R. Samant

Effects of radiation and total androgen blockade on serum hemoglobin, testosterone, and erythropoietin in patients with localized prostate cancer

OBJECTIVE The objective of the present study was to evaluate the incidence, time of onset, and extent of hemoglobin, testosterone, and erythropoietin changes in patients with localized prostate cancer receiving either radiation alone or radiation combined with total androgen blockade (tab). METHODS The study enrolled 35 patients (median age: 69 years) with clinically localized prostate cancer who received 3-dimensional conformal radiation with or without tab. Patients were generally treated with radiation alone (group 1), radiation plus short-term (≤6 months) tab (group 2), or radiation plus long-term (≥2 years) tab (group 3). Serum hemoglobin, testosterone, and erythropoietin in these patients were prospectively evaluated. RESULTS The mean baseline serum hemoglobin for group 1 (n = 20), group 2 (n = 6), and group 3 (n = 9) was 149 g/L, 153 g/L, and 143 g/L respectively. We observed no significant decline in serum hemoglobin, testosterone, or erythropoietin among patients treated with radiotherapy alone. A significant drop in serum testosterone was noted in the group 2 and 3 patients within 1 month (p < 0.001), reaching a plateau at approximately 6 months. That change was followed by a significant decline (p < 0.001) in serum hemoglobin at 3-6 months (137 g/L in group 2 and 129 g/L in group 3). We observed a small but statistically significant increase in serum erythropoietin (p < 0.001) of 8 U/L in group 2 and 4 U/L in group 3 after 6 months of tab. No immediate recovery in serum hemoglobin, testosterone, or erythropoietin was observed upon completion of tab. CONCLUSIONS Although conformal radiotherapy alone for localized prostate cancer had no effect on serum hemoglobin, testosterone, or erythropoietin, tab led to a significant decline in testosterone, which was followed by decline in hemoglobin that was not a result of a deficiency of erythropoietin.

Current practice in total-body irradiation: results of a Canada-wide survey

BACKGROUND Total-body irradiation (tbi) is used to condition patients before bone marrow transplant. A variety of tbi treatment strategies have been described and implemented, but no consensus on best practice has been reached. We report on the results of a survey created to assess the current state of tbi delivery in Canada. RESULTS A 19-question survey was distributed to 49 radiation oncology programs in Canada. Responses were received from 20 centres, including 12 centres that perform tbi. A variety of tbi dose prescriptions was reported, although 12 Gy in 6 fractions was used in 11 of the 12 centres performing tbi. Half of the centres also reported using a dose prescription unique to their facility. Most centres use an extended-distance parallel-opposed-pair technique, with the patient standing or lying on a stretcher against a wall. Others translate the patient under the beam, sweep the beam over the patient, or use a more complicated multi-field technique. All but 1 centre indicated that they attenuate the lung dose; only 3 centres indicated attenuating the dose for other organs at risk. The survey also highlighted the considerable resources used for tbi, including extra staff, prolonged planning and treatment times, and use of locally developed hardware or software. CONCLUSIONS At transplant centres, tbi is commonly used, but there is no commonly accepted approach to planning and treatment delivery. The important discrepancies in practice between centres in Canada creates an opportunity to prompt more discussion and collaboration between centres, improving consistency and uniformity of practice.

Rapid palliative radiotherapy: comparing IG-IMRT with more conventional approaches

Purpose: To assess the efficiency of an integrated imaging, planning, and treatment delivery system to provide image-guided intensity-modulated radiotherapy (IG-IMRT) for patients requiring palliative radiotherapy (PRT). Methods: Between December 2006 and May 2008, 28 patients requiring urgent PRT were selected to undergo single-session megavoltage computed tomography (MV-CT) simulation, IMRT treatment planning, position verification and delivery of the first faction of radiotherapy on a helical Tomotherapy ® unit. The time required to complete each step was recorded and compared to our standard approach of using either fluoroscopic or CT-based simulation, simplified treatment planning and delivery on a megavoltage unit. Results: Twenty-eight patients were treated with our integrated IG-IMRT protocol. The median age was 72 years, with 61% men and 39% women. The indications for PRT were: painful bone and soft tissue metastasis (75%); bleeding lesions (14%); and other reasons (11%). The areas treated included the following: hip and/or pelvis (42%); spine (36%); and other areas (21%). The most commonly used dose prescription was 20 Gy in five fractions. Average times for the integrated IG-IMRT processes were as follows: image acquisition, 15 minutes; target delineation, 16 minutes; IMRT treatment planning, 9 minutes; treatment position verification, 10 minutes; and treatment delivery, 12 minutes. The average total time was 62 minutes compared to 66 minutes and 81 minutes for fluoroscopic and CT-simulation-based approaches, respectively. The IMRT dose distributions were also superior to simpler plans. Conclusions: PRT with an integrated IG-IMRT approach is efficient and convenient for patients, and has potential for future applications such as single-fraction radiotherapy.

Sci-Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques - 10: Results from Canada Wide Survey on Total Body Irradiation Practice

Purpose: Total Body Irradiation (TBI) is delivered to a relatively small number of patients with a variety of techniques; it has been a challenge to develop consensus studies for best practice. This survey was created to assess the current state of TBI in Canada. Methods: The survey was created with questions focusing on the radiation prescription, delivery technique and resources involved. The survey was circulated electronically to the heads of every clinical medical physics department in Canada. Responses were gathered and collated, and centres that were known to deliver TBI were urged to respond. Results: Responses from 20 centres were received, including 12 from centres that perform TBI. Although a variety of TBI dose prescriptions were reported, 12 Gy in 6 fractions was used in 11 centres while 5 centres use unique prescriptions. For dose rate, a range of 9 to 51 cGy/min was reported. Most centres use an extended SSD technique, with the patient standing or lying down against a wall. The rest use either a “sweeping” technique or a more complicated multi-field technique. All centres but one indicated that they shield the lungs, and only a minority shield other organs. The survey also showed that considerable resources are used for TBI including extra staffing, extended planning and treatment times and the use of locally developed hardware or software. Conclusions: This survey highlights that both similarities and important discrepancies exist between TBI techniques across the country, and is an opportunity to prompt more collaboration between centres.

Pulmonary toxicity following total body irradiation for acute lymphoblastic leukaemia: The Ottawa Hospital Cancer Centre (TOHCC) experience

Purpose To review the incidence of clinically significant pulmonary toxicity following total body irradiation (TBI) as a part of the conditioning regimen for acute lymphoblastic leukaemia (ALL) patients undergoing bone marrow transplantation (BMT) at The Ottawa Hospital Cancer Centre. Methods This is a retrospective review of ALL patients who received TBI in The Ottawa Hospital Bone Marrow Transplant Program (TOH-BMT) as part of their conditioning regimen from 1991 to 2011 inclusive. The patients were treated using a locally developed translating-couch irradiation technique. We have analysed all available data for the first 100 days following TBI to determine the incidence of radiation-induced pulmonary toxicities. Results Of the total 622 patients undergoing TBI during the specified period, 88 had ALL. Median age at BMT was 30 years and the conditioning regimens varied. A total of 74 (84%) patients received 12 Gy/6 F/BID of TBI. A total of 55 (63%) patients have died, 32 (36%) within the 1st year after BMT. In the 1st year, pulmonary events were reported for 24 (27%) patients, and the follow-up notes were unavailable for seven (8%). Pulmonary toxicities were reported as the cause of death for six patients, five (6%) within the 1st year. It is estimated that the total number of deaths in the 1st year possibly attributed to radiation-induced lung injury was four (4·5%). Eight (9%) patients had symptoms suggestive of non-lethal grade 2–3 radiation-induced pneumonitis. Conclusions TBI continues to be an important component of the conditioning regimen for ALL patients undergoing BMT, and the incidence of radiation-induced pulmonary injury, using our technique and lung dose, is comparable to the published literature.