: The vagina is the most common site of locoregional failure in surgical stage IB, IC, and II (occult) endometrial adenocarcinoma. The objective of this study is to evaluate the therapeutic efficacy of vaginal vault brachytherapy alone for surgical stage I patients with high-risk features. MATERIALS AND METHODS: The study group consists of high-risk stage I patients with either stage IB grade (G) 3 or any grade IC disease. From February 1991 to August 1997, 124 patients with endometrial carcinoma were treated postoperatively with high-dose-rate vaginal vault brachytherapy as the only adjuvant treatment. All patients were surgically staged. Among them, 38 patients were identified as high risk. Twelve patients had stage IBG3, 14 had ICG1, 9 had ICG2, and 3 had ICG3 disease. The median age was 67 years (range 41 to 86 years). A dose of 21 Gy in three fractions of 7 Gy each was delivered to a prescription depth of 0.5 cm from the surface of the vaginal applicator using high-dose-rate brachytherapy. RESULTS: The median follow-up was 30 months (range 7 to 91 months). No patient has developed a vaginal or pelvic recurrence. Three patients developed tumor recurrence in the upper abdomen at 11, 18, and 37 months. Two of the three patients with recurrent disease also had history of breast cancer. In one patient, breast cancer was diagnosed 4.8 years prior and in the second 3 years subsequent to the diagnosis of endometrial cancer. The 5-year actuarial overall survival and disease-free survival are 93 and 87%, respectively. There was no treatment-related grade 3 or 4 morbidity observed. CONCLUSIONS: For patients with surgical stage IBG3 and IC, excellent local control and minimal morbidity has been observed with the selective use of vaginal brachytherapy alone. Further studies and longer follow-up are warranted.

Adenocarcinoma↗
PubMed1999

Boron neutron capture therapy for glioblastoma multiforme: interim results from the phase I/II dose-escalation studies

OBJECTIVE: The primary objective of these Phase I/II dose-escalation studies is to evaluate the safety of boronophenylalanine (BPA)-fructose-mediated boron neutron capture therapy (BNCT) for patients with glioblastoma multiforme (GBM). A secondary purpose is to assess the palliation of GBM by BNCT, if possible. METHODS: Thirty-eight patients with GBM have been treated. Subtotal or gross total resection of GBM was performed for 38 patients (median age, 56 yr) before BNCT. BPA-fructose (250 or 290 mg BPA/kg body weight) was infused intravenously, in 2 hours, approximately 3 to 5 weeks after surgery. Neutron irradiation was begun between 34 and 82 minutes after the end of the BPA infusion and lasted 38 to 65 minutes. RESULTS: Toxicity related to BPA-fructose was not observed. The maximal radiation dose to normal brain varied from 8.9 to 14.8 Gy-Eq. The volume-weighted average radiation dose to normal brain tissues ranged from 1.9 to 6.0 Gy-Eq. No BNCT-related Grade 3 or 4 toxicity was observed, although milder toxicities were seen. Twenty-five of 37 assessable patients are dead, all as a result of progressive GBM. No radiation-induced damage to normal brain tissue was observed in postmortem examinations of seven brains. The minimal tumor volume doses ranged from 18 to 55 Gy-Eq. The median time to tumor progression and the median survival time from diagnosis (from Kaplan-Meier curves) were 31.6 weeks and 13.0 months, respectively. CONCLUSION: The BNCT procedure used has been safe for all patients treated to date. Our limited clinical evaluation suggests that the palliation offered by a single session of BNCT is comparable to that provided by fractionated photon therapy. Additional studies with further escalation of radiation doses are in progress.

Journal Article↗
PubMed1998

Boron neutron-capture therapy (BNCT) for glioblastoma multiforme (GBM) using the epithermal neutron beam at the Brookhaven National Laboratory.

OBJECTIVE: Boron neutron-capture therapy (BNCT) is a binary form of radiation therapy based on the nuclear reactions that occur when boron (10B) is exposed to thermal neutrons. Preclinical studies have demonstrated the therapeutic efficacy of p-boronophenylalanine (BPA)-based BNCT. The objectives of the Phase I/II trial were to study the feasibility and safety of single-fraction BNCT in patients with GBM. MATERIALS AND METHODS: The trial design required (a) a BPA biodistribution study performed at the time of craniotomy; and (b) BNCT within approximately 4 weeks of the biodistribution study. From September 1994 to July 1995, 10 patients were treated. For biodistribution, patients received a 2-hour intravenous (i.v.) infusion of BPA-fructose complex (BPA-F). Blood samples, taken during and after infusion, and multiple tissue samples collected during surgical debulking were analyzed for 10B concentration. For BNCT, all patients received a dose of 250 mg BPA/kg administered by a 2-hour i.v. infusion of BPA-F, followed by neutron beam irradiation at the Brookhaven Medical Research Reactor (BMRR). The average blood 10B concentrations measured before and during treatment were used to calculate the time of reactor irradiation that would deliver the prescribed dose. RESULTS: 10B concentrations in specimens of scalp and tumor were higher than in blood by factors of approximately 1.5 and approximately 3.5, respectively. The 10B concentration in the normal brain was < or = that in the blood; however, for purposes of estimating radiation doses to normal brain endothelium, it was always assumed to be equal to blood. BNCT doses are expressed as gray-equivalent (Gy-Eq), which is the sum of the various physical dose components multiplied to appropriate biologic effectiveness factors. The dose to a 1-cm3 volume where the thermal flux reached a maximum was 10.6 +/- 0.3 Gy-Eq in 9 patients and 13.8 Gy-Eq in 1 patient. The minimum dose in tumor ranged from 20 to 32.3 Gy-Eq. The minimum dose in the target volume (tumor plus 2 cm margin) ranged from 7.8 to 16.2 Gy-Eq. Dose to scalp ranged from 10 to 16 Gy-Eq. All patients experienced in-field alopecia. No CNS toxicity attributed to BNCT was observed. The median time to local disease progression following BNCT was 6 months (range 2.7 to 9.0). The median time to local disease progression was longer in patients who received a higher tumor dose. The median survival time from diagnosis was 13.5 months. CONCLUSION: It is feasible to safely deliver a single fraction of BPA-based BNCT. At the dose prescribed, the patients did not experience any morbidity. To further evaluate the therapeutic efficacy of BNCT, a dose-escalation study delivering a minimum target volume dose of 17 Gy-Eq is in progress.

Aged↗
PubMed1998

Rapidly alternating chemotherapy and radiotherapy instead of cystectomy for the treatment of muscle-invasive carcinoma of the urinary bladder: long term results of a pilot study.

BACKGROUND: The authors studied rapidly alternating chemotherapy and radiotherapy as the initial treatment for patients with muscle-invasive transitional cell carcinomas of the urinary bladder whose advanced age and lack of strength precluded cystectomy. METHODS: Twenty-one patients with T2 (28%) or T3 (72%) NXM0 carcinomas were treated by transurethral resection followed by chemoradiotherapy. Their median age was 73 years. The chemotherapy (consisting of methotrexate, vinblastine, doxorubicin, and cisplatin) was given during Weeks 1, 4 and 7. Radiotherapy (1.8-2 Gray [Gy] twice a day, to a total dose of 18-20 Gy per week) was given during Weeks 2, 5 and 8, for a final dose of 40 Gy to the pelvis plus 14-20 Gy boost to the affected bladder. RESULTS: There was 1 treatment-related death (5% of patients), but otherwise the acute toxicity was relatively mild. Cystoscopy 1 month after chemoradiotherapy did not reveal invasive cancer in any patient. Subsequent cystoscopies detected recurrent invasive cancer in 3 patients after 30, 44, and 82 months, respectively. The observed survival rate after 5 years was 37%, the cause specific survival rate was 63%, the metastasis free rate was 71%, and the local control rate was 80%. Eighty-four percent of patients had normal bladder function. CONCLUSIONS: Transurethral resection plus chemoradiotherapy was successful in preserving bladder function in the majority of the patients. The survival and progression free rates compared favorably with what has been reported recently after radical cystectomy and chemotherapy, and they add to the growing body of evidence that chemoradiotherapy might be a safe, effective alternative to cystectomy for many patients with muscle-invasive carcinoma of the urinary bladder.

Aged↗
PubMed1998

Steffee variable screw placement system in the management of unstable thoracolumbar fractures: a Third World experience.

Twenty consecutive patients with unstable thoracolumbar fractures were taken up for posterior spinal stabilization using the Steffee VSP system at the earliest opportunity. Patients were followed up from 20 to 38 months. 70% patients were operated within 3 weeks of sustaining injury (group 1) while injury-operation interval exceeded 3 weeks in 30% (group II). The average preoperative kyphotic angle was 19.35 degrees which improved to 8.70 degrees, the correction being much more in group I (17.60 degrees to 5.3 degrees) compared to group II (22.90 degrees to 14.40 degrees). The average preoperative vertebral body height was 57.75% which improved to 79.75%, the correction being much more in group I (61.20 to 88.40%) compared to group II (51.40 to 63.70%). No patients deteriorated neurologically while 7 out of 16 patients with neurological deficit showed improvement by one or more Frankel Grade (43.75%). It is concluded that reasonable correction of deformity, fair chance of neurological recovery and significant reduction of recumbency associated complications can be expected even when surgery is delayed.

Adolescent↗
PubMed1998

Biodistribution of p-boronophenylalanine in patients with glioblastoma multiforme for use in boron neutron capture therapy.

OBJECTIVE: The success of boron neutron capture therapy depends on the safety and specificity of the boron delivery agent. As a preface to clinical boron neutron capture therapy of glioblastoma multiforme, a biodistribution study of intravenous p-boronophenylalanine (BPA) in patients undergoing craniotomy for resection of glioblastoma was performed. METHODS: Varying doses of intravenously administered BPA-fructose (130-250 mg BPA per kilogram of body weight) were given to patients 2 to 3 hours prior to the start of craniotomy for either suspected or known glioblastoma multiforme. Blood samples were collected over a 48-hour period for boron assay. At surgery, multiple samples of tumor, brain, and scalp were obtained for boron and histological analysis. RESULTS: Seventeen patients were studied; all but one had glioblastoma multiforme. No adverse effects from the BPA infusions were noted. The boron concentration in the blood reached a maximum at the end of the BPA infusion and was proportional to the administered dose of BPA. Normal brain concentrations of boron generally were equal to or less than that in blood. Tumor-blood boron ratios were highly variable: 1.6 +/- 0.8 (mean +/- standard deviation; n = 187; range, 0.3-3.5). The observed heterogeneity of BPA uptake in glioblastoma samples appears to correlate with the degree of cellularity observed on histological examination. CONCLUSION: Intravenous BPA administration up to a dose of 250 mg/kg is safe and well tolerated. BPA uptake in surgical samples of glioblastoma tissue is variable and may depend on the fraction of viable tumor cells in the individual sample. Further clinical studies using BPA as a boron delivery agent for boron neutron capture therapy of glioblastoma multiforme appear warranted.

Boron Compounds↗
PubMed1998

A primary intrapelvic hydatid cyst presenting with foot drop and a gluteal swelling: a case report.

A primary hydatid cyst in the pelvis is rare, and usually presents with pressure symptoms affecting the adjacent abdominal organs. We describe such a cyst which protruded through the sciatic notch and presented as a gluteal swelling with a foot drop due to compression of the lumbosacral nerve roots. Surgical excision and postoperative treatment with albendazole for six weeks were effective in controlling the disease and preventing recurrence.

Adult↗
PubMed1998

Biodistribution of boronophenylalanine in patients with glioblastoma multiforme: boron concentration correlates with tumor cellularity.

Boron-10 (10B) concentrations were measured in 107 surgical samples from 15 patients with glioblastoma multiforme who were infused with 95 atom% 10B-enriched p-boronophenylalanine (BPA) intravenously for 2 h just prior to surgery at doses ranging from 98 to 290 mg BPA/kg body weight. The blood 10B concentration reached a maximum at the end of the infusion (ranging from 9.3 to 26.0 microg 10B/g) and was proportional to the amount of BPA infused. The boron concentrations in excised tumor samples ranged from 2.7 to 41.3 microg 10B/g over the range of administered BPA doses and varied considerably among multiple samples from individual patients and among patients at the same BPA dose. A morphometric index of the density of viable-appearing tumor cells in histological sections obtained from samples adjacent to, and macroscopically similar to, the tumor samples used for boron analysis correlated linearly with the boron concentrations. From that correlation it is estimated that 10B concentrations in glioblastoma tumor cells were over four times greater than concurrent blood 10B concentrations. Thus, in the dose range of 98 to 290 mg BPA/kg, the accumulation of boron in tumor cells is a linear function of BPA dose and the variations observed in boron concentrations of tumor specimens obtained surgically are largely due to differences in the proportion of nontumor tissue (i.e. necrotic tissue, normal brain) present in the samples submitted for boron analysis. The tumor:blood 10B concentration ratio derived from this analysis provides a rationale for estimating the fraction of the radiation dose to viable tumor cells resulting from the boron neutron capture reaction based on measured boron concentrations in the blood at the time of BNCT without the need for analysis of tumor samples from individual patients.

Boron↗
PubMed1997

Boron neutron capture therapy for glioblastoma multiforme using p-boronophenylalanine and epithermal neutrons: trial design and early clinical results.

A Phase I/II clinical trial of boron neutron capture therapy (BNCT) for glioblastoma multiforme is underway using the amino acid analog p-boronophenylalanine (BPA) and the epithermal neutron beam at the Brook-haven Medical Research Reactor. Biodistribution studies were carried out in 18 patients at the time of craniotomy using an i.v. infusion of BPA, solubilized as a fructose complex (BPA-F). There were no toxic effects related to the BPA-F administration at doses of 130, 170, 210, or 250 mg BPA/kg body weight. The tumor/ blood, brain/blood and scalp/blood boron concentration ratios were approximately 3.5:1, 1:1 and 1.5:1, respectively. Ten patients have received BNCT following 2-hr infusions of 250 mg BPA/kg body weight. The average boron concentration in the blood during the irradiation was 13.0 +/- 1.5 micrograms 10B/g. The prescribed maximum dose to normal brain (1 cm3 volume) was 10.5 photon-equivalent Gy (Gy-Eq). Estimated maximum and minimum doses (mean +/- sd, n = 10) to the tumor volume were 52.6 +/- 4.9 Gy-Eq (range: 64.4-47.6) and 25.2 +/- 4.2 Gy-Eq (range: 32.3-20.0), respectively). The estimated minimum dose to the target volume (tumor +2 cm margin) was 12.3 +/- 2.7 Gy-Eq (range: 16.2-7.8). There were no adverse effects on normal brain. The scalp showed mild erythema, followed by epilation in the 8 cm diameter field. Four patients developed recurrent tumor, apparently in the lower dose (deeper) regions of the target volume, at post-BNCT intervals of 7,5,3.5 and 3 months, respectively. The remaining patients have had less than 4 months of post-BNCT follow-up. BNCT, at this starting dose level, appears safe. Plans are underway to begin the dose escalation phase of this protocol.

Adult↗
PubMed1997

Computational dosimetry and treatment planning for boron neutron capture therapy.

The technology for computational dosimetry and treatment planning for Boron Neutron Capture Therapy (BNCT) has advanced significantly over the past few years. Because of the more complex nature of the problem, the computational methods that work well for treatment planning in photon radiotherapy are not applicable to BNCT. The necessary methods have, however, been developed and have been successfully employed both for research applications as well as human trials, although further improvements in speed are needed for routine clinical applications. Computational geometry for BNCT applications can be constructed directly from tomographic medical imagery and computed radiation dose distributions can be readily displayed in formats that are familiar to the radiotherapy community.

Animals↗
PubMed1997

Is axillary dissection always indicated in invasive breast cancer?

In light of the changing trends in the diagnosis and management of invasive breast cancer, the practice of routine axillary dissection should be reevaluated. A growing number of patients with breast cancer are diagnosed as having small tumors with an associated low risk of lymph node metastases. The pathologic features of the primary tumor are increasingly being used as a prognostic guide for recommendations about adjuvant systemic therapy, and there are recent reports suggesting a superior prognostic value for tumor cells detected in bone marrow, as compared to axillary lymph node metastases. Consequently, axillary lymph node status is no longer the single prognostic guide for recommendations about adjuvant systemic therapy. For treatment of the axilla, there is evidence that, in clinical N0 patients, radiation therapy to the axilla is an effective alternative to axillary dissection. Finally, there are cost and morbidity considerations for patients undergoing axillary dissection in whom the indications of the procedure are equivocal. In the management of invasive breast cancer, a selective policy toward axillary lymph node dissection should be considered. This review discusses the nonsurgical management of the axilla; ie, radiation therapy to the axilla and observation of the axilla as an alternative to axillary dissection.

Axilla↗