[Permanent implant brachytherapy for early, organ-confined prostate cancer]. / Permanens implantációs prosztata-brachyterápia korai, szervre lokalizált prosztatarák kezelésére.

PURPOSE: Implementation of permanent prostate implant (PPI) brachytherapy in Hungary and presentation of initial experience. PATIENTS AND METHODS: Between December 2008 and 2010, thirty-nine patients with low (n=26) and intermediate (n=13) risk prostate cancer were treated with PPI. Their mean age and initial PSA were 66 year (51-80 year) and 9 ng/ml (3,2-15 ng/ml). Iodine-125 loose seeds were implanted under spinal anaesthesia using the FIRST system (Nucletron, The Netherlands). Needles were inserted into the prostate through the perineum according to the preplan based on transrectal ultrasound images. The treatment plan was modified according to updated positions of the needles on live US images. The prescribed dose to the prostate was 145 Gy. Seed loading was performed under real-time US assistance. Implanted sources were checked by X-ray and CT images. Patients were discharged one day after the implantation. On follow-up visits PSA and toxicity were registered. RESULTS: The mean follow-up was 10 months (3-27 months), the median number of seeds was 53 (30-78), their mean activity was 0.48 mCi (0.41-0.52 mCi). The mean coverage of the prostate by the prescribed dose was 96% (92-98%). The mean percent dose of the prescribed dose that covered the 90% of the prostate (D90), 2 cm3 of the rectum (Dr2cm3) and 10% of the urethra (Du10) were 113% (104-121%), 85% (48-121%) and 124% (98-146%) respectively. Deviation from the requested dose-volume constraints never exceeded 3%. Acute >grade 2 proctitis, grade 2 and 3 cysto-prostatitis were observed in 0 (0%), 13 (33.3%) and 1 (2.6%) cases. Biochemical relapse occurred in one patient (2.6%). CONCLUSION: This is a report of the first application of PPI in Hungary. The observed rate of acute proctitis was negligible, the rate and severity of acute cysto-prostatitis was tolerable. With the use of intraoperative planning, dose distributions met the dose-volume constraints in most of the cases. The biochemical control is excellent but the follow-up time is still short.

[Repeated radiotherapy in locally recurrent nasopharyngeal cancer]. / Az epipharynxrák lokális kiújulásának ismételt sugárkezelése.

PATIENTS AND METHODS: In the period between 1993 and 2000, 20 patients with nasopharyngael cancer were re-irradiated for locally recurrent carcinomas. The median duration between primary treatment and recurrence was 30 months. Brachytherapy was the method most frequently used in 10 cases alone, and in 8 cases in combination with external beam therapy. 2 patients underwent only external beam therapy. The external irradiation was performed with CT/MRI-based treatment planning. Brachytherapy involved a high dose rate afterloading method. The cumulative dose of re-irradiation was 20-60 Gy. RESULTS: After a median follow-up of 37 months the overall survival and the local control were 60% (12/20) and 58% (7/12), respectively. 7 of the 12 surviving patients are currently tumour-free. After primary irradiation xerostomy occurred in all patients as an unavoidable side-effect of the treatment. A severe (grade 3 or higher according to the Common Toxicity Criteria version 2.0) late-side effect has so far been observed in 2 cases (10%). Authors' results lie in the medial range of the data in the international literature, though the rate of radiogen side-effects in the patient group is low. Both results are assumed to be a consequence of the re-irradiation dose being lower than the value considered optimum in the recent literature. CONCLUSIONS: Re-irradiation of locally recurrent nasopharyngeal cancers is an efficient treatment modality, which should be used as a combination of external beam therapy and brachytherapy. The optimum cumulative dose is about 50-60 Gy. This dose results in a 5 years survival rate of about 40% with an acceptable (30%) risk. The results of re-irradiation may be improved, if PET is used to determine the extent of the surviving tumour tissue. This can help in the choice of the proper treatment modality.

Loose versus stranded seeds in permanent prostate brachytherapy: dosimetric comparison of intraoperative plans.

PURPOSE: To compare target volume coverage and critical organ dosimetry of intraoperative treatment plans for loose seed (LS) and stranded seed (SS) (125)I permanent implants for low and intermediate risk prostate cancer. METHODS: Two hundred and five patients who underwent permanent seed brachytherapy were included in the study. For prostate dosimetry V90, V100, V150, V200, D90 and COIN were used. The dose to urethra and rectum was determined by the maximal dose and relative doses that cover specified volumes. Means and standard deviations were calculated and statistically compared. RESULTS: On average, 54 (range, 30-78) and 48 (range, 31-67) seeds were implanted in the prostate with individual median activities of 0.62 U (range, 0.52-0.70 U) and 0.71 U (range, 0.65-0.71 U) for LS and SS technique, respectively. The target coverage was slightly better with SS (V100: 98% vs. 96%,p < 0.05; D90: 172 Gy vs. 166 Gy, p < 0.05), but more conformal dose distributions were observed with LS (COIN: 0.70 vs. 0.63, p < 0.05). The dose homogeneity did not differ significantly between the two groups. Regarding the dose to urethra and rectum all dose parameters were significantly lower with LS. CONCLUSIONS: LS resulted in less dose to the urethra and rectum compared to SS in intraoperative dosimetry. A slightly better target volume coverage with decreased conformity of dose distribution is reported with SS. More studies are necessary to determine how these results will affect postoperative dosimetry, and ultimately, clinical outcome.

Reirradiation of locally recurrent nasopharyngeal carcinoma.

PURPOSE: To study the efficacy of reirradiation as salvage treatment in patients with locally recurrent nasopharyngeal carcinoma. PATIENTS AND METHODS: Between 1993 and 2000, 20 consecutive patients (twelve males and eight females) with nasopharyngeal cancer, previously irradiated in different Hungarian institutions, were reirradiated for biopsy-proven locally recurrent tumor. Histologically, 85% of the patients had WHO type III, 5% type II, and 10% type I disease. Stages I-IV (AJCC 1997 staging system) were assigned to five (25%), seven (35%), five (25%), and three (15%) patients, respectively; none of them had distant metastases, and only eight (40%) displayed regional dissemination. The median time period between termination of primary treatment and local recurrence was 30 (range, 10-204) months. Brachytherapy was the method most frequently used: in ten cases alone (especially for rT1 tumors), and in eight cases in combination with external beam therapy. Two patients with locally advanced disease underwent external beam therapy only. The median dose in the event of brachytherapy alone was 20 Gy (4 x 5 Gy or 5 x 4 Gy, range, 16-36 Gy), and the dose range for exclusive external irradiation was 30-40 Gy. In cases of combined irradiation, a median 20-Gy brachytherapy (range, 16-40 Gy) was associated with 30-40 Gy of external irradiation. Radiotherapy was supplemented by neck dissection (six patients), nasopharyngectomy (one patient), or chemotherapy (eleven patients). RESULTS: 16 patients were reirradiated once, three twice, and one patient three times, with a median equivalent dose for tumor effect of 36 Gy (mean, 44 Gy; range, 19-117 Gy; the estimated alpha/beta-ratio was 10 Gy). The median equivalent dose of reirradiation for late effect on normal tissue (with an estimated 70% delivery of the tumor dose) amounted to 30 Gy (mean, 37 Gy; range, 13-101 Gy, estimated alpha/beta-ratio 3 Gy). After a median follow-up of 37 (range, 12-72) months, the overall survival was 60% (12/20). Seven of the twelve surviving patients are currently tumor-free. After primary irradiation, xerostomy occurred in all patients as an unavoidable side effect of treatment. Following reirradiation, a severe (grade 3 or higher) late toxicity (CTC criteria, version 2) has been observed in two tumor-free patients (10%) so far (necrosis of soft palate and paresis of glossopharyngeal nerve). CONCLUSION: Retreatment of nasopharyngeal carcinoma with radiotherapy (preferably a combined modality), can result in longterm local control and survival in a substantial proportion of patients, at the price of an acceptable morbidity.