Biomedical subjects

Shalom Kalnicki

Publications and source records attributed to Shalom Kalnicki.

12 recordsLinked to original sources

PubMed2007

Survival and toxicity differences between 5-day and weekly cisplatin in patients with locally advanced cervical cancer.

BACKGROUND: Cisplatin (CDDP) administration concomitant with radiotherapy (RT) for the treatment of locally advanced cervical cancer has evolved from an inpatient 5-day every 21-day regimen to a weekly outpatient regimen. This study was designed to test for differences in progression-free survival (PFS) and toxicity between the 2 regimens. METHODS: In all, 77 consecutive patients at a single institution with stage IB2-IV cervical cancer were included in this analysis (using the International Federation of Gynecologists and Obstetricians staging system). All patients were treated with CDDP, external beam RT, and 2 9-Gy high-dose-rate brachytherapy treatments. Two cohorts were compared: 1) 5-day, patients treated from 1995 to 2001 with CDDP 20 mg/m(2) x 5 days every 21 days concomitant with RT; 2) weekly, treated after May 2001 with CDDP 40 mg/m(2) weekly concomitant with RT. RESULTS: In all, 50 patients were treated with the 5-day regimen and 27 patients with the weekly regimen. There were no significant demographic differences between the groups. Overall 3-year PFS, controlling for stage, was 90% and 76% for 5-day and weekly groups, respectively (P = .01). Adjusting for stage, age, and completion of treatment, the risk of treatment failure among the weekly group was 3.46 times higher than the 5-day group (P = .02). The weekly group had a 3.43 times higher risk of developing acute toxicities than the 5-day group (P = .02) in advanced-stage patients. CONCLUSIONS: Patients who received weekly CDDP have a shorter 3-year PFS. Patients with advanced-stage cervical cancer who received weekly CDDP had significantly more acute toxicities. These data should be confirmed in a multi-institutional, randomized, controlled study.

Antineoplastic Agents↗

PubMed2006

Abdominal organ motion measured using 4D CT.

PURPOSE: To measure respiration-induced abdominal organ motion using four-dimensional computed tomography (4D CT) scanning and to examine the organ paths. METHODS AND MATERIALS: During 4D CT scanning, consecutive CT images are acquired of the patient at each couch position. Simultaneously, the patient's respiratory pattern is recorded using an external marker block taped to the patient's abdomen. This pattern is used to retrospectively organize the CT images into multiple three-dimensional images, each representing one breathing phase. These images are analyzed to measure organ motion between each phase. The displacement from end expiration is compared to a displacement limit that represents acceptable dosimetric results (5 mm). RESULTS: The organs measured in 13 patients were the liver, spleen, and left and right kidneys. Their average superior to inferior absolute displacements were 1.3 cm for the liver, 1.3 cm for the spleen, 1.1 cm for the left kidney, and 1.3 cm for the right kidney. Although the organ paths varied among patients, 5 mm of superior to inferior displacement from end expiration resulted in less than 5 mm of displacement in the other directions for 41 of 43 organs measured. CONCLUSIONS: Four-dimensional CT scanning can accurately measure abdominal organ motion throughout respiration. This information may result in greater organ sparing and planning target volume coverage.

Abdomen↗

PubMed2006

Does breast size affect the scatter dose to the ipsilateral lung, heart, or contralateral breast in primary breast irradiation using intensity-modulated radiation therapy (IMRT)?

PURPOSE: To evaluate the relationship between the primary breast volume and dose received by the ipsilateral lung, heart (for left-breast cancers), and contralateral breast during primary breast irradiation using intensity-modulated radiation therapy (IMRT). METHODS AND MATERIALS: Sixty-five patients with breast carcinoma were treated using 6-MV photons with IMRT technique using the Eclipse Planning System following breast conserving surgery. All patients had a treatment planning CT scan. The primary breast, ipsilateral lung, and heart were contoured on the axial CT slices. The primary breast volume was calculated using the Eclipse Planning System. The mean ipsilateral lung and heart doses were obtained from the dose-volume histogram. The contralateral breast dose was measured using paired thermoluminescent dosimeters (TLDs) placed on the patient's contralateral breast, 4 cm from the center of the medial border of the primary breast irradiation field. RESULTS: The mean dose delivered with photons to the primary breast for all patients was 49.97 Gy. The mean volume of the primary irradiated breast was 1167.9 cc. As a percentage, the mean ipsilateral lung, heart, and contralateral breast doses were 11.2%, 6.1%, and 7.2%, respectively. The primary breast volume positively correlated with the contralateral breast dose (P < 0.0005). There was no significant correlation between the breast volume and the ipsilateral lung or heart dose (P = 0.463 and 0.943, respectively). CONCLUSION: This study suggests that the primary breast size significantly affects the scatter dose to the contralateral breast but not the ipsilateral lung or heart dose when using IMRT for breast irradiation.

Breast↗

PubMed2005

Intensity modulated radiation therapy (IMRT) reduces the dose to the contralateral breast when compared to conventional tangential fields for primary breast irradiation.

PURPOSE: To determine the dose received by the contralateral breast during primary breast irradiation using IMRT compared to conventional tangential field techniques. METHODS AND MATERIALS: Between March 2003 and March 2004, 83 patients with breast carcinoma were treated using 6, 10, or mixed 6/18 MV photons (65 with tangential IMRT technique and 18 with 3-dimensional technique using tangential fields with wedges) for primary breast irradiation following breast-conserving surgery. Paired thermoluminescent dosimeters (TLDs) were placed on each patient's contralateral breast, 4 and 8 cm from the center of the medial border of the tangential field. The TLDs were left on the patient during a single fraction and then measured 24 h afterwards. RESULTS: The mean dose delivered with photons to the primary breast for all patients was 4999 cGy (SD = 52) with a mean single fraction dose of 199 cGy (SD = 8). The mean percent of the prescribed dose to the contralateral breast measured at the 4- and 8-cm positions were 7.19% (SD = 2.28) and 4.63% (SD = 2.12), respectively, for patients treated with IMRT compared to 11.22% (SD = 2.73) and 10.70% (SD = 3.44), respectively, for the patients treated with conventional tangential field techniques. This represented a 36% and 57% reduction at the 4 and 8-cm contralateral positions, respectively, in the mean dose to the contralateral breast using IMRT compared to 3-D technique which was statistically significant (p < 0.0005, <0.0005, respectively). CONCLUSION: Primary breast irradiation with tangential IMRT technique significantly reduces the dose to the contralateral breast compared to conventional tangential field techniques.

Breast↗

PubMed2005

CyberKnife Frameless Radiosurgery for the treatment of extracranial benign tumors.

Limited data exists for the use of radiosurgery for benign extracranial tumors. The purpose of this study was to evaluate the feasibility, toxicity, and local control of patients with benign extracranial lesions treated with the CyberKnife Frameless Radiosurgery System. From September 2001 thru January 2004, 59 benign tumors in 44 patients were treated using the CyberKnife a frameless image-guided radiosurgery system. Of these tumors, there were 21 neurofibromas, ten schwannomas, eight meningiomas, eight hemangioblastomas, seven paragangliomas, two hemangiopericytomas, one pseudotumor, one ependymoma, and one arteriovenous malformation (AVM). The anatomic locations of these tumors were spinal (25 cervical, four thoracic, 14 lumbar, and two sacral), neck (eight), orbital (three), brainstem (one), and foramen magnum (one). All patients were treated in a single fraction except three lesions were treated in a fractionated manner. The median treatment delivery time per fraction was 59 minutes (range 11-194). Twenty three lesions initially underwent surgical resection. Ten lesions received prior external beam radiation with a median dose 48 Gy (range 40-54 Gy), and one lesion received two prior CyberKnife treatments for a total dose of 32 Gy to the 80% isodose line. The median follow-up was eight months (range 1-25 months). Acute and late toxicity was graded using the National Cancer Institute Common Toxicity Criteria (CTC) scale. Symptomatic response was documented as "improved," "stable," or "progression". The median tumor dose delivered was 16.0 Gy to the 80% isodose line (range 10-31 Gy). The median tumor volume was 4.3 cc (range 0.14-98.6 cc). The median spinal cord volume receiving more than 8 Gy was 0.035 cc (range 0-2.5 cc) and the median maximum spinal cord dose 11.5 Gy (range 0-19.8 Gy). There were no patients that suffered a significant (Grade 3, 4, or 5) acute toxicity. There was no observed late toxicity. 78% of patients experienced an improvement of their pre-treatment symptoms while only one patient experienced symptom progression. Of the 26 patients who underwent follow-up imaging, the local control rate was 96%. This study suggests that CyberKnife Radiosurgery is a safe and efficacious treatment modality for benign tumors, even for those patients with recurrent previously irradiated lesions.

Brain Neoplasms↗

PubMed2004

Hybrid PET-CT simulation for radiation treatment planning in head-and-neck cancers: a brief technical report.

PURPOSE: To prospectively study the impact on tumor and normal tissue delineation for RT planning by use of hybrid PET-CT simulation for patients with head-and-neck cancer. METHODS AND MATERIALS: Twenty-one patients were simulated in treatment position on a hybrid PET-CT scanner. Images were transferred to the Varian Eclipse planning system. Abnormal areas of fluorodeoxyglucose (FDG) uptake were contoured on PET for the gross tumor volume of primaries (GTVp) and abnormal nodal region of primaries (ABNp) then compared with the same CT gross tumor volumes (GTVc) and abnormal nodal region (ABNc). A statistical analysis was performed to evaluate the correlation of PET and CT volumes. RESULTS: Positron emission tomography demonstrated the primary in all cases, whereas CT did not find the primary in 3 cases. In 8 patients, additional areas of disease were seen only in PET. The average ratio of GTVc/GTVp was 3.1 (range, 0.3-23.6), whereas for ABNc/ABNp was 0.7 (range, 0-4). Volumes for the primaries were significantly larger on CT than on PET (p = 0.002) but not for nodal regions (p = 0.5). CONCLUSIONS: Hybrid PET-CT simulation is feasible and provides valuable information that results in greater delineation of normal tissues from tumor bearing areas at high risk for recurrence. This finding may further improve therapeutic window for IMRT for head-and-neck cancers.

Adult↗

PubMed2004

CyberKnife frameless stereotactic radiosurgery for spinal lesions: clinical experience in 125 cases.

OBJECTIVE: The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. Its use for the treatment of spinal lesions has been limited by the availability of effective target-immobilizing devices. Conventional external beam radiotherapy lacks the precision to allow delivery of large doses of radiation near radiosensitive structures such as the spinal cord. The CyberKnife (Accuray, Inc., Sunnyvale, CA) is an image-guided frameless stereotactic radiosurgery system that allows for the radiosurgical treatment of spinal lesions. This study evaluated the feasibility and effectiveness of the treatment of spinal lesions with a single-fraction radiosurgical technique using the CyberKnife. METHODS: The CyberKnife system uses the coupling of an orthogonal pair of x-ray cameras to a dynamically manipulated robot-mounted linear accelerator with six degrees of freedom that guides the therapy beam to the intended target without the use of frame-based fixation. Real-time imaging allows the tracking of patient movement. Cervical spine lesions were located and tracked relative to cranial bony landmarks; lower spinal lesions were tracked relative to fiducial bone markers. In this prospective cohort evaluation of a spine radiosurgery technique, 125 spinal lesions in 115 consecutive patients were treated with a single-fraction radiosurgery technique (45 cervical, 30 thoracic, 36 lumbar, and 14 sacral). There were 17 benign tumors and 108 metastatic lesions. All dose plans were calculated on the basis of computed tomographic images acquired from 1.25-mm slices with an inverse treatment planning technique. Radiosurgical circular cones ranging in diameter from 5 to 40 mm were used. RESULTS: Tumor volume ranged from 0.3 to 232 cm(3) (mean, 27.8 cm(3)). Seventy-eight lesions had received external beam irradiation previously. Tumor dose was maintained at 12 to 20 Gy to the 80% isodose line (mean, 14 Gy); canal volume receiving more than 8 Gy ranged from 0.0 to 1.7 cm(3) (mean, 0.2 cm(3)). No acute radiation toxicity or new neurological deficits occurred during the follow-up period (range, 9-30 mo; median, 18 mo). Axial and radicular pain improved in 74 of 79 patients who were symptomatic before treatment. CONCLUSION: This is the first large prospective evaluation of this frameless image-guided spinal radiosurgery system. The CyberKnife system was found to be feasible, safe, and effective. The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and symptomatic response. This technique offers a successful therapeutic modality for the treatment of a variety of spinal lesions as a primary treatment or for lesions not amenable to open surgical techniques, in medically inoperable patients, in lesions located in previously irradiated sites, or as an adjunct to surgery.

Adult↗

PubMed2003

CyberKnife frameless single-fraction stereotactic radiosurgery for tumors of the sacrum.

OBJECT: The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. The experience with radiosurgery for the treatment of spinal and sacral lesions is more limited. Sacral lesions should be amenable to radiosurgical treatment similar to that used for their intracranial counterparts. The authors evaluated a single- fraction radiosurgical technique performed using the CyberKnife Real-Time Image-Guided Radiosurgery System for the treatment of the sacral lesion. METHODS: The CyberKnife is a frameless radiosurgery system based on the coupling of an orthogonal pair of x-ray cameras to a dynamically manipulated robot-mounted linear accelerator possessing six degrees of freedom, which guides the therapy beam to the intended target without the need for frame-based fixation. All sacral lesions were located and tracked for radiation delivery relative to fiducial bone markers placed percutaneously. Eighteen patients were treated with single-fraction radiosurgery. Tumor histology included one benign and 17 malignant tumors. Dose plans were calculated based on computerized tomography scans acquired using 1.25-mm slices. Planning treatment volume was defined as the radiographically documented tumor volume with no margin. Tumor dose was maintained at 12 to 20 Gy to the 80% isodose line (mean 15 Gy). Tumor volume ranged from 23.6 to 187.4 ml (mean 90 ml). The volume of the cauda equina receiving greater than 8 Gy ranged from 0 to 1 ml (mean 0.1 ml). All patients underwent the procedure in an outpatient setting. No acute radiation toxicity or new neurological deficits occurred during the mean follow-up period of 6 months. Pain improved in all 13 patients who were symptomatic prior to treatment. No tumor progression has been documented on follow-up imaging. CONCLUSIONS: Stereotactic radiosurgery was found to be feasible, safe, and effective for the treatment of both benign and malignant sacral lesions. The major potential benefits of radiosurgical ablation of sacral lesions are relatively short treatment time in an outpatient setting and minimal or no side effects. This new technique offers a new and important therapeutic modality for the primary treatment of a variety of sacral tumors or for lesions not amenable to open surgical techniques.

Adult↗

PubMed2003

CyberKnife frameless single-fraction stereotactic radiosurgery for benign tumors of the spine.

OBJECT: The role of stereotactic radiosurgery in the treatment of benign intracranial lesions is well established. Its role in the treatment of benign spinal lesions is more limited. Benign spinal lesions should be amenable to radiosurgical treatment similar to their intracranial counterparts. In this study the authors evaluated the effectiveness of the CyberKnife for benign spinal lesions involving a single-fraction radiosurgical technique. METHODS: The CyberKnife is a frameless radiosurgery system in which an orthogonal pair of x-ray cameras is coupled to a dynamically manipulated robot-mounted linear accelerator possessing six degrees of freedom, whereby the therapy beam is guided to the intended target without the use of frame-based fixation. Cervical spine lesions were located and tracked relative to skull osseous landmarks; lower spinal lesions were tracked relative to percutaneously placed fiducial bone markers. Fifteen patients underwent single-fraction radiosurgery (12 cervical, one thoracic, and two lumbar). Histological types included neurofibroma (five cases), paraganglioma (three cases), schwannoma (two cases), meningioma (two cases), spinal chordoma (two cases), and hemangioma (one case). Radiation dose plans were calculated based on computerized tomography scans acquired using 1.25-mm slices. Planning treatment volume was defined as the radiographic tumor volume with no margin. The tumor dose was maintained at 12 to 20 Gy to the 80% isodose line (mean 16 Gy). Tumor volume ranged from 0.3 to 29.3 ml (mean 6.4 ml). Spinal canal volume receiving more than 8 Gy ranged from 0.0 to 0.9 ml (mean 0.2 ml). All patients tolerated the procedure in an outpatient setting. No acute radiation-induced toxicity or new neurological deficits occurred during the follow-up period. Pain improved in all patients who were symptomatic prior to treatment. No tumor progression has been documented on follow-up imaging (mean 12 months). CONCLUSIONS: Spinal stereotactic radiosurgery was found to be feasible, safe, and effective for the treatment of benign spinal lesions. Its major potential benefits are the relatively short treatment time in an outpatient setting and the minimal risk of side effects. This new technique offers an alternative therapeutic modality for the treatment of a variety of benign spinal neoplasms in cases in which surgery cannot be performed, in cases with previously irradiated sites, and in cases involving lesions not amenable to open surgical techniques or as an adjunct to surgery.

Adult↗

PubMed2003

Evaluation of CyberKnife frameless real-time image-guided stereotactic radiosurgery for spinal lesions.

BACKGROUND: This study evaluated the CyberKnife frameless image-guided radiosurgery system for the treatment of spinal lesions. METHODS: This system utilizes the coupling of an orthogonal pair of X-ray cameras to a dynamically manipulated robot-mounted linear accelerator that guides the therapy beam to the intended target without the use of frame-based fixation. Cervical spine lesions are located and tracked relative to skull bony landmarks; lower spinal lesions are tracked relative to fiducial markers. 125 spinal lesions in 115 consecutive patients were treated with a single-fraction radiosurgery technique. RESULTS: Tumor volume ranged from 0.3 to 232 ml (mean 27.8 ml). Tumor radiation dose was maintained at 12-20 Gy to the 80% isodose line (mean 14 Gy); the spinal cord or canal volume receiving greater than 8 Gy ranged from 0.0 to 1.7 ml (mean 0.2 ml). No acute radiation toxicity or new neurological deficits occurred during the follow-up period (3-24 months). CONCLUSIONS: The CyberKnife system was found to be feasible, safe and effective. The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and good response.

Adult↗

PubMed2002

Feasibility of frameless single-fraction stereotactic radiosurgery for spinal lesions.

OBJECT: The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. Its use for the treatment of spinal lesions has been limited by the availability of effective target-immobilizing devices. In this study the authors evaluated the CyberKnife Real-Time Image-Guided Radiosurgery System for spinal lesion treatment involving a single-fraction radiosurgical technique. METHODS: This frameless image-guided radiosurgery system uses the coupling of an orthogonal pair of x-ray cameras to a dynamically manipulated robot-mounted linear accelerator possessing six degrees of freedom, which guides the therapy beam to the target without the use of frame-based fixation. Cervical lesions were located and tracked relative to osseous skull landmarks; lower spinal lesions were tracked relative to percutaneously placed gold fiducial bone markers. Fifty-six spinal lesions in 46 consecutive patients were treated using single-fraction radiosurgery (26 cervical, 15 thoracic, and 11 lumbar, and four sacral). There were 11 benign and 45 metastatic lesions. Tumor volume ranged from 0.3 to 168 ml (mean 26.7 ml). Thirty-one lesions had previously received external-beam radiotherapy with maximum spinal cord doses. Dose plans were calculated based on computerized tomography scans acquired using 1.25-mm slices. Tumor dose was maintained at 12 to 18 Gy to the 80% isodose line; spinal cord lesions receiving greater than 8 Gy ranged from 0 to 1.3 ml (mean 0.3 ml). All patients tolerated the procedure in an outpatient setting. No acute radiation-induced toxicity or new neurological deficits occurred during the follow-up period. Axial and radicular pain improved in all patients who were symptomatic prior to treatment. CONCLUSIONS: Spinal stereotactic radiosurgery involving a frameless image-guided system was found to be feasible and safe. The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and symptomatic response. This procedure offers a successful alternative therapeutic modality for the treatment of a variety of spinal lesions not amenable to open surgical techniques; the intervention can be performed in medically untreatable patients, lesions located in previously irradiated sites, or as an adjunct to surgery.

Feasibility Studies↗

PubMedDate not supplied

Intensity-modulated radiation therapy (IMRT) reduces the dose to the contralateral breast when compared to conventional tangential fields for primary breast irradiation: initial report.

PURPOSE: This study was designed to compare the dose received by the contralateral breast during primary breast irradiation using intensity-modulated radiotherapy with the dose received via conventional tangential field techniques. METHODS/MATERIALS: Between March 2003 and March 2004, 44 patients with breast carcinoma were treated using 6-, 10-, or mixed 6/18-MV photons(36 with tangential intensity-modulated radiotherapy technique and eight with three-dimensional technique using tangential fields with wedges) for primary breast irradiation after breast-conserving surgery. Paired thermoluminescent dosimeters were placed on each patient's contralateral breast, 4 cm from the center of the medial border of the tangential field. The thermoluminescent dosimeters were left on the patient during a single fraction and then measured 24 hours later. RESULTS: The mean dose delivered with photons to the primary breast for all patients was 4998 cGy [SD = 52], and the mean single fraction dose was 200 cGy [SD = 9]. The mean percent of the prescribed dose to the contralateral breast was 7.74% (SD = 2.35) for patients treated with intensity-modulated radiotherapy, compared with 9.74% [SD = 2.04] for the patients treated with conventional tangential field techniques. This represented a 20% reduction in the mean dose to the contralateral breast with the use of intensity-modulated radiotherapy when compared with the dose received via the three-dimensional technique, a result that was statistically significant. CONCLUSION: Primary breast irradiation with tangential intensity-modulated radiotherapy technique significantly reduces the dose to the contralateral breast when compared with conventional tangential techniques.

Breast Neoplasms↗