A weekly hypofractionated radiotherapeutic schedule for bladder carcinoma in elderly patients: local response, acute and late toxicity, dosimetric parameters and pain relief

PURPOSE

To investigate the early and late toxicity of a hypofractionated radiotherapy (RT) schedule to treat muscle- invasive bladder cancer in relation to radiation parameters according to the organs at risk.

METHODS

Forty-three patients with T2-T3 bladder carcinoma were irradiated with a weekly hypofractionated schedule with a total dose of 36 Gy in 6 fractions. Included in this study were elderly patients with poor performance status or unfit for surgery, while they complained of daily pain on urination. Pain evaluation was assessed with the use of the visual analogue scale (VAS) of pain, acute and late toxicities were assessed using the combined RTOG/EORTC criteria by using a dose of 50 Gy (D50), and the relapse free survival (RFS) was estimated from the date of recurrence.

RESULTS

No acute side effects were observed in the majority of the patients. Grade I rectal toxicity was registered in 67.4% of the patients, while grade II and III were noted in 30.25% and 2.37percnt; of the patients, respectively. The worst late rectal toxicity was grade I in 30.2% of the patients. The VAS score of pain showed a significant improvement after the hypofractionated schedule. There was a significant correlation between acute and late toxicity on the one hand and the D50 dosimetric parameter on the other. The Kaplan-Meier plot showed a median RFS of 15 months, while age did not have any impact on RFS in patients above or under 75 years of age.

CONCLUSION

The performed hypofractionated schedule permitted delivery of an increased radiation dose without increased toxicity, and with a high probability of local control for elderly patients with low survival perspective.

Intraoperative radiation therapy on pancreatic cancer patients: a review of the literature

Pancreatic cancer is rarely curable, and the overall survival rate at 5 years is under 4%. This study aimed to assess the efficacy, effectiveness and safety of intraoperative radiation therapy (IORT) as treatment in pancreatic cancer, by means of a systematic review of the literature. We searched Pubmed from 1980 until 2010 by means of prospective randomized trials. The aim was to assess the potential impact of IORT on local control, quality of life and overall survival. The search was restricted to articles published in English. IORT offers the opportunity to administer high doses of irradiation to areas of neoplastic involvement while attempting simultaneously to spare normal tissues in the region from potentially damaging radiation exposure. However, the results were not in favour of IORT in the case of pancreatic cancer in locally advanced and metastatic stages. There is no clear evidence to indicate the IORT as more effective than other therapies in treating pancreatic cancer.

The potential role of hypofractionated accelerated radiotherapy to cosmesis for stage I-II breast carcinoma: a prospective study

PURPOSE

To evaluate the acute and late effects as well as the cosmetic results of an accelerated hypofractionated radiotherapeutic schedule in breast cancer irradiation.

METHODS

Fifty-four patients with stage I-II invasive breast cancer receiving postoperative radiotherapy (RT) after lumpectomy and axillary node dissection were studied. All patients received RT with 6 MV linear accelerator with a total tumor dose of 53 Gy (Equivalent dose-EQD2- 60 Gy), 2.65 Gy per fraction, in 20 fractions. Acute and late effects as well as cosmetic results were assessed using the European Organization for Research and Treatment of Cancer and Radiation Therapy Oncology Group (EORTC-RTOG) Cosmetic Rating System.

RESULTS

By the end of RT 66.7% of the patients developed no toxicity, while 24.1% showed grade 1 and 9.3% grade 2 acute skin toxicity. After 6 months 90.7% of women showed grade 0 late toxicity while 100% of women recovered completely 2 years after RT. There was no local or distant recurrence during 5-year follow up.

CONCLUSION

The accelerated hypofractionated schedule appears to be an acceptable alternative to the traditional longer RT schedules, without late toxicity.

Radiobiological modelling of dose-gradient effects in low dose rate, high dose rate and pulsed brachytherapy

This paper presents a generalization of a previously published methodology which quantified the radiobiological consequences of dose-gradient effects in brachytherapy applications. The methodology uses the linear-quadratic (LQ) formulation to identify an equivalent biologically effective dose (BED(eq)) which, if applied uniformly to a specified tissue volume, would produce the same net cell survival as that achieved by a given non-uniform brachytherapy application. Multiplying factors (MFs), which enable the equivalent BED for an enclosed volume to be estimated from the BED calculated at the dose reference surface, have been calculated and tabulated for both spherical and cylindrical geometries. The main types of brachytherapy (high dose rate (HDR), low dose rate (LDR) and pulsed (PB)) have been examined for a range of radiobiological parameters/dimensions. Equivalent BEDs are consistently higher than the BEDs calculated at the reference surface by an amount which depends on the treatment prescription (magnitude of the prescribed dose) at the reference point. MFs are closely related to the numerical BED values, irrespective of how the original BED was attained (e.g., via HDR, LDR or PB). Thus, an average MF can be used for a given prescribed BED as it will be largely independent of the assumed radiobiological parameters (radiosensitivity and alpha/beta) and standardized look-up tables may be applicable to all types of brachytherapy treatment. This analysis opens the way to more systematic approaches for correlating physical and biological effects in several types of brachytherapy and for the improved quantitative assessment and ranking of clinical treatments which involve a brachytherapy component.