Quality of interstitial PDR-brachytherapy-implants of head-and-neck-cancers: predictive factors for local control and late toxicity?

BACKGROUND AND PURPOSE: Parameters and indices related to the implant geometry in use for describing the quality of volume implants in interstitial brachytherapy were developed on the basis of LDR-brachytherapy. The aim of our study was to evaluate their usefulness for predicting late toxicity and local control in the PDR-brachytherapy of head-and-neck-tumors. PATIENTS AND METHODS: Between January 2000 and October 2004, 210 patients were treated with PDR-brachytherapy which was administered either postoperatively or as definitive treatment. Brachytherapy was used as sole treatment in some cases while in others a combination with EBRT was used. For assessment of quality of implants we analyzed the following indices and parameters using the univariate chi2 test and multivariate logistic regression analysis: V85, V120 and V150 (volume enclosed by the surface of the 85%-, 120%- and 150%-isodose), UI (uniformity index), QI (quality index), HI (homogeneity index), VGR (volume gradient ratio), DNR (dose non-uniformity ratio), LD (low dose), HD (high dose), PD (peak dose) and the intersource spacing. RESULTS: After a median follow-up of 24 months (4-50) the rate of - usually transient - soft tissue necrosis (STN) was 11%, osteoradionecrosis (ORN) was seen in 7.6% of cases and local relapse occurred in 7% of cases. Univariate analysis shows a significant influence on the development of soft tissue necrosis for V85, and on osteoradionecrosis for HD and PD. In the multivariate analysis a correlation between soft tissue necrosis and QI was found. For local control a correlation with QI, VGR and minimal tube distance was found using univariate analysis. CONCLUSIONS: Using interstitial PDR-brachytherapy in head-and-neck-tumors the probability of local control and of the development of soft tissue necrosis or osteoradionecrosis is dependent on dose and volume parameter like the volume of the reference isodose, the high and peak dose values, on the homogeneity of the dose distribution, quantified by the quality index or the volume gradient ratio as well on the minimal tube distance.

Influence of intravenous amifostine on xerostomia, tumor control, and survival after radiotherapy for head-and- neck cancer: 2-year follow-up of a prospective, randomized, phase III trial.

PURPOSE: To evaluate chronic xerostomia and tumor control 18 and 24 months after initial treatment with amifostine in a randomized controlled trial of patients with head-and-neck cancer; at 12 months after radiotherapy (RT), amifostine had been shown to reduce xerostomia without changing tumor control. METHODS AND MATERIALS: Adults with head-and-neck cancer who underwent once-daily RT for 5-7 weeks (total dose, 50-70 Gy) received either open-label amifostine (200 mg/m2 i.v.) 15-30 min before each fraction of radiation (n = 150) or RT alone (control; n = 153). RESULTS: Amifostine administration was associated with a reduced incidence of Grade > or =2 xerostomia over 2 years of follow-up (p = 0.002), an increase in the proportion of patients with meaningful (>0.1 g) unstimulated saliva production at 24 months (p = 0.011), and reduced mouth dryness scores on a patient benefit questionnaire at 24 months (p < 0.001). Locoregional control rate, progression-free survival, and overall survival were not significantly different between the amifostine group and the control group. CONCLUSIONS: Amifostine administration during head-and-neck RT reduces the severity and duration of xerostomia 2 years after treatment and does not seem to compromise locoregional control rates, progression-free survival, or overall survival.

GEC-ESTRO recommendations for brachytherapy for head and neck squamous cell carcinomas.

Both primary and recurrent squamous cell carcinoma of the head and neck are classic indications for brachytherapy. A high rate of local tumor control at the cost of limited morbidity can be achieved with brachytherapy through good patient selection, meticulous source implantation and careful treatment planning. However, no randomized trials have been performed, and there is scant evidence in the literature especially regarding practical clinical recommendations for brachytherapy for head and neck subsites. The Head and Neck Working Group of the European Brachytherapy Group (Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) therefore decided to formulate the present consensus recommendations for low-dose rate, pulsed-dose rate and high-dose rate brachytherapy. The use of brachytherapy in combination with external beam radiotherapy and/or surgery is also covered as well as the use of brachytherapy in previously irradiated patients. Given the paucity of evidence in the literature, these recommendations are mainly based on clinical experience accumulated by the members of the working group over several decades and the respective publications. The recommendations cover in a general part (1) patient selection, the pre-treatment work up and patient care, (2) treatment strategy, (3) target definition, (4) implant techniques, (5) dose and dose rate prescription, (6) treatment planning and reporting, (7) treatment monitoring (8) catheter removal, and (9) post-treatment patient care and follow-up. The recommendations are then specified for the classical brachytherapy tumor sites following an analogue more focussed structure (patient selection, implant technique, target definition, dose and dose rate prescription, results): lip, oral mucosa, mobile tongue, floor of mouth, oropharynx, nasopharynx, paranasal sinuses.