Biomedical subjects

Perry W Grigsby

Publications and source records attributed to Perry W Grigsby.

53 records · Page 3Linked to original sources

PubMed2003

Posttherapy surveillance monitoring of cervical cancer by FDG-PET.

PURPOSE: To evaluate the effect of irradiation and chemotherapy for carcinoma of the uterine cervix on posttreatment tumor uptake of the glucose analog (18)F-fluorodeoxyglucose (FDG) imaged by positron emission tomography (PET) and to assess the utility of FDG-PET for surveillance monitoring. MATERIALS AND METHODS: This was a retrospective review of 76 patients with a new diagnosis of carcinoma of the uterine cervix who underwent pre- and posttreatment whole-body FDG-PET. Posttreatment FDG-PET was performed 2.4-10.4 months (median 4.2) after irradiation completion. RESULTS: After treatment, persistent abnormal FDG uptake in the cervix was found in 18% (14 of 76), in the pelvic lymph nodes in 16% (9 of 55), in the paraaortic lymph nodes in 45% (5 of 11), and in the supraclavicular lymph nodes in 75% (3 of 4). Eleven patients developed new sites of increased FDG uptake. In relation to the findings on posttreatment PET, the 2-year progression-free survival rate was 86% for patients with no abnormal FDG uptake at any site and 40% for those with persistent abnormal uptake; there were no survivors at 2 years among patients who developed new sites of abnormal FDG uptake (p <0.0001). A multivariate analysis of prognostic factors demonstrated that any posttreatment abnormal FDG uptake (persistent or new) was the most significant prognostic factor (p <0.0001) for death from cervical carcinoma. CONCLUSIONS: FDG-PET is a valuable tool to evaluate the response of primary cervical carcinoma and lymph node metastasis to treatment and for the surveillance of patients after initial therapy.

Adenocarcinoma↗

PubMed2003

PET-guided IMRT for cervical carcinoma with positive para-aortic lymph nodes-a dose-escalation treatment planning study.

PURPOSE: To evaluate a treatment planning method for dose escalation to the para-aortic lymph nodes (PALNs) based on positron emission tomography (PET) with intensity-modulated radiotherapy (IMRT) for cervical cancer patients with PALN involvement. One goal of this process was not to modify the traditional treatment of the pelvic region. METHODS AND MATERIALS: PET images for 4 cervical cancer patents with PALN involvement were registered with their corresponding CT scans. Positive PALNs were identified on PET images, and the surrounding critical structures were delineated on CT images. The treatment machine central axis (CAX) was placed at the level of the L4-L5 vertebral body interspace. There were two distinct treatment regions: the para-aortic bed superior to the CAX and the whole pelvis region inferior to the CAX. IMRT was used for treatment planning of PALN bed irradiation. The positive PALNs identified on PET images were defined as the gross target volume, and the para-aortic bed was defined as the clinical target volume. The radiation doses were escalated from the conventional 45 Gy to 59.4 Gy for the gross target volume and 50.4 Gy for the clinical target volume in 33 fractions. The pelvis area was treated with conventional treatment methods, AP-PA beams to 50.4 Gy in 28 fractions with a brachytherapy implant boost. The placement of the CAX allowed the two treatment regions to be abutted using the treatment machine's independent jaws. RESULTS: Dose escalation to positive PALNs, as identified on PET images, and the PALN bed is feasible with IMRT. Treatment plans for 4 patients revealed that escalated prescription doses could be delivered to target volumes while maintaining acceptable doses to the surrounding critical structures. Strategic placement of the treatment isocenter allows the IMRT region (PALN bed) and whole pelvis fields to be treated with a relatively uniform dose distribution in the abutment region. CONCLUSION: This study indicates that PET-guided IMRT could be used in a clinical trial in an attempt to escalate doses delivered to patients with cervical cancer who have positive PALNs.

Female↗

PubMed2003

Occult supraclavicular lymph node metastasis identified by FDG-PET in patients with carcinoma of the uterine cervix.

PURPOSE: The objective was to evaluate the frequency and prognostic significance of occult supraclavicular lymph node metastases identified by 2-[(18)F]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) in patients with cervical carcinoma. PATIENTS AND METHODS: Between March 1998 and January 2002, 186 patients with a new diagnosis of cervical cancer underwent whole-body FDG-PET before therapy. Fourteen patients had abnormal FDG uptake in left supraclavicular lymph nodes without palpable disease. All 14 patients underwent sonographically guided fine-needle aspiration of the left supraclavicular lymph nodes. One patient refused therapy, 6 were treated with palliative intent, and 7 received definitive irradiation and concurrent chemotherapy. Survival was calculated by the Kaplan-Meier method. RESULTS: The overall frequency of FDG-positive left supraclavicular lymph nodes was 8% (14/186). Metastasis was pathologically confirmed in all 14 patients. Therefore, the positive predictive value of abnormal FDG uptake in left supraclavicular lymph nodes was 100%. Nineteen percent of all patients (35/186) had abnormal FDG uptake in para-aortic lymph nodes. The frequency of positive FDG uptake in the left supraclavicular lymph nodes was 40% (14/35) in those with para-aortic lymph node uptake and 15% in those with stage IIIb disease. The median overall survival was 7.5 months. At last follow-up, 11 patients were dead and 3 were alive with disease. All patients developed metastatic disease, most commonly to bone and lung. CONCLUSION: The positive predictive value of abnormal FDG uptake in left supraclavicular lymph nodes was 100%. Prognosis for these patients was dismal despite aggressive therapy.

Female↗

PubMed2003

The irradiation tolerance dose of the proximal vagina.

PURPOSE: The purpose of this investigation was to determine the irradiation tolerance level and complication rates of the proximal vagina to combined external irradiation and low dose rate (LDR) brachytherapy. Also, the mucosal tolerance for fractionated high dose rate (HDR) brachytherapy is further projected based on the biological equivalent dose (BED) of LDR for an acceptable complication rate. MATERIALS AND METHODS: Two hundred seventy-four patients with stages I-IV cervical carcinoma treated with irradiation therapy alone from 1987 to 1997 were retrospectively reviewed for radiation-associated late sequelae of the proximal vagina. All patients received LDR brachytherapy and 95% also received external pelvic irradiation. Follow-up ranged from 15 to 126 months (median, 43 months). The proximal vagina mucosa dose from a single ovoid (single source) or from both ovoids plus the tandem (all sources), together with the external irradiation dose, were used to derive the probability of a complication using the maximum likelihood logistic regression technique. The BED based on the linear-quadratic model was used to compute the corresponding tolerance levels for LDR or HDR brachytherapy. RESULTS: Grades 1 and 2 complications occurred in 10.6% of patients and Grade 3 complications occurred in 3.6%. There were no Grade 4 complications. Complications occurred from 3 to 71 months (median, 7 months) after completion of irradiation, with over 60% occurring in the first year. By logistic regression analysis, both the mucosal dose from a single ovoid or that from all sources, combined with the external irradiation dose, demonstrate a statistically significant fit to the dose response complication curves (both with P=0.016). The single source dose was highly correlated with the all source dose with a cross-correlation coefficient 0.93. The all source dose was approximately 1.4 times the single source dose. Over the LDR brachytherapy dose rate range, the complication rate was relatively stable to small variations of the underlying tumor biological characteristics and the dose rate. The complication rates change approximately an absolute 1% over the range of the alpha-beta ratio (alpha/beta) from 2 to 4 Gy and repair constant (mu) of 0.46/h to 0.60/h. The complication rates increased an absolute 2% over the mucosa dose rate from 1.75 to 3.50 Gy/h. They markedly increased as the dose rate increased above 3.00 Gy/h as in HDR brachytherapy. The projected HDR Grade 3 tolerance varied from 25 Gy for one fraction to 57 Gy for six fractions in addition to 20 Gy external irradiation for nominal 3-5% complication rates. The traditional LDR tolerance dose of 150 Gy was shown to yield nominal 11% and 4% Grades 1 and 2 and Grade 3 sequelae, respectively. CONCLUSIONS: The traditional 150 Gy LDR tolerance dose (single source plus external irradiation) can be relaxed to 175 Gy or equivalently a full mucosal dose of 238 Gy (all sources plus external irradiation) for a nominal 5% Grade 3 complication rate. Higher fractionation is necessary with four to six fractions in HDR therapy for similar rates of sequelae. The mucosal surface dose from a single ovoid, which can be readily computed, remains a convenient tolerance check for treatment planning purposes.

Adult↗

PubMed2003

Improved prognostic value of 18F-FDG PET using a simple visual analysis of tumor characteristics in patients with cervical cancer.

UNLABELLED: In patients with cervical cancer, it is important to estimate prognosis at the time of diagnosis. This study using PET with (18)F-FDG was undertaken to determine whether a simple and fast visual analysis of characteristics of the primary tumor before initiation of treatment could achieve this goal. METHODS: Forty-seven patients with cervical cancer who were to be treated by combined radiation therapy and chemotherapy were imaged before beginning treatment. They were then followed for up to 3 y for evidence of recurrence or death. Images of the chest, abdomen, and pelvis were obtained 40-90 min after administration of 370-555 MBq (10-15 mCi) (18)F-FDG. Three observers then independently graded the primary tumor for size (0 = small, 1 = moderate, 2 = large), shape (0 = spherical, 1 = nonspherical), heterogeneity of uptake (0 = none, 1 = moderate, 2 = marked), and presence of lymph nodes (0 = none, 1 = pelvic, 2 = paraaortic, 3 = distant). The scores were summed to achieve a total score. A statistical calculation demonstrated that a score cutoff of 4 best separated patients with a good prognosis from patients with a bad prognosis. Kaplan-Meier analysis was used to compute progression-free survival and overall survival. Evaluation of lymph nodes alone was compared with the grading of tumor characteristics. RESULTS: Observers 1 and 2 scored 26 patients as having a good prognosis and 21 as having a bad prognosis. Observer 3 scored 30 and 17, respectively, a statistically insignificant difference. Survival curves were almost identical for the 3 observers. For progression-free survival, approximately 12% of patients with a good score had disease recurrence whereas approximately 75% with a bad score had disease recurrence. For overall survival, approximately 10% (good) and 80% (bad) died. Evaluation of lymph nodes also separated the groups, but not as well as did visual analysis alone. The combination of the 2 was only slightly superior to visual assessment alone. CONCLUSION: A simple, rapid, and highly reproducible system is described for visual grading of characteristics of the primary tumor in patients with cervical cancer at the time of diagnosis. This approach separates patients with a poor prognosis from those who will do well, thus providing a new tool for accurate estimation of prognosis.

Adult↗

PubMed2002

Physiologic FDG-PET three-dimensional brachytherapy treatment planning for cervical cancer.

PURPOSE: To compare conventional two-dimensional (2D) orthogonal radiography-based brachytherapy treatment planning for cervical cancer with a three-dimensional (3D) treatment planning technique based on 18F-fluoro-deoxyglucose-positron emission tomography (FDG-PET). METHODS AND MATERIALS: Eleven cervical cancer patients were included in this prospective study that evaluated one tandem and ovoid brachytherapy procedure for each patient. The patient underwent FDG-PET of the pelvis to visualize the tumor followed by a second FDG-PET scan with the FDG isotope placed inside the tandem and ovoid applicators to visualize the treatment source positions for 3D treatment planning. The tumor volumes were delineated using a binary threshold technique in which the threshold FDG-PET image intensity was 40% of the peak tumor intensity. RESULTS: FDG-PET provides a reliable estimate of the cervical cancer volume and 3D spatial relationship of the tumor to the tandem and ovoid applicators. The maximal bladder and rectal doses determined from the 3D FDG-PET dose-volume histograms were found to be higher than those obtained using 2D treatment planning. The minimal dose to the tumor volume defined by FDG-PET ranged from 50 to 475 cGy for treatment plans designed to deliver 650 cGy to Point A and exhibited an inverse correlation with tumor volume. CONCLUSION: Physiologic FDG-PET brachytherapy treatment planning is feasible and accurate relative to conventional 2D treatment planning. The use of FDG-PET offers a unique method for tumor visualization and identifies the limitations of conventional brachytherapy treatment planning for coverage of large tumors and estimation of the dose to normal structures. This technique has the potential for improving isodose tumor coverage for patients with cervical cancer while sparing critical structures.

Brachytherapy↗

PubMed2002

Childhood and adolescent thyroid carcinoma.

OBJECTIVES: This analysis was performed to evaluate the influence of clinical and treatment factors on local tumor control, control of distant metastasis, survival, and complications in children and adolescents with thyroid carcinoma. METHODS: The records of 56 children and adolescents with papillary and follicular carcinoma of the thyroid were reviewed. They ranged in age from 4 to 20 years. There were 43 females and 13 males. At diagnosis, 15 (27%) patients had disease confined to the thyroid, 34 (60%) had additional lymph node metastasis to the neck or upper mediastinum, and 7 (13%) also had lung metastasis. Treatment consisted of a total thyroidectomy in 48 patients, a subtotal thyroidectomy in 4 patients, and a lobectomy in 4 patients. All 56 patients received postoperative thyroid hormone suppressive therapy. (131)I was administered to 82% (46 of 56) of patients after their initial surgery. RESULTS: The overall survival rate was 98% with a follow-up of 0.6-30.7 years (with a median follow-up of 11.0 years). The one death that occurred in this patient population was the result of a congenital heart defect and was unrelated to thyroid carcinoma. The 10-year progression-free survival rate was 61%. Nineteen patients (34%) experienced a recurrence of their thyroid carcinoma. The time to first recurrence of disease ranged from 8 months to 14.8 years (mean, 5.3 years). None of those with disease confined to the thyroid developed recurrent disease. The recurrence rate was 50% (17 of 34) in patients with lymph node metastasis and 29% (2 of 7) in patients with lung metastasis (P = 0.02). Tumor characteristics were evaluated for time to first recurrence utilizing the logistic likelihood ratio test to predict disease recurrence. Thyroid capsule invasion (P = 0.02), soft tissue invasion (P = 0.03), positive margins (P = 0.006), and tumor location at diagnosis (thyroid only vs. thyroid and lymph nodes vs. thyroid, lymph nodes, and lung metastasis, P = 0.02) were significant for developing recurrent disease. Patients younger than 15 years old at diagnosis were more likely to have more extensive tumor at diagnosis than patients who were 15 years and older (thyroid only vs. thyroid and lymph nodes vs. thyroid, lymph nodes, and lung metastasis, P = 0.02). CONCLUSION: Carcinoma of the thyroid in children and adolescents has little risk of mortality but a high risk of recurrence. Younger patients present with a more advanced stage of disease and are more likely to have disease recurrence. Total thyroidectomy and lymph node dissection, followed by postoperative (131)I therapy, thyroid hormone replacement (suppressive) administration, and diligent surveillance are warranted.

Adolescent↗

PubMed2002

Measurement of tumor volume by PET to evaluate prognosis in patients with advanced cervical cancer treated by radiation therapy.

PURPOSE: This study evaluated the usefulness of tumor volume measurement with positron emission tomography (PET) in patients with advanced cervical cancer treated by radiation therapy. METHODS AND MATERIALS: Fifty-one patients underwent PET before treatment. Primary tumor volume was determined, and volume, FIGO stage, and presence of lymph nodes on the PET study were compared to progression-free survival (PFS) and overall survival (OS). RESULTS: Tumor volume, lymph node disease, and stage were predictive of PFS, whereas volume and lymph node involvement predicted OS. Lymph node status did not correlate with volume. Dividing patients according to whether the tumor volume was more or less than 60 cm(3) predicted PFS and OS. Separation of patients with tumor volumes <or=60 cm(3) and no lymph node disease vs. any other combination was strongly predictive of PFS and OS. CONCLUSIONS: The following conclusions were drawn regarding patients with advanced cervical cancer treated with radiation therapy: (1) Tumor volume can be accurately measured by PET; (2) Tumor volume separates patients with a good prognosis from those with a poorer prognosis; (3) A subset of patients with relatively small tumors and no lymph node involvement does remarkably well; (4) Tumor volume does not correlate with the presence of lymph node disease.

Adenocarcinoma↗

PubMed2002

Applicator-guided intensity-modulated radiation therapy.

PURPOSE: We are introducing a novel method for delivering highly conformal dose distributions to cervical cancer tumors using external beam intensity-modulated radiation therapy. The method, termed applicator-guided intensity-modulated radiation therapy (AGIMRT), will use an applicator substitute placed in the vagina and uterus to provide spatial registration and immobilization of the gynecologic organs. The main reason for the applicator substitute will be to localize the fornices, cervix, and uterus with the expectation that the other nearby organs will also be reproducibly positioned with respect to the applicator substitute. Intensity-modulated radiation therapy (IMRT) dose distributions will be used as a substitute for high-dose-rate intracavitary brachytherapy procedures. The flexibility of IMRT will enable customized dose distributions that have the potential to reduce complications and improve local control, especially for locally advanced disease. METHODS AND MATERIALS: To test the advantages of IMRT over intracavitary brachytherapy, volumetric scans of three cervical cancer patients were obtained with implanted CT-compatible applicators. IMRT dose distribution simulations using tomotherapy, were compared against intracavitary brachytherapy using cesium tubes to investigate the dosimetric differences of the two modalities. Because these tumor volumes do not image well on CT, the target volumes were defined as the isodose surface containing the traditional point A, defined as 2 cm superior to the vaginal fornices and 2 cm lateral to the intrauterine canal. One patient had a uterus that wrapped superior and anterior to the bladder. For this case, the cervix and uterus were selected as the target volume. To determine the potential for using an applicator substitute to localize internal organs, the posterior bladder and anterior rectal surfaces were localized relative to the colpostats. Comparisons of the colpostat-localized surfaces were conducted for two scan studies for 3 patients. RESULTS: The IMRT distributions covered the point-A isodose surfaces while reducing doses to the bladder and rectum. Brachytherapy showed extensive underdose regions in the target volume for the wrapped-around target. Spatial positioning was better than 0.7 and 1.3 cm in the rectum and bladder, respectively, indicating the potential that an applicator substitute may be able to localize these structures. CONCLUSIONS: AGIMRT has the potential for improving critical structure avoidance while maintaining highly reproducible and accurate internal organ registration found with brachytherapy.

Female↗

PubMed2002

PET-guided three-dimensional treatment planning of intracavitary gynecologic implants.

PURPOSE: Positron emission tomography (PET) provides physiologic information that is not available from computed tomography (CT) or magnetic resonance studies. PET images may allow more accurate delineation of three-dimensional treatment planning target volumes of brachytherapy gynecologic (GYN) implants. This study evaluates the feasibility of using PET as the sole source of target, normal structure, and applicator delineation for intracavitary GYN implant treatment planning. MATERIALS AND METHODS: Standard Fletcher-Suit brachytherapy tandem and colpostat applicators were used for radiation delivery. After insertion of the applicator in the operating room, the patient was taken to a PET scanner, where 555 MBq (15 mCi) 18F-fluorodeoxyglucose (18F-FDG) was administered intravenously. Forty-five minutes later, three localization tubes containing 18F-FDG were inserted into the source afterloading compartments of the tandem and colpostat. A whole-pelvis scan was performed, and the images were transferred to a commercial brachytherapy three-dimensional treatment planning system. A Foley catheter was inserted into the urinary bladder while the patient was in the operating room. The regions of radioactivity in the three applicator tube image were contoured for reconstruction of the applicator, along with the bladder, rectum, and 18F-FDG-defined target volumes. A treatment plan was generated that included dose-volume histograms and three-dimensional dose distribution displays, allowing the physician an opportunity to determine if adequate target coverage and normal-tissue sparing had been obtained. For a more conservative approach, three-dimensional dose distributions and dose-volume histograms delivered with conventional source arrangements and loading could be observed. The accuracy of applicator localization from the PET images was verified using a water phantom containing two aluminum CT-compatible tandems. The PET-defined and CT scan applicator reconstructions were compared. RESULTS: Feasibility of using PET images for treatment planning of brachytherapy intracavitary GYN implants has been demonstrated. A phantom study demonstrated applicator reconstruction accuracy in the axial direction to be better than 2 mm. Reconstruction accuracy in the longitudinal direction (principally craniocaudal) was similar to the PET scanner's voxel size of 4.3 mm. CONCLUSIONS: Brachytherapy intracavitary GYN implant design has traditionally been based on patient tumor staging, palpation, and clinical experience. PET images have the potential to provide better spatial information about the relationship of tumor and normal structures to the applicator. This information can be used to optimize the delivery of radiation therapy treatments. Thus far, six patients have been scanned using this process.

Brachytherapy↗

PubMed2002

Vaginal cancer.

Carcinoma of the vagina is an uncommon gynecologic cancer in the United States and throughout the world. Carcinoma in situ of the vagina and very early stage invasive carcinoma of the vagina may be treated with surgery. However, the standard therapeutic intervention for patients with carcinoma of the vagina is radiation therapy. In early stage vaginal carcinoma, radiation therapy is chosen for definitive treatment to preserve the anatomy and function of the vagina. In more advanced stages of vaginal carcinoma, radiation therapy is chosen as the standard treatment to avoid exenterative surgery, preserve anatomy and function, and to treat known or presumed lymph node metastasis. No randomized studies comparing irradiation alone versus irradiation and chemotherapy have been performed for patients with advanced carcinoma of the vagina. The standard therapy for patients with advanced cervical carcinoma is irradiation and concurrent cisplatin-based chemotherapy. Because the etiology and epidemiology of vaginal carcinoma appears identical to those of patients with invasive cervical carcinoma, patients with advanced vaginal carcinoma should be treated with irradiation and concurrent cisplatin-based chemotherapy.

Antineoplastic Agents↗

PubMed2002

Anaplastic thyroid carcinoma: comparison of conventional radiotherapy and hyperfractionation chemoradiotherapy in two groups.

Anaplastic thyroid carcinoma (ATC) is a highly aggressive neoplasm with a poor prognosis. Curative management of these tumors has been difficult secondary to delayed diagnosis and advanced disease at presentation. Treatment modalities including surgery and fractionated radiotherapy have had limited success in controlling these tumors. Median survival time is often measured in months. A review of all patients treated between 1952 and 1999 identified 32 patients with anaplastic or poorly differentiated thyroid carcinoma. Patients were divided into two groups: those treated between 1952 to 1980 (9 patients, group 1) and those treated between 1981 and 1999 (23 patients, group 2). Most group 1 patients received once-daily radiotherapy and most group 2 patients received twice-daily radiotherapy with concurrent chemotherapy. A variety of radiotherapy techniques were used. Chemotherapy consisted of doxorubicin, paclitaxel, vincristine, or cisplatin. Eleven patients presented with lymph node metastasis and two patients had distant metastases at diagnosis. The most common clinical presentation was a neck mass in 17 patients. In group 1, one patient was treated with surgery only, four with surgery and radiotherapy and four with radiotherapy alone. In group 2, 1 patient was treated with surgery only; 3 with surgery and radiotherapy; 10 with radiotherapy and chemotherapy; 5 with surgery, radiotherapy, and chemotherapy; and 5 with radiotherapy alone. Overall 2-year survival rates were 44% for group 1 and 52% for group 2. Two-year progression-free survival (PFS) was 53% for group 1 and 38% for group 2. Five (16%) patients died within 60 days of diagnosis. Severe side effects included skin sequelae (one patient) and osteoradionecrosis of the mandible (one patient). There were 10 (52%) long-term survivors (>2 years). Clinicopathologic features associated with extended survival were limited extent of disease and inclusion in group 2. Among patients with ATC surgery, hyperfractionated radiotherapy in conjunction with chemotherapy is associated with better survival but not PFS compared to conventional radiotherapy.

Antineoplastic Agents↗

PubMed2002

Update on radiation therapy for endometrial cancer.

The best clinical outcomes for patients with endometrial cancer seem to be achieved with either surgery alone or a combination of surgery and radiation therapy. Although once administered preoperatively, irradiation is now rarely given prior to surgery in this population. After surgical staging, most patients receive postoperative adjuvant therapy based on their pathologic risk factors. Although prospective randomized trials in these patients are limited, recent studies have attempted to determine the best management strategies for the disease. Based on these investigations, treatment recommendations are outlined for patients who are surgically staged and for those with incomplete surgical staging. Also described is the use of irradiation in recurrent endometrial cancer after surgery alone, as well as palliative radiation. In addition, ongoing prospective randomized trials are described.

Endometrial Neoplasms↗

PubMedDate not supplied

High dose ratio (HDR) cervical ring applicator to control bleeding from cervical carcinoma.

The objective of this study was to evaluate the use of the high dose rate (HDR) cervical ring applicator to control acute cervical bleeding from carcinoma of the uterine cervix. This study consists of 15 patients presenting with invasive carcinoma of the uterine cervix with acute vaginal bleeding requiring transfusion. Initial irradiation, delivered emergently because of vaginal bleeding, consisted of two fractions (5 Gy each fraction to the surface of the cervix) utilizing the HDR intracavitary vaginal ring applicator. Two fractions were administered at one week intervals for a total of 10 Gy to the surface of the cervix. Irradiation doses from the HDR ring applications were not considered into the composite total dose to point A. Diagnostic imaging evaluation and initiation of external irradiation were commenced during this initial weekly interval between fractions. Vaginal bleeding requiring no additional transfusions was achieved in 93% (14/15) of patients. No acute or long-term Grades 3, 4, or 5 bowel or bladder sequelae were noted. In conclusion, HDR cervical ring brachytherapy is effective in controlling acute vaginal bleeding and can be delivered without undue acute or long-term toxicity.

Brachytherapy↗

PubMedDate not supplied

Functional imaging in treatment planning in radiation therapy: a review.

The remarkable technical developments obtained in radiation oncology have resulted in an increasing use of image-based treatment planning in radiation therapy for three-dimensional and intensity modulated radiation therapy, stereotactic irradiation and image-guided brachytherapy. There has been increased use of computer-based record and verify systems as well as electronic portal imaging to enhance treatment delivery. From the data presented it is evident that PET scanning and other functional imaging techniques play a major role in the definition of tumor extent and staging of patients with cancer. The recent introduction of a combined CT and PET scanner will substantially simplify image acquisition and treatment planning.

Brachytherapy↗

PubMedDate not supplied

Uncertainties in radiation therapy: target definition in carcinoma of the uterine cervix.

In treatment of patients with carcinoma of the cervix, as in any other malignant tumor, accurate identification of target volumes is critical to enhance precision of radiation therapy planning and delivery. These results in improved locoregional tumor control lead to lower incidence of distant metastases and improved survival. Also, radiation therapy morbidity is decreased, enhancing quality of life. Various imaging techniques are available to achieve better target delineation and this can be enhanced with image fusion. Available innovative treatment techniques to optimize the use of radiation therapy for these patients are illustrated.

Female↗

PubMedDate not supplied

Postoperative irradiation in cervical cancer: prognostic factors and outcome.

PURPOSE: The aim of this study was to evaluate prognostic factors and outcomes in patients with cervical cancer who underwent hysterectomy followed by pelvic irradiation. METHODS: This was a retrospective chart review of 140 patients with carcinoma of the cervix. The indications for irradiation were an incidental finding of invasive cancer, positive lymph nodes, parametrial extension of tumor, and positive or close margins. RESULTS: The 10-year cause-specific and overall survival rates were 72% and 69%, respectively. Recurrences developed at the following sites: five in the pelvis, four in the pelvis and with distant metastasis, and 13 with distant metastasis. Parametrial extension of tumor was the only significant prognostic factor for developing recurrent disease (p=0.004). Complications were grade 3 in 10 and grade 4 in 18. Leg edema occurred in patients undergoing radical hysterectomy and lymph node dissection, but not in patients undergoing simple hysterectomy (p=0.01), and was more likely if irradiation was begun within six weeks of surgery compared with starting irradiation after six weeks (p=0.02). CONCLUSION: Pelvic irradiation produced pelvic control of disease in 94%. Distant metastasis was the most common site of failure. Chronic toxicity was greatest if irradiation was begun less than six weeks postoperatively.

Brachytherapy↗