Beam angle selection for intensity-modulated radiotherapy (IMRT) treatment of unresectable pancreatic cancer: are noncoplanar beam angles necessary?

BACKGROUND AND PURPOSE: External beam radiation therapy with concurrent chemotherapy (CRT) is widely used for the treatment of unresectable pancreatic cancer. Noncoplanar (NCP) 3D conformal radiotherapy (3DCRT) and coplanar (CP) IMRT have been reported to lower the radiation dose to organs at risk (OARs). The purpose of this article is to examine the utility of noncoplanar beam angles in IMRT for the management of pancreatic cancer. MATERIALS AND METHODS: Sixteen patients who were treated with CRT for unresectable adenocarcinoma of the pancreatic head or neck were re-planned using CP and NCP beams in 3DCRT and IMRT with the Varian Eclipse treatment planning system. RESULTS: Compared to CP IMRT, NCP IMRT had similar target coverage with slightly increased maximum point dose, 5,799 versus 5,775 cGy (p = 0.008). NCP IMRT resulted in lower mean kidney dose, 787 versus 1,210 cGy (p < 0.0001) and higher mean liver dose, 1,208 versus 1,061 cGy (p < 0.0001). Also, NCP IMRT resulted in similar mean stomach dose, 1,257 versus 1,248 cGy (p = 0.86) but slightly higher mean small bowel dose, 981 versus 866 cGy (p < 0.0001). CONCLUSIONS: The NCP IMRT was able to significantly decrease bilateral kidney dose, but did not improve other dose-volume criteria. The use of NCP beam angles is preferred only in patients with risk factors for treatment-related kidney dysfunction (AU)

Beam angle selection for intensity-modulated radiotherapy (IMRT) treatment of unresectable pancreatic cancer: are noncoplanar beam angles necessary?

BACKGROUND AND PURPOSE: External beam radiation therapy with concurrent chemotherapy (CRT) is widely used for the treatment of unresectable pancreatic cancer. Noncoplanar (NCP) 3D conformal radiotherapy (3DCRT) and coplanar (CP) IMRT have been reported to lower the radiation dose to organs at risk (OARs). The purpose of this article is to examine the utility of noncoplanar beam angles in IMRT for the management of pancreatic cancer. MATERIALS AND METHODS: Sixteen patients who were treated with CRT for unresectable adenocarcinoma of the pancreatic head or neck were re-planned using CP and NCP beams in 3DCRT and IMRT with the Varian Eclipse treatment planning system. RESULTS: Compared to CP IMRT, NCP IMRT had similar target coverage with slightly increased maximum point dose, 5,799 versus 5,775 cGy (p = 0.008). NCP IMRT resulted in lower mean kidney dose, 787 versus 1,210 cGy (p < 0.0001) and higher mean liver dose, 1,208 versus 1,061 cGy (p < 0.0001). Also, NCP IMRT resulted in similar mean stomach dose, 1,257 versus 1,248 cGy (p = 0.86) but slightly higher mean small bowel dose, 981 versus 866 cGy (p < 0.0001). CONCLUSIONS: The NCP IMRT was able to significantly decrease bilateral kidney dose, but did not improve other dose-volume criteria. The use of NCP beam angles is preferred only in patients with risk factors for treatment-related kidney dysfunction.

SU-E-J-170: Clinical Evaluation of Positioning Accuracy of Two Immobilization Devices for Stereotactic Body Radiotherapy Using Cone Beam CT.

PURPOSE: To evaluate the patient positioning accuracy and reproducibility of two commercially available immobilization systems for Stereotactic Body Radiotherapy (SBRT) treatment. METHODS: Forty one patients with lung (n=21) or liver (n=20) malignancies were assigned to one of the two immobilization devices: Elekta stereotactic body frame (SBF) with built-in stereotactic coordinate system and Civco modular indexing based frame (MIF) without stereotactic reference. All patients underwent the same simulation and planning procedure followed by cone beam CT (CBCT) guided treatment setup. A total of 151 CBCT images were analyzed. The systematic and random isocenter setup errors of the two systems were calculated and compared based on the daily setup corrections under CBCT guidance. RESULTS: There was not statistically significant difference between the two systems in terms of systematic setup errors in all three translational directions, for both lung and liver patients. The random errors for the lung patients under SBF setup were 1.8mm, 2.0mm and 2.9mm for the vertical, longitudinal and lateral directions, respectively compared to 3.6mm, 4.1mm, and 4.2mm for MIF. A similar trend was also observed for liver patients. The random errors of liver MIF setup reached 3.5mm, 6.1mm and 5.7mm for the vertical, longitudinal and lateral directions, respectively, with relatively smaller errors 1.7mm, 3.4mm and 2.6mm with SBF setup. Repeated CBCTs occurred for MIF system in 42.4% and 40.7% of the lung and liver treatment to verify couch corrections based on the institutional tolerance, resulting in prolonged setup time. Only 25% and 13.6% of the lung and liver treatment with SBF required with repeated CBCT. CONCLUSIONS: Without stereotactic coordinate reference, the body frame system tended to have larger random setup errors and patient positioning accuracy inevitably relies on the volumetric imaging guidance. Patient comfort and reproducibility should be clearly considered for selecting a system.

Treatment of anal carcinoma in immune-compromised patients

BACKGROUND: Immune-compromised populations show an increased incidence of anogenital tract neoplasms. This study was undertaken to evaluate local control (LC), overall survival (OS) and toxicity in immune-compromised patients with anal carcinoma treated with radiotherapy with or without chemotherapy. METHODS: We identified 25 patients with anal carcinoma and human immunodeficiency virus (HIV) infection or history of solid-organ transplant on chronic medical immune-suppression. Median age and follow-up were 44 years and 26 months respectively. AJCC T-stages were Tis (4%), T1 (8%), T2 (58%) and T3 (29%). N-stages were N0 (79%), N1 (4%), N2 (13%) and N3 (4%). One patient had metastatic disease at diagnosis. Seventy-five percent received concurrent chemoradiotherapy. Median radiation dose to the primary tumour was 50 Gy. RESULTS: One-, 3- and 5-year LC without salvage therapy was 87%, 87% and 70% respectively. One-, 3- and 5-year actuarial OS was 96%, 73% and 61% respectively. One-, 3- and 5-year OS was 100% for treatment time (TT) <50 days and 57%, 38% and 0% for TT > or =50 days (p=0.0009). All patients had acute grade 2-3 skin toxicity. Acute grade 3-4 gastrointestinal (GI), genitourinary (GU) and haematological toxicity occurred in 8%, 0% and 38%. Late grade 3-4 skin, GI and GU toxicity occurred in 8%, 4% and 0%. CONCLUSIONS: Most HIV-positive and organ transplant patients receiving radiotherapy with or without chemotherapy experience acute toxicity but few have chronic complications. T-stage and CD4 level in HIV-positive patients predict for LC. T-stage and TT predict for OS (AU)

Role of stereotactic body radiotherapy in the management of primary hepatocellular carcinoma. Rationale, technique and results.

Hepatocellular carcinoma (HCC) is the most frequently occurring primary tumour of the liver in adults and the third most common cause of cancer-related deaths in the world. The incidence of HCC is increasing both in Europe and in the United States due to the increasing prevalence of hepatitis C. Of recognised importance, when making decisions regarding the most appropriate management of a patient with HCC, is the involvement of a multidisciplinary team of hepatologists, hepatobiliary surgeons, a liver transplant team, interventional radiologists, and medical and radiation oncologists. This manuscript reviews the role of stereotactic body radiotherapy in HCC.

Role of stereotactic body radiotherapy in the management of primary hepatocellular carcinoma. Rationale, technique and results

Hepatocellular carcinoma (HCC) is the most frequently occurring primary tumour of the liver in adults and the third most common cause of cancer-related deaths in the world. The incidence of HCC is increasing both in Europe and in the United States due to the increasing prevalence of hepatitis C. Of recognised importance, when making decisions regarding the most appropriate management of a patient with HCC, is the involvement of a multidisciplinary team of hepatologists, hepatobiliary surgeons, a liver transplant team, interventional radiologists, and medical and radiation oncologists. This manuscript reviews the role of stereotactic body radiotherapy in HCC (AU)

Microscopic and macroscopic tumor and parenchymal effects of liver stereotactic body radiotherapy.

PURPOSE: To describe the histologic and volumetric changes in normal liver tissue after stereotactic body radiotherapy (SBRT) for liver metastases. METHODS AND MATERIALS: Pre- and post-SBRT imaging studies were analyzed to evaluate the effect of SBRT on normal liver volume (NLV) in 15 patients treated in a prospective clinical trial. Two other patients underwent exploratory surgery after SBRT and histologic analyses of the irradiated liver were performed to characterize the pathologic effects of SBRT. RESULTS: In the 15 patients studied quantitatively, the total NLV had decreased transiently at 2-3 months after SBRT and then began to regenerate at 3-8 months after SBRT. The median NLV reduction at the maximal observed effect was 315 cm(3) (range, 125-600) or 19% (range, 13-33%). Among the several dosimetric parameters evaluated, the strongest linear correlation was noted for the NLV percentage receiving 30 Gy as a predictor of maximal NLV reduction (r(2) = 0.72). The histologic changes observed 2 and 8 months after SBRT demonstrated distinct zones of tissue injury consistent with localized veno-occlusive disease. CONCLUSION: The well-demarcated focal parenchymal changes after liver SBRT (demonstrated both radiographically and histologically) within the high-dose zone are consistent with a threshold dose-induced set of phenomena. In contrast, the more global effect of NLV reduction, which is roughly proportional to whole organ dose parameters, resembles more closely an effect determined from radiobiologically parallel architecture. These observations suggest that modeling of normal tissue effects after liver SBRT might require different governing equations for different classes of effects.

Concurrent chemotherapy and radiation in cervical cancer

No disponible

Extracraneal stereotactic radioablation. Review of biological basis, tecnique and clinical experience

No disponible

Radioablación estereotáctica extracraneal. Revisión de las bases biológicas, técnica y experiencia clínica preliminar / Extracranial stereotactic radioablation. Review of biological basis, technique and preliminary clinical experience

La radioablación estereotáctica extracraneal es una nueva y estimulante modalidad de tratamiento en la que se administran dosis grandes hipofraccionadas de irradiación a los tumores extracraneales. En el presente artículo revisamos brevemente el razonamiento, las implicaciones biológicas del hipofraccionamiento “extremo” la técnica de tratamiento y los datos publicados. Además se presentarán los datos de un ensayo clínico fase I en pacientes con cáncer de pulmón de células no pequeñas (NSCLC) inoperable, estadio clínico I, realizado en la Indiana University (AU)

High-dose-rate brachytherapy for vaginal cancer: learning from treatment complications.

Historically, early stage vaginal cancer has been treated with low-dose-rate (LDR) brachytherapy with or without external beam radiation therapy (EBRT). Complication rates have been low and treatment efficacious. Although high-dose-rate (HDR) brachytherapy has been used for cervical cancer in many countries for over a decade, only more recently has it been integrated into treatment plans for vaginal cancer. This paper describes three patients treated with HDR brachytherapy who experienced significant late effects. Given the very limited amount of literature regarding the use of HDR brachytherapy in vaginal cancer, this analysis potentially contributes to an understanding of treatment-related risk factors for complications among patients treated with this modality.A focused review of hospital and departmental treatment records was done on three patients treated with HDR brachytherapy. Abstracted information included clinical data, treatment parameters (technique, doses, volume, combinations with other treatments) and outcomes (local control, survival, early and late effects). A review of the available literature was also undertaken. All patients had significant complications. Although statistical correlations between treatment parameters and complications are impossible given the limited number of patients, this descriptive analysis suggests that vaginal length treated with HDR brachytherapy is a risk factor for early and late effects, that the distal vagina has a lower radiation tolerance than the upper vagina with HDR as in LDR, and that combining HDR with LDR as done in our experience carries a high risk of late toxicity. Integration of HDR brachytherapy techniques into treatment plans for early stage vaginal cancers must be done cautiously. The etiology of the significant side effects seen here is likely to be multifactorial. For users of HDR brachytherapy in vaginal cancer, there is a need to further refine and standardize treatment concepts and treatment delivery. Ideally this will be based on continued careful observation and reporting of both favorable and unfavorable outcomes and experiences.

Integrating radiation therapy in the curative management of ovarian cancer: current issues and future directions.

Although important advances in surgery, chemotherapy (CT), and radiation therapy (RT) have been made, overall survival for patients with ovarian cancer (OC) has not changed significantly. Despite its long history in the treatment of OC and its proven curative role in patients with microscopic or minimal residual disease, the proper role of RT in the management of OC is not clearly established. Although the use of primary adjuvant RT (whole abdominal irradiation) has declined in the last 15 years, there has been a resurgence of interest in RT as part of a combined modality approach and as salvage therapy for patients with small-volume persistent disease after primary cytoreductive surgery and platinum-based CT. This article reviews the evidence supporting the use of RT alone or combined with chemotherapy as primary adjuvant therapy or in the salvage setting. Current issues in the radiotherapeutic management are discussed along with ideas for future clinical research directions.

Radiotherapy in epithelial ovarian cancer: state of the art.

Modern advances in surgery, chemotherapy (CT) and radiotherapy (RT) have not, unfortunately, impacted the overall survival for patients with ovarian cancer (OC). Despite its long history in the treatment of OC and its proven curative role in patients with microscopic or minimal residual disease, the proper role of RT in the management of OC is controversial and not clearly established. Similarly, the potential roles of RT in the consolidative treatment and as salvage therapy following CT failure remain controversial. In the present review current issues in the radiotherapeutic management are discussed along with possible future clinical research directions.

New techniques in the radiotherapeutic treatment of gynecological malignancies.

The management of patients with gynecological malignancies serves as a prominent example of the importance of multi-modality oncologic therapy. Optimal treatment of these patients requires the skillful implementation of surgery, radiation therapy and chemotherapy. The decision to use simple versus combined modality therapy is crucial and best carried out in centers in which an experienced and coordinated multidisciplinary team is available. In this article, we have reviewed the most recent data regarding the role of radiation therapy in gynecological malignancies and have pointed out those areas where additional confirmatory studies are needed.

Episcleral iridium-192 wire therapy for choroidal melanomas.

PURPOSE: To evaluate the effectivity of high-dose episcleral iridium-192 wires in the treatment of choroidal melanoma. METHODS AND MATERIALS: In 1983, the Departments of Radiation Oncology and Ophthalmology at the Clínica Puerta de Hierro, Madrid, Spain, initiated a clinical study using removable episcleral iridium-192 wires in the treatment of choroidal melanoma. Sixty-six evaluable patients were treated from January 1983 through July 1992. Two patients had a small sized tumor (3%), 28 had a medium sized tumor (42%), and 36 patients had a large tumor (54%). The mean follow-up was 40 months (6-118 months). The dose to the apex of the tumor ranged from 66 to 97 Gy (mean 76.6 Gy), and the doses at 2 mm depth ranged from 77 to 433 Gy (mean 200 Gy). RESULTS: Tumor regression or stabilization was observed in 53 of the 66 patients (90%). Visual acuity improved following treatment in 5 out of 54 patients (9%), remaining unchanged in 30 out of 54 (56%), and decreased in 19 out of 54 (35%) patients. The remaining seven patients had undergone enucleation. Late complications have been documented in 20 out of 66 patients (30%), including 6 patients in whom enucleation was required because of radiation-related complications. The probability of survival and survival free of local progression was 93% at 5 years and 79% at 10 years. The probability of retaining the treated eye is 82% after the fifth year posttreatment. CONCLUSIONS: Treatment of choroidal melanomas with episcleral iridium-192 wires is as effective as treatment with other radioactive applications. We feel that our results using iridium-192 wires are comparable to the other methods. However, we think that our technique is simple to implement, relatively inexpensive, and well tolerated.

Chordoma: results of radiation therapy in eighteen patients.

Between 1975 and 1990, eighteen patients with a histologically proven diagnosis of chordoma were treated at our institution. All patients initially underwent a surgical procedure and were referred for irradiation due to residual disease or postsurgical relapse. The mean dose administered was 50.1 Gy (range, 29.9-64.8 Gy). Eight patients were treated according to a hyperfractionated schedule. The overall actuarial 5-year survival and 5-year progression-free survival were 38% and 17%, respectively. The progression-free interval was longer for patients receiving doses greater than 48 Gy when compared with doses below 40 Gy (actuarial 5-year progression-free survival of 31 +/- 35% vs. 0%, respectively; p = 0.04). We conclude that in the treatment of chordoma, the administration of high radiation doses may increase the disease-free interval. The objective response and dose-response relationships were analyzed in twelve patients for whom sequential CT scans were available.

Combined hyperthermia and irradiation in the treatment of superficial tumors: results of a prospective randomized trial of hyperthermia fractionation (1/wk vs 2/wk).

From December 1984 to December 1989, 240 superficially located recurrent/metastatic malignant lesions (173 patients) were enrolled in a prospective randomized study of one versus two hyperthermia fractions per week. In the majority of patients, the dose of radiation therapy was less than 4000 cGy over 4 to 5 weeks. Stratification was by tumor size, site, and histology. The goal of the hyperthermia sessions were 42.5 degrees C for 45-60 min minimum intra-tumor measured temperature. Hyperthermia was given after radiation within 30-60 min. External applicators, both microwave (over 90% of treatments) and ultrasound, were used. Overall, complete response rate in 222 evaluable lesions was 56.3% (125/222) with a minimum follow-up of 6 months and a maximum follow-up of 52 months. The complete response rate for once a week versus twice a week hyperthermia group was 54.7% and 57.8%, respectively. The severe complication rate was 18% (41/222). There was no difference between the two treatment arms. Cox regression analyses were performed to study the prognostic significance of patient characteristics, tumor characteristics, and treatment parameters. Detailed analysis and results are presented.

Cervical metastases from unknown primaries: radiotherapeutic management and appearance of subsequent primaries.

Between 1964 and 1986, 72 patients who presented with squamous or undifferentiated metastatic carcinoma to neck nodes, where the primary tumor could not be found by standard clinical procedures, were treated at the Mallinckrodt Institute of Radiology. These cases were managed in the following manner: biopsy and radiotherapy in 46 out of 72 patients, radiotherapy (RT) and a planned neck dissection in 14 out of 72, and neck dissection after failure to achieve a complete response (CR) with RT in 12 out of 72. Minimum follow-up was 2 years. The initial CR rates for stages N1, N2a, N2b, N3a, and N3b were 83%, 93%, 61%, 50%, and 33%, respectively. The long-term neck tumor control for the same stages was 83%, 71%, 67%, 44%, and 50%, respectively. One patient had soft tissue necrosis and two had carotid artery ruptures, one of which left no symptomatic sequelae. Twenty-one out of 72 patients developed subsequent primary tumor. Only one of these patients survived. This incidence was not affected significantly by prophylactic treatment of the mucosal areas except in patients with bilateral neck nodes, undifferentiated or poorly differentiated histologies, and/or posterior cervical node involvement. A multivariate analysis showed that prognosticators of an improved disease-free survival were: a complete clearance of tumor by the end of radiotherapy (p less than 0.0009) and no appearance of a subsequent primary tumor (p = 0.035). The only factor that correlated with an increased loco-regional control was having a complete response by the end of radiotherapy (p less than 0.00009). The recommended management and possible ways of preventing the appearance of subsequent primaries will be discussed.

Individual risk of abdominal disease in patients with stages I and II supradiaphragmatic Hodgkin's disease. A rule index based on 341 laparotomized patients.

A multivariate analysis of the prognostic factors for clinical Stages I and II supradiaphragmatic Hodgkin's disease was carried out with a logistic regression model in 341 patients. The proportion of patients with positive staging laparotomy was greater in males, in individuals with several sites involved, mixed cellularity (MC) or lymphocyte depletion (LD) histologic types, systemic symptoms, or in patients with lower cervical involvement and higher erythrocyte sedimentation rate (ESR), serum copper, and LDH levels. Histology, presence of systemic symptoms (fever and sweats), and number of involved nodal regions were independent predictors of positive laparotomy. Mediastinal involvement is correlated to a significantly lower risk of positive laparotomy. Based on these observations, the individual risk for each patient of occult abdominal disease has been defined.