Technology in cancer research & treatment
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Technol. Cancer Res. Treat. · Feb 2009
Total marrow irradiation with helical tomotherapy for bone marrow transplantation of multiple myeloma: first experience in Asia.
Three Asian patients with plasma cell myeloma stage IIIa with IgG predominant were selected for autologous hematopoietic cell transplantation (HSCT). Total marrow irradiation (TMI) tomotherapy planned with melphalan 140 mg/m2 as a preconditioning regimen of HSCT. Two image sets of computed tomography (CT) were scanned with 2.5 mm and 5 mm for the upper and lower part of the plan, respectively. ⋯ The margin of PTV could be less than 1 cm under good fixation and close position confirmation with MVCT. Antiemetics should be prescribed in the whole course of TMI for emesis prevention. TMI technique replaced TBI technique with 8 Gy as conditioning regiment for multiple myeloma could be acceptable for the Asian and the outcomes were feasible for the Asian.
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Technol. Cancer Res. Treat. · Dec 2008
Dose escalated, hypofractionated radiotherapy using helical tomotherapy for inoperable non-small cell lung cancer: preliminary results of a risk-stratified phase I dose escalation study.
To improve local control for inoperable non-small cell lung cancer (NSCLC), a phase I dose escalation study for locally advanced and medically inoperable patients was devised to escalate tumor dose while limiting the dose to organs at risk including the esophagus, spinal cord, and residual lung. Helical tomotherapy provided image-guided IMRT, delivered in a 5-week hypofractionated schedule to minimize the effect of accelerated repopulation. Forty-six patients judged not to be surgical candidates with Stage I-IV NSCLC were treated. ⋯ The median survival was 18 months with 2-year overall survival of 46.8% +/- 9.7% for this cohort, 50% of whom were stage IIIB and 30% stage IIIA. Dose escalation can be safely achieved in NSCLC with lower than expected rates of pneumonitis and esophagitis using hypofractionated image-guided IMRT. The maximum tolerated dose has yet to be reached.
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Technol. Cancer Res. Treat. · Aug 2008
Comparative StudyComparison of daily couch shifts using MVCT (TomoTherapy) and B-mode ultrasound (BAT System) during prostate radiotherapy.
The purpose of this study was to compare daily couch shifts after prostate localization between megavoltage CT (MVCT, Hi-ART TomoTherapy) and b-mode ultrasound (BAT system). Nine hundred and thirteen couch shifts from 22 consecutive patients treated using MVCT localization were compared to 853 shifts from 23 randomly selected patients treated using b-mode ultrasound prostate localization. Shifts were made in three principal axes based on prostate position after comparing daily images to the initial planning CT. ⋯ When compared to MVCT, the use of BAT for prostate localization results in greater variability of positional adjustments in vertical and CC directions. This likely reflects differences in the ability to precisely align b-mode ultrasound contours to KVCT images, as well as prostate excursion in vertical and CC direction caused by the ultrasound probe. These considerations need to be made when defining treatment volumes, and argue for the use of less disruptive techniques for daily prostate localization.
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Technol. Cancer Res. Treat. · Jun 2008
Comparative StudyComparison of helical tomotherapy versus conventional radiation to deliver craniospinal radiation.
The purpose of this study was to investigate whether helical tomotherapy would better dose-limit growing vertebral ring apophyses during craniospinal radiation as compared to conventional techniques. Four pediatric patients with M0 medulloblastoma received tomotherapy craniospinal radiation (23.4 Gy, 1.8 Gy/fx) by continuous helical delivery of 6 MV photons. Weekly blood counts were monitored. ⋯ Tomotherapy radiation reduced neutrophil, platelet, and erythrocyte hemoglobin levels during treatment. Tomotherapy provides improved dose avoidance to growing vertebrae as compared to conventional craniospinal radiation. However, the long-term effects of tomotherapy dose avoidance on spine growth and large volume low dose radiation in children are not yet known.
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Technol. Cancer Res. Treat. · Jun 2007
Conductive interstitial thermal therapy (CITT) device evaluation in VX2 rabbit model.
We have developed a conductive interstitial thermal therapy (CITT) device to precisely and reliably deliver controlled thermal doses to the surgical margins at the cavity site following tumor resection, intraoperatively. The temperature field created by CITT ablation of a perfused tissue was modeled with a finite element package Femlab. The modeling suggested that a maximum probe temperature of 120 degrees C and an ablation time of 20 minutes were required to ablate highly perfused tissue such as the VX2 carcinoma. ⋯ Cells in the thermally fixed region stained for PCNA (proliferating cell nuclear antigen) and were bounded by the carbonized layer at the cavity wall, and by necrotic cells that exhibit nuclear fragmentation and cell dissociation, 5 to 10 mm away from the CITT probe. Adjacent tissue outside the target region was spared with a clear demarcation between ablated and normal viable tissue. It is suggested that the CITT device can be used, clinically, to inhibit local recurrence by creating negative surgical margins following the resection of a primary tumor in non-metastatic early staged tumors.