Optimum fractionation for high-dose-rate endoesophageal brachytherapy following external irradiation of early stage esophageal cancer

PURPOSE: To establish the optimum fractionation for high-dose-rate (HDR) endoesophageal brachytherapy (EBT) for early stage esophageal cancer from retrospective data of patients treated with different HDR schedules following external beam irradiation (EBI). METHODS AND MATERIALS: The study population consisted of 35 consecutive early stage esophageal cancer patients who received EBI to the mediastinum, plus EBT, between May 1992 and November 1995 at the Hiroshima University Medical Center and Hiroshima City Hospital. All patients were treated with EBI, with doses ranging from 50 to 61 Gy. The spinal cord was spared after 44-45 Gy. HDR EBT was performed using a double-balloon applicator in conjunction with an Ir-192 remote afterloading system. One group of 10 patients was given a weekly endoesophageal boost of 4 or 5 Gy at a distance of 5 mm from the applicator surface over a period of 1-2 weeks. Another group of 25 patients was treated with 4 or 5 endoesophageal boosts with a fraction dose of either 2.5 or 2 Gy for 1 week. The linear quadratic (LQ) formula was used to calculate the biologically effective dose (BED) for tumor (Gy10) and esophageal mucosa (Gy3); Gy10 means alpha/beta equals 10 Gy, and Gy3 means alpha/beta equals 3 Gy.The Kaplan-Meier method was used to calculate the local control and late complication rates, while the Cox-Mantel test was used to evaluate statistical significance (p < 0.01). RESULTS: Nine (26%) of the 35 patients recurred locally and 7 (20%) had late complications (esophageal ulcer grade by RTOG/EORTC criteria > 1). The 5-year overall survival, local control, and late complication rates were 38%, 57%, and 26%, respectively. The probability of local recurrence was not affected by the treatment parameters. Results from the LQ formula significantly correlate with data on late complications. A BED > 134 Gy3 and a fraction number = < 3 were associated with late complications (grade > 1). BED analysis showed that the fractionation dose should be decreased to 2.5 or 2.0 Gy at a distance of 5 mm from the applicator surface, and the number of doses increased to 4 or 5, respectively, to yield a satisfactory BED (< 134 Gy3). CONCLUSION: A significant reduction in endoesophageal brachytherapy dose per fraction is necessary to reduce late complications. Our current treatment protocol for early-stage esophageal cancer consists of EBI of 60 Gy followed by 4 EBT doses at a fraction dose of 2.5 Gy applied over 1 week.     

外放疗后鼻咽癌残存灶近距离治疗的近期疗效

 自1992年7月至1995年7月，我们对鼻咽癌首程治疗后，鼻咽腔内仍有残存病灶者35例采用近距离治疗补充照射，参考点放射剂量4～6Gy／次，2次／周，共2～4次，近距离治疗总剂量12～18Gy。结果显示1、3年肿瘤局部控制率分别为94．3％、73．3％，近期疗效满意，尤以T_1-2期病例为优。随诊期内未见严重放射性并发症。     

High dose rate brachytherapy for superficial cancer of the esophagus

PURPOSE: We analyzed our experience with external radiotherapy, combined modality treatment, or HDR brachytherapy alone to limited esophageal cancers. METHODS AND MATERIALS: From 1991 to 1996, 25 patients with limited superficial esophagus carcinomas were treated by high dose rate brachytherapy. The mean age was 63 years (43-86 years). Five patients showed superficial local recurrence after external radiotherapy. Eleven patients without invasion of the basal membrane were staged as Tis. Fourteen patients with tumors involving the submucosa without spreading to the muscle were staged as T1. Treatment consisted of HDR brachytherapy alone in 13 patients, external radiotherapy and brachytherapy in 8 cases, and concomitant chemo- and radiotherapy in 4 cases. External beam radiation was administered to a total dose of 50 Gy using 2 Gy daily fractions in 5 weeks. In cases of HDR brachytherapy alone (13 patients), 6 applications were performed once a week. RESULTS: The mean follow-up is 31 months (range 24-96 months). Twelve patients received 2 applications and 13 patients received 6 applications. Twelve patients experienced a failure (48%), 11/12 located in the esophagus, all of them in the treated volume. One patient presented an isolated distant metastasis. In the patients treated for superficial recurrence, 4/5 were locally controlled (80%) by brachytherapy alone. After brachytherapy alone, 8/13 patients were controlled (61%). The mean disease-free survival is 14 months (1-36 months). Overall survival is 76% at 1 year, 37% at 2 years, and 14% at 3 years. Overall survival for Tis patients is 24% vs. 20% for T1 (p = 0.83). Overall survival for patients treated by HDR brachytherapy alone is 43%. One patient presented with a fistula with local failure after external radiotherapy and brachytherapy. Four stenosis were registered, two were diagnosed on barium swallowing without symptoms, and two required dilatations. CONCLUSION: High dose rate brachytherapy permits the treating of patients with superficial esophageal cancer with good tolerance. Early tumors, located in the mucosa, might be treated by HDR brachytherapy alone or by a combined modality treatment in which HDR brachytherapy can take place like a boost. This approach may cure localized recurrences.     

High-dose-rate brachytherapy boost following concurrent chemoradiotherapy for esophageal carcinoma.

PURPOSE: To assess the efficacy, toxicity, and the optimum dose of high-dose-rate brachytherapy following chemoradiotherapy (CRT) compared with a historical group of patients treated with a combination of external beam and brachytherapy (RT alone). METHODS AND MATERIALS: Fifty-three patients with localized esophageal cancer received concurrent chemoradiotherapy followed by brachytherapy. The chemotherapy regimen was a combination of cisplatin 60 mg/m2 on day 1 and fluorouracil 600 mg/m2 continuous infusion from days 1-4 during the first and last week of external irradiation. Radiotherapy consisted of external irradiation to a total dose of 40-61 Gy (median 50 Gy) and brachytherapy to 8-24 Gy (median 16 Gy) in 2-4 fractions. RESULTS: Acute toxicity was well tolerated. A fistula occurred in one patient 1 week after completion of external irradiation. Local control was achieved in 32/53 (60%) compared with 42% of the RT group (p = 0.029). Local control rates of the CRT group were significantly better than those of the RT group in Stages II and III. Late toxicity (esophageal ulceration and strictures) occurred in 18 (34%) of the CRT group compared with 12% in the RT group (p = 0.013). Severe late toxicity (RTOG/EORTC criteria Grade 3-4) occurred in six patients (15%) whose chemotherapy was followed by 16-24 Gy via brachytherapy compared with 2.5% in the RT group (p = 0.010). CONCLUSION: Combined chemoradiotherapy and brachytherapy boost achieved better local control than radiotherapy alone. However, a high level of severe late toxicity was observed especially with 16-24 Gy via brachytherapy.     

The role of brachytherapy in early-stage nasopharyngeal carcinoma

To present the treatment results and assess the optimal radiation dose and the role of brachytherapy in early stage nasopharyngeal cancer (NPC).

One hundred eighty-three patients with Stage I and II (American Joint Committee on Cancer Staging System, 1987) NPC completed the planned radiotherapy in our institution from 1979 to 1991. In 133 patients, radiotherapy was given to the nasopharynx by external beam to 64.8–68.4 Gy. Further boost was done by high dose rate (HDR) brachytherapy for 5–16.5 Gy in one to three fractions. For the remaining 50 patients, a course of external radiotherapy to the nasopharynx for 68.4–72 Gy was given to nasopharynx. Age (>40 or not) sex, neck boost or not, brachytherapy, and irradiation dose were analyzed to determine significant factors that influence the probabilities of local control and actuarial survival.

The 5-year disease-specific survival was 85.8% and local control was 83%. Only the brachytherapy and irradiation dose significantly affected the results. The use of the brachytherapy had significant impact on overall survival and local control. Furthermore, we compared the prognostic effect of various radiation dosage among Group I of 50 patients (<72.5 Gy, no brachytherapy, excluding four patients who received brachytherapy), Group II of 71 patients (72.5–75 Gy; one to two fractions of brachytherapy), and Group III of 58 patients (>75 Gy; three fractions of brachytherapy). Five-year disease-specific survival rates of Group I, Group II, and Group III were 77, 95.5, and 82.4%, respectively. Five-year local control rates were: 73.7, 93.9, and 79.5%. We found that the Group II had the best actuarial survival and local control rate (log-rank test, p < 0.05). Most patients receiving brachytherapy encountered foul odor because of nasopharynx crust; 12 of them had palate or sphenoid sinus floor perforation or nasopharynx necrosis. None of the patients without brachytherapy experienced the same complications.

The optimal radiotherapy dose to the nasopharnyx area in early stage NPC may be within 72.5 to 75 Gy by our treatment protocol. A dose of more than 75 Gy did not have significant local control or survival advantage. The use of brachytherapy to elevate radiation dose had significant local control and survival benefit for early stage NPC patients, but the fractionation size should be decreased to reduce the complications.     

Low-dose-rate brachytherapy is superior to high-dose-rate brachytherapy for bladder cancer

PURPOSE: To determine the efficacy and safety of a high-dose-rate (HDR) brachytherapy schedule in the treatment of bladder cancer and to investigate the impact of different values of repair half-times and alpha/beta ratios on the design of the HDR schedule. METHODS AND MATERIALS: Between 2000 and 2002, 40 patients with T1G3 and T2 bladder carcinoma were treated with 30 Gy external beam radiotherapy followed by interstitial HDR brachytherapy to a total dose of 32 Gy in 10 sessions of 3.2-Gy fractions in two fractions daily with a 6-h interfraction interval. The local control rate and toxicity were compared with a historical group of 108 patients treated with 30 Gy external beam radiotherapy followed by 40-Gy interstitial low-dose-rate (LDR) brachytherapy. The HDR schedule was designed to be biologically equivalent to the previously used LDR schedule with the linear-quadratic model, including incomplete mono-exponential repair. RESULTS: The local control rate at 2 years was 72% for HDR vs. 88% for LDR brachytherapy (p = 0.04). In the HDR group, 5 of 30 evaluable patients encountered serious late toxicity: 4 patients developed a contracted bladder with inadequate capacity (<100 mL), and 1 patient required cystectomy because of a painful ulcer at the implant site. In the LDR group, only 2 of 84 assessable patients developed serious late toxicity. One patient developed a persisting vesicocutaneous fistula and the other a urethral stricture due to fibrosis. The difference in observed late toxicity for HDR vs. LDR was statistically significant (p = 0.005). The increased late toxicity with the HDR schedule compared with the LDR schedule suggests a short repair half-time of 0.5-1 h for late-responding normal bladder tissue. CONCLUSION: Local control of HDR brachytherapy for bladder cancer was disappointing and late toxicity unexpectedly high. The increase in late toxicity suggested a short repair half-time of 0.5-1 h for late-responding normal bladder tissue, which would not support HDR brachytherapy in the treatment of bladder cancer. The analysis demonstrated that the calculation of equivalent HDR schedules on the basis of the LDR schedules used in clinical practice might be hazardous.     

High-dose-rate brachytherapy in uterine cervical carcinoma

PURPOSE: High-dose-rate (HDR) brachytherapy is in wide use for curative treatment of cervical cancer. The American Brachytherapy Society has recommended that the individual fraction size be <7.5 Gy and the range of fractions should be four to eight; however, many fractionation schedules, varying from institution to institution, are in use. We use 9 Gy/fraction of HDR in two to five fractions in patients with carcinoma of the uterine cervix. We found that our results and toxicity were comparable to those reported in the literature and hereby present our experience with this fractionation schedule. METHODS AND MATERIALS: A total of 121 patients with Stage I-III carcinoma of the uterine cervix were treated with HDR brachytherapy between 1996 and 2000. The total number of patients analyzed was 113. The median patient age was 53 years, and the histopathologic type was squamous cell carcinoma in 93% of patients. The patients were subdivided into Groups 1 and 2. In Group 1, 18 patients with Stage Ib-IIb disease, tumor size <4 cm, and preserved cervical anatomy underwent simultaneous external beam radiotherapy to the pelvis to a dose of 40 Gy in 20 fractions within 4 weeks with central shielding and HDR brachytherapy of 9 Gy/fraction, given weekly, and interdigitated with external beam radiotherapy. The 95 patients in Group 2, who had Stage IIb-IIIb disease underwent external beam radiotherapy to the pelvis to a dose of 46 Gy in 23 fractions within 4.5 weeks followed by two sessions of HDR intracavitary brachytherapy of 9 Gy each given 1 week apart. The follow-up range was 3-7 years (median, 36.4 months). Late toxicity was graded according to the Radiation Therapy Oncology Group criteria. RESULTS: The 5-year actuarial local control and disease-free survival rate was 74.5% and 62.0%, respectively. The actuarial local control rate at 5 years was 100% for Stage I, 80% for Stage II, and 67.2% for Stage III patients. The 5-year actuarial disease-free survival rate was 88.8% for Stage I, 76.52% for Stage II, and 50.4% for Stage III patients. Local failure occurred in 2 (11.1%) of the 18 Group 1 patients and in 20 (21.0%) of the 95 Group 2 patients. Distant failure occurred in none of the Group 1 patients and in 8 (8.4%) of the 95 Group 2 patients. None of the patients developed Grade 3 rectal toxicity. Grade 3 bladder toxicity was observed in 2 patients. The actuarial risk of Grade 3 or worse late toxicity was 3.31%. CONCLUSION: The results of our study indicate that HDR brachytherapy at 9 Gy/fraction is both safe and effective in the management of carcinoma of the cervix, with good local control and a minimum of normal tissue toxicity.     

External beam radiation therapy with or without high-dose-rate intraluminal brachytherapy for patients with superficial esophageal carcinoma.

BACKGROUND: Clinical results of external beam radiation therapy (RT) with or without intraluminal brachytherapy (IBT) for patients with superficial esophageal carcinoma were evaluated retrospectively. METHODS: Between 1985 and 1996, 21 patients with superficial esophageal squamous cell carcinoma were treated by external beam RT, with or without high dose rate IBT, with curative intent. There were 18 males and 3 females; their median age was 67 years (range, 51-85 years). Eight patients were treated by external beam RT alone (60-69 gray [Gy]), whereas the remaining 13 patients were treated by IBT after external beam RT. Most patients in the IBT group received 2 or 3 fractions of IBT of 4 Gy after external beam RT of 50-56 Gy. RESULTS: All of the 21 tumors showed complete regression at the end of RT. Local recurrence was noted in 4 patients in the group that received external beam RT alone and in 2 patients in the IBT group. Salvage therapy was successful for 4 patients. Local control probability and cause specific survival probability for the IBT group were significantly higher than those for the group that received external beam RT alone (P < 0.05 for both). The 3-year local control and cause specific survival rates for the IBT group were 85% and 100%, respectively, whereas those for the external beam RT group were 45% and 67%, respectively. Transient esophageal ulcers were noted in two patients in the IBT group. CONCLUSIONS: External beam RT and IBT is a safe and effective treatment modality for patients with superficial esophageal carcinoma.     

Percutaneous and endobronchial high dose rate brachytherapy for lung cancer

Endobronchial and percutaneous high dose rate (HDR) brachytherapy was performed with a microSelectron HDR using iridium-192 as a radiation source. As spontaneous pain was uncontrollable by external beam radiation (EBR), chemotherapy, hyperthermia or a combination of these treatment methods, three patients with lung cancer infiltration into the chest wall underwent percutaneous HDR brachytherapy for palliation of severe pain. Selectron needles were inserted under CT guidance and the irradiation dose was set to 10 or 12 Gy at the point 1 cm from the center of the radiation source. A total of 2-4 selectron needles was introduced by means of a template. Irradiation was performed once a week for 1-2 weeks depending on the degree of alleviation of spontaneous pain. In all 3 cases, alleviation of spontaneous pain occured within 7 days after the completion of HDR brachytherapy, and the mean pain score decreased from a value of 2 to 1 within 2 weeks. After discharge from the hospital, the pain score remained between 1-4 in all 3 patients. One problem in percutaneous brachytherapy is the possible hindrance of multiple selectron needle insertion through the template by the ribs depending on the location of the lesion. Six patients aged 51-75 years were subjected to endobronchial HDR brachytherapy. Two of these patients had postoperative recurrence of lung cancer, and 3 patients received concomitant chemotherapy. Brachytherapy was performed 3.4 months (average) after the administartion of 40-70 Gy of EBR. Endobronchial irradiation was performed at a dose of 7 Gy, measured at 1 cm from the center of the radiation source, once a week over a 3 week period for a total of 21 Gy. With the exception of 2 patients who died due to systemic exacerbation, local control of the illness has been good. In endobronchial HDR brachytherapy, it is important to develop a system for altering radiation dose in response to changes in the caliber of the tracheobronchial tree and the degree of the tumor invasion under the bronchial mucosa.     

Results of low- and high-dose-rate interstitial brachytherapy for T3 mobile tongue cancer.

PURPOSE: To evaluate the treatment results of low-dose-rate (LDR) and high-dose-rate (HDR) interstitial brachytherapy (ISBT) for T3 mobile tongue cancer. MATERIAL AND METHODS: Between 1974 and 1992, 61 patients with T3 mobile tongue cancer were treated with LDR ISBT using (192)Ir hairpins with or without single pins. In addition, between 1991 and 1999, 14 patients were treated with HDR ISBT. For nine patients treated with ISBT alone, the total dose was 59-94 Gy (median 72 Gy) within one week in LDR ISBT and 60 Gy/10 fractions/5 days in HDR ISBT. For 66 patients treated with a combination therapy of external beam radiotherapy (EBRT) and ISBT, the total dose was 12.5-60 Gy (median 30 Gy) of EBRT and 50-112 Gy (median 68 Gy) within 1 week in LDR ISBT or 32-60 Gy (median 48 Gy)/8-10 fractions/5-7 days in HDR ISBT. RESULTS: The 2- and 3-year local control rates of all patients were both 68%. The 2- and 3-year local control rates of patients treated with LDR ISBT were both 67%, and those with HDR ISBT were both 71%. The local control rate of patients treated with HDR ISBT was similar to those with LDR ISBT. CONCLUSIONS: ISBT for T3 mobile tongue cancer is effective and acceptable. The treatment result of HDR ISBT is almost similar to that of LDR ISBT for T3 mobile tongue cancer.     

Results and complications of high dose rate and low dose rate brachytherapy in carcinoma of the cervix: Cerrahpa?a experience.

PURPOSE: To evaluate the results and complications of treatment with high dose rate (HDR) compared to low dose rate (LDR) brachytherapy in cervical carcinoma. METHODS: Three hundred and seventy patients who were treated with external irradiation and intracavitary brachytherapy and followed for more than 2 years between 1978 and 1998 have been recently updated. The low dose rate group consisted of 77 cases treated between 1978 and 1982 and HDR group consisted of 293 cases treated between 1982 and 1998. All patients first received external irradiation with 60Co or 9-18 MV photons and a median dose of 54 Gy was given in 6 weeks. In the LDR group, intracavitary treatment was given with Manchester applicators loaded with radium (30 mg) in an intrauterine tube and 20 mg in vaginal ovoids. The dose delivered to point A was on average 32 Gy in one application. In the HDR group, a total dose of 24 Gy was given to point A in three insertions 1 week apart. The dose rate was 0.62 Gy at point A. RESULTS: The 5-year pelvic control rate was found to be 73% in the HDR group, compared with 86% in the radium group for stage I cases. In stage IIB and IIIB cases, the rates were 68% and 45% for HDR and 65% and 53% for LDR, respectively. In all stages, there was no statistical difference in pelvic control and survival rates between the two groups. Overall incidence of late complications was found as 31.1% and 31.9% in HDR and LDR groups, respectively. The grade 2-4 late complication rate was 14% in the HDR group compared to 19% in the LDR group (P>0.05). CONCLUSION: HDR brachytherapy in the management of the cervix appears to be a safe and efficacious approach. Pelvic control, survival and complications rates are quite similar when compared with LDR.     

3D conformal HDR brachytherapy and external beam irradiation combined with temporary androgen deprivation in the treatment of localized prostate cancer.

PURPOSE: To evaluate treatment outcome of 3D conformal high dose rate (HDR) brachytherapy and external beam irradiation (EBRT) combined with temporary androgen deprivation for patients with localized prostate cancer. PATIENTS AND METHODS: Between January 1997 and September 1999 we treated 102 patients with stage T1-3 N0 M0 prostate cancer. Stage T1-2 was found in 71, T3 in 31 patients. Median pretreatment PSA level was 15.3 ng/ml. After ultrasound-guided transrectal implantation of four afterloading needles, CT based 3D brachytherapy planning was performed. All patients received four HDR implants using a reference dose per implant of 5 or 7Gy. Time between each implant was 14 days. After brachytherapy EBRT followed up to 39.6 or 45.0 Gy. All patients received temporary androgen deprivation, starting 2-19 months before brachytherapy, ending 3 months after EBRT. RESULTS: Median follow-up was 2.6 years (range 2.0-4.1 years). Actuarial biochemical control rate was 87% at 2 years and 82% at 3 years. In 14 patients we noted biochemical failure, in five patients clinical failure. Overall survival was 90%, disease specific survival 98.0% at 3 years. Acute grade 3 toxicity occurred in 4%, late grade 3 toxicity in 5%. One patient developed a prostatourethral-rectal fistula as late grade 4 toxicity. The conformal quality of 300 HDR implants was analyzed using dose volume histograms. CONCLUSIONS: 3D conformal HDR brachytherapy and EBRT combined with temporary androgen deprivation is an effective treatment modality for prostate cancer with minimal associated toxicity and encouraging biochemical control rates after a median follow-up of 2.6 years.     

The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for carcinoma of the cervix

PURPOSE: This report presents guidelines for using high-dose-rate (HDR) brachytherapy in the management of patients with cervical cancer, taking into consideration the current availability of resources in most institutions. METHODS: Members of the American Brachytherapy Society (ABS) with expertise in HDR brachytherapy for cervical cancer performed a literature review, supplemented their clinical experience to formulate guidelines for HDR brachytherapy of cervical cancer. RESULTS: The ABS strongly recommends that definitive irradiation for cervical carcinoma must include brachytherapy as a component. Each institution should follow a consistent treatment policy when performing HDR brachytherapy, including complete documentation of treatment parameters and correlation with clinical outcome, such as pelvic control, survival, and complications. The goals are to treat Point A to at least a total low-dose-rate (LDR) equivalent of 80-85 Gy for early stage disease and 85-90 Gy for advanced stage. The pelvic sidewall dose recommendations are 50-55 Gy for early lesions and 55-65 Gy for advanced ones. The relative doses given by external beam radiation therapy (EBRT) vs. brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional preference. As with LDR brachytherapy, every attempt should be made to keep the bladder and rectal doses below 80 Gy and 75 Gy LDR equivalent doses, respectively. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. While recognizing that many efficacious HDR fractionation schedules exist, some suggested dose and fractionation schemes for combining the EBRT with HDR brachytherapy for each stage of disease are presented. These recommendations are intended only as guidelines, and the suggested fractionation schemes have not been thoroughly tested. The responsibility for the medical decisions ultimately rests with the treating radiation oncologist. CONCLUSION: Guidelines are established for HDR brachytherapy for cervical cancer. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose-reporting policies. These guidelines will be modified, as image-based treatment becomes more widely available.     

Low-dose intraoperative brachytherapy in soft tissue sarcomas involving neurovascular structure.

BACKGROUND AND PURPOSE: To evaluate intraoperative brachytherapy in the management of soft tissue sarcomas involving neurovascular structures, its impact on local control and complications. PATIENTS AND METHODS: Between 01/1989 and 12/2002, 98 patients received an intraoperative implant in conjunction with conservative surgery. Brachytherapy was part of the initial treatment (79 cases) or performed in recurrent disease (19 cases). We studied primary sarcomas involving neurovascular structures treated with conservative surgery and intraoperative brachytherapy (n = 6) or intraoperative brachytherapy and external irradiation (n = 73). Conservative surgery was performed as first treatment (51 cases), after chemotherapy (21 cases) and after primary external radiation (seven cases). Brachytherapy was performed according to Paris system rules. Patients were loaded with Iridium 192 (64 cases) or connected to a Microselectron PDR (15 cases). Mean dose given by brachytherapy was 20 Gy. Mean dose given of external radiotherapy was 46 Gy. RESULTS: With a median follow-up of 58 months, 5-year actuarial survival was 69% and local free disease at 5 years was 90%. Acute side-effects occurred in 22/79 requiring surgical repair in 10 patients. Late side-effects occurred in 35/79. No patient required amputation for complications. Prognostic factors were studied for the occurrence of acute and late side-effects and local control. CONCLUSIONS: Intraoperative brachytherapy is efficient with excellent local control rates in soft tissue sarcomas presenting with neurovascular involvement and offers an acceptable conservative option.     

单管式子宫颈癌后装施源器前瞻性随机对照Ⅱ期临床研究近期疗效

目的 观察自主研发的单管式子宫颈癌后装施源器与标准Fletcher三管施源器的临床疗效以及安全性。 方法 选取 2011-2017年就诊的子宫颈癌初诊患者,随机分为外照射+单管式后装组(专利单管组)和外照射+ Fletcher三管式后装组。外照射采用6 MV X线四野盒式或前后对穿野照射,30 Gy后改野挡铅行后装治疗,1 次/周,剂量为A点7 Gy,共 5~6次(A点生物等效剂量:80~90 Gy)。外照射时同步使用顺铂(40 mg/m²)化疗,1 次/周,治疗结束随访其疗效及不良反应并对比。 结果 符合入组条件并完成治疗,Fletcher三管组 150例,专利单管组 149例。两组近期疗效以及急性期不良反应相近(P>0.05)。Fletcher三管组有效率为94.0%,专利单管组为94.7%。≥3级急性期血液学不良反应,Fletcher三管组为 76例(50.7%),专利单管组为 61例(40.9%)(P=0.195)。 结论 专利单管式子宫颈癌后装施源器与标准Fletcher三管施源器近期疗效相当,且急性期不良反应相似。     

Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer

PURPOSE: To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed. METHODS AND MATERIALS: Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level >or=10.0 ng/mL, Gleason score >or=7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose <93 Gy (58 patients) and high-dose biologically effective dose >93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure. RESULTS: The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p <0.001). Improvement occurred in the cause-specific survival in favor of the brachytherapy high-dose level (p = 0.014). On multivariate analysis, a low-dose level, higher Gleason score, and higher nadir value were associated with increased biochemical failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%. CONCLUSION: Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause-specific survival with higher doses. These results, coupled with the low risk of complications, the advantage of not being radioactive after implantation, and the real-time interactive planning, define a new standard for treatment.     

Comparison of low and high dose rate brachytherapy in the treatment of uterine cervix cancer. Retrospective analysis of two sequential series

PURPOSE: This retrospective analysis aims to report on the comparative outcome of cervical cancer patients treated with low dose rate (LDR) and high dose rate (HDR) brachytherapy. METHODS AND MATERIALS: From 1989 to 1995, 190 patients were treated with low dose rate (LDR) brachytherapy (LDR group) and from 1994 to 2001, 118 patients were treated with high dose rate (HDR) brachytherapy (HDR group). FIGO stage distribution for the LDR group was Stage I: 6.3%; Stage II: 57.4%; and Stage III: 36.3% and for the HDR group Stage I: 9.3%; Stage II: 43.2%; and Stage III: 47.4%. All patients were treated with telecobalt external-beam radiotherapy (EBR). Median doses of LDR brachytherapy at Point A were 40 Gy and 50 Gy for patients treated with 1 and 2 implants, respectively. All patients from the HDR group were treated with 24 Gy in 4 fractions of 6 Gy to Point A. Survival, disease-free survival, local control, and late complications at 5 years, were endpoints compared for both groups. RESULTS: Median follow-up time for LDR and HDR groups was 70 months (range, 8-127 months) and 33 months (range, 4-117 months), respectively. For all stages combined, overall survival, disease-free survival, and local control at 5 years were better in the LDR group (69% vs. 55%, p = 0.007; 73% vs. 56%, p = 0.002; and 74% vs. 65%; p = 0.04, respectively). For clinical Stages I and II, no differences was seen in overall survival, disease-free survival, and local control at 5 years between the two groups. For clinical Stage III, overall survival and disease-free survival at 5 years were better in the LDR group than in the HDR group (46% vs. 36%, p = 0.04 and 49% vs. 37%, p = 0.03, respectively), and local control was marginally higher in the LDR group than in the HDR group (58% vs. 50%, p = 0.19). The 5-year probability of rectal complications was higher in the LDR group than in the HDR group (16% vs. 8%, p = 0.03) and 5-year probability of small bowel and urinary complications was not statistically different between the the LDR group and the HDR group (4.6% vs. 8.9%, p = 0.17 and 6% vs. 3%, p = 0.13, respectively). CONCLUSIONS: This comparative series suggests similar outcome for Stages I and II patients treated with either HDR or LDR brachytherapy. Lower overall and disease-free survival and marginally lower local control were observed for Stage III patients treated with HDR brachytherapy. Less late rectal complications were observed in the HDR group patients. These findings were probably the result of the relatively low HDR brachytherapy dose delivered at Point A.     

3D打印模板辅助标准化施源器在ⅢB期宫颈癌影像引导自适应近距离治疗中的应用

目的 探讨3D打印模板辅助标准化施源器在宫颈癌影像引导自适应近距离治疗(BT)中的应用。方法 对 23例外照射(45Gy分25次)后宫旁受侵袭范围较大的 ⅢB期宫颈癌患者行MRI引导自适应BT,处方剂量为7 Gy/次,共4次。根据外照射前后MRI中肿瘤消退情况确定BT范围,预估应用标准化腔内联合组织间插植(IC+IS)施源器剂量欠量区域。对欠量区域虚拟经会阴组织间插植针道,并优化植入角度、间距、深度等。应用图形设计软件设计辅助插植模板,并使用3D打印技术打印辅助模板,并与标准化施源器结合紧密。在全麻条件下超声引导完成IC+IS,术后对患者行MRI定位扫描。将定位MRI传入治疗计划系统进行靶区和危及器官勾画,并给予IC+IS治疗计划设计优化,最终完成计划评估及治疗。结果 3D打印个体化插植模板平均打印时间为(3.5±1.0) h,辅助模板共引导植入插植针382根,单分次(4.2±1.5)根,剂量权重比为(16.49±9.50)%。靶区EQD2Gy,α/β=10剂量高危靶 区D90%为(90.45±3.03) Gy,中危靶 区D90%为(66.46±3.68) Gy。膀胱、直肠、小肠、乙状结肠的 D2cm³EQD2Gy,α/β=3分别为(82.69±2.60)、(73.20±2.52)、(69.35±3.32)、(69.39±3.27) Gy,均满足临床剂量要求。1年和 2年局部控制率、无远处转移生存率、总生存率分别为96%和87%、87%和70%、96%和78%。结论 利用3D打印技术制作的辅助插植施源器可以有效弥补现有标准化施源器在 ⅢB期宫颈癌临床BT时大体积靶区剂量的不足,为晚期宫颈癌BT提供了较为有效的方法。