Breast radiotherapy (RT) using tangential fields (TgF): a prospective evaluation of the dose distribution in the sentinel lymph node (SLN) area as determined intraoperatively by clip placement.

BACKGROUND: Randomized trials have established that patients with limited involvement of sentinel lymph node (SLN) do not require axillary lymph node dissection (ALND). The similar outcome in patients with ≤2 positive SLN with or without additional ALND is attributed, in part, to tangential fields (TgF) RT. We evaluated the dose distribution in the SLN biopsy area (SLNBa) as determined intraoperatively by clips placement for radiotherapy (RT) optimization. METHODS: This prospective study included 25 patients who had breast conservation. Titanium clips were used intraoperatively to mark the SLNBa. All patients had 3D-conformal RT using standard (STgF) or high tangential fields (HTgF). Axillary levels, SLNBa, and organs at risk were contoured on a CT scan. Dose distribution and overlap between TgF and target volumes were analyzed. RESULTS: The average doses delivered to axilla levels I-III and SLNBa were 25, 5, 2, and 33 Gy, respectively. The average dose delivered to SLNBa was higher using HTgF with better coverage of the axilla. Only 12 of 25 patients (48 %) had their SLNBa completely covered by the TgF. There was no impact of TgF size on ipsilateral lung dose. The mean heart dose delivered using STgF was lower than HTgF. CONCLUSIONS: In the era of SLNB, axilla and SNLBa RT technique has to be standardized to deliver adequate dose. We recommend the use of HTgF or direct axillary RT techniques (such as in AMAROS trial) in patients with metastases in SLN without ALND completion, when only TgF are expected to cure potential residual disease in the axilla.

Invasive lobular carcinoma of the breast: MRI pathological correlation following bilateral total mastectomy.

BACKGROUND: Invasive lobular carcinoma (ILC) is more often multifocal and bilateral than invasive ductal carcinoma. MRI is usually recommended for detection of all ILC sites. The performance of known diagnostic breast MRI criteria for ILC characterization has not been evaluated to date using bilateral mastectomy specimens as gold standard. PURPOSE: To determine the value of BI-RADS 2006 MRI criteria for ILC detection and characterization, using pathological examination of bilateral mastectomy specimens as the reference standard. MATERIAL AND METHODS: Between 2004 and 2007, we retrospectively included all patients with pathologically documented ILC referred to our institution for bilateral mastectomy and preoperative bilateral breast MRI. The location, diameter, and characteristics (BI-RADS) of all lesions were compared with pathological findings. The sensitivity and positive predictive value of bilateral breast MRI for the diagnosis of ILC were calculated. Association of MRI BI-RADS categorical variables and characterization of ILC were assessed (Fisher exact test). RESULTS: Among 360 patients treated for ILC in 2004-2007, 15 patients qualified for this study. Thirty-one ILC foci were found on pathological examination (30 ipsilateral and 1 contralateral tumor; mean diameter 23 mm; range 2-60 mm) and all were identified on MRI, with 90% of masses and 10% non-mass-like enhancements; MRI features significantly associated with ILC included absence of smooth margins (P = 0.02) and rim-shaped enhancement (P = 0.039). Enhancement kinetics of the 31 foci were evenly distributed among wash-out, plateau, and persistent profiles. Eleven additional lesions were seen on MRI, mainly corresponding to fibrocystic disease; 91% presented as masses and 9% had a wash-out profile. CONCLUSION: Based on the 2006 BI-RADS criteria, breast MRI shows a high sensitivity for ILC detection, at the expense of a 26% false-positive rate, suggesting that a pathological proof by US- or MR-guided biopsy is required in case of suspicious MRI images in this context.

Long-term results of breast cancer irradiation treatment with low-dose-rate external irradiation.

PURPOSE: The aim of this study was to assess beam therapy with low-dose-rate (LDR) external irradiation in a group of patients with breast cancer. METHODS AND MATERIALS: This trial compared, from 1986 to 1989, patients with advanced breast cancer treated either by conventional fractionation or low-dose-rate (LDR) external radiotherapy (dose-rate 15 mGy/min, 5 sessions of 9 Gy delivered on 5 consecutive days). RESULTS: A total of 21 patients were included in the fractionated therapy arm. At follow-up 15 years after treatment, 7 local recurrences had occurred, 3 patients had died of cancer, 18 patients were alive, 10 were without evidence of disease, and 6 had evidence of disease. A total of 22 patients had been included in the LDR arm of the study. Of these, 11 had received a dose of 45 Gy; thereafter, in view of severe local reactions, the dose was reduced to 35 Gy. There was no local recurrence in patients who had received 45 Gy, although there were 2 local recurrences among the 11 patients after 35 Gy. The sequelae were severe in patients who received 45 Gy but were comparable to those observed in patients treated by fractionated radiotherapy who received 35 Gy. The higher efficacy of tumor control in patients treated by LDR irradiation as well as the lower tolerance of normal tissue are probably related to the lack of repopulation. CONCLUSION: Although the patient numbers in this study are limited, based on our study results we conclude that the data for LDR irradiation are encouraging and that further investigation is warranted.

Role of radiation therapy in melanomas: Systematic review and best practice in 2016.

Radiotherapy has been used for skin cancers since early after the discovery of X-rays. The introduction of sophisticated surgery techniques and information of the general population on potential late radiation-induced toxicity and carcinogenesis have led to limiting indications in the dermatologist community. However, radiotherapy (RT) has undergone considerable developments, essentially including technological advances, to sculpt radiation delivery, with demonstration of the benefit either alone or after adding concomitant cytotoxic agents or targeted therapies. Although side effects due to high doses and/or the use of old RT techniques have been significantly decreased, the risk of atrophic scars, ulcerations or secondary cancers persist. In this systematic review, we aim to discuss indications for RT in melanomas with focus on new advances that may lead to rehabilitating this treatment option according to the tumor radiosensitivity and clinical benefit/risk ratio. Melanomas have been considered as radioresistant tumors for many years.