PURPOSE:To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT). METHODS AND MATERIALS:102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor. RESULTS:The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P<.01). Late skin toxicity was no worse than grade 2 in either group, without significant differences between the 2 groups. In the ipsilateral breast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P<.05). Physician assessment showed that >75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups. CONCLUSIONS:APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI.

Presentamos los resultados de tolerancia de la adición de sobreimpresión hipofraccionada después de irradiación global hipofraccionada de la mama. Se incluyeron pacientes con cirugía conservadora y tratadas mediante hipofraccionamiento de 2,67 Gy/día hasta 40 Gy sobre la mama. La sobreimpresión del lecho tumoral se realizó a dosis de 16 o 8 Gy según los criterios de riesgo para recaída local: tamaño tumoral, grado, márgenes o presencia de carcinoma ductal in situ, o nada en ausencia de dichos factores. Se trataron 110 pacientes. Los grupos de riesgo se distribuyeron en alto, medio o bajo, con 51, 54 y 5 pacientes, respectivamente. Un 4,5% no presentaron toxicidad aguda. Las pacientes presentaron dermitis grado i o ii en el 38,2 y 47,3% de los casos, respectivamente. No se observaron diferencias en la toxicidad aguda dependiendo de la dosis de sobreimpresión. Tras un seguimiento medio de 2 años, en 79 casos (71,8%) no hubo cambios cutáneos crónicos. Apareció fibrosis leve en 24 pacientes (21,8%) y de grado ii en 7 pacientes. La sobreimpresión hipofraccionada parece bien tolerada y las toxicidades aguda y crónica son leves. No parece haber impacto de la dosis total acumulada en la incidencia de fibrosis. We present the results of adding a hypofractionated boost after whole-breast hypofractionated radiotherapy and report patient tolerance of this procedure. Patients were included after conservative surgery and underwent adjuvant therapy. The whole breast was treated at 2.67 Gy per fraction up to 40 Gy. The boost was performed at different dose levels (16 or 8 Gy) according to the presence of risk factors for local recurrence (tumor size, histologic grade, margin status or the presence of carcinoma in situ) or nothing in case of their absence. A total of 110 patients were treated. The distribution into high-, middle- and low-risk groups was 51, 54 and 5 patients, respectively. There was no toxicity in 4.5% of the patients. Grade i or ii dermatitis was found in 38.2 and 47.3%, respectively. No differences were observed in acute dermatitis depending on boost doses. After a follow-up of 2 years, there were no chronic skin or subcutaneous changes in 79 patients (71.8%). Mild fibrosis occurred in 24 patients (21.8%) and grade ii fibrosis occurred in 7 patients. Hypofractionated boost seems to be well tolerated. Acute and chronic toxicities are mild. The cumulative dose does not seem to increase the incidence of fibrosis at the boost area compared with the whole breast.

The position of PTV in prostate cancer radiation therapy is affected by rectal distension. A distended rectum at the planning CT scan reduces disease control in this scenario. The introduction of dietary and laxative protocols significantly decreases feces and rectal gas and reduces rectum distension at the CT planning scan. We tried to work with foreign dietary protocols but they had not result in our environment. As a result we have implemented a local protocol in our population of prostate cancer patients treated by external-beam radiation therapy. Objectives are to study the feasibility of the new protocol and to compare rectal distension and rectal toxicity in patients before and after the implementation of the protocol. We designed a "Mediterranean adaptation" of the Dutch protocol published by Smitsmans et al. The protocol consists of a local antiflatulent diet and the intake of 1 g/5 mL of magnesium hydroxide daily, starting 4 days before acquisition of the planning CT scan and 4 days before radiation therapy treatment up to the end of treatment. Patients were treated by three-dimensional conformal radiation therapy or intensity-modulated radiation therapy without image-guided radiation therapy techniques. CT planning scans of patients before the implementation of the protocol were compared against scans of patients subject to the new protocol. Rectal volume between the two groups was compared. Rectal distension was assessed calculating the average of the Cross-Sectional Area (CSA defined as the rectal volume divided by the length). Rectal toxicity was assessed according to RTOG scoring criteria. Eighty-seven no-protocol patients were compared against 92 patients subject to the new protocol. The rectal distension were significantly lower among the protocol patients with an average CSA of 7.39 (+/- 0.54) cm2 vs 9.29 (+/- 0.92) cm2; α = 0.05, p = 0.0027. On the other hand, grade 3 rectal toxicity (rectal bleeding during radiation therapy), were significantly lower among the protocol patients (3% vs13%) α = 0.05, p = 0.034. This protocol is feasible in our population and reduces rectum distension at the CT planning scan. In addition rectal bleeding during radiation therapy is significantly lower in protocol patients.