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Biomedical subjects

L Eapen

Publications and source records attributed to L Eapen.

At least 19 recordsLinked to original sources
PubMed2006

The preferred treatment for stage I seminoma: a survey of Canadian radiation oncologists.

AIMS: To evaluate the preferences of radiation oncologists for managing stage I seminoma. MATERIALS AND METHODS: An electronic survey evaluating the management of stage I seminoma patients was sent to Canadian radiation oncologists to determine their treatment recommendations and preferences. RESULTS: The survey completion rate was 74% among eligible respondents (78/105). Most (56%) felt that surveillance was the preferred treatment for patients, whereas 31% thought that adjuvant radiotherapy was best, 1% chose adjuvant chemotherapy as being the preferred option and 12% were unsure. Most would choose the same treatment for themselves if they were diagnosed with stage I seminoma. A previously published survey found that most respondents considered radiotherapy as the best option. CONCLUSIONS: Most Canadian radiation oncologists now favour surveillance for most stage I seminoma patients.

Canada↗
PubMed2005

Clinical use of a commercial Monte Carlo treatment planning system for electron beams.

In 2002 we fully implemented clinically a commercial Monte Carlo based treatment planning system for electron beams. The software, developed by MDS Nordion (presently Nucletron), is based on Kawrakow's VMC++ algorithm. The Monte Carlo module is integrated with our Theraplan Plustrade mark treatment planning system. An extensive commissioning process preceded clinical implementation of this software. Using a single virtual 'machine' for each electron beam energy, we can now calculate very accurately the dose distributions and the number of MU for any arbitrary field shape and SSD. This new treatment planning capability has significantly impacted our clinical practice. Since we are more confident of the actual dose delivered to a patient, we now calculate accurate three-dimensional (3D) dose distributions for a greater variety of techniques and anatomical sites than we have in the past. We use the Monte Carlo module to calculate dose for head and neck, breast, chest wall and abdominal treatments with electron beams applied either solo or in conjunction with photons. In some cases patient treatment decisions have been changed, as compared to how such patients would have been treated in the past. In this paper, we present the planning procedure and some clinical examples.

Algorithms↗
PubMed2001

Treatment planning aids in prostate cancer: friend or foe?

BACKGROUND: Rectal barium is commonly used as a treatment planning aid for prostate cancer to delineate the anterior rectal wall. Previous research at the Ottawa Regional Cancer Centre demonstrated that retrograde urethrography results in a systematic shift of the prostate. We postulated that rectal barium could also cause prostate motion. PURPOSE: The study was designed to evaluate the effects of rectal barium on prostate position. METHODS AND MATERIALS: Thirty patients with cT1-T3 prostate cancer were evaluated. Three fiducial markers were placed in the prostate. During simulation, baseline posterior-anterior and lateral films were taken. Repeat films were taken after rectal barium opacification. The prostate position (identified by the fiducials) relative to bony landmarks was compared before and after rectal barium. Films were analyzed using PIPsPro software. RESULTS: The rectal barium procedure resulted in a significant displacement of the prostate in the anterior and superior direction. The mean displacement of the prostate measured on the lateral films was 3.8 mm (SD: 4.4 mm) in the superior direction and 3.0 mm (SD: 3.1) in the anterior direction. CONCLUSIONS: Rectal barium opacification results in a systematic shift of the prostate. This error could result in a geographic miss of the target; therefore, alternate methods of normal tissue definition should be used.

Aged↗
PubMed1998

The relationship between biochemical failure and time to nadir in patients treated with external beam therapy for T1-T3 prostate carcinoma.

PURPOSE AND BACKGROUND: To determine a prostatic-specific antigen (PSA) nadir value and time to nadir that predict a high probability of freedom from biochemical failure in men treated with external beam therapy for prostate cancer. MATERIALS AND METHODS: Between January 1990 and March 1994, 228 men with T1-T3 adenocarcinoma of the prostate received a radical course of external beam irradiation with no prior or adjuvant hormonal therapy. All men had pre- and post-treatment serum PSA evaluations, and were followed up for at least 24 months, to ensure PSA nadir was reached. Biochemical failure was defined as three successive post-treatment rises in serum PSA, regardless of the magnitude of elevation. RESULTS: Overall, 4-year biochemical disease-free survival (BDFS) was 42%. PSA nadir was predictive of subsequent BDFS. For those whose serum PSA nadir was < or =1 ng/ml, 4-year BDFS was 70%, versus 12% for those with serum PSA nadir > 1 ng/ml (P = < 0.001). The 4-year BDFS for patients with time to nadir < or =1 year, was 28%, versus 58% for those with time to nadir > 1 year (P < 0.001). For patients with PSA nadir < or =1 ng/ml, 4-year BDFS was 75% for those with time to nadir > 1 year, versus 61% for those with time to nadir < or =1 year (P < 0.021). In multivariate analysis, PSA nadir(< or =1 ng/ml versus >1 ng/ml, and time to nadir (< or =1 year versus > year) were independent predictors of BDFS alone with pre-treatment PSA and Gleason score. CONCLUSION: Only those who achieved PSA nadir < or =1 ng/ml following external beam therapy have a favourable chance of lasting biochemical disease control, while those with nadir > 1 ng/ml have a high subsequent failure rate. The prognosis is better in patients with late time to nadir. In addition to PSA nadir, time to nadir, pretreatment PSA, and Gleason score were of independent prognostic significance.

Actuarial Analysis↗
PubMed1998

Is prostate specific antigen density an important prognostic indicator for patients with prostate cancer treated with external beam therapy?

The purpose of this study was to determine if prostate specific antigen density (PSAD) is a predictor of outcome following external beam radiotherapy for prostate cancer, and to compare it with other prognostic factors. Between January 1990 and December 1993, 205 patients with T1-T3 adenocarcinoma of the prostate received a radical course of external beam irradiation, with no prior or adjuvant hormonal therapy. All patients had pre- and post-treatment serum prostate specific antigen (PSA) evaluation. They were followed up for at least 24 months. PSAD was defined as the ratio of pre-treatment serum PSA to the prostate volume, as determined from CT treatment planning scans. Prostate volumes were calculated using the prostate ellipse formula. Median PSA density was 0.37, with a range 0.01-6.7. Biochemical failure was defined as three consecutive rises in serum PSA, regardless of the magnitude of elevation. 4-year biochemical disease-free survival (BDFS) for patients with PSAD < or = 0.3 was 60%, compared with 22% for patients with PSAD > 0.3 (p = < 0.001). In a multivariate analysis, pre-treatment PSA (p = < 0.001), Gleason score (p = 0.002), and stage (p = 0.03) were independent predictors of BDFS, while PSAD was not an important prognosticator (p = 0.62). Pre-treatment serum PSA is the most important prognosticator of BDFS, following external beam radiotherapy, for patients with prostate cancer. PSA density did not predict treatment outcome.

Adenocarcinoma↗
PubMed1998

[Treatment of cancer of the bladder in elderly patients with an intra-arterial chemotherapy and radiotherapy combination: 10-year experience].

PURPOSE: Analysis of the results obtained in elderly (75 years and older) included a phase II trial combining intra-arterial cisplatin and concurrent radiation into invasive bladder cancer. PATIENTS AND METHODS: Thirty-five patients (28 males and 7 females) were accrued from 1985 to 1996. There were 1 Ta, 4 T2, 11 T3A, 12 T3B, 3 T4A, and 4 T4B patients. Nine had unilateral hydronephrosis and two bilateral hydronephrosis. There were 28 transurethral resections which were incomplete in 23 patients. Intra-arterial cisplatin was given as 2-4 hours infusion (60-90 mg/m2) split through both internal iliac arteries on day 1, 14, 21, and 42. Irradiation to the pelvis was started on day 14 and consisted of 40 Gy/20 fractions followed by a boost of 20 Gy/10 fractions to the tumor with margins of 2 cm. RESULTS: Thirty (86%) completed fully the protocol. One patient died from sepsis secondary to the treatment. The tumor response was evaluable in 29 patients and complete response was observed for 27 of them. Five of these 27 patients had an isolated bladder relapse which was salvaged by cystectomy in two patients. There were 11 deaths from bladder cancer (31% of the patients): 9 from distant metastase, one from local failure, and one from treatment. CONCLUSION: This combined modality yields excellent results with high complete response rate and good tolerance. This approach may therefore be particularly appropriate for the elderly.

Aged↗
PubMed1998

Comorbid survival among elderly male participants of the Canada health survey: relevance to prostate cancer screening and treatment.

This study assessed the survival of a nationally representative sample of older Canadian men, taking into account common comorbid conditions. Mortality follow-up between 1978 and 1989 was conducted for male participants of the Canada Health Survey who were at least 60 years of age at baseline. The proportional hazards model and life table methods were used to examine survival by comorbidity status. Comorbid conditions examined included history of stroke and/or heart disease, high blood pressure, chronic bronchitis or emphysema, diabetes and smoking status, but excluded cancer because of small numbers. For those subjects aged 80 and older, comorbidity was not a significant predictor of survival. A large portion of men between the ages of 60 and 79, even those with pre-existing comorbid conditions, survived at least 10 years after interview. In a clinical setting, more detailed information on comorbid conditions can be obtained to better estimate long-term survival. Notwithstanding, our findings may have implications for the administration of population-based health interventions (e.g. the use of prostate-specific antigen [PSA] blood tests for the early detection of prostate cancer). In particular, our results suggest that there may be little benefit in restricting access to PSA screening based on survival probability in men under age 80.

Aged↗
PubMed1996

PROMACE-MOPP and intrathecal chemotherapy for CNS lymphomas.

UNLABELLED: We conducted a Phase II study of PROMACE-MOPP and intrathecal (IT) therapy followed by cranial radiation in 7 patients (4 male, 3 females) with diffuse large cell lymphomas (including one T cell) involving the central nervous system (CNS). Median age was 47 years (range, 25-78). Median performance status was 2 (range, 2 to 3). Two patients had positive CSF cytology. No patients had prior chemotherapy or radiotherapy. Treatment consisted of PROMACE (cyclophosphamide 650 mg/m2, etoposide 120 mg/m2 days 1 and 8, methotrexate (MTX) 1.5 g/m2 and folinic acid 50 mg/m2 (x 5) day 15, and prednisone 60 mg/m2 days 1-14) x 3-4 courses. MOPP consisted of mustargen 6 mg/m2 and vincristine 1.4 mg/m2 days 1 and 8, procarbazine 100 mg/m2 and prednisone 40 mg/m2 po days 1-14 x 3-4 courses. IT drugs were MTX 20 mg and hydrocortisone 20 mg day 1 and cytosine arabinoside 100 mg day 8, courses 2 to 6, or more frequently if CSF cytology was positive. Following MOPP, 4000 cGy whole brain radiation (XRT) and 2000 cGy boost was given. Response was evaluated before XRT. Two patients declined XRT, 3 declined MOPP and 2 declined IT drugs. Two patients had extracerebral disease and 5 were primary CNS lymphomas. Response after PROMACE was CR: 3 patients; PR 2: stable 1. One patient, with extracerebral disease, experienced PR in the abdomen and CR by CT scan in the brain, but had persistent positive CSF cytology. This patient died from pneumocystis pneumonia 10 weeks after her last CSF cytology and 17 weeks after her diagnosis. After PROMACE +/- MOPP 6 patients experienced CR's. Median (range) survival was 100 (17-334) weeks, with 1 patient lost to follow up at 32 weeks. Toxicity included febrile neutropenia; 6 patients; pneumocystis pneumonia: 1 (fatal); thrombocytopenia; 5; stomatitis: 3; diarrhea; 2; nausea; 3. CONCLUSION: This regimen is active in the treatment of CNS lymphomas, although toxicity is substantial.

Adult↗
PubMed1996

The role of palliative radiotherapy in advanced head and neck cancer.

The role of radiotherapy in the palliation of patients with advanced cancer of the head and neck is not clear. Several distinctive characteristics of advanced head and neck cancer contribute to the complexities in the choice of appropriate palliative management strategies. Palliative treatment may be the appropriate management for a proportion of patients with advanced disease, but the current stage groupings of head and neck cancer are not sufficient for use in the reliable identification of such a patient group. Controversy arises because of the difficulties in distinguishing patients who should be offered conventional treatment with curative intent from those appropriate for treatment with palliative intent. A structured review of the cancer and quality of life literature identified 298 references pertaining to palliative radiotherapy in head and neck cancer, 26 of which met the criteria for inclusion in this review. An expert panel discussed the literature, and concluded that insufficient information precluded estimations of the frequency, degree of, or duration of symptomatic relief that radiation offered to those patients not cured of their disease. Moreover, the currently available literature does not address the toxicity or appropriate dose and fractionation of palliative radiotherapy in this setting. Further studies are necessary to evaluate clinical endpoints appropriate to the use of radiotherapy in the palliative management of patients with advanced head and neck cancer. Studies are also needed to refine the current clinical classification of patients, allowing the identification of patients suitable for palliative management.

Clinical Trials as Topic↗
PubMed1995

Asymmetric arc technique for posterior pharyngeal wall and retropharyngeal space tumors.

PURPOSE: Tumors of the posterior pharyngeal wall and nasopharyngeal cancer with retropharyngeal extension can partly encircle the cervical vertebrae. Treating the patient within spinal cord tolerance can cause a geographic miss. A simple technique has been developed to avoid this problem. METHODS AND MATERIALS: The standard fields for posterior pharyngeal wall and nasopharyngeal tumors are used up to 36-40 Gy. A planning computed tomography (CT) scan is taken during the second or third week of treatment with the patient fitted in a new shell ensuring that the cord is straight and parallel to the treatment couch. The asymmetric arc technique consists of two posterior arcs with closure of one jaw beyond the central axis. Each arc delivers the total dose to each ipsilateral side, while the median region of the U-shaped volume is treated by the summation of both arcs. RESULTS: We have treated 10 patients using asymmetric arcs in the last 3 years. This technique proved to be a versatile way of treating targets wrapped around the spine. The technique allows better individualization for target volume irregularities than the partial rotation with a central bar.

Humans↗
PubMed1994

Cisplatin and radiation in the treatment of tumors of the central nervous system: pharmacological considerations and results of early studies.

PURPOSE: To review the human central nervous system pharmacology of cisplatin, factors that affect cisplatin uptake in tumors, and use alone and with radiation for the treatment of primary brain tumors. METHODS AND MATERIALS: The authors review their own prior published and unpublished experience and data published by other groups on the above issues. RESULTS: Cisplatin is one of the most active chemotherapy drugs available for the treatment of solid tumors. It is synergistic with several other agents, including radiation. While it attains only low concentrations in the normal central nervous system, concentrations and plasma-tissue transfer constants for human intracerebral tumors are comparable to those in extracerebral tumors. Tumor type appears to be a more important determinant of platinum concentration than is tumor location, and gliomas do achieve lower concentrations than do other intracerebral or extracerebral tumors. Several other factors have also been identified that correlate with concentrations of cisplatin achieved in human tumors. While cisplatin alone and in combination with other drugs does have some degree of efficacy against primary brain tumors, combining it with cranial irradiation has generally not resulted in any substantial improvement in outcome to date, although some individual studies have been somewhat encouraging. New approaches are currently under investigation. CONCLUSION: Human pharmacology studies provide a rationale for use of cisplatin in the treatment of human brain tumors, and human and in vitro studies suggest some manipulations that might potentially further augment tumor platinum concentrations. While clinical studies suggest that cisplatin combinations may be of some value vs. human primary brain tumors and brain metastases, and while in vitro studies suggest that cisplatin potentiates radiation efficacy, no combination of cisplatin plus radiation yet tested has appeared to be superior to radiation alone.

Brain Neoplasms↗
PubMed1994

Placebo-controlled randomized trial of infusional fluorouracil during standard radiotherapy in locally advanced head and neck cancer.

PURPOSE: To determine whether the addition of infusional fluorouracil (I-FU) to standard radiotherapy improves survival at acceptable toxicity in patients with locally advanced squamous cell head and neck cancer (SCHNC). PATIENTS AND METHODS: Consenting patients with an Eastern Cooperative Oncology Group (ECOG) performance status < or = 2; with stage III or IV SCHNC of the oral cavity, oropharynx, hypopharynx, or larynx; and who were recommended for radiotherapy with curative intent received 66 Gy of radiation therapy delivered in 2-Gy fractions once daily 5 days per week for 6 1/2 weeks. Those in the experimental arm received I-FU 1.2 g/m2/d, as a 72-hour infusion in the first and third weeks of radiation. Saline infusions were used in the placebo arm. RESULTS: One hundred seventy-five patients were randomized (88 to I-FU and 87 to placebo), and the treatment arms were well balanced. The complete response rate was 68% for I-FU and 56% for placebo (P = .04). The overall median survival duration was 33 months for I-FU and 25 months for placebo (P = .08). Progression-free survival also favored I-FU (P = .06). Toxicity was greater in I-FU patients, but did not interfere with the scheduled delivery or completion of radiation. CONCLUSION: The addition of I-FU to standard radiation in SCHNC improved the complete response rate and was associated with beneficial trends in progression-free and overall survival compared with radiation alone. I-FU patients also experienced greater morbidity, but this did not compromise delivery of radiotherapy.

Aged↗
PubMed1993

Phase II study of lonidamine plus radiotherapy in the treatment of brain metastases.

Twenty-nine patients received the cytotoxic radiosensitizing agent lonidamine before, during, and after cranial irradiation for brain metastases. One patient was ineligible (meningioma). In 28 eligible patients, median survival was 29 weeks (range, 2 to > 220 weeks). Nine patients (32%) survived > 1 year and 3 (11%) survived > 2 years. The major toxic effects of lonidamine were myalgias, nausea and vomiting, somnolence, and ototoxicity. There was no evidence that radiation skin toxicity or cerebral toxicity was increased by the addition of lonidamine. None of the patients experienced shrinkage of their extracerebral disease on lonidamine. Median survival duration in this study was at the upper limit of that reported in the literature for radiation alone, and the proportion of 2 year survivors was also higher than usual for radiation alone. Hence, further studies may be warranted.

Adult↗
PubMed1993

The Head and Neck Radiotherapy Questionnaire: a morbidity/quality-of-life instrument for clinical trials of radiation therapy in locally advanced head and neck cancer.

PURPOSE: The purpose of this study was to develop and validate an instrument for clinical trials to measure radiation-related acute morbidity and quality of life from the perspective of patients with head and neck cancer (HNC) treated with radiotherapy. METHODS: The Head and Neck Radiotherapy Questionnaire (HNRQ) was developed by a panel of health care workers and patients, was pretested in a pilot study of HNC patients, and was validated in a randomized double-blind trial of concomitant fluorouracil (FUra) infusional therapy (1.2 g/m2 per 24 hours) or saline placebo administered for 72 hours in the first and third weeks of a 6 1/2-week course of radiation therapy. The HNRQ was validated against existing toxicity and performance status indices, all of which were measured weekly for the 6 1/2 weeks of treatment and for 4 weeks posttreatment. RESULTS: There were three a priori constructs: (1) that the HNRQ scores would conform to a shallow U-shaped pattern to reflect declining quality of life (increasing morbidity) during radiation and recovery posttreatment; (2) that the HNRQ would correlate with existing toxicity indices (World Health Organization [WHO] stomatitis, Byfield stomatitis, WHO skin toxicity, Eastern Cooperative Oncology Group [ECOG] and Karnofsky performance status); and (3) that the HNRQ would discriminate between FUra and placebo groups. The HNRQ and its domain scores all showed a change from baseline reflecting increased morbidity during radiation (analysis of variance [ANOVA], P < .00001). The HNRQ correlated well with all other indices (r > or = .60), and domain scores correlated best with other indices that assess the same symptom complex (eg, HNRQ skin domain and WHO skin toxicity index, r = .77). There was a significant difference in HNRQ scores between the FUra and placebo groups during radiation (ANOVA, P = .0007), and all HNRQ domains also discriminated between the treatment groups. CONCLUSION: The HNRQ is a valid measure of acute morbidity due to radiation therapy in patients with locally advanced HNC, and may be useful as an outcome measure for future clinical trials of radiation treatment strategies.

Carcinoma, Squamous Cell↗
PubMed1991

Therapeutic irradiation over a permanent cardiac pacemaker.

Therapeutic irradiation of fields containing cardiac pacemakers presents a unique problem to pacemaker physicians and radiation oncologists alike. The present case involved a proposed radiation field containing both subclavian pockets. As an alternative solution, the Cordis model 334A implantable pulse generator was irradiated using a backup temporary pacemaker that was kept outside of any significant radiation exposure. A total of 60 Gy was delivered in 30 fractions, with backup temporary pacing and continuous ECG monitoring used for the first 5 fractions. Frequent re-evaluation of pacing and sensing function revealed no changes as a result of irradiation; following radiotherapy, transtelephonic monitoring showed normal pacemaker function for a 4 month follow-up. This represents a useful alternative, particularly for nonmultiprogrammable pacemakers that are made of more radiation-resistant technology.

Aged↗
PubMed1989

Intraarterial cisplatin and concurrent radiation for locally advanced bladder cancer.

Between 1983 and 1987 25 patients with invasive bladder cancer (16 stage tumor 3 (T3) and nine stage T4) were treated with intraarterial cisplatin and concurrent radical radiation (20/25) or intraarterial cisplatin, concurrent preoperative radiation, and cystectomy (5/25). One patient died from treatment-related toxicity. Other toxicities have been what one would expect from the individual treatment modalities except for a sensory sacral root neuropathy in 11 of 24 (46%) patients. Twenty-three of 24 (96%) patients achieved a complete response (CR) and the projected actuarial 2-year survival is 90%. Only one of the 23 complete responders has had an invasive local recurrence. The excellent complete local response and survival rates achieved warrant further study of the combination of intraarterial cisplatin and radiation as a bladder-preserving strategy.

Aged↗
PubMed1988

Brain metastases with an unknown primary: a clinical perspective.

A review of 43 patients with cerebral metastases, an unknown primary, and no other sites of metastases is presented. 27/43 (62.7%) had solitary metastases and 37.2% (16/43) had multiple metastases. Surgical treatment involved complete resection in 30.2%, subtotal resection in 37.2% and biopsy alone or no surgical procedure in the remainder. 39/43 patients underwent whole brain irradiation with the majority receiving 3,000-4,000 rads/10-20 fractions. Overall survival was 52% at six months and 20% at one year, and was significantly better in patients with solitary as opposed to multiple metastases (p less than 0.03). A failure analysis including autopsy data demonstrates that (28/41) 68.3% of patients died of progressive intracranial disease without extracerebral metastases. Implications for treatment strategies are discussed.

Actuarial Analysis↗