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.

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.