Assessing the dose rate delivery of helical TomoTherapy prostate and head & neck treatments.

The dose rate distributions delivered to 55 prostate and head & neck (H&N) cancer patients treated with a helical TomoTherapy (HT) system were resolved and assessed with regard to pitch and field width defined during treatment planning. Statistical analysis of the studied cases showed that the median treatment delivery time was 4.4 min and 6.3 min for the prostate and H&N cases, respectively. Dose rate volume histogram data for the studied cases showed that the 25% and 12% of the volume of the planning target volumes of the prostate and H&N cases are irradiated with a dose rate of greater or equal to 1 Gy min-1. Quartile dose rate (QDR) data confirmed that in HT, where the target is irradiated in slices, most of the dose is delivered to each voxel of the target when it travels within the beam. Analysis of the planning data from all cases showed that this lasts for 68 s (median value). QDRs results showed that using the 2.5 cm field width, 75% of the prescribed dose is delivered to target voxels with a median dose rate of at least 3.2 Gy min-1and 4.5 Gy min-1, for the prostate and H&N cases, respectively. Systematically higher dose rates were observed for the H&N cases due to the shallower depths of the lesions in this anatomical site. Delivered dose rates were also found to increase with field width and pitch setting, due to the higher output of the system which, in general, results in accordingly decreased total treatment time. The biological effect of the dose rate findings of this work needs to be further investigated using in-vitro studies and clinical treatment data.

Hypofractionated irradiation for gliomas with 45.5Gy in 13 fractions: a retrospective study.

AIM: The aim of the present retrospective study was to evaluate the efficacy and toxicity of a hypofractionated radiotherapy (HFRT) schedule for grade IV glioblastoma multiforme (GBM). METHODS: Fourteen elderly patients with KPS less than 70, received 13 fractions of 350cGy with 3D-conformal technique (3DCRT) and non-coplanar fields. Acute and late skin and CNS toxicity was graded according to EORTC/RTOG criteria. RESULTS: The median follow-up was 9 months. All patients completed the irradiation without interruptions due to toxicity and received temozolomide (TMZ) after the completion of 3DCRT. The KPS during RT and at follow-up was not significantly changed (P=0.108). The median overall survival was 7 months. No severe skin acute or late toxicity was noted. In terms of CNS toxicity, only one patient presented grade III toxicity requiring hospitalization for two days. The irradiation schedule of 45.5Gy in 13 fractions seems effective and without moderate or severe toxicity. CONCLUSION: The suggested HFRT schedule might be an alternative one, for elderly patients with dismal prognosis, unfit for six weeks of daily irradiation. Prospective studies are needed for further validation of our results, especially with the use of TMZ.

Evaluation of efficacy and toxicity in two different hypofractionated 3D-conformal external beam radiotherapy schedules in localised muscle invasive bladder cancer.

PURPOSE: To evaluate the efficacy as well as acute and late toxicity of two different accelerated hypofractionated 3D-conformal radiotherapy (Hypo-3DCRT) schedules in patients with bladder cancer. METHODS: Between February 2006 and June 2011, 50 elderly patients with cT1-2N0 bladder carcinoma were treated with Hypo-3DCRT. Mean age was 75 years. All patients were medically inoperable, with poor performance status, who couldn't tolerate either cystectomy or radical external beam irradiation on a daily basis. A dose of 36 Gy in 6 weekly fractions (arm A, N=39) or 39.96 Gy of 3.33 Gy twice daily, once a week, for 6 weeks (arm B, N=11) were prescribed. The primary study endpoints were the evaluation of acute/late gastrointestinal (GI) toxicity according to the EORTC/RTOG scale together with the visual analogue bladder-related pain score (VAS). RESULTS: The GI acute toxicities were: grade 1: arm A 24/39 (61.5%), arm B 9/11 (81.8%); grade 2: arm A 14/39 (35.9%), arm B 1/11 (9.1%); grade 3: arm A 1/39 (9.1%) (x(2), p=0.29). Only grade 1 late GI toxicity was seen and was significantly higher in arm A: arm A 17/39 (43.6%) and arm B 1/11 (9.1%) (x(2), p=0.037). The reduction of VAS score was similar in both arms (p=0.065). The median relapse free survival (RFS) was 15 and 16 months for arm A and B, respectively (log rank, p=0.71). CONCLUSIONS: Beyond the non-randomized design of the trial, the Hypo-3DCRT schedules used appear to be an acceptable alternative to the traditional longer radiotherapy (RT) schedules for elderly patients unfit for daily irradiation.

Sucralfate gel as a radioprotector against radiation induced dermatitis in a hypo-fractionated schedule: a non-randomized study.

External beam radiotherapy with high doses provokes many acute skin reactions, such as erythema and moist desquamation. Many topical preparations are used in radiation oncology departments in the skin care. Sucralfate humid gel, a colloidal physical form of the anti-ulcer drug sucralfate, promotes epithelial regeneration and activates cell proliferation. Based on this knowledge, we performed a non-randomized clinical trial to evaluate the efficacy of topical sucralfate gel in 30 breast cancer patients receiving postoperative accelerated hypofractionated photon beam therapy. The comparison was performed with 30 patients as historical controls. The acute reaction of the skin was significantly lower in the group receiving the sucralfate gel (p<0.05, Mann Whitney test), while 90% of the patients had no evidence of radiation induced skin toxicity. There was no sucralfate gel related toxicity reported by any patient in this study. More patients in a randomized way are needed for more definite results.

Clinical implementation of total skin electron beam (TSEB) therapy: a review of the relevant literature.

Total skin electron beam therapy has been in medical service since the middle of the last century in order to confront rare skin malignancies. Since then various techniques have been developed, all aiming at better clinical results in conjunction with less post-irradiation complications. In this article every available technique is presented in addition to physical parameters of technique establishment and common dose fractionation. This study also revealed the preference of the majority of institutes the last 20 years in "six dual field technique" at a high dose rate, which is a safe and effective treatment.

Hypofractionated radiotherapy in non small cell lung cancer: a review of the current literature.

Hypofractionated irradiation has an established role in the palliative treatment of patients with advanced medically inoperable non - small cell lung cancer (NSCLC ) and poor performance status. Also hypofractionated radiotherapy merits careful consideration in the curative treatment of patients with Stage I and II disease using contemporary technology. The biological effect of radiation on tumours is increased as the overall treatment time is shortened. Hypofractionated field radiotherapy offers acceptable palliation with minimal toxicity. The rates of palliation for hemoptysis , chest pain , cough and dyspnea reported from studies with very short regimen ( 8,5 Gy x 2 ), are comparable to those of other trials that used more protracted palliative treatment . The observed toxicity is minimal, and no cases of oesophagitis, pneumonitis, or radiation myelopathy developed. The minimal toxicity is a reflection of both the low biologic total dose and the tight RT design. Therefore the radiation side effects appear to be related to the technique of RT delivered rather than the patient's PS. Hence, widely believed dogmas concerning the tolerance of critical structures to conventionally fractionated doses, such as the dose-volume effect, total dose, and time (latency) dependency, has to be re-evaluated for hypofractionated radiation therapy. As well there is data suggesting that the small stages I - II NSCLC are likely to benefit from hypofractionated regimens too. Hypofractionated stereotactic radiotherapy is a new technically complex approach to the treatment of early-stage nonsmall cell lung cancer. It is capable to deliver much higher doses to the cancer than is possible with standard techniques, and as a result, rates of tumour control are high and similar to what can be achieved by surgical resection. Refinements of technique and dose as well as randomized data are required before stereotactic radiotherapy can be endorsed as a standard of care for patients with inoperable peripherally located T1 non small cell lung cancer. A clear advantage of the very short hypofractionated palliative regimen is that it allows patients with a short expected survival time to spend more of their remaining time away from the hospital.