Course Of Pelvic Radiotherapy Research Articles

A new technique for performing interstitial implants for gynecologic malignancies using transvaginal ultrasound guidance

ObjectivesThis study concerns a new technique that aims to achieve precise interstitial brachytherapy of pelvic recurrent tumors under transvaginal ultrasound (US) guidance, enhance the conformity index of the brachytherapy (BT), and improve the curative effect of radiotherapy for gynecological oncology patients with pelvic relapse.MethodsA real-time transvaginal US-guided interstitial implant device was developed to assist in implant BT. Prior to implant brachytherapy, the size and location of the tumor in the pelvis and the interrelationship with adjacent organs were first assessed with intracavitary ultrasound. The transvaginal US-guided interstitial implant device was then placed on the endoluminal ultrasound probe, the probe was oriented intravaginally to determine a safe needle path, the implant needle was placed into the needle passage of the device, and the implant needle was inserted into the tumor tissue in the direction guided by the ultrasound puncture guide line. After the implant needle was placed in place, the cover of the transvaginal US-guided interstitial implant device was opened perpendicular to the ultrasound probe, and the needle was separated from the ultrasound probe smoothly, and then the cover was re-covered for subsequent implantation.ResultsIn this study, 56 patients who underwent real-time transvaginal ultrasound-guided implantation for gynecologic oncology were enrolled, and insertion of 736 implant needles was completed. Among them, 13 patients had recurrent pelvic tumors after cervical cancer surgery and 6 patients had recurrent pelvic tumors after endometrial cancer surgery. Thirty-two patients who underwent radical radiation therapy for cervical cancer did not have adequate regression of parametrial invaded tissue after completion of standard EBRT treatment; and 5 patients had recurrent tumors in the radiation field after previous standard course of pelvic radiotherapy. The accuracy of the implant therapy was improved. The radiotherapy dose for recurrent pelvic masses was successfully increased, and the cumulative dose of external irradiation combined with BT was augmented to 80–100 Gy. The use of a new device for transvaginal implant for recurrent masses located in the lateral wall of the pelvic cavity was successful.ConclusionThis intravascular US-guided interstitial implant device can realize interstitial implant with the shortest path under transvaginal US guidance. With convenient operation, high precision, and good security, the device not only improves the accuracy of implant therapy, but it also reduces the risks of anesthesia and organ injury, so it is suitable for widespread promotion and use.

Using a Weekly Patient-Reported Outcome Questionnaire to Track Acute Toxicity in Patients Undergoing Pelvic Radiotherapy for Gynecologic Cancers.

There are limited patient-reported outcome (PRO) data tracking changes in toxicity in patients actively undergoing radiotherapy. Between 2015–2019, acute toxicity was prospectively measured in 698 patients undergoing a 5-week course of pelvic radiotherapy for gynecologic cancers using a weekly PRO questionnaire. Our questionnaire was able detect a pattern of onset and resolution of acute gastrointestinal (GI) and genitourinary (GU) toxicity in 27 out of 32 questions. Logistic regression analysis showed that increasing GI and GU toxicity at week 2 could predict for severe toxicity at week 5. However, due to a low number of severe events, univariate results could not be productively added to a multivariate model. We observed a >70% response rate for all sections of the questionnaire, except for questions on sexual and vaginal health, which had a 13% average response rate. By demonstrating that PRO data can be used to track acute toxicity during radiotherapy, there is a need to further examine how this tool may be implemented in the clinic to provide complex, adaptive care, such as early side effect management, and modifying radiation delivery in real-time.

Predicting the Optimal Bladder Volume to Minimize the Dose to the Organs at Risk in Carcinoma Cervix Treated With Modern Radiotherapy.

Whilst planning external beam radiotherapy (EBRT) for carcinoma cervix, bladder volume is an important consideration in deciding dose to other organs at risk (OARs). Though conformal techniques like volumetric-modulated radiotherapy (VMAT) have reduced the dose received by the OARs, there is still scope for improvement by utilizing other techniques. Planning with a full bladder is one such strategy that pushes a part of the bladder wall and the bowel away from the planning target volume (PTV). This is complicated by the fact that holding urine becomes increasingly more difficult along the course of pelvic radiotherapy. This makes the bladder volume threshold important to reduce the doses received by the OARs. We aim to assess the optimal bladder volume to spare OARs in patients with carcinoma cervix treated with VMAT.The data of 81 patients of carcinoma cervix stage IB2-IVB treated with EBRT using VMAT followed by brachytherapy was prospectively collected in this study. The patients were advised to void and drink 500 ml of water, 30 minutes following which, a simulation scan was acquired. The target was contoured according to the Japanese Clinical Oncology Group guidelines and OARs in line with Radiation Therapy Oncology Group guidelines. Constraints to the bowel, bladder, rectum, and sigmoid were V45 < 195cc, V45 < 35%, V45 < 45% and V45 < 45% respectively. A dose of 50.4 Gy in 28 fractions was prescribed to the PTV using VMAT. The generated plans were analyzed and acceptable plans were finalized for treatment with higher priority to PTV coverage while minimizing the OAR doses. The bladder volumes at simulation and the doses received by the OARS were correlated using Pearson's correlation. A receiver operating characteristic (ROC) curve was constructed to find the cut-off value of the bladder volume which facilitated achieving the dose constraints to the significantly correlated OARs with acceptable specificity and sensitivity.A correlational analysis of the bladder volume with the OAR dose constraints revealed that there was a significant negative weak correlation with the V45 Gy of the bladder and the bowel. A ROC curve was constructed assessing bladder volume against the achievability of the bladder dose constraint. The area under the curve was 0.78 showing a fairly accurate relationship between the variables. A bladder volume of 270cc is noted to be the best cut-off to achieve the bladder dose constraint with a sensitivity and specificity of approximately 75% and 80% respectively. The curve for bladder volume and achievability of bowel constraints yielded a curve with poor accuracy and an area under the curve of 0.64 and so further analysis for the same was abandoned given the low sensitivity and specificity of the attained cut-off (approximately 65%).Increasing bladder volume has reduced the doses received by bowel and bladder. A volume of 270cc is to be aimed at to achieve the V45 Gy of the bladder in patients of carcinoma cervix being treated with VMAT.S. Kombathula: None. J. Pandjatcharam: None. D. Kannikanti: None. A. Menon: None. J.M. Mathew: None. T. Elumalai: None. M. Sinnatamby: None.

Impact of Pelvic Radiotherapy on Gut Microbiota of Gynecological Cancer Patients Revealed by Massive Pyrosequencing

Although pelvic irradiation is effective for the treatment of various cancer types, many patients who receive radiotherapy experience serious complications. Gut microbial dysbiosis was hypothesized to be related to the occurrence of radiation-induced complications in cancer patients. Given the lack of clinical or experimental data on the impact of radiation on gut microbiota, a prospective observational study of gut microbiota was performed in gynecological cancer patients receiving pelvic radiotherapy. In the current study, the overall composition and alteration of gut microbiota in cancer patients receiving radiation were investigated by 454 pyrosequencing. Gut microbial composition showed significant differences (P < 0.001) between cancer patients and healthy individuals. The numbers of species-level taxa were severely reduced after radiotherapy (P < 0.045), and the abundance of each community largely changed. In particular, the phyla Firmicutes and Fusobacterium were significantly decreased by 10% and increased by 3% after radiation therapy, respectively. In addition, overall gut microbial composition was gradually remolded after the full treatment course of pelvic radiotherapy. In this set of cancer patients, dysbiosis of the gut microbiota was linked to health status, and the gut microbiota was influenced by pelvic radiotherapy. Although further studies are needed to elucidate the relationship between dysbiosis and complications induced by pelvic radiotherapy, the current study may offer insights into the treatment of cancer patients suffering from complications after radiation therapy.

Split-Course, High-Dose Palliative Pelvic Radiotherapy for Locally Progressive Hormone-Refractory Prostate Cancer

Local progression, in patients with hormone-refractory prostate cancer, often causes significant morbidity. Pelvic radiotherapy (RT) provides effective palliation in this setting, with most published studies supporting the use of high-dose regimens. The aim of the present study was to examine the role of split-course hypofractionated RT used at our institution in treating this group of patients. A total of 34 men with locoregionally progressive hormone-refractory prostate cancer, treated with a split course of pelvic RT (45-60 Gy in 18-24 fractions) between 2000 and 2008 were analyzed. The primary endpoints were the response rate and actuarial locoregional progression-free survival. Secondary endpoints included overall survival, compliance, and acute and late toxicity. The median age was 71 years (range, 53-88). Treatment resulted in an overall initial response rate of 91%, a median locoregional progression-free survival of 43 months, and median overall survival of 28 months. Compliance was excellent and no significant late toxicity was reported. The split course pelvic RT described has an acceptable toxicity profile, is effective, and compares well with other high-dose palliative regimens that have been previously reported.

Radiation induced-late bowel toxicity: role of argon plasma coagulation

AbstractPurpose: The purpose of this study was to identify predictors and treatment outcome of late bowel toxicity after three dimensional pelvic radiotherapy for genitourinary malignancies and also to describe our experience with Argon Plasma Coagulation (APC) in this toxicity.Patients and methods: Between March 2004 and March 2010, all patients who had completed a course of pelvic radiotherapy for genitourinary malignancies at our Institute were enrolled in this study. Every patient with lower GI symptoms underwent sigmoidoscopy and accordingly, some patients were subjected to intervention by APC.Results: One hundred and thirty-six patients met all inclusion criteria. Median FU period was 37 months. Chronic diarrhoea was scored as Grade 1 or 2 in 35 patients (25.7%). Chronic proctitis was scored as Grade 1 or 2 in 17 patients (12.5%) and Grade 3 in 6 patients (4.4%), 25 patients developed chronic bleeding per rectum, 16 (11.8%) were Grade 1 or 2, while 9 patients (6.6%) were Grade 3. Both maximum rectal dose and comorbidity ≥1 significantly correlated with the development of chronic proctitis (p = 0.040 for both).Endoscopic findings showed mucosal injury in 59 cases (84.29%) and vascular injury in 42 patients (60%). APC was successful in controlling bleeding and other symptoms in 14 cases (82.4%) and 16 cases (70%) respectively.Conclusion: Three dimensional pelvic radiotherapy using two-phase technique is associated with a low level of Grade 3 late lower gastrointestinal toxicities. The most common presenting symptom is chronic diarrhoea. Both maximum rectal dose and comorbidity ≥1 significantly predict the development of chronic proctitis. APC is an effective, safe and well-tolerated treatment for chronic radiation proctitis.

The Reliability of Lymph-node Staging in Rectal Cancer After Preoperative Chemoradiotherapy

To determine the prognostic significance of the nodal stage and number of nodes recovered in the surgical specimen after preoperative synchronous chemoradiation (SCRT) and surgery for locally advanced or unresectable rectal cancer. One hundred and eighty-two consecutive patients with locally advanced or unresectable (T3/T4) rectal carcinomas were entered on a prospective database and treated in this department with preoperative chemoradiation, followed 6-12 weeks later by surgical resection. Most patients received chemotherapy in the form of low-dose folinic acid and 5-fluorouracil (5-FU) 350 mg/m2 via a 60-min infusion on days 1-5 and 29-33 of a course of pelvic radiotherapy delivered at a dose of 45 Gy in 25 fractions over 33 days to a planned volume. After resection, patients with a positive circumferential margin (< or = 1 mm), extranodal deposits or Dukes' C histology received adjuvant 5-FU-based-chemotherapy (n = 40). After SCRT, 161 patients underwent resection. Twenty-one patients remained unresectable or refused an exenterative operation. Median follow-up is 36 months. Down-staging was achieved in most patients, with 19 having a complete pathological response (pT0). The median number of lymph nodes recovered for all patients was five (range 0-21). The 3-year survival rate for node-positive patients is 47%, for node-negative patients with less than three lymph nodes recovered is 62% and for node-negative patients with three or more lymph nodes recovered is 70%. Compared with node-positive patients, simple regression models revealed a reduced hazard ratio (HR) of 0.72 (0.36-1.43) for node-negative patients with less than three nodes recovered and 0.48 (0.26-0.89) for node-negative patients with three or more lymph nodes recovered. In a multivariate model, including nodal status, excision status, age and sex only positive excision margins significantly predicted a poor outcome: HR = 3.05 (1.55-5.97). The number of nodes found after preoperative chemoradiation is a significant prognostic factor by univariate analysis. In this study, patients with node-negative histology, and at least three nodes recovered, had better long-term survival than patients in whom two or less nodes were recovered or with positive nodes. This effect was attenuated by the inclusion of excision status in multivariate models.

Do Serum Levels of Eosinophil Granule-derived Protein Change in Patients Undergoing Pelvic Radiotherapy?

Eosinophils have an important role in the pathogenesis of inflammatory bowel disease, with faecal levels of the eosinophil granule proteins, eosinophil cationic protein (ECP) and eosinophil protein X (EPX) reflecting disease activity. Eosinophil crypt abscesses are a characteristic histological finding in acute gastrointestinal radiation-induced mucosal damage. This pilot study aimed to investigate changes in serum levels of ECP/EPX during pelvic radiotherapy. Patients with no history of inflammatory bowel disease, starting a 5-week course of pelvic radiotherapy, had serum ECP/EPX levels measured before radiotherapy and during the fourth week of treatment. Bowel toxicity was graded at week 4 using the Common Toxicity Criteria Scale. Fifteen patients who were to undergo adjuvant radiotherapy for gynaecological cancer were recruited. The mean serum levels of ECP and EPX before treatment were 17.3 microg/l (range 2.0-49.3 microg/l) and 37.3 microg/l (range 12.0-94.0 microg/l), respectively. The mean serum levels during week 4 of radiotherapy for ECP and EPX were 43.0 microg/l (range 2.4-164.0 microg/l) and 38.7 microg/l (range 9.0-79.0 microg/l), respectively. Serum ECP levels increased at week 4 compared with levels before radiotherapy (P = 0.02). Acute bowel toxicity was seen in 12 patients (80%) at week 4: Grade 1 in 25% patients and Grade 2 in 75%. In this small study, no correlation was seen between acute bowel toxicity at week 4 and serum ECP or EPX levels. Serum ECP levels increase in response to pelvic irradiation. This may reflect the known involvement of eosinophils in the acute response to radiotherapy. Further study is required to determine when levels start to rise and their relationship to the degree of acute bowel toxicity.

Testicular dose and hormonal changes after radiotherapy of rectal cancer

Background and purpose To measure the dose received by the testicles during radiotherapy for rectal cancer and to determine the contribution of each field of the pelvic box and the relevance for hormonal status. Materials and methods In 11 patients (mean age 55.2 years) testicular doses were measured with an ionisation chamber between 7 and 10 times during the course of pelvic radiotherapy (50 Gy) for rectal carcinoma. Before and several months after radiotherapy luteinizing hormone, follicle stimulating hormone and total testosterone serum levels were determined. Results The mean cumulative radiation exposure to the testicles was 3.56 Gy (0.7–8.4 Gy; 7.1% of the prescribed dose). Seventy-three percent received more than 2 Gy to the testicles. Fifty-eight percent of the measured dose was contributed by the p.a. field, 30% by the a.p. field and 12% by the lateral fields. Mean LH and FSH levels were significantly increased after therapy (350%/185% of the pre-treatment values), testosterone levels decreased to 78%. No correlation could be found between changes of hormones and doses to the testis, probably due to the low number of evaluated patients. Conclusions Radiotherapy of rectal carcinoma causes significant damage to the testis, as shown by increased levels of gonadotropins after radiotherapy. Most of the gonadal dose is delivered by the p.a. field, due to the divergence of the p.a. beam towards the testicles. The reduction in testosterone level may be of clinical concern. Patients who will receive radiotherapy for rectal carcinoma must be instructed about a high risk of permanent infertility, and the risk of endocrine failure (hypogonadism). Larger studies are needed to establish the correlation between testicular radiation dose and hormonal changes in this group of patients.

An analysis of intratreatment and intertreatment displacements in pelvic radiotherapy using electronic portal imaging

Purpose : To evaluate the relative frequency and magnitude of intratreatment and intertreatment displacements in the patient positioning for pelvic radiotherapy using electronic portal imaging. Methods and Materials : Five hundred ninety-four electronic portal images of seven patients treated with a four-field pelvic technique were evaluated. All patients were treated prone without an immobilization device. Two fields were treated per day, from which an average of two electronic portal images were obtained for each field. No treatment was interrupted or adjusted on the basis of these images. Each image was aligned to the corresponding simulation film to measure the displacements in the mediolateral, craniocaudal, and anteroposterior directions relative to the simulated center. The intertreatment displacement was the displacement measured from the initial image for each daily treated field. For each daily treated field the intratreatment displacement was calculated by subtracting the displacement measured on the initial image from the displacement measured on the final image. Results : The frequency of intertreatment displacements exceeding 10 mm was 3%, 16%, and 23% for the mediolateral, craniocaudal, and anteroposterior translations, respectively. There were no intratreatment displacements exceeding 10 mm ( p < 0.001). The frequency of intertreatment displacements exceeding 5 mm was 40, 52, and 51% for the mediolateral, craniocaudal, and anteroposterior translations, respectively; whereas, the frequency of intratreatment displacements exceeding 5 mm was 1, 5, and 7% for the same translations, respectively ( p < 0.001). The standard deviation of the intertreatment displacements was at least three times as great as the standard deviation of the intratreatment displacements for all translations. These deviations were greater than the precision limit of the measurement technique, which is approximately 1 mm. Each patient had one direction where systematic error predominated in intertreatment positioning. Random error predominated for intratreatment positioning and for the other two directions in intertreatment positioning. Conclusions : During a course of pelvic radiotherapy, the frequency of intertreatment displacements exceeding 5 and 10 mm is significantly greater than the frequency of intratreatment displacements of these magnitudes. Errors in intertreatment positioning are predominantly systematic in one direction for each patient, whereas intratreatment error is predominantly random. Because patients do not move considerably during the daily treatment of a pelvic field, a single electronic portal image per daily field may be considered representative of the treated position.

Coexistent immature teratoma of the uterus and endometrial adenocarcinoma complicated by gliomatosis peritonei

A 37-year-old nulliparous woman presented with severe vaginal bleeding due to a primary immature teratoma of the uterus (Grade II on the Norris scale). The subsequent hysterectomy specimen showed well-differentiated endometrial adenocarcinoma. Mature glial implants were present on both ovaries and throughout the omentum. Postoperative recovery was uneventful and the patient received a course of pelvic radiotherapy. She has remained well with no evidence of recurrence. Primary benign solid teratoma of the uterus is rare. This appears to be the first reported case of primary immature uterine teratoma.