International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
PSA doubling time kinetics during prostate cancer biochemical relapse after external beam radiation therapy.
To investigate whether prostate-specific antigen PSA doubling time (PSADT) is constant in men with biochemical prostate cancer relapse after external beam radiotherapy (EBRT). ⋯ PSA initially rises more rapidly after AA cessation, probably because of testosterone recovery. A subgroup of patients, who received secondary intervention after treatment with radiotherapy alone, showed a change in PSADT, to a faster velocity. This greater than constant exponential PSA growth is presumably the catalyst for secondary intervention. Otherwise, PSADT did not change during prostate cancer biochemical relapse.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Clinical experience with chronomodulated infusional 5-fluorouracil chemoradiotherapy for pancreatic adenocarcinoma.
To evaluate retrospectively the efficacy and chronic toxicities of concurrent radiotherapy and chronomodulated infusion 5-fluorouracil (5-FU) in patients with pancreatic adenocarcinoma. ⋯ Chronomodulated 5-FU administration, based on the concept of chronotolerance, has relatively low acute toxicity. Our median survival rate was greater than that after most chemoradiotherapy programs that result in more acute toxicity. Additional study is warranted to evaluate chronomodulated radiosensitizing chemotherapy schedules in prospective trials and with attention to late effects after radiotherapy, including diabetes mellitus.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Why to start the concomitant boost in accelerated radiotherapy for advanced laryngeal cancer in week 3.
We analyzed toxicity and the local control rates for advanced laryngeal cancer, treated with two accelerated fractionation schedules. The main difference between the schedules was the onset of the concomitant boost, in Week 3 or Week 4. Overall treatment time and total dose were equivalent. ⋯ In our study the timing of the boost in accelerated radiotherapy for advanced laryngeal cancer was an independent factor for local control, favoring the use of a concomitant boost in Week 3. This finding may indicate that accelerated repopulation of tumor cells starts early in the treatment phase.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
An automatic CT-guided adaptive radiation therapy technique by online modification of multileaf collimator leaf positions for prostate cancer.
To propose and evaluate online adaptive radiation therapy (ART) using in-room computed tomography (CT) imaging that detects changes in the target position and shape of the prostate and seminal vesicles (SVs) and then automatically modifies the multileaf collimator (MLC) leaf pairs in a slice-by-slice fashion. ⋯ ART corrected for interfraction changes in the position and shape of the prostate and SVs and gave dose distributions that were considerably closer to the planned dose distributions than could be achieved with simple alignment strategies that neglect shape change. The ART proposed in this investigation requires neither contouring of the daily CT images nor extensive calculations; therefore, it may prove to be an effective and clinically practical solution to the problem of interfraction shape changes.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Stereotactic proton beam therapy for intracranial arteriovenous malformations.
To investigate hypofractionated stereotactic proton therapy of predominantly large intracranial arteriovenous malformations (AVMs) by analyzing retrospectively the results from a cohort of patients. ⋯ Stereotactic proton beam therapy applied in a hypofractionated schedule allows for the safe treatment of large AVMs, with acceptable results. It is an alternative to other treatment strategies for large AVMs. AVMs are likely not static entities, but probably undergo vascular remodeling. Factors influencing angiogenesis could play a new role in a form of adjuvant therapy to improve on the radiosurgical results.