Palliative two-dimensional radiotherapy of pancreatic carcinoma: a feasibility study.

AIMS AND BACKGROUND: The aim of the study was to analyze the dose to be administered with two-dimensional involved-field palliative radiotherapy in advanced pancreatic carcinoma with respect to current dose-volume constraints (QUANTEC). METHODS AND STUDY DESIGN: The following standard regimens were evaluated: 30 Gy at 3 Gy/fraction (regimen A), 36 Gy at 2.4 Gy/fraction (regimen B), 45 Gy at 1.8 Gy/fraction (regimen C), and 50 Gy at 2 Gy /fraction (regimen D). The following constraints were considered: spinal cord Dmax <50 Gy, duodenum Dmax <55 Gy, liver Dmean <30 Gy, kidneys Dmean <15 Gy. For dose/fraction different from 1.8-2 Gy, the correction of constraints using a value of alpha/beta = 3 for late effects was considered. The calculation of dose/volume constraints was repeated for three different radiation beams: cobalt unit, 6 MV photons, and 15 MV photons. Standard field sizes were used and adapted according to the different beam types, using the parameters of our previous study. Respect of dose-volume constraints was assessed for each type of beam and treatment (dose per fractionation) in all patients. Treatments were considered acceptable in case of: 1) respect of the constraints for spinal cord and duodenum in all patients; 2) respect in >10/15 patients of constraints for kidneys and liver. Therefore, minor violations (<10%) of the constraints for these organs were accepted (in less than 5/15 patients), in consideration of the palliative aim of treatment. RESULTS: In regimen A (30 Gy, 3 Gy/fraction), evaluated constraints were respected in all patients, regardless of the type of energy. In regimen B (36 Gy, 2.4 Gy/fraction), constraints were met in all patients undergoing irradiation with 6 and 15 MV photons. However, using the cobalt unit, kidney constraint was respected only in 5 of 15 patients. In regimens C and D (45 Gy, 1.8 Gy/fraction and 50 Gy, 2 Gy/fraction, respectively), the constraint for the kidney was respected only in 2-5 patients, depending on the energy used. Furthermore, using 50 Gy, the spinal cord constraint was not respected in 2-3 patients, depending on the beam used. Therefore, only the following treatments were considered acceptable: 1) 30 Gy, 3 Gy/fraction, regardless of the energy used; 2) 36 Gy, 2.4 Gy/fraction, only for treatments performed with linear accelerator (6-15 MV). CONCLUSIONS: The clinical benefits of radiotherapy in pancreatic tumors should not be withheld from patients treated in centers only with two-dimensional technology. Prospective trials, particularly in developing countries, would be useful to evaluate the efficacy in this setting of involved-field two-dimensional treatments using the dose and fractionation defined in this analysis.

Forward-planned intensity modulated radiation therapy using a cobalt source: A dosimetric study in breast cancer.

This analysis evaluates the feasibility and dosimetric results of a simplified intensity-modulated radiotherapy (IMRT) treatment using a cobalt-therapy unit for post-operative breast cancer. Fourteen patients were included. Three plans per patient were produced by a cobalt-60 source: A standard plan with two wedged tangential beams, a standard tangential plan optimized without the use of wedges and a plan based on the forward-planned "field-in-field" IMRT technique (Co-FinF) where the dose on each of the two tangential beams was split into two different segments and the two segments weight was determined with an iterative process. For comparison purposes, a 6-MV photon standard wedged tangential treatment plan was generated. Dmean, D98%, D2%, V95%, V107%, homogeneity, and conformity indices were chosen as parameters for comparison. Co-FinF technique improved the planning target volume dose homogeneity compared to other cobalt-based techniques and reduced maximum doses (D2%) and high-dose volume (V110%). Moreover, it showed a better lung and heart dose sparing with respect to the standard approach. The higher dose homogeneity may encourage the adoption of accelerated-hypofractionated treatments also with the cobalt sources. This approach can promote the spread of breast conservative treatment in developing countries.

Patterns of practice of palliative radiotherapy in Africa, Part 1: Bone and brain metastases.

PURPOSE: To provide data on the pattern of practice of palliative radiotherapy (RT) on the African continent. METHODS AND MATERIALS: A questionnaire was distributed to participants in a regional training course of the International Atomic Energy Agency in palliative cancer care and sent by e-mail to other institutions in Africa. Requested information included both infrastructure and human resources available and the pattern of RT practice for metastatic and locally advanced cancers. RESULTS: Of 35 centers contacted, 24 (68%) completed the questionnaire. Although RT is used by most centers for most metastatic cancers, liver and lung metastases are treated with chemotherapy. Of 23 centers, 14 (61%) had a single RT regimen as an institutional policy for treating painful bone metastases, but only 5 centers (23%) of 23 used 8 Gy in 1 fraction. Brain metastases were being treated by RT to the whole brain to 30 Gy in 10 fractions, either exclusively (n=13, 56%) or in addition to the use of 20 Gy in 5 fractions (n=3, 14%). CONCLUSION: Radiotherapy is a major component of treatment of cancer patients in African countries. There is consensus among few centers for treatment schedules for almost all sites regarding time and dose-fractionation characteristics of RT regimens used and/or indications for the use of RT in this setting.

Contraindications to cisplatin based chemoradiotherapy in the treatment of cervical cancer in Sub-Saharan Africa.

BACKGROUND AND PURPOSE: We conducted a prospective study to assess the eligibility of patients presenting with cervical cancer in the developing world for chemoradiotherapy. MATERIAL AND METHODS: Patients with biopsy proven cervical cancer were eligible. Workup included history, examination, pre-treatment Karnofsky performance score, evaluation under anaesthesia to establish FIGO stage, complete blood count, renal and liver functions tests, HIV test and ultrasound of the abdomen and pelvis. EXCLUSION CRITERIA: stage IA, stage IV, HIV status positive, Karnofsky performance score <60, age >70 years, hydronephrosis, haemoglobin <8 g/dL, white cell count <2,000/microL, platelets <100,000/microL, creatinine >97 micromol/L. RESULTS: 314 patients were included. After workup, 47 patients (15.1%) were eligible for combined modality treatment and 190 (60.5%) were not eligible. Eligibility could not be established in 77 cases (24.4%). 37 (11.6%) of the group were HIV positive, HIV status was not established in 38.4% of cases. The most frequently encountered exclusion criteria were hydronephrosis and anaemia. Application of a haemoglobin cut off point of 8 g/dL for cisplatin based chemotherapy resulted in the exclusion of 55 (17.4%) patients. A limit of 10 g/dL excluded an additional 11 patients. Hydronephrosis was diagnosed on ultrasound in 99 (31.4%) patients. 56% had unilateral hydronephrosis, 44% had bilateral hydronephrosis. CONCLUSIONS: A small proportion of our patients with cervical cancer would benefit from chemoradiotherapy with concomitant cisplatin, illustrating the difficulties of applying "standard" treatment to the developing world. The introduction of national screening programmes and the provision of accessible radiotherapy facilities should be the major priorities in the developing world setting.

Epidemic and endemic Kaposi's sarcoma: a comparison of outcomes and survival after radiotherapy.

We retrospectively studied the outcomes of 80 Epidemic and African-Endemic Kaposi's Sarcoma (EKS and AKS) patients treated with radiotherapy doses of 8.0 Gy. The objective response for EKS at one month was 74 and 58% for AKS while 5-year survival for EKS was 27 and 46% for AKS.