三维适形放疗配合腔内后装治疗宫颈癌的临床研究

Objective: The aim of our study was to evaluate the outcome and complications of cervical cancer patients undergoing conventional intracavitary brachytherapy (ICBT) treated with 3D-conformal radiotherapy (3DCRT). Methods: Sixty cervical cancer patients were divided randomly into the conformal group and the conventional group. Thirty patients treated with 3D-conformal radiotherapy in the 3DCRT group, when the whole pelvic received DT 40 Gy, a planning CT scan of each patient was obtained and the second 3DCRT therapy plan was taken. Then, continued to irradiate to 50 Gy. At last, 3DCRT was boosted at local involved volumes to the total close of 60 Gy. When 3DCRT was combined with intracavitary brachytherapy, the dose of brachytherapy to point A was 30 Gy/5 fractions. In the conventional group, after a total tumor dose of 40 Gy was delivered by the whole pelvic irradiation, the four-field technique was used to irradiate the total pelvic and regional nodes (median close of 10 Gy), and the involved volumes were boosted to 60 Gy and the dose of brachytherapy to point A was 30 Gy-36 Gy/5-6 fractions. Moreover, both groups were combined with intracavitary brachytherapy respectively. Results: The 1, 2, 3-year survival rates for the 3DCRT group and the conventional group were 96.7%, 93.3%, 90.0% and 86.6%, 76.7%,70% respectively (P = 0.04, P = 0.02 and P = 0.02). There was a statistically significant difference between the two groups.Compared to the two groups each other in toxic effects, except for the Ⅰ-Ⅱ grade rectal and bladder reaction and pelvic fibrosis which was lower in the 3DCRT group (P = 0. 007, P = 0. 006 and P = 0. 015), the side effects were similar and well tolerated in two groups. Conclusion: The all-course 3DCRT combined with intracavitary brachytherapy can be considered as an effective and feasible approach to cervical cancer and may significantly improve the survival rate and reduce the late toxicity. This new rote for 3DCRT merits need further evaluation with large patient numbers and longer follows up.     

Combined treatment of inoperable carcinomas of the uterine cervix with radiotherapy and regional hyperthermia. Results of a phase II trial

AIM: The disappointing results for inoperable, advanced tumors of the uterine cervix after conventional radiotherapy alone necessitates improving of radiation therapy. Simultaneous chemotherapy or altered radiation fractionation, such as accelerated regimen, increase acute toxicity and treatment is often difficult to deliver in the planned manner. The purpose of this phase II study was to investigate the toxicity and effectiveness of a combined approach with radiotherapy and regional hyperthermia. PATIENTS AND METHODS: From January 1994 to October 1995 18 patients with advanced carcinomas of the uterine cervix were treated in combination with radiotherapy and hyperthermia. The patients were treated with 6 to 20 MV photons delivered by a linear accelerator in a 4-field-box technique to a total dose of 50.4 Gy in 28 fractions. In the first and fourth week 2 regional hyperthermia treatments were each applied with the Sigma-60 applicator from a BSD-2000 unit. After this a boost to the primary tumor was given with high-dose-rate iridium-192 brachytherapy by an afterloading technique with 4 x 5 Gy at point A to a total of 20 Gy and for the involved parametrium anterioposterior-posterioanterior to 9 Gy in 5 fractions. RESULTS: The acute toxicity was low and similar to an external radiotherapy alone treatment. No Grade III/IV acute toxicity was found. The median age was 47 years (range 34 to 67 years). In 16 of 18 patients a rapid tumor regression was observed during combined thermo-radiotherapy, which allowed the use of intracavitary high-dose-rate brachytherapy in these cases. Complete and partial remission were observed in 13 and 4 cases, respectively. One patient did not respond to the treatment. The median follow-up was 24 months (range 17 to 36 months). The local tumor control rate was 48% at 2 years. Median T20, T50 and T90 values were 41.7 degrees C (range 40.3 to 43.2 degrees C), 41.1 degrees C (range 39.2 to 42.5 degrees C) and 39.9 degrees C (range 37.7 to 41.9 degrees C), respectively. Cumulative minutes of T90 > 40 degrees C (Cum40T90) and cumulative minutes, which were isoeffective to 43 degrees C, were calculated (CEM43T90, CEM43T50, CEM43T20). CEM43T90 was found to be a significant parameter in terms of local tumor control for the 4 hyperthermia treatments (p = 0.019). CONCLUSIONS: This treatment modality has proved to be feasible and well tolerable. The rapid tumor shrinkage in the combined approach of radiotherapy with hyperthermia before beginning brachytherapy seems to be a good prerequisite for improving of the disappointing results in cure of advanced cancer of the uterine cervix.     

A pilot study on concurrent platinum chemotherapy and intracavitary brachytherapy for locally advanced cancer of the uterine cervix

This study aims to evaluate the feasibility, toxicity and efficacy of concurrent chemotherapy with platinum compounds and brachytherapy, for locally advanced carcinoma of the cervix (Stages IIA/B, IIIA). The hypothesis was that synchronous chemo-brachytherapy may be sufficient to cause down-staging of the tumour, to render it operable, and hopefully improve the prognosis. 36 women with locally advanced cervical cancer were treated with concomitant brachytherapy and chemotherapy before surgery and/or definitive external radiotherapy. All patients received two caesium-137 Selectron MDR applications, 1 week apart. The dose calculated to point A for each implant was 20-25 Gy. Chemotherapy consisting of continuous cisplatin infusion (50 mg m2) and of carboplatin (300 mg m-2) was given simultaneously with intracavitary irradiation during the first and second application, respectively. The combined therapy was followed when feasible by radical hysterectomy, pelvic lymphadenectomy and pelvic radiotherapy. Patients deemed ineligible for surgery because of poor response were given full dose external radiotherapy. 31/36 patients were treated by Wertheim hysterectomy of whom 10 had negative lymph nodes and resection margins. Definitive external radiotherapy was given in the remaining five patients. Overall, 83% were disease free at 2.8 years mean follow-up. The most frequent acute side-effects of chemobrachytherapy were nausea and vomiting. No renal toxicity was observed. Thrombocytopenia was seen in five patients and was responsible for delayed surgery in four patients. Concerning late effects, two patients developed grade 2 intestinal sequelae, two mild frequency and two vaginal stenosis. One rectovaginal and one vesicovaginal fistula developed in two patients; and a third patient had a fistula associated with tumour recurrence. Concurrent brachytherapy and chemotherapy with platinum compounds is well tolerated and effective in reducing tumour bulk before definitive local treatment (surgery or external radiotherapy), in patients with locally advanced carcinoma of the uterine cervix.     

Computed tomography analysis of causes of local failure in radiotherapy for cervical carcinoma

BACKGROUND: The authors analyzed the radiation dose to the periphery of the cervix and area of the cervix in relation to local failure of radiotherapy for carcinoma of the cervix using computed tomography (CT) images. METHODS: Between 1981-1990, 127 consecutive patients were treated with definitive radiotherapy. Ninety-nine of these patients had CT images taken at the time of intracavitary therapy. Of these 99 patients, 80 were eligible for this analysis. After CT scanning, isodose curves relative to the point A dose were superimposed on the CT images. The minimum percent dose and minimum dose at the periphery of the cervix were estimated. The area of the cervix also was measured. These factors were examined in relation to the local tumor control rate. RESULTS: Histograms of both the minimum percent dose and the cervical area showed significant differences between the local control and local failure groups (P <0.001). The local control rates were related to both the minimum percent dose and the cervical area, and differed significantly over and below the values of 60% and 18 cm2 (P <0.001 each), respectively. The local control patients, over and below the line: Y = -0.220X + 21.2, in which X (gray [Gy]) and Y (Gy) are the whole pelvis dose and the minimum dose, respectively, could be well differentiated with significance (91.7% vs. 25.0%; P <0.001). CONCLUSIONS: Computed tomography analysis indicated that the local tumor control rate was related strongly to the minimum percent dose, the cervical area, and the pair of whole pelvis and minimum dose values. These factors were found to be more useful than the point A dose in predicting local tumor control.     

Comparison of stereotactic radiosurgery and brachytherapy in the treatment of recurrent glioblastoma multiforme

The purpose of this study was to compare the efficacy of stereotactic radiosurgery (SRS) and brachytherapy in the treatment of recurrent glioblastoma multiforme (GBM). The patients had either progressive GBM or pathologically proven GBM at recurrence after previous treatment for a lower grade astrocytoma. Thirty-two patients were treated with interstitial brachytherapy, and 86 received treatment with stereotactic radiosurgery (SRS). The patient characteristics were similar in the two groups. Those patients treated with SRS had a median tumor volume of 10.1 cm3 and received a median peripheral tumor dose of 13 Gy. Patients treated with brachytherapy had a median tumor volume of 29 cm3. Median dose to the periphery of the tumor volume was 50 Gy delivered at a median dose rate of 43 cGy/hour. Twenty-one patients (24%) treated with SRS were alive, with a median follow-up of 17.5 months. Median actuarial survival, measured from the time of treatment for recurrence, for all patients treated with SRS was 10.2 months, with survivals of 12 and 24 months being 45 and 19%, respectively. A younger age and a smaller tumor volume were predictive of better outcome. The tumor dose, the interval from initial diagnosis, and the need for reoperation were not predictive of outcome after SRS. Five patients (16%) treated with brachytherapy were alive, with a median follow-up of 43.3 months. The median actuarial survival for all patients treated with brachytherapy was 11.5 months. Survivals of 12 and 24 months were 44 and 17%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extraordinary features in the Chlamydomonas reinhardtii chloroplast genome: (1). rps2 as part of a large open reading frame; (2). A C. reinhardtii specific repeat sequence

PURPOSE: To evaluate the clinical efficacy of local vaginal lidocaine application for pain relief during high-dose-rate (HDR) intracavitary brachytherapy for patients with cervical cancer, and to investigate sequential changes in serum levels of lidocaine during the procedures. METHODS AND MATERIALS: This prospective study was designed to examine the analgesic effect, physical response, and side effects of local anesthesia during HDR intracavitary brachytherapy. Forty patients were enrolled. All patients received 10-15 MV X-rays to the pelvis with a total dose of 45-59.4 Gy 5-6 weeks before undergoing HDR intracavitary brachytherapy. All patients underwent first intracavitary brachytherapy under general anesthesia. These patients were randomly allocated to receive one of two different treatment protocols as follows: (1) treatment session - control session - treatment session - control session; or (2) control session - treatment session- control session - treatment session. In the treatment sessions, topical anesthesia was administered using 4 ml of 10% lidocaine solution sprayed liberally on the cervix and vagina during intracavitary brachytherapy. In the control sessions, a placebo was administered in the same manner during brachytherapy. The Hensche's applicators for brachytherapy were inserted into the cervix and vagina 5 min after lidocaine application. The visual analogue scale (VAS) was used to assess pain and discomfort during brachytherapy. Blood pressure and heart rates were measured to evaluate the physiological response. Another prospective study was then performed to investigate the sequential changes of serum lidocaine levels during the anesthetic procedure. Eleven additional patients with similar disease state and demographic characteristics were enrolled and blood samples were obtained before, and 5, 15, 30, and 45 min after the initiation of lidocaine application. RESULTS: The mean VAS values recorded during the treatment sessions and control sessions were 49.9 +/- 24.1 versus 60.1 +/- 24.8, respectively. The value of VAS in the treatment session was significantly lower than that of the control session (p < 0.001). No statistically significant differences were found in the changes of blood pressure and heart rate and in the incidence of side effects during these two types of sessions (p > 0.05). In the drug-level study, serum levels of lidocaine reached a peak 5 min after the initiation of local anesthesia. The mean peak concentrations (Cmax) of lidocaine were 0.50 +/- 0.45 microg/ml. CONCLUSION: Local vaginal anesthesia with 10% lidocaine solution can significantly decrease the degree of painful sensation during HDR intracavitary brachytherapy, and is safe to administer for the procedure for cervical cancer.     

Simplified method for three-dimensional evaluation of interstitial brachytherapy applications

Although three-dimensional (3-D) treatment planning has primarily been used for external beam radiation therapy, the advantages of 3-D treatment planning can be realized for brachytherapy applications. As with teletherapy, the use of 3-D treatment planning for brachytherapy can provide both superior dose distribution as well as detailed evaluations of the relationship of dose and volume in critical structures and target tissues. Conventional 3-D treatment planning uses computed tomography (CT) scans to localize structures; however, localizing individual brachytherapy sources on each CT slice can be impractical for routine clinical use. In the transition from two-dimensional to 3-D localization and dose evaluation of interstitial perineal templates in particular, a practical method of seed localization on a postimplant CT dataset has been developed. This method does not utilize dummy sources and, as such, does not require individual seed locations to be identified. Instead, the position of the afterloading catheter is defined as a reference line by connecting its location as seen on the axial CT slices and seed locations defined along its length. Full volumetric calculations can then be performed, including dose-volume histograms (DVH) for critical organs and tumor volumes. Source localization and normal tissue doses were calculated using both orthogonal films and the 3-D method for a series of perineal template guided implants. Point dose calculations of the rectum and bladder were obtained from orthogonal films and were then compared to the corresponding DVHs for these organs.     

Specificity of the BAX polymerase chain reaction system for detection of the foodborne pathogen Listeria monocytogenes

PURPOSE: The purpose of this study was to evaluate the toxicity and efficacy of twice-daily external irradiation to the pelvis and para-aortics with brachytherapy and concurrent chemotherapy for carcinoma of the cervix with positive para-aortic lymph nodes. METHODS AND MATERIALS: This study was designed to administer twice-daily radiation doses of 1.2 Gy to the pelvis and para-aortics at 4- to 6-h intervals, 5 days per week. The total external radiation doses were 24 to 48 Gy to the whole pelvis, 12 to 36 Gy parametrial boost, and 48 Gy to the para-aortics with an additional boost to a total dose of 54 to 58 Gy to the known metastatic para-aortic site. One or two intracavitary applications were performed to deliver a total minimum dose of 85 Gy to point A. Cisplatin (75 mg/m2, days 1 and 22) and 5-FU (1000 mg/m2/24 h x 4 days; days 1 and 22) were given for two or three cycles. RESULTS: Twenty-nine patients with clinical Stages I to IV carcinoma of the cervix with biopsy-proven para-aortic lymph nodes were enrolled in this study. Hyperfractionated external radiotherapy was completed in 86% (25 of 29). Brachytherapy was given in two applications to 48% (14 of 29), 31% (9 of 29) had one intracavitary application, 14% (4 of 29) had no brachytherapy, one had three applications, and one had five HDR applications. Radiotherapy was completed per protocol in 69%. Three courses of chemotherapy were given to 24% (7 of 29), 72% (21 of 29) received two courses, and one patient did not receive chemotherapy. The acute toxicity from chemotherapy was Grade 1 in 3%, Grade 2 in 17%, Grade 3 in 48%, and Grade 4 in 28%. Radiotherapy toxicity was Grade 1 in 7%, Grade 2 in 34%, Grade 3 in 21%, and Grade 4 in 28%. One Grade 5 toxicity occurred and the patient died from a myocardial infarction from chemotherapy and radiotherapy colitis during her course of therapy. The median follow-up time was 18.9 months. The overall survival estimates were 59% at 1 year and 47% at 2 years. The probability of local-regional failure was 38% at 1 year and 49% at 2 years. The probability of disease failure at any site was 45% at 1 year and 59% at 2 years. CONCLUSION: The results suggest that twice-daily external irradiation to the pelvis and para-aortics with brachytherapy and concurrent chemotherapy resulted in an unacceptably high rate (31%, 9 of 29) of Grade 4 nonhematologic toxicity. One patient died from complications of therapy. Radiotherapy was completed per protocol in 69%. The survival estimates appear no better than standard fractionation radiotherapy without chemotherapy. Additional follow-up is necessary for long-term survival estimates.     

Zamifenacin (UK-76, 654) a potent gut M3 selective muscarinic antagonist, reduces colonic motor activity in patients with irritable bowel syndrome

PURPOSE: Retrospective studies suggest that prolonged treatment time adversely affects control rates of squamous carcinomas managed by radiotherapy. From 1989 to 1994 a prospective clinical trial was conducted to assess the feasibility and efficacy of concomitant boost accelerated superfractionated (CBASF) radiotherapy for advanced uterine cervical carcinoma. METHODS AND MATERIALS: Twenty newly diagnosed patients with FIGO stage III squamous cell carcinoma of the cervix were irradiated using a CBASF regimen. Patients received 45 Gy administered to the whole pelvis in 25 fractions in 5 weeks. On Monday, Wednesday, and Friday of the last 3 weeks, an additional 1.6 Gy boost was given 6 hours after the whole pelvis treatment. The 9 boost treatments, totaling 14.4 Gy, were given via lateral fields encompassing the parametria and primary tumor for a cumulative tumor dose of 59.4 Gy. A single low-dose rate brachytherapy procedure was performed within 1 week after the external beam radiotherapy to raise the point A dose to 85-90 Gy in 42 days. Primary endpoints of analysis were local control, complications, and patterns of failure. Results are compared with the outcomes of 21 patients treated with conventionally fractionated (CF) radiotherapy during the same years. RESULTS: Median total treatment time was 46 days in the CBASF group (range 37-62). Median follow-up interval among surviving CBASF patients is 3.8 years. The four-year actuarial local control rates are 78% and 70% in the CBASF and CF groups, respectively (p = ns). Only 2 CBASF patients required a treatment break because of acute toxicity, but severe late complications occurred in 8/20 CBASF patients for a crude rate of 40%. Distant failure was more common than local failure in the CBASF group, and para-aortic node failure occurred in six of the eight CBASF patients with distant failure. CONCLUSIONS: In the management of stage III cervix cancer, the CBASF regimen produced a trend toward improved local control when compared with the CF regimen, shifting the patterns of failure toward a higher rate of isolated distant failures. The high frequency of para-aortic node failure warrants consideration of elective treatment to this region in stage III patients treated with curative intent. Although the high local control rate of the CBASF regimen supports further investigation of accelerated treatment regimens for locally advanced cervix cancer, the unacceptable risk of late complications necessitates refinement in technique and scheduling to improve the therapeutic ratio.     

Mixed mesodermal tumor of the ovary. Description of a case with a small primary neoplastic mass. Anatomo-clinical and histogenetic considerations]

Forty-one patients with locally advanced hypopharyngeal carcinomas were followed for at least 3 years (median, 60 months) after simultaneous radiochemotherapy. Conventionally fractionated radiotherapy was administered as 5 x 2 Gy/week to a total dose of 30 Gy within 3 weeks. From the fourth week an accelerated hyperfractionated schedule was used as 2 x 1.4 Gy/day five days weekly given exclusively to the first order target volume of macroscopic tumor (adding up to a total dose of 72 Gy in six weeks). The second and third order target volumes received conventional fractionation only to 60 Gy and 50 Gy, respectively. The moderate acceleration of the concomitant boost scheme in the second half was counterbalanced during the first week by the introduction of a 5-fluorouracil bolus of 350 mg/M2 with 200 mg/M2 folinic acid and a subsequent continuous infusion using the same dose each 24 h for 5 days. Additionally, a Mitomycin-C bolus of 10 mg/M2 was infused at the fifth day and on the first day of the sixth week. Six weeks after treatment the patients were restaged. In cases with residual carcinoma salvage surgery was performed (11 patients). Late effects of therapy were analyzed according to the Lent-Soma index and life quality according to the European Organisation for Research and Treatment of Cancer-Module. Late effects of treatment were tolerable and were controlled locally. The 3-year-survival rate was 39%, with a local-regional recurrence-free control rate of 71%. Fifty-two percent of all cases of death were caused by distant metastases, secondary carcinomas or other diseases not related to tumor recurrence. The poor prognosis of hypopharyngeal carcinomas despite acceptable local tumor control may be due to specific biological factors present in affected patients.     

Neural activity in areas V1, V2 and V4 during free viewing of natural scenes compared to controlled viewing

BACKGROUND AND PURPOSE: The three-dimensional (3D) dose distribution in combination with 3D anatomy of 13 patients treated for cervical carcinoma with intracavitary brachytherapy was analyzed. The aim of this study was to determine the correlation between a dose value obtained from the integral dose volume histogram (DVH) of the rectum and (a) the Nederlands Kanker Instituut (NKI) point of reference for the rectum dose (R) and (b) the highest dose to the frontal rectum wall in the transverse CT slice near the top of the vagina through point R. RESULTS: The correlation between the DVH rectum dose value for 2 cm3 in the highest dose region and the rectum dose at point R was poor (regression coefficient 0.50). On the contrary, however, the correlation between the DVH rectum dose value for 2 cm3 in the highest dose region and the maximum rectum dose value in a transverse CT slice through point R was good (regression coefficient 0.90). CONCLUSIONS: The maximal rectum dose value obtained from a transverse CT slice near the top of the vagina through point R was found to be a more representative point for the rectal dose burden and might therefore show a good correlation with complications. The point of reference for the rectal dose (R) was found not to be a reliable estimation of the maximal dose in the rectum.     

Results of postoperative radiotherapy of cervix carcinoma after radical versus non radical hysterectomy

We studied the outcome of our 68 cervix carcinoma patients treated either with: 1) radical surgery and postoperative 192Ir high-dose rate afterloading brachytherapy or postoperative radiotherapy to the whole pelvis or with 2) standard hysterectomy and postoperative radiotherapy to the whole pelvis. Forty-eight women were treated by radical hysterectomy from 1988 to 1992 and--due to risk factors--by postoperative radiotherapy (Group 1), 20 other patients (Group 2) pretreated with standard hysterectomy were admitted to the university hospital for postoperative radiotherapy of the whole pelvis. Postoperative radiotherapy consisted of 39.6 Gy total dose using the box technique, plus two afterloading applications with a single dose of 7.5 Gy and 6 Gy external beam therapy to the pelvic lymph nodes sparing the midline. Comparing the Kaplan-Meier plots of both groups, the tumor related survival curve, the locoregional control and the rates of metastatic disease were nearly identical. But in the analysis of special subgroups, patients with positive lymph nodes after standard hysterectomy and postoperative radiotherapy had a worse prognosis (75% three years' survival rate) than patients after radical surgery (86% three years' survival rate). Lymphangiosis was a negative prognostic factor for the patients pretreated with standard hysterectomy (60% versus 80% three years' survival rate), but not for patients after radical surgery (80% three years' survival rate), despite the same radiotherapy in both groups. CONCLUSION: Standard hysterectomy fails to be an adequate treatment for early cervix carcinoma because moderately dosed postoperative radiotherapy cannot achieve complete locoregional control in all cases of positive lymph nodes or invasion of lymph vessels. However, based on the empirical results of many authors and our own results, postoperative radiotherapy is further indicated in high risk cases of cervix carcinoma after radical surgery.     

The existence of "Nederwiet", a new fact in the history of cannabis

Our purpose was to examine the role of radiotherapy in the management of phyllodes tumor of the breast. Eight patients were treated with adjuvant radiotherapy for nonmetastatic phyllodes tumor of the breast at the M.D. Anderson Cancer Center between December 1988-August 1993. Tumors were classified as benign (n=2), borderline (indeterminate; n=1), or malignant (n=5). Median follow-up was 36.5 months. Primary surgery consisted of either lumpectomy in 2 patients or mastectomy in 6 patients. Seven patients received adjuvant radiation therapy to the breast or chest wall to a dose of 60 Gy. One patient received 50 Gy to the breast, followed by an interstitial boost of 20 Gy for a total of 70 Gy. Radiotherapy was administered for a combination of reasons, including bulky tumor volume, positive margins, recurrence, and/or malignant histology. There were no local or distant failures. This retrospective review suggests that adjuvant radiotherapy may be underutilized in the treatment of phyllodes tumor of the breast, particularly in patients with adverse features. Although treatment to the breast or chest wall (not the lymphatics) to a dose of 60 Gy appears effective, a dose-response has not been established, and lower doses (50-60 Gy) may be equally effective.     

Obsessive-compulsive disorder and separation anxiety

Little is known about the effects of intracavitary brachytherapy (ICB) performed in the presence of pyuria resulting from external beam pelvic irradiation for cervical cancer (CC). A retrospective study of one decade of ICB for CC showed that brachytherapy was performed in the presence of pyuria in 26 women. Twelve women without pyuria during ICB served as a control group. Antibiotic therapy was routinely administered during intracavitary application. The crude survival rate at 5 years was 39% in patients with pyuria and 42% in women without pyuria; the corresponding local recurrence rates were 23% and 17%; the serious complication rates were 12% and 0% respectively. Intracavitary brachytherapy in the presence of pyuria may have a limited adverse effect on the outcome of women with cancer of the cervix.     

Mid-Infrared Diode Laser Spectroscopy of X ; 1 A '' HC35 Cl

PURPOSE: Ultrasound (US)-guided permanent prostate implants typically use US prostate volumes to plan the implant procedure and CT prostate volumes for 3D dosimetric evaluation of the implant. Such a protocol requires that CT and US prostate volumes be registered. We have studied the impact of prostate volume registration on postimplant dosimetry for patients with low-grade prostate cancer treated with combined US and fluoroscopic-guided permanent implants. METHODS AND MATERIALS: A US image set was obtained with the patient in the lithotomy position to delineate the prostate volume that was subsequently used for treatment planning. Each plan was customized and optimized to ensure complete coverage of the US prostate volume. After implant, a CT scan was obtained for postimplant dosimetry with the patient lying supine. Sources were localized on CT by interactively creating orthogonal images of small cubes, whose dimensions were slightly larger than the source, to assure unique identification of each seed. Ultrasound and CT 3D surfaces were registered using either (a) the rectal surface and base of the prostate, or (b) the Foley balloon and urethra as the alignment reference. A dose distribution was assigned to the US prostate volume based on the CT source distribution, and the dose-volume histogram (DVH) was calculated. RESULT: Prostate volumes drawn from US images differ from those drawn from CT images with the CT volumes being typically larger than the US volumes. Urethral registration of the prostate volume based on aligning the prostatic urethra generates a dose distribution that best follows the preimplant plan and is geometrically the preferable choice for dosimetry. CONCLUSION: The dose distribution and the DVH for the US prostate is sensitive to the mode of registration limiting the ability to determine if acceptable dose coverage has been achieved.     

Treatment-related myelodysplastic syndrome following abdominopelvic radiotherapy for endometrial cancer

A patient with grade II endometrial adenocarcinoma underwent TAH/BSO. The tumor penetrated 50% of the myometrium. A lesion from the serosa of the sigmoid colon was removed and contained metastatic adenocarcinoma. Metastatic tumor was also found in the common iliac lymph nodes. Postoperatively the patient was treated with abdominopelvic radiotherapy to 30 Gy. The pelvis was boosted to a dose of 46.2 Gy. The vaginal apex was then treated with three applications of high-dose-rate brachytherapy to a total dose of 12 Gy. The patient was doing well with no evidence of recurrence 52 months following treatment when she was diagnosed with a myelodysplastic syndrome. Cytogenetic analysis revealed aberrations of chromosomes 5 and 7, which is highly suggestive of a treatment-related process. Myelodysplasia induced by radiotherapy alone is an unusual but recognized event.     

PC-assisted three-dimensional description of organs containing tubular structures, applied on the epididymis of the rat

AIM: Although the relationship between the dose delivered to adjacent organs (urinary bladder and rectum) and the frequency and severity of treatment complications has been reported in many series, the factors influencing pelvic dose distribution are not well defined. The aim of the study was to assess retrospectively the influence of the size of cervical cancer brachytherapy applicators (ovoids and uterine tandems) on pelvic dose distribution and the impact of various therapy-dependent factors on patient anatomy and on dose distribution in particular applications. PATIENTS AND METHOD: The subject of this study were 356 cervical cancer patients treated with Selectron LDR as a part of their radical radiotherapy. Analysed factors included preceding external beam radiotherapy (EBRT) or brachytherapy applications, use of general anaesthesia for application and the system of pellet loading. RESULTS: Significant correlation was found between the size of applicators and doses to bladder, rectum and points B: larger vaginal applicators produced lower dose in bladder and rectum and higher dose in point B (all p < 0.0001), longer uterine tandems produced lower dose in rectum and higher dose in point B (both p < 0.0001). Significant decrease in the frequency of use of large applicators (ovoids: p < 0.0001, tandems: p = 0.055) and worsening of dose distribution, i.e. higher doses to critical organs (respectively: bladder p = 0.0012, rectum p = 0.02) and lower point B dose (p = 0.0001) were observed at consecutive brachytherapy applications. Similar situation occurred in patients, who received EBRT prior to brachytherapy (ovoids: p < 0.001, tandem: p = 0.04, bladder dose: p = 0.009, rectal dose: p = 0.073, point B dose: p = 0.059). Vaginal applicators were larger (p = 0.026) and the dose distribution was better (bladder: p = 0.023, rectum: p = 0.002, point B: p = 0.0001) in patients who had their insertions performed under general anaesthesia. The comparison of 2 consecutively used systems of pellet loading revealed more favourable dose distribution: lower dose for bladder (p = 0.014) and higher dose for point B (p < 0.0001) for the system, which utilised more sources in ovoids and in the distal part of the uterine tandem, in spite of more frequent use of smaller applicators in this group of patients. In multivariate analysis ovoid size was related to preceding external beam radiotherapy (p = 0.025). Uterine tandem length was dependent on the number of preceding intracavitary applications (p < 0.001) and preceding external beam radiotherapy (p = 0.007). Bladder dose was related to preceding brachytherapy (p = 0.011) and the pattern of pellet loading (p = 0.031). Rectal dose was dependent only on the use of general anaesthesia during application (p = 0.001) and point B dose was dependent on the pattern of pellet loading (p < 0.001) and marginally-on the use of preceding external beam radiotherapy (p = 0.06). CONCLUSIONS: The results of this study allow for identification of treatment-related factors determining pelvic dose distribution in cervical cancer brachytherapy and may potentially enable optimisation of this distribution in particular clinical situation.     

Radiotherapy for cervical cancer with high-dose rate brachytherapy correlation between tumor size, dose and failure

This is a retrospective analysis of 659 patients with cervical squamous cell carcinoma with a minimum follow-up of 2 years at Keio University Hospital between May 1974 and March 1990. All patients were treated with external radiation (50 Gy) and high-dose rate (HDR) intracavitary brachytherapy (20-34 Gy). The 5-year survival rates in each stage gradually decreased with the advance of the stage (I, 84%; II, 71%; III, 47%; and IVa, 12%). When 366 patients with stage III were classified into three groups according to tumor size, i.e. small (S, 102 patients), medium (M, 145) and large (L, 119), a survival gradient of small > medium > large was demonstrated and the differences between them were significant. At follow-up visits conducted between 1 and 2 months after completion of treatment, 135 patients (20%) had physical indications of residual disease. The larger the tumor size, the more likely was residual disease by 2 months. The patients with residual disease had a significantly higher rate of the pelvic failure than those without it. There was no significant correlation between radiation doses by RALS and pelvic failure rates, except in the stage III-L group. In the stage III-L group, intracavitary doses of 24 Gy or less to point A could be correlated with the higher pelvic failure rate and the lower survival rate, in contrast to doses of 27 Gy or more. The incidence of major rectosigmoid complications was 11.8% with doses of 24 Gy or less to point A, 8.1% with 27 Gy and 19.2% with doses of 30 Gy or more.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fractionated high dose rate intraluminal brachytherapy in palliation of advanced esophageal cancer

PURPOSE: To optimize the dose of fractionated brachytherapy for palliation of advanced esophageal cancer. METHODS AND MATERIALS: One hundred and seventy-two patients with advanced esophageal cancer were randomized to receive 12 Gy/2 fractions (group A); 16 Gy/2 fractions (group B), and 18 Gy/3 fractions (group C) by high dose rate intraluminal brachytherapy (HDRILBT). Treatment was given weekly and dose prescribed at 1 cm from the source axis. Patients were followed up monthly and assessed for dysphagia relief and development of complications. RESULTS: Twenty-two patients died before completing treatment due to advanced disease and poor general condition. The overall survival was 19.4% at the end of 12 months for the whole group (A--9.8%, B--22.46%, C--35.32%; p > 0.05). The dysphagia-free survival was 28.9% at 12 months for the whole group (A--10.8%, B--25.43%, C--38.95%; p > 0.05). Forty-three patients developed fibrotic strictures needing dilatation (A--5 of 35, B--15 of 60, C--23 of 55; p = 0.032). Twenty-seven patients had persistent luminal disease (A--11, B--6, C--10), 15 of which progressed to fistulae (A--7, B--2, C--6; p = 0.032). There was no effect of age, sex, race, histology, performance status, previous dilation, presenting dysphagia score, presenting weight, grade, tumor length, and stage on overall survival, dysphagia-free, and complication-free survival (p > 0.05). On a multivariate analysis, brachytherapy dose (p = 0.002) and tumor length (p = 0.0209) were found to have a significant effect on overall survival; brachytherapy dose was the only factor that had an impact on local tumor control (p = 0.0005), while tumor length was the only factor that had an effect on dysphagia-free survival (p = 0.0475). When compared to other forms of palliation currently available (bypass surgery, laser, chemotherapy, intubation, external radiotherapy), fractionated brachytherapy gave the best results with a median survival of 6.2 months. CONCLUSIONS: Fractionated brachytherapy is the best modality for palliation of advanced esophageal cancer. It offers the best palliation to patient when compared to all other modalities currently available. The optimal brachytherapy dose ranges between 16 Gy in two fractions and 18 Gy in three fractions given a week apart.