Comparison and Evaluation of Different Radiotherapy Techniques Using Biodosimetry Based on Cytogenetics.

While rapid technological advances in radiotherapy techniques have led to a more precise delivery of radiation dose and to a decreased risk of side effects, there is still a need to evaluate the efficacy of the new techniques estimating the biological dose and to investigate the radiobiological impact of the protracted radiotherapy treatment duration. The aim of this study is to compare, at a cytogenetic level, advanced radiotherapy techniques VMAT and IMRT with the conventional 3D-CRT, using biological dosimetry. A dicentric biodosimetry assay based on the frequency of dicentrics chromosomes scored in peripheral blood lymphocytes from prostate cancer patients and PC3 human prostate cancer cell line was used. For each patient blood sample and each subpopulation of the cultured cell line, three different irradiations were performed using the 3D-CRT, IMRT, and VMAT technique. The absorbed dose was estimated with the biodosimetry method based on the induced dicentric chromosomes. The results showed a statistically significant underestimation of the biological absorbed dose of ~6% for the IMRT and VMAT compared to 3D-CRT irradiations for peripheral blood lymphocytes, whereas IMRT and VMAT results were comparable without a statistically significant difference, although slightly lower values were observed for VMAT compared to IMRT irradiation. Similar results were obtained using the PC3 cell line. The observed biological dose underestimation could be associated with the relative decreased dose rate and increase irradiation time met in modulated techniques compared to the conventional 3D-CRT irradiations.

Prognostic Value of MRS Metabolites in Postoperative Irradiated High Grade Gliomas.

PURPOSE: We studied the prognostic significance of Magnetic Resonance Spectroscopy (MRS) in operated high grade gliomas. MATERIALS AND METHODS: Twelve patients were treated with radiotherapy and Temozolomide. The MRS data were taken four weeks after operation (before radiotherapy) and every six months after the completion of RT. The N-acetyl aspartate, choline, creatine, and myo-inositol parameters were quantified, analyzed, and correlated to recurrence-free survival (RFS). RESULTS: The median RFS was 26.06 months. RFS was significantly worse in elderly patients (P = 0.001) along with the higher choline/creatine ratios at either baseline (P = 0.003) or six months post Radiotherapy (P = 0.042). Median RFS was 23 months in high choline/creatine levels ≥ 2 at 6 months after radiotherapy and 11 months for those with < 2 choline/creatine levels. There was a significant correlation of maximum difference of choline/creatine ratio with RFS (rho = 0.64, P = 0.045). CONCLUSION: Age and choline/creatine ratio are strong independent prognostic factors in high grade gliomas.

Long-term results of LINAC-based stereotactic radiosurgery for acoustic neuroma: the Greek experience.

PURPOSE: To estimate the value of LINAC-based stereotactic radiosurgery (SRS) for the long-term local control of unilateral acoustic neuromas. MATERIALS AND METHODS: Twenty patients (median age 66; range 57-80 years) with unilateral acoustic neuroma underwent LINAC-based SRS from May 2000 through June 2004 with a dose of 11-12 Gy. The follow-up period ranged from 36 to 84 months (median follow-up period: 55 months). Before SRS none of the patients had useful hearing. The follow-up consisted of repeat imaging studies and clinical examination for assessment of facial and trigeminal nerve function at 6-month intervals for the first year and yearly thereafter. RESULTS: Eleven tumors (58%) decreased in size and eight (42%) remained stable. One tumor showed a minor increase in size on the MRI done 6 months after SRS in comparison with the pretreatment MRI; however, a subsequent decrease was noticed on the next radiographic assessment and the tumor remained stable from then on. None of the tumors increased in size in the long-term follow-up, thus giving an overall growth control of 100% for the patients in this study. None of the patients had useful hearing before SRS, so hearing level was not assessed during follow-up. No patient developed new, permanent facial or trigeminal neuropathy. CONCLUSION: LINAC-based SRS with 11-12 Gy provides excellent tumor control in acoustic neuroma and has low toxicity even after long-term follow-up.

Apoptotic and inflammation markers in oral mucositis in head and neck cancer patients receiving radiotherapy: preliminary report.

GOAL OF WORK: The aim of this study was to investigate the expression of pro-apoptotic protein p53 and anti-apoptotic proteins BCl-2 and MCl-1, as well as the expression of pro-inflammatory cytokines tumor necrosis factor (TNF) and interleukin-1beta (IL-1beta) in patients developing mucositis during radiotherapy for head and neck cancer. MATERIALS AND METHODS: Thirty-five patients receiving radiotherapy for head/neck cancer were included in this study. Patients were examined before radiotherapy. Oral mucositis was recorded weekly during radiotherapy. Cytologic smears from the oral cavity were taken with a brush. Immunocytochemical staining was performed by the use of p53, BCl-2, MCl-1 TNF and IL-1beta monoclonal antibodies. MAIN RESULTS: P53 was expressed in 1 of 15 smears before the initiation of radiotherapy (6.5%) compared to 3 of 7 smears from patients with grade III mucositis (43%) during radiotherapy. BCl-2 was expressed in 15 of 15 smears before radiotherapy (100%) and in three of seven patients with grade III mucositis (43%) during radiotherapy. MCl-1 was expressed in 10 of 14 samples before radiotherapy (71.5%) and in two of seven patients with grade III (28.5%) mucositis during radiotherapy. TNF was expressed in 9 of 14 patients before radiotherapy (64%) and in six of seven patients with grade III mucositis during radiotherapy (86%). IL-1beta was detected in 7 of 14 patients before radiotherapy (50%) compared to 6 of 7 patients with grade III mucositis during radiotherapy (86%). CONCLUSION: Our preliminary results indicate an induction of apoptosis and inflammation in the oral mucosa in patients developing mucositis during radiotherapy for head/neck cancer.

Herpes simplex virus-1 (HSV-1) infection in radiation-induced oral mucositis.

GOAL OF WORK: The aim of the study was to investigate the incidence of herpes simplex virus-1 (HSV-1) infection in mucositis during head and neck cancer radiotherapy. PATIENTS AND METHODS: Sixty patients with malignant head and neck tumor, eligible to receive radiotherapy, who were referred to the Dental Oncology Unit, entered the study. Sixteen patients (26.6%) received concomitant chemotherapy. Mucositis was recorded weekly. Smears taken from the ulcers of mucositis grade 2, or 3, or 4 were stained with Papanicolaou and alkaline phosphatase/antialkaline phosphatase immunocytochemical method to identify HSV-1. MAIN RESULTS: Forty-eight of all 60 patients developed ulcerative mucositis. Smear was available from 29 of 48 patients with ulcerations. HSV-1 infection was identified in 14 of 29 smears available (48.2%). Mucositis healed or was reduced after 1 week of antiviral treatment in 11 of those 14 HSV-1-positive patients; 3 patients responded to 1 g/day of valacyclovir, 7-2 g/day, and 1 patient responded to i.v. acyclovir. Ulcerations recurred after quitting antivirals. Three patients did not respond to 1 g/day of valacyclovir. No HSV-1-negative patient responded to acyclovir (P = 0.000). CONCLUSION: HSV-1 was isolated from 14 of 29 available smears taken from 48 patients with ulcerative mucositis. The incidence of HSV-1 infection during radiotherapy was estimated as being 14 of all 48 patients at risk (29.1%). Healing or reduction in the grade of mucositis after antivirals in HSV-1 positive patients, combined with the negative response to antivirals in HSV-1 negative patients, denoted that HSV-1 infection was a component of ulcerative radiation mucositis in those HSV-1-positive patients.

Effect of fluconazole antifungal prophylaxis on oral mucositis in head and neck cancer patients receiving radiotherapy.

GOAL OF WORK: The aim of the study is to evaluate the effect of fluconazole antifungal prophylaxis on the severity of mucositis in head and neck cancer patients receiving radiotherapy. PATIENTS AND METHODS: Sixty-three patients, with malignant head and neck tumor, eligible to receive radiotherapy, entered the study. Thirty-four patients (group A) received 100 mg/day of fluconazole prophylaxis during radiotherapy and were compared with 29 patients, who received radiotherapy alone (group B). The two groups were similar in terms of patients and radiotherapy characteristics. Smear to test for Candida carriage was taken before and after radiotherapy. Oral candidiasis was diagnosed using the criteria described before. Oral mucositis was recorded according to EORTC/RTOG criteria. MAIN RESULTS: A significant reduction of severe mucositis at the end of radiotherapy (14.7 vs 44.8%, p=0.018) and of interruptions (0 vs 17.2%, p=0.017) was observed in group A. Candidiasis was prevented (0 vs 34.5%, p=0.001), with a significant reduction of Candida carriage of 40.7% (p=0.001). CONCLUSION: Fluconazole prophylaxis showed a significant beneficial impact on the severity of mucositis and on radiotherapy interruptions in this group of patients. The current study provides data on the build of a randomized controlled trial on the effect of fluconazole prophylaxis on treatment schedule and quality of life of the patients during head and neck radiotherapy.

Phase II multicenter randomized study of amifostine for prevention of acute radiation rectal toxicity: topical intrarectal versus subcutaneous application.

PURPOSE: To investigate the cytoprotective effect of subcutaneous vs. intrarectal administration of amifostine against acute radiation toxicity. METHODS AND MATERIALS: Patients were randomized to receive amifostine either intrarectally (Group A, n = 27) or a 500-mg flat dose subcutaneously (Group B, n = 26) before irradiation. Therapy was delivered using a four-field technique with three-dimensional conformal planning. In Group A, 1,500 mg of amifostine was administered intrarectally as an aqueous solution in 40 mL of enema. Two different toxicity scales were used: the European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group (RTOG) rectal and urologic toxicity criteria and the Subjective-RectoSigmoid scale based on the endoscopic terminology of the World Organization for Digestive Endoscopy. Objective measurements with rectosigmoidoscopy were performed at baseline and 1-2 days after radiotherapy completion. The area under the curve for the time course of mucositis (RTOG criteria) during irradiation represented the mucositis index. RESULTS: Intrarectal amifostine was feasible and well tolerated without any systemic or local side effects. According to the RTOG toxicity scale, Group A had superior results with a significantly lower incidence of Grades I-II rectal radiation morbidity (11% vs. 42%, p = 0.04) but inferior results concerning urinary toxicity (48% vs. 15%, p = 0.03). The mean rectal mucositis index and Subjective-RectoSigmoid score were significantly lower in Group A (0.44 vs. 2.45 [p = 0.015] and 3.9 vs. 6.0 [p = 0.01], respectively), and the mean urinary mucositis index was lower in Group B (2.39 vs. 0.34, p < 0.028). CONCLUSIONS: Intrarectal administration of amifostine (1,500 mg) seemed to have a cytoprotective efficacy in acute radiation rectal mucositis but was inferior to subcutaneous administration in terms of urinary toxicity. Additional randomized studies are needed for definitive decisions concerning the cytoprotection of pelvic irradiated areas.

A phase II randomized study of topical intrarectal administration of amifostine for the prevention of acute radiation-induced rectal toxicity.

PURPOSE: To investigate the cytoprotective effect of intrarectal amifostine administration on acute radiation-induced rectal toxicity. PATIENTS AND METHODS: 67 patients with T1b-2 N0 M0 prostate cancer were randomized to receive amifostine intrarectally (group A, n = 33) or not (group B, n = 34) before irradiation. Therapy was delivered using a four-field technique with three-dimensional conformal planning. In group A, 1,500 mg amifostine was administered intrarectally as an aqueous solution in a 40-ml enema. Two different toxicity scales were used: EORTC/RTOG rectal and urologic toxicity criteria along with a Subjective-RectoSigmoid (S-RS) scale based on the endoscopic terminology of the World Organization for Digestive Endoscopy. Objective measurements with rectosigmoidoscopy were performed at baseline and 1-2 days after the completion of radiotherapy. The area under curve for the time course of mucositis (RTOG criteria) during irradiation represented the mucositis index (MI). RESULTS: Intrarectal amifostine was feasible and well tolerated without any systemic or local side effects. According to the RTOG toxicity scale, five out of 33 patients showed grade 1 mucositis in group A versus 15 out of 34 patients with grade 1/2 in group B (p = 0.026). Mean rectal MI was 0.3 +/- 0.1 in group A versus 2.2 +/- 0.4 in group B (p < 0.001), while S-RS score was 3.9 +/- 0.5 in group A versus 6.3 +/- 0.7 in group B (p < 0.001). The incidence of urinary toxicity was the same in both groups. CONCLUSION: Intrarectal administration of amifostine seems to have a cytoprotective efficacy in acute radiation-induced rectal mucositis. Further randomized studies are needed for definitive therapeutic decisions.

Oral candidiasis in head and neck cancer patients receiving radiotherapy with amifostine cytoprotection.

This controlled study assessed the incidence of oral candidiasis, a xerostomia-related complication, in head and neck cancer patients receiving radiotherapy, with amifostine cytoprotection. Thirty-eight patients received 500 mg amifostine i.v., prior to each radiotherapy fraction, while 16 patients received radiotherapy alone. Oral candidiasis was diagnosed according to the criteria described before. Subjective xerostomia scales were completed by all patients. Mucositis was evaluated using the RTOG criteria. Oral candidiasis was diagnosed in 11/38 amifostine patients and in 9/16 controls (P = 0.07). Severe xerostomia was reported by 4/38 amifostine patients and by 7/16 controls. Oral candidiasis was reduced with amifostine cytoprotection. Oral candidiasis is suggested as an objective, early, though indirect, endpoint for amifostine's radioprotective effect on salivary glands.