High Dose Rate Intracavitary Radiotherapy Research Articles

Estimation of pelvic lymph node dose contribution from HDR ICBT in cervical cancer

Context: Dose received to each pelvic group of lymph nodes, namely obturator (OB), internal iliac (II), and external iliac (EI), is less certain. This study is conducted to evaluate the dose delivered to these nodal groups so that this can be considered while planning external beam radiotherapy external beam radiation therapy (EBRT) boost in patients with gross pelvic lymph nodes. Aims: This study aimed to estimate the dose contribution to pelvic lymph nodes in three-dimensional high-dose-rate intracavitary radiotherapy (HDR-ICRT) of cervical cancer patients. Settings and Design: This was a single-arm retrospective observational study among 25 locally advanced carcinoma cervix patients treated with definitive chemoradiation. Materials and Methods: EI, II, and OB groups of lymph nodes were delineated on computed tomography data sets of selected 25 patients, and D100, D50, and D2cc to each lymph node were analyzed. The dose received by each pelvic lymph node group from all the 3 fractions of HDR-ICRT, corresponding equivalent 2 Gy dose, and percentage of brachytherapy (BT) contribution to each pelvic lymph node were calculated. Results: Mean D100 received by EI, II, and OB lymph node groups after summation across 3 fractions was 1.1 Gy, 2.34 Gy, and 3.11 Gy, respectively. Mean 2 Gy equivalent doses (D100) were 1.66 Gy, 3.41 Gy, and 4.53 Gy, respectively. Corresponding percentage of the dose received by EI, II, and OB was 4.89%, 10.43%, and 13.83% when 7.5 Gy per fraction for 3 fractions was prescribed to Point A. Conclusions: There is a significant contribution from HDR intracavitary BT to the pelvic lymph nodes in the radical treatment of cervical cancer. The dosimetric results given in this work can be used by a radiation oncologist to estimate BT doses to affected lymph nodes and integrate them into the preceding EBRT planning phase.

Pulsed-dose-rate vs. high-dose-rate intracavitary radiotherapy for locally advanced carcinoma of cervix: A prospective randomized study

PurposeTo compare late radiation toxicities in patients with carcinoma of cervix treated with pulsed-dose-rate (PDR) vs. high-dose-rate (HDR) intracavitary radiotherapy (ICRT). Methods and MaterialsBetween July 2010 to April 2012, 37 patients with Stage IIB-IIIB (International Federation of Gynecology and Obstetrics 2009) squamous cell carcinoma of cervix were randomized to receive either HDR (7 Gy each in three fractions, repeated weekly) or PDR (70 cGy hourly pulses for 39 hours, total 27 Gy) ICRT after external beam radiotherapy. Late rectal and bladder toxicities were assessed using Radiation Therapy Oncology Group criteria, and vaginal toxicity was graded as per common terminology criteria for adverse events. Overall survival and disease-free survival were estimated using Kaplan–Meier method. ResultsNineteen patients received HDR and 18 received PDR ICRT with median followup 34 and 29 months, respectively. In HDR vs. PDR arm, late rectal toxicities grade ≥2 (16.7% vs. 21.1%, p = 1.000), grade ≥3 (10.5% vs. 0%, p = 0.486), late bladder toxicities grade ≥2 (10.5% vs. 0%, p = 0.486), and late vaginal toxicities grade ≥2 (15.8% vs. 5.6%, p = 0.604) were not statistically different. For HDR and PDR ICRT groups, 4-year disease-free survival was 67.1% vs. 71.8% (p = 0.195) and overall survival was 77% vs. 75% (p = 0.322), respectively. ConclusionIn this small group of patients, there were fewer events in form of late radiation toxicities in PDR arm, although statistically not significant. Further studies are required to define role of PDR compared to HDR ICRT in cervical carcinoma.

New approach to relieving pain and distress during high-dose-rate intracavitary irradiation for cervical cancer.

To relieve the pain and distress experienced by women who undergo high-dose-rate intracavitary radiotherapy (HDR-ICRT) for cervical cancer and to improve the current status of gynecologic brachytherapy in Japan, a new intravenous anesthetic protocol involving the administration of a combination of propofol and ketamine was developed. The primary aim of this study is to investigate the efficacy and safety of this new anesthetic protocol during HDR-ICRT for cervical cancer. All the patients who were diagnosed with cervical cancer between December 2008 and February 2011, treated with three-channel brachytherapy and subjected to the new sedation protocol, were evaluated. A visual analog scale (VAS) was used to assess the pain during brachytherapy, and we collected VAS score at the next HDR-ICRT. Toxicities were graded using the Common Toxicity Criteria, version3. A total of 178 sessions of HDR-ICRT were delivered to 57 patients. The patients' median VAS pain score was 0 (range, 0-10). The most frequent side effect was Grade 1-2 nausea, which occurred in 33 sessions (34%). However, 13 of 14 patients received concurrent cisplatin chemotherapy. None of the patients experienced Grade 3 or 4 adverse events. We have demonstrated that our new intravenous anesthetic protocol produces appropriate effects and can be performed by radiation oncologists who were required to finish training in basic life support and the cooperative system of emergency according to in-house guideline.

Tailored radiotherapeutic strategies for disseminated uterine cervical cancer patients.

BackgroundTo investigate the role of radiotherapy (RT) in and to suggest radiotherapeutic strategies for patients presenting with disseminated cervical cancer.MethodsWe retrospectively analyzed 50 patients diagnosed as the disseminated cervical cancer with distant lymph nodal or visceral organ metastasis between September 1980 and August 2012. Patients were divided into two subgroups according to visceral organ metastasis: 35 patients diagnosed with distant lymph node metastasis only (group A) and 15 patients with visceral organ metastasis (group B). All patients received external beam RT to the pelvis (median dose 45 Gy) and high-dose rate intracavitary RT (median dose 30 Gy). Thirty-nine patients (78%) received chemotherapy.ResultsMedian follow-up time was 74 months. The 5-year pelvic control rate (PCR) was 85.8%, and the progression-free survival (PFS), and overall survival (OS) rates were 28.7%, and 36.2%, respectively. The major treatment failure was systemic progression (32 patients, 64%). The 5-year PCRs in groups A and B were 87.4% and 74.7%, respectively (p > 0.05). Meanwhile, PFS and OS rates for group A were significantly better than those for group B (35.3% vs. 13.3%, p = 0.010; and 46.3% vs. 13.3%, p = 0.009, respectively).ConclusionOur data revealed considerable prognostic heterogeneity in disseminated cervical cancer. Even though a high PCR was achieved in patients treated with definitive RT, survival outcomes were dependent on progression of visceral organ metastasis. Therefore, personalized RT and chemotherapy treatment strategies according to the presence of visceral organ metastasis in disseminated cervical cancer patients may help improve clinical outcomes.

Symptom relief effect of palliative high dose rate intracavitary radiotherapy for advanced esophageal cancer with dysphagia.

Intracavitary radiotherapy (ICRT) for the palliative treatment of advanced esophageal cancer with dysphagia is currently performed at the University of Tokyo Hospital (Tokyo, Japan). In the present study, 24 patients exhibiting advanced esophageal cancer with dysphagia received palliative ICRT. ICRT, which was delivered 5 mm below the esophageal mucous membrane, with the exception of one case, was administered at a dose of 6 Gy/fraction. Specific patients additionally underwent definitive or palliative external beam radiation therapy for esophageal cancer a minimum of three months prior to ICRT. The effect of treatment on symptom alleviation was examined by comparing the dysphagia score prior to and following ICRT, with the patients’ medical records and a questionnaire used to calculate a dysphagia score ranging from zero (no dysphagia) to four (total dysphagia). In consideration of the individual efficacy of the treatment, the maximum number of repeated ICRT fractions was four (median, 1.7 times). A trend in the improvement of the symptom of dysphagia was observed in response to esophageal ICRT, with the average dysphagia score markedly decreasing from 2.54 to 1.65, however, the difference was not significant (P=0.083). Furthermore, pain was the most frequent side-effect of the esophageal ICRT and no patients exhibited severe complications. Thus, esophageal ICRT at a dose of 6 Gy/fraction may present an effective strategy for relieving the symptom of dysphagia in cases of advanced esophageal cancer.

High-dose-rate Intracavitary Radiotherapy in the Management of Cervical Intraepithelial Neoplasia 3 and Carcinoma In Situ Presenting With Poor Histologic Factors After Undergoing Excisional Procedures

To assess the effectiveness of high-dose-rate intracavitary radiotherapy (HDR-ICR) in patients with cervical intraepithelial neoplasia 3 (CIN 3) and carcinoma in situ (CIS) presenting with poor histologic factors for predicting residual disease after undergoing diagnostic excisional procedures. This study was a retrospective analysis of 166 patients with CIN 3 (n=15) and CIS (n=151) between October 1986 and December 2005. They were diagnosed by conization (n=158) and punch biopsy (n=8). Pathologic analysis showed 135 cases of endocervical gland involvement (81.4%), 74 cases of positive resection margins (44.5%), and 52 cases of malignant cells on endocervical curettage (31.3%). All patients were treated with HDR-ICR using Co⁶⁰ or Ir¹⁹² at a cancer center. The dose was prescribed at point A located 2 cm superior to the external os and 2 cm lateral to the axis of the tandem for intact uterus. Median age was 61 years (range, 29-77). The median total dose of HDR-ICR was 30 Gy/6 fractions (range, 30-52). At follow-up (median, 152 months), 2 patients developed recurrent diseases: 1 CIN 2 and 1 invasive carcinoma. One hundred and forty patients survived and 26 patients died, owing to nonmalignant intercurrent disease. Rectal bleeding occurred in one patient; however, this symptom subsided with conservative management. Our data showed HDR-ICR is an effective modality for CIN 3 and CIS patients presenting with poor histologic factors after excisional procedures. HDR-ICR should be considered as a definitive treatment in CIN 3 and CIS patients with possible residual disease after undergoing excisional procedures.

Treatment results of radical radiotherapy of carcinoma uterine cervix using external beam radiotherapy and high dose rate intracavitary radiotherapy

To report the outcome of carcinoma cervix patients treated radically by external beam radiotherapy and high dose rate intracavitary radiotherapy. From January 2005 to December 2006, a total of 709 newly diagnosed cases of carcinoma cervix were reported in our department. All cases were staged according to the International Federation of Gynecologist and Oncologist staging system. Out of 709 cases, 342 completed radical radiotherapy and were retrospectively analyzed for the presence of local residual disease, local recurrence, distant metastases, radiation reaction, and disease free survival. There were 11(3.22%), 82(23.98%), 232(67.83%), and 17(4.97%) patients in stages I, II, III, and IV, respectively. The median follow up time for all patients was 36 months (range 3 -54 months). The overall treatment time (OTT) ranged from 52 to 69 days (median 58 days). The 3 year disease free survival rate was 81.8%, 70.7%, 40.08%, and 11.76% for stages I, II, III, and IV, respectively. There were 91 (26.6%) cases with local residual diseases, 27(7.9%) developed distant metastasis, and 18(5.26%) pts had local recurrence. The results of this study suggest that radical radiotherapy with HDR brachytherapy was appropriate for the treatment of early staged cancer of uterine cervix. For locally advanced cancer of cervix addition of concurrent chemotherapy, higher radiation doses, reduction of overall treatment time to less than 8 weeks, and use of latest radiotherapy techniques such as IMRT is recommended to improve the results.

Phase I Study of Concurrent Chemoradiotherapy With Weekly Cisplatin and Paclitaxel Chemotherapy for Locally Advanced Cervical Carcinoma in Japanese Women

The purpose of this study was to evaluate the use of concurrent chemoradiotherapy involving weekly administration of cisplatin and paclitaxel for the treatment of locally advanced cervical carcinoma in Japanese women. Twenty Japanese patients were registered for this phase I study. Radiation therapy was performed using external irradiation and high-dose rate intracavitary irradiation of the pelvis. Chemotherapy was performed once a week until termination of the radiation therapy. The dose of cisplatin was decided as 30 mg/m2, and the initial dose of paclitaxel was set as 30 mg/m2, with a planned incremental increase of 10 mg/m2 up to 70 mg/m2. When 3 to 6 patients were registered at each dose level and dose-limiting toxicity (DLT) was noted in more than 3 patients, the dose level was assumed to be the maximum tolerated dose. Among the 20 patients, 1 patient experienced DLT during 2 courses because of dehydration and arrhythmia. In another patient, chemotherapy was discontinued after 4 courses because of a hypersensitivity reaction to paclitaxel at dose level 3. No patient experienced DLT resulting from hematologic toxicities. All patients underwent radiation therapy according to schedule without any discontinuations. A complete response was obtained in 16 patients. Based on the results obtained from this study, weekly administration of 30 mg/m2 cisplatin and 50 mg/m2 paclitaxel with concurrent chemoradiotherapy can be considered a tolerable and safe dose for the treatment of locally advanced cervical carcinoma in Japanese women.

Effect of High-Dose-Rate 192Ir Source Activity on Late Rectal Bleeding After Intracavitary Radiation Therapy for Uterine Cervix Cancer

This retrospective study analyzed the effect of the activity of high-dose-rate (HDR) (192)Ir source on late rectal bleeding after HDR intracavitary radiotherapy (ICRT) in patients with uterine cervix cancer. One hundred thirty-two patients who underwent HDR-ICRT and external beam radiotherapy (EBRT) were analyzed. The rectal point dose in ICRT was calculated by inserting a lead wire into the rectal lumen and summed with the whole-pelvic EBRT dose. The rectal biologic effective dose (BED) was calculated. The relationship between averaged source activity or the BED and late rectal bleeding were analyzed. Three-year actuarial rectal bleeding probabilities were 46% (> or =100 Gy(3)) and 18% (< or = 100 Gy(3)), respectively (p < 0.005). When patients were divided into four groups according to rectal BED (> or = or < or =100 Gy(3)) and source activity (> or = or < or =2.4 cGy.m(2).h(-1)), the group with both a high BED and high activity showed significantly greater probability (58% at 3 years; p < 0.005). It was noted that the probability of the group with BED of 100 Gy(3) or greater was high, but that was not the case with 2.4 cGy.m(2).h(-1) or less. This is the first clinical report concerning the source activity effect of HDR (192)Ir on late rectal bleeding in patients undergoing HDR-ICRT. This suggests that when source activity is higher than 2.4 cGy.m(2).h(-1), ICRT should be performed with more caution not to exceed 100 Gy(3) in total.

Phase II Study of Radiation Therapy Combined with Weekly Nedaplatin in Locally Advanced Uterine Cervical Carcinoma: Kitasato Gynecologic Radiation Oncology Group (KGROG 0501)

In order to evaluate the safety and efficacy of chemoradiotherapy using nedaplatin for locally advanced uterine cervical carcinoma in Japanese patients, we have started a single-institute phase II trial. Eligibility criteria include: (i) pathologically proven squamous cell carcinoma or adenocarcinoma, (ii) clinical FIGO stage Ib, IIa, or IIb with bulky tumor (> 40 mm) or pelvic lymph node swelling, or (iii) clinical FIGO stage IIIa, IIIb and IVa, (iv) no para-aortic lymph node swelling. A combination of external beam radiation and high dose rate intracavitary irradiation is given. Nedaplatin (30 mg/m2) is intravenously infused on a weekly basis for five times. The primary endpoint is 3-year overall survival, and the secondary endpoints are tumor response, 2-year overall survival, 3-year progression-free survival, acute adverse events, protocol treatment compliance, and late adverse events. We plan to recruit 45 patients within 3 years.

Incidence and temporal pattern of anorexia, diarrhea, weight loss, and leukopenia in patients with cervical cancer treated with concurrent radiation therapy and weekly cisplatin: Comparison with radiation therapy alone

Objective. To investigate the temporal patterns of anorexia, diarrhea, weight loss, and leukopenia in chemoradiation therapy (CRT) for cervical cancer compared with radiation therapy (RT) alone. Methods. Acute toxicities in 43 patients receiving RT alone and 40 patients receiving CRT were retrospectively analyzed. Patients were treated with a combination of external beam irradiation and high-dose rate intracavitary irradiation. Cisplatin was given once a week for 5 weeks concurrently with the external beam irradiation. CRT was divided into low-dose CRT group (cisplatin, 20–30 mg/m 2, n = 16) and high-dose CRT group (cisplatin, 35–40 mg/m 2, n = 24). Toxicities were evaluated before, every week up to 7 weeks during the cycle, and 12 weeks after initial irradiation, according to the National Cancer Institute Common Toxicity Criteria version 2. Results. In the high-dose CRT group, anorexia during the first 5 weeks, leukopenia after 5 weeks, and weight loss after 3 weeks were significantly higher than those in the RT alone group. In the low-dose CRT group, anorexia between 1 and 2 weeks, leukopenia after 5 weeks, and weight loss between 3 and 4 weeks were significantly higher than those in the RT alone group. Diarrhea between 1 and 2 weeks in the high-dose CRT group ( P = 0.037, P = 0.025) and between 2 and 3 weeks in the low-dose CRT group ( P = 0.015, P = 0.036) was significantly lower compared with RT alone. Conclusion. These data can help us understand when patients are likely to develop maximal toxicities and to manage them with optimal timing.

Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer

The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO2) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high–dose rate intracavitary irradiation. The pO2was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO2before radiation therapy was 17.3 ± 10.8 mm Hg. The 3-year local control rates of patients with pO2≤ 20 mm Hg and pO2&gt; 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO2was 23.6 ± 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO2≤ 20 mm Hg and pO2&gt; 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.

Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer

The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.

Dosimetric parameters that predict late rectal complications after curative radiotherapy in patients with uterine cervical carcinoma

Late rectal complication (LRC) was a major late complication in patients with uterine cervical carcinoma who were treated with a combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary irradiation (HDR-ICR). For the current study, the authors retrospectively evaluated dosimetric parameters that were correlated with LRC > or = Grade 2 in patients with uterine cervical carcinoma who were treated with curative radiotherapy, and they analyzed the appropriate dose estimates to the rectum that were predictive for LRC > or = Grade 2. Between July 1994 and September 2002, 157 patients who were diagnosed with Stage IB-IIIB cervical carcinoma and were treated with definitive radiotherapy were included. EBRT (41.4-66 grays [Gy] in 23-33 fractions) to the whole pelvis was delivered to all patients, with midline shielding performed after a 36-50.4 Gy external dose. HDR-ICR (21-39 Gy in 6-13 fractions to Point A) was administered at a rate of 2 fractions weekly after midline shielding of EBRT. LRC was scored using Radiation Therapy Oncology Group criteria. The total biologically effective dose (BED) at specific points, such as Point A (BED(Point A)), rectal point (BED(RP)), and maximal rectal point (BED(MP)), was determined by a summation of the EBRT and HDR-ICR components, in which the alpha/beta ratio was set to 3. Analyzed parameters included patient age, tumor size, stage, concurrent chemotherapy, ICR fraction size, RP ratio (dose at the rectal point according to the Point A dose), MP ratio (dose at the maximal rectal point according to the Point A dose), EBRT dose, BED(Point A), BED(RP), and BED(MP). The 5-year actuarial overall rate of LRC > or = Grade 2 in all patients was 18.4%. Univariate analysis showed that the RP ratio, MP ratio, EBRT dose, BED(Point A), BED(RP), and BED(MP) were correlated with LRC > or = Grade 2 (P < 0.05). Multivariate analysis showed that, of all clinical and dosimetric parameters evaluated, only BED(RP) was correlated with LRC > or = Grade 2 (P = 0.009). The 5-year actuarial rate of LRC > or = Grade 2 was 5.4% in patients with a BED(RP) < 125 Gy(3) and 36.1% in patients with a BED(RP) > or = 125 Gy(3) (P < 0.001). BED(RP) was a useful dosimetric parameter for predicting the risk of LRC > or = Grade 2 and should be limited to < 125 Gy(3) whenever possible to minimize the risk of LRC > or = Grade 2 in patients with uterine cervical carcinoma who are treated with a combination of EBRT and HDR-ICR. Cancer 2005.

Radiation therapy of cervical cancer: Current status in Korea and recent developments

Brachytherapy is an essential part of the radiotherapy for uterine cervical cancer. Since 1979, high dose rate (HDR) brachytherapy has been used for the treatment of uterine cervical cancer in Korea; the number of institutions employing HDR has been increasing. At 40 radiation oncology departments out of 53 in Korea, HDR brachytherapy was practiced in 2004. Approximately in 1,000 of patients, brachytherapy was done annually and among these, HDR proportions were 75-80%. In Korea, treatment results for HDR are comparable with the low dose rate (LDR) system series and appear to be a safe and effective alternative to LDR for the treatment of cervical carcinoma. The studies from the major centers report the five-year survival rate of cervical cancer as, 78-86% for Stage I, 68-85% for stage II, and 38-56% for Stage III. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiation dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. Recently a three-dimensional conformal radiotherapy (3DCRT) or an intensity-modulated radiotherapy (IMRT), which allow for a high degree of conformity to the target volume have been used for the uterine cervical cancer. Several studies have reported the superiority of IMRT, over the conventional technique, in reducing the small bowel dose. The author will introduce the small bowel displacement system (SBDS)-assisted IMRT for cervical cancer patients. Positional changes of the uterus during radiotherapy, which can degrade the accuracy of 3DCRT and IMRT, will be discussed.

Patterns of brachytherapy practice for patients with carcinoma of the cervix (1996–1999): A patterns of care study

To analyze the details of brachytherapy (BT) practice in patients treated for carcinoma of the cervix in the USA from 1996–1999 Radiation facilities were randomly selected from two strata: those that treated <500 or ≥500 cancer patients/yr. Patients were randomly selected from lists of eligible patients treated at each facility. A total of 442 patients records were reviewed in 59 facilities to obtain data about their characteristics, evaluation, tumor extent, and treatment. National estimates were made using weights that reflected the relative contribution of each institution and of each patient within the sampled institutions. From our survey we estimate that 16,375 patients were treated in the U.S. during this study period. Unless otherwise specified BT practice was based on the 408 patients who had their BT or all their treatment at the surveyed facility. 91.5% of patients underwent BT at the initial treating institution; 8.5% were referred to a second site for BT. 42% of U.S. facilities referred at least some patients to a second facility for BT. Of U.S. facilities that treated ≤2 eligible patients per year, 61% referred all of their patients to a second facility for BT or treated with external RT alone; none of the U.S facilities with larger experiences (>2 eligible pts/yr) referred all their patients to a second facility for BT treatment but 28% referred some patients to an outside facility for BT. Overall, 94% of patients who completed treatment with curative intent received BT. Of patients who had BT, 77.8%, 13.3%, and 0.9% respectively were treated with low dose-rate (LDR), high dose-rate (HDR), or a combination of HDR and LDR BT; 7.9% had interstitial BT (5.7% LDR and 1.9% HDR, 0.3% Mixed). In facilities that treated >2 pts per year, 15.5% and 9.4% of BT procedures included HDR or interstitial respectively; in facilities that treated fewer patients, 3.4% had HDR BT and only 1.2% had interstitial BT. Patients treated with LDR intracavitary radiotherapy (ICRT) had 1 (27.8%), 2 (70%) or 3 (2.2%) implants. For curative patients who completed RT with LDR ICRT without hysterectomy the median BT dose to Pt A was 4031 cGy and the median total dose to Pt A was 8288 cGy. Patients were treated with HDR ICRT using a variety of treatment schedules using 1–2 fractions (fxs) (8%), 3–4 fxs (17%), 5–6 fxs (39%), 7–9 fxs (34%), or had 12 fxs (3%); fractions sizes were <500 (29%), 500– <600 (25%), 600 (28%), >600 (8%), or unknown (9%). For patients treated with HDR, the median total dose to Pt A (corrected for fraction size using an α/β = 10) was 8580 cGy (5617–11606). At institutions treating <500 pts/yr, the % of patients receiving a BT dose <40 Gy was statistically higher than at institutions treating≥500 pts/yr (p < 0.0001). For LDR ICRT, 7.4% had no bladder and rectal doses recorded for all their implants, whereas in HDR ICRT, 75% had no bladder and rectal doses recorded for all their implants. The median total duration of RT was identical for patients who had HDR or LDR ICRT (57 days). For LDR at institutions treating <500 pts/yr, the % of patients with treatment duration >56 days was significantly greater than at institutions ≥500 pts/yr (p = 0.0002). Of the patients who had LDR ICRT implants, 65% were treated using tandem and shielded FSD colpostats; other patients had mini ovoids (11%), cylinders (4%), Henschke (4%), or mixed applicators (15%). In contrast, of patients treated with HDR ICRT, 69% had tandem and rings, 18% FSD ovoids, 8% mini ovoids, and 6% other or mixed applicators. The median duration of treatment and median Pt A dose were very similar for patients treated with HDR or LDR. Patients with HDR were treated using a variety of treatment schedules. Different applicator types were favored for LDR vs. HDR. 75% of patients treated with HDR had no BT bladder or rectal doses recorded, suggesting that full dosimetric calculations were only performed for the first fraction in many institutions. Facility size significantly impacted on referral to another institution for BT, BT dose, and treatment duration

High-dose rate versus low-dose rate intracavitary radiotherapy in the treatment of cervical carcinoma: a meta-analysis

Purpose/Objective: Controversy still persists regarding the clinical efficacy of high dose rate (HDR) intracavitary radiotherapy (ICR), which was introduced in early 1960s, compared with conventional low dose rate (LDR) ICR in the treatment of cervical carcinoma. We performed meta-analysis to determine the effectiveness of HDR ICR compared to LDR ICR for overall survival, disease free survival, local recurrence, and complication rate of rectum and bladder in the treatment of cervical carcinoma.

The trail of the development of high-dose-rate brachytherapy for cervical cancer in Japan.

The differences in radiotherapeutic treatment systems for cervical cancer between the United States and Japan can be attributed either to the tolerance of high-risk organs, or dosimetry itself. High-dose-rate (HDR) brachytherapy is the standard treatment for uterine cervix carcinoma in Japan. In addition, HDR Co-60 afterloading machines have been gradually replaced with Ir-192 micro-source afterloading machines during the past ten years. This implies that it has now become impossible to conduct a prospective comparative study of HDR versus low-dose-rate (LDR) brachytherapy for cervical cancer in Japan. An examination of the history of HDR intracavitary radiotherapy for uterine cervix carcinoma in Japan led us to the conclusion that HDR intracavitary brachytherapy for the treatment of cervical cancer is as effective as LDR intracavitary brachytherapy in terms of both survival and complications. In Japan, studies on the former can be drawn from a long experience of more than 35 years.

Measurement of serum squamous cell carcinoma antigen levels as a predictor of radiation response in patients with carcinoma of the uterine cervix.

Optimal timing of the measurement of serum squamous cell carcinoma (SCC) antigen during radiation therapy (RT) and its significance for predicting the response of cervical carcinoma patients as early as possible remain unknown. Sixty-three patients with SCC of the uterine cervix who received RT only were studied. Patients were treated with a combination of external beam irradiation and high-dose rate intracavitary irradiation. The serum SCC antigen level was measured before, every 2 or 3 weeks during, and 1 or 2 months after RT. Clinical outcome was divided into complete response and incomplete response. Forty-seven patients (74.6%) had serum SCC antigen levels 1.5 ng/mL (the reference value) before RT. Normalization of serum SCC antigen levels at the end of RT were found to be significantly correlated with complete response in the SCC-positive patients. It was especially noted that in patients with serum SCC levels between 5-30 ng/mL before RT, a > 70% decrease in the serum SCC antigen level at 4 weeks was correlated significantly with complete response. In this group, a significant correlation also was found between a > 70% decrease in serum SCC level at 4 weeks and the normalization of SCC at the end of RT. The current study data suggest that the serum SCC antigen level not only before, but also during and at the end of RT can predict the response of patients with cervical carcinoma and help in identifying those patients who are at high risk of local recurrence and/or distant metastasis.

In vivo dosimetric analysis between rectal dose and rectal complication in patients with cervix cancer treated with high dose rate intracavitary radiotherapy

In vivo dosimetric analysis between rectal dose and rectal complication in patients with cervix cancer treated with high dose rate intracavitary radiotherapy