International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2000
Short-course intensity-modulated radiotherapy for localized prostate cancer with daily transabdominal ultrasound localization of the prostate gland.
To present our initial observations on the clinical feasibility of the technique of short-course intensity-modulated radiotherapy (SCIM-RT) in the treatment of localized prostate cancer coupled with daily transabdominal ultrasound localization of the prostate. The proposed regimen consists of a hypofractionated course delivering 70.0 Gy in 28 fractions. ⋯ The delivery of our proposed hypofractionated-schedule SCIM-RT in combination with daily target localization/alignment with the BAT transabdominal ultrasound system is clinically feasible. It is an alternative method of dose escalation in the treatment of localized prostate cancer. The proposed schedule would significantly increase convenience to patients due to the decrease in overall treatment time. Preliminary acute toxicity results are extremely encouraging. Long-term follow-up is needed to assess late complications and treatment efficacy.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2000
Radiobiological considerations in the design of fractionation strategies for intensity-modulated radiation therapy of head and neck cancers.
The dose distributions of intensity-modulated radiotherapy (IMRT) treatment plans can be shown to be significantly superior in terms of higher conformality if designed to simultaneously deliver high dose to the primary disease and lower dose to the subclinical disease or electively treated regions. We use the term "simultaneous integrated boost" (SIB) to define such a treatment. The purpose of this paper is to develop suitable fractionation strategies based on radiobiological principles for clinical trials and routine use of IMRT of head and neck (HN) cancers. The fractionation strategies are intended to allow escalation of tumor dose while adequately sparing normal tissues outside the target volume and considering the tolerances of normal tissues embedded within the primary target volume. ⋯ IMRT dose distributions are most conformal when designed to be delivered as SIB. Using isoeffect radiobiological relationships and published HN data, fractionation strategies can be designed in which the nominal dose levels to the primary, regional disease and electively treated volumes are appropriately adjusted, each receiving different dose/fx. Normal tissues outside the treated volumes are at reduced risk in such strategies since they receive lower total dose as well as lower dose/fx. However, the late effect toxicities of tissues embedded within the primary target volume and assumed to receive the same dose as the primary may pose a problem. The efficacy and safety of the proposed fractionation strategies will need to be evaluated with careful clinical trials.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2000
Nodal basin recurrence following lymph node dissection for melanoma: implications for adjuvant radiotherapy.
To analyze patterns of failure in malignant melanoma patients with lymph node involvement who underwent complete lymph node dissection (LND) of the nodal basin. To determine prognostic factors predictive of local recurrence in the lymph node basin in order to select patients who may benefit from adjuvant radiotherapy. ⋯ Malignant melanoma patients with nodal involvement have a significant risk of nodal basin failure after LND if they have cervical involvement, ECE, >3 positive lymph nodes, clinically involved nodes, or any node larger than 3 cm. Patients with these risk factors should be considered for adjuvant radiotherapy to the lymph node basin to reduce the incidence of nodal basin recurrence. Patients with nodal basin failure are at higher risk of developing distant metastases.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2000
Randomized Controlled Trial Multicenter Study Clinical TrialPostoperative neoadjuvant chemotherapy before radiotherapy as compared to immediate radiotherapy followed by maintenance chemotherapy in the treatment of medulloblastoma in childhood: results of the German prospective randomized trial HIT '91.
The German Society of Pediatric Hematology and Oncology (GPOH) conducted a randomized, prospective, multicenter trial (HIT '91) in order to improve the survival of children with medulloblastoma by using postoperative neoadjuvant chemotherapy before radiation therapy as opposed to maintenance chemotherapy after immediate postoperative radiotherapy. ⋯ Maintenance chemotherapy would seem to be more effective in low-risk medulloblastoma, especially in patients older than 6 years of age. Neoadjuvant chemotherapy was accompanied by increased myelotoxicity of the subsequent radiotherapy, causing a higher rate of interruptions and an extended overall treatment time. Delayed and/or protracted radiotherapy may therefore have a negative impact on outcome. M2/3 disease was associated with a poor survival in both arms, suggesting the need for a more intensive treatment. Young age and M2/3 stage were negative prognostic factors in medulloblastoma, but residual or M1 disease was not, suggesting a new stratification system for risk subgroups. High quality of radiotherapy may be a major contributing factor for the overall outcome.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2000
Neurobehavioral toxicity of total body irradiation: a follow-up in long-term survivors.
Total body irradiation (TBI) in preparation for bone marrow transplantation (BMT) is a routine treatment of hematological malignancy. A retrospective and a prospective group study of long-term cerebral side effects was performed, with a special emphasis on neurobehavioral toxicity effects. ⋯ The incidence of long-term neurobehavioral toxicity was very low for the present TBI/BMT regimen.