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L Grimard

Publications and source records attributed to L Grimard.

At least 19 recordsLinked to original sources
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↗
PubMed2003

[Radiation sensitivity testing and late neurological complications following radiosurgery for AVM: the use of SF2 from fibroblasts as a predictive factor].

PURPOSE: To identify SF2 as a prognostic factor of late complications from radiosurgery in patients treated for AVM. PATIENTS AND METHODS: Five patients with AVM treated in three canadian institutions and who suffered clinically significant neurological sequelaes secondary to radiosurgery were identified. Their fibroblasts were cultured and their radiation sensitivity tested to determine the SF2 for each patient. RESULTS: Patients who developed a neurological complication from radionecrosis, secondary to radiosurgery had an SF2 different than the two control patients with AVM and no complications and also from a group of five cancer patients without late radiation complications (P = 0.005). CONCLUSION: Radiosurgery is an elective procedure. The identification of a subgroup of patients who are radiosensitive and at a higher risk of radiation induced complications can allow the treatment team to reduce the risk of such complications. SF2 as a new predictive factor should be incorporated in predictive models of risk from treatment of AVM by radiosurgery. This work needs to be confirmed in a larger cohort of patients.

Cell Survival↗
PubMed1998

Bone marrow metastasis in astrocytic gliomata.

With the increasing survival time of many pediatric patients with malignancies, unexpected symptoms or signs require diligent search for rare complications or second cancers related to the disease or treatment. We recently encountered a patient with extensive glioblastoma multiforme who developed pancytopenia six months after completion of treatment with craniospinal radiation and chemotherapy with etoposide and cyclophosphamide. Bone marrow aspirate and biopsy confirmed bone marrow metastasis from the brain tumor. He showed good partial remission with chemotherapy with carmustine and cis-platinum as demonstrated by serial bone marrow aspirate for cytology and cytogenetics and enjoyed good quality of life for eight months. 14 other patients with astrocytic glioma, two of whom are children, are reported in the literature to have diffuse bone marrow metastasis. Therefore, in patients with malignant astrocytic tumor, bone marrow metastasis, though not common, should be considered when bone pain or cytopenias occur, especially when prolonged.

Adolescent↗
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↗
PubMed1997

[Late effects of ionizing radiations on head and neck region tissues].

Numerous structures are included in the irradiated volume of patients presenting with head and neck cancer: skin, mucosa, bone, teeth, cartilage, muscles, salivary glands, etc. Curative intent treatment of such tumours requires aggressive approach which can lead to severe sequellae. These sequellae are in most cases dose-dependent and volume-dependent. However, an appropriate technique might decrease the severity of such sequellae. Details of these late changes are presented, including their pathophysiology, clinical syndromes, potential treatment, and prevention.

Dose-Response Relationship, Radiation↗
PubMed1996

Childhood medulloblastoma in Ontario, 1977-1987: population-based results.

A retrospective review was carried out to study children, not more than 16 years old, with a confirmed diagnosis of medulloblastoma, who were residents of the Province of Ontario at the time of diagnosis between 1977 and 1987 inclusive. The provincial tumour registry provided the population database. One hundred and eight children with medulloblastoma were identified of whom 72 (67%) were initially treated at University of Toronto Centres and 36 (33%) at other Health Science Centres, hospitals, and Regional Cancer Centres (RCC) in Ontario. The hospital/Cancer Centre records were reviewed. The 5-year relapse-free survival (RFS) for all patients treated in Ontario was 58% (SE = 5%). Those treated in Toronto had a 5-year RFS of 65% (SE = 6%) compared to 44% (SE = 8%) for those treated in other RCCs in the province (P = 0.02). Relapse-free survival for the RCCs ranged from 25 to 60%, with a trend for improved survival with increasing centre size. Univariate analysis of determinants of relapse-free survival for all 108 patients showed the following variables to be significant: T-stage (Tx + T1 + T2 vs. T3A + T3B) P = 0.0004, M-stage (M0 + Mx vs. M1-4) P = 0.0006, extent of resection (total vs. less than total) P = 0.002, radiotherapy (craniospinal irradiation and posterior fossa boost vs. other) P = 0.02, and treatment centre (Toronto centres vs. RCC) P = 0.02. Cases treated at centres outside metropolitan Toronto had a nearly two-fold (relative risk = 1.93; 95% confidence interval = 1.07, 3.47) greater risk of recurrence or death than those seen in Toronto. However, in multivariate analysis this difference was not quite significant (P = 0.07) after controlling for stage (T and M), extent of resection, meningitis, and gender. These data suggest that patients with medulloblastoma should be referred for treatment to large centres with major pediatric neurosurgical and oncology resources.

Cerebellar Neoplasms↗
PubMed1996

The role of palliative thoracic radiotherapy in non-small cell lung cancer.

Non-small cell lung cancer is the most common cause of cancer death in both males and females. Despite this high incidence and mortality, comparatively little research has addressed the palliative treatment of thoracic symptoms. Until recently, information regarding the indications and effectiveness of radiation in this setting was obtained from retrospective reviews of single institutional experiences. More recently, three major randomized trials from the UK Medical Research Council (1991, 1992, 1994) have addressed the use of external beam radiation in randomized comparisons of different dose and fractionation strategies for patients with non-small cell lung cancer and symptoms due to intra-thoracic tumor. These studies show that shorter fractionation schemes provide equivalent palliation and essentially equivalent survival in the patient groups studied. Moreover, they provide estimates of the probability of successful palliation of common symptoms, and estimates of the toxicity of each regimen. A panel of oncologists with expertise in radiation oncology, medical oncology and epidemiology discussed the above trial results and a literature review. The panel concluded that radiation was indicated in the palliation of hemoptysis, chest pain, dysphagia, and dyspnea, and that the results of the MRC studies provided reasonable estimations of the efficacy and toxicity of radiation in this setting. These studies show that symptoms are more often than not improved with palliative radiotherapy (symptom improvement rates ranged from about 50 to 85%) and that palliation lasted for a substantial portion of the patients' remaining survival. The panel could not reach uniform consensus on the appropriate fractionation for radiation given with palliative intent. The panel agreed that favourable patients with stage IIIB NSCLC should be offered combined modality therapy with the intent of prolonging survival, and that patient preferences regarding the risks and benefits of this therapy should be considered. Further study was recommended, namely, a randomized trial evaluating five fractions of radiation vs a single fraction, using patient-based evaluation of palliation. The panel also recommended phase II development of a combined chemotherapy and low-dose radiation protocol appropriate for future study.

Carcinoma, Non-Small-Cell Lung↗
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↗
PubMed1995

Interstitial brachytherapy for penile carcinoma: an alternative to amputation.

From 1987 to 1994, 15 patients with penile saquamous cell carcinoma were referred to the Ottawa Regional Cancer Centre. Seven had already been managed surgically. The other eight were treated with interstitial implantation. Mean age was 58 years (range 39-80). Two patients had previous incomplete local excision and six had biopsy only, with tumor from 1.5 to 4 cm in diameter. Six tumors were located on the glans, one on the corona and one at the base. All were clinically node negative. Six patients were implanted using a rigid technique with a fixed array of steel needles in pre-drilled plexiglass templates, and two with flexible nylon tubing. Implants were manually afterloaded with Iridium-192 wire. The prescribed dose of 60-65 Gy was delivered in 2.5-5.5 days. Local tumor control is 100% at a mean follow-up of 37 months (range 6-64). One patient died of metastases at 15 months with the primary controlled. The remaining seven patients are alive without evidence of disease. Six who were sexually active, continue to be so. One patient has a urethral stricture requiring dilatations. Cosmesis is generally good: mild to moderate hypopigmentation, telangiectasia and fibrosis may develop at the implant site. Intersititial brachytherapy for T1 or minimally invasive T2 penile squamous cell cercinoma up to 4 cm in diameter provides excellent local control with preservation of function and is a viable alternative to amputation.

Journal Article↗
PubMed1993

Effect of intersource spacing on local control and complications in brachytherapy of mobile tongue and floor of mouth.

From 1971 to 1988, 133 T1 and 141 T2 biopsy-proven squamous cell carcinomas of mobile tongue and floor of mouth were definitively managed by Iridium-192. Implantations were performed using either guide gutters or afterloading plastic catheters. The prescribed dose at the reference isodose (85% of the basal dose rate, Paris system) was 60-70 Gy. Total dose was not adjusted to dose rate or tumor volume. Results of the 274 implants have been analysed to look for a possible influence of intersource spacing on local control and necrosis. Follow up for patients free of local recurrence is 1-180 months with median of 35 months. The 274 tumors were divided into two groups according to intersource spacing: 9-14 mm (n = 204), and 15-20 mm (n = 70). At 5 years, the estimated local control (Kaplan Meier) was 86% and 76%; respectively (p = 0.13); the necrosis rate was 33% and 46%, respectively (p = 0.04). Multivariate analysis shows that dose and activity of wires were significantly related to local control, while only tumor site was predictive of necrosis; there was a non-statistically significant relationship between intersource spacing of wires and local control (p = 0.055). When considering only patients with oral tongue cancers, necrosis was significantly related to activity of wires (p = 0.013), and there was a non-significant trend to a relationship between necrosis and intersource spacing (p = 0.066) and tumor diameter (p = 0.065). For patients with floor of mouth cancer, none of these factors was significantly related to necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Brachytherapy of neck metastases.

Brachytherapy with iridium 192 was used in 20 patients with recurrent or persistent neck metastases from a primary head and neck carcinoma. Nine patients had intra-operative brachytherapy in combination with a neck dissection. Three patients had an implant as a boost following external beam radiotherapy. Eight patients were treated by brachytherapy alone for unresectable neck recurrence ranging from 5 to 10 cm in diameter. Nineteen patients were evaluable for neck control: 15 patients had complete clearance of tumor and 13 patients were controlled at time of death or last follow-up. There were few complications from treatment. Five patients are alive at 5, 14, 16, 22, and 27 months post-implant with two patients having developed a second primary. Seven patients died from distant metastases, four from regional disease and four from intercurrent illness. Indications are summarized for this frequently forgotten but useful last option for patients with persistent or recurrent neck metastases.

Aged↗
PubMed1992

Dosimetry of intraluminal brachytherapy.

Dose specification in intraluminal brachytherapy varies considerably in the literature. A terminology is proposed, inspired from the Paris System of interstitial brachytherapy, to define some dosimetric guidelines. The dose is specified in the central plane which is a plane perpendicular to the source and passing through its centre. The reference dose rate is calculated in this plane. The treated volume is the volume encompassed by the reference isodose. The hyperdose sleeve is the volume receiving a dose equal to or greater than twice the reference dose. A study of the dose distribution along a linear source of iridium-192 was undertaken. Results obtained, also valid for caesium-137 and cobalt-60, show that the radius of the hyperdose sleeve is relatively independent of the length of the source. It is approximately 0.6 times the distance between the source axis and the point of dose specification when the active length varies from 3 to 20 cm. Reporting not only the dose, but also the thickness of tissue covered by the reference isodose and the thickness of tissue included in the hyperdose sleeve, is recommended to assist in evaluation of the results of treatment and to facilitate the exchange of clinical information in intraluminal brachytherapy. Practical examples are given.

Brachytherapy↗
PubMed1991

Effect of dose rate on local control and complications in definitive irradiation of T1-2 squamous cell carcinomas of mobile tongue and floor of mouth with interstitial iridium-192.

From 1971 to 1988, 134 T1 and 145 T2 biopsy-proven squamous cell carcinomas of mobile tongue and floor of mouth were definitively managed by iridium-192. Implantations were performed using either guide gutters or afterloading plastic catheters. The prescribed dose at the reference isodose (85% of the basal dose rate, Paris system) was 60-70 Gy. Total dose was not adjusted to dose rate or tumor volume. Results of the 279 implants have been analysed to look for a possible influence of dose rate on local control and necrosis. Follow-up patients free of local recurrence is 1-180 months with average of 51 months. The 279 tumors were divided in four groups according to dose and dose rate: greater than or equal to 62.5 Gy and greater than or equal to 0.5 Gy/h (n = 130), greater than or equal to 62.5 Gy and less than 0.5 Gy/h (n = 36), less than 62.5 Gy and greater than or equal to 0.5 Gy/h (n = 81), less than 62.5 Gy and less than 0.5 Gy/h (n = 32). The four groups were comparable according to age, sex, tumor diameter and macroscopic aspect. At 5 years, the estimated local control (Kaplan Meier) was 93, 87, 79 and 52%, respectively (dose adjusted to dose rate: p less than 0.001, dose rate adjusted to dose: p less than 0.01, Log-rank); the necrosis rate was 44, 24, 37 and 5%, respectively (dose adjusted to dose rate: p = 0.08, dose rate adjusted to dose: p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Squamous Cell↗
PubMed1990

Conservative management of tumors of the rectum by radiotherapy and local excision.

Twenty-five patients with invasive adenocarcinoma of the rectum were treated by preoperative external irradiation (35 Gy), local excision, and peroperative placement of a plastic tube loop in the tumor bed for perioperative brachytherapy (20 or 25 Gy). Patients treated were too frail for radical resection (14 patients) or had refused a permanent colostomy (11 patients). With a mean follow-up of 40.5 months, there have been 5 patients with local relapse, 3 of whom had salvage abdominoperineal resections: 2 have no evidence of disease and 1 has developed distant metastatic disease. The 20 patients with local control have normally functioning sphincters; 1 has developed distant metastatic disease. This combined approach was designed to expand the curative role of local resection in carcinoma of the rectum. The surgical techniques are thoroughly described and the potential role and indications of this approach are discussed.

Adenocarcinoma↗
PubMed1990

Comparison of curietherapy versus external irradiation combined with curietherapy in stage II squamous cell carcinomas of the mobile tongue.

One hundred and ten patients with Stage II epidermoid carcinomas of the mobile tongue were treated by interstitial irradiation (Group I: 85 patients) or external irradiation to the primary and the regional lymphatics followed by an interstitial boost (Group II: 25 patients). The neck was managed by either an elective neck dissection (43 patients) completed by external irradiation in 13 patients with pathological specimen or close follow-up (40 patients) with therapeutic neck dissection for relapses (7 patients) in Group I. Primary local control was 88% in Group I and 36% in Group II. Regional control was 91% in Group I and 5/6 in Group II for patients whose primary tumor was controlled. Five-year absolute disease-free survival (DFS) was 42% in Group I and 24% in Group II, but there was an imbalance in the distribution of larger tumors favoring Group I. There were 30 radiation-induced complications and four patients required corrective surgery. This retrospective analysis showed better results in patients whose primary was treated by interstitial irradiation alone which has the extra advantage of preserving salivary function.

Adult↗
PubMed1990

Iridium-192 curietherapy for T1 and T2 epidermoid carcinomas of the floor of mouth.

From 1970 to 1986, 117 patients with T1 (47) or T2 (70) epidermoid carcinomas of the floor of the mouth (SCC) were treated by iridium-192 implantation (192 Ir). The dose was prescribed according to the Paris System and varied over those years. Follow-up information was available on 116 patients. There were 46 T1N0, 47 T2N0, and 23 T2N1-3. Neck management varied for the 93 N0 patients consisting of surveillance (24 T1, 17 T2) or elective neck dissection (22 T1:all pN-, 30 T2: 20 pN-, 10 pN+). Cause specific survival rates were 94% for T1N0, 61.5% for T2N0, and 28% for T2N1-3 at 5 years. Primary local control was 93.5%, 74.5%, and 65%, respectively, and 98%, 79%, and 65% after salvage. Patients with gingival extension or a tumor size over 3 cm (T2b) had a local control of 50% (9/18) and 58% (15/26), respectively. Nodal control was 93.5% for Stage I, 85% for Stage II, and 48% for T2N1-3 patients. There was no difference in nodal control with regard to treatment policy for Stage I-II patients. There were few complications including three deaths: two from surgery and one from 192 Ir. Nodal status, tumor size defined as T1, T2a (less than or equal to 3 cm), T2b (greater than 3 cm), and gingival extension were the only independent prognostic factors. The management of T1N0 and T2N0 SCC by 192 Ir to a dose of 65 or 70 Gy, using the Paris System, is recommended for lesions 3 cm or less and without gingival extension.

Adult↗