Intraoperative radiotherapy for parotid cancer: a single-institution experience.

PURPOSE: Our practice policy has been to provide intraoperative radiotherapy (IORT) at resection to patients with head-and-neck malignancies considered to be at high risk of recurrence. The purpose of the present study was to review our experience with the use of IORT for primary or recurrent cancer of the parotid gland. METHODS AND MATERIALS: Between 1982 and 2007, 96 patients were treated with gross total resection and IORT for primary or recurrent cancer of the parotid gland. The median age was 62.9 years (range, 14.3-88.1). Of the 96 patients, 33 had previously undergone external beam radiotherapy as a component of definitive therapy. Also, 34 patients had positive margins after surgery, and 40 had perineural invasion. IORT was administered as a single fraction of 15 or 20 Gy with 4-6-MeV electrons. The median follow-up period was 5.6 years. RESULTS: Only 1 patient experienced local recurrence, 19 developed regional recurrence, and 12 distant recurrence. The recurrence-free survival rate at 1, 3, and 5 years was 82.0%, 68.5%, and 65.2%, respectively. The 1-, 3-, and 5-year overall survival rate after surgery and IORT was 88.4%, 66.1%, and 56.2%, respectively. No perioperative fatalities occurred. Complications developed in 26 patients and included vascular complications in 7, trismus in 6, fistulas in 4, radiation osteonecrosis in 4, flap necrosis in 2, wound dehiscence in 2, and neuropathy in 1. Of these 26 patients, 12 had recurrent disease, and 8 had undergone external beam radiotherapy before IORT. CONCLUSIONS: IORT results in effective local disease control at acceptable levels of toxicity and should be considered for patients with primary or recurrent cancer of the parotid gland.

Patient preferences and physician practice patterns regarding breast radiotherapy.

PURPOSE: There are multiple current strategies for breast radiotherapy (RT). The alignment of physician practice patterns with best evidence and patient preferences will enhance patient autonomy and improve cancer care. However, there is little information describing patient preferences for breast RT and physician practice patterns. METHODS AND MATERIALS: Using a reliable and valid instrument, we assessed the preferences of 5,000 randomly selected women (with or without cancer) undergoing mammography. To assess practice patterns, 2,150 randomly selected physician-members of American Society for Radiation Oncology were surveyed. RESULTS: A total of 1,807 women (36%) and 363 physicians (17%) provided usable responses. The 95% confidence interval is < ± 2.3% for patients and < ± 5.3% for physicians. Patient preferences were hypofractionated whole breast irradiation (HF-WBI) 62%, partial breast irradiation (PBI) 28%, and conventionally fractionated whole breast irradiation (CF-WBI) 10%. By comparison, 82% of physicians use CF-WBI for more than 2/3 of women and 56% never use HF-WBI. With respect to PBI, 62% of women preferred three-dimensional (3D)-PBI and 38% favor brachytherapy-PBI, whereas 36% of physicians offer 3D-PBI and 66% offer brachytherapy-PBI. 70% of women prefer once-daily RT over 10 days vs. twice-daily RT over 5 days. 55% of physicians who use PBI do not offer PBI on clinical trial. CONCLUSIONS: HF-WBI, while preferred by patients and supported by evidence, falls behind the unproven and less preferred strategy of PBI in clinical practice. There is a discrepancy between women's preferences for PBI modality and type of PBI offered by physicians. Further alignment is needed between practice patterns, patient preferences, and clinical evidence.

Intraoperative radiation therapy for advanced cervical metastasis: a single institution experience.

BACKGROUND: The purpose of this study is to review our experience with the use of IORT for patients with advanced cervical metastasis. METHODS: Between August 1982 and July 2007, 231 patients underwent neck dissections as part of initial therapy or as salvage treatment for advanced cervical node metastases resulting from head and neck malignancies. IORT was administered as a single fraction to a dose of 15 Gy or 20 Gy in most pts. The majority was treated with 5 MeV electrons (112 pts, 50.5%). RESULTS: 1, 3, and 5 years overall survival (OS) after surgery + IORT was 58%, 34%, and 26%, respectively. Recurrence-free survival (RFS) at 1, 3, and 5 years was 66%, 55%, and 49%, respectively. Disease recurrence was documented in 83 (42.8%) pts. The majority of recurrences were regional (38 pts), as compared to local recurrence in 20 pts and distant failures in 25 pts. There were no perioperative fatalities. CONCLUSIONS: IORT results in effective local disease control at acceptable levels of toxicity. Our results support the initiation of a phase III trial comparing outcomes for patients with cervical metastasis treated with or without IORT.

Accelerated partial breast irradiation: a dosimetric comparison of three different techniques.

PURPOSE: We report the first single-institutional dosimetric comparison of patients treated with three forms of accelerated partial breast irradiation: interstitial HDR brachytherapy, the MammoSite balloon apparatus, and 3D conformal external beam quadrant irradiation (3D-CRT). METHODS: A retrospective dosimetric comparison of interstitial HDR brachytherapy, MammoSite balloon brachytherapy, and 3D-CRT was performed. Thirty patients including 10 from each treatment technique were included for a dosimetric comparison of the dose received by the ipsilateral breast, PTV, heart, and ipsilateral lung. Interstitial patients were treated with 4 Gy in 8 fractions to 32 Gy, and the MammoSite patients were treated with 3.4 Gy in 10 fractions to 34 Gy. 3D-CRT patients were treated with 3.85 Gy in 10 fractions to 38.5 Gy using multiple isocentric beams. The CT images from simulation or implant evaluation were transferred into our 3D treatment planning software. The lumpectomy cavities were outlined for every patient, except the MammoSite patients, where the cavity was defined by the balloon edge. The PTV was constructed as a uniform expansion of 1.5 cm for all interstitial HDR patients, 1.0 cm for the MammoSite patients, and a 1.0 cm expansion in addition to the CTV expansion of 1.0 cm (n=2), and 1.5 cm (n=8) for the 3D-CRT patients. The CTV expansion for 3D-CRT and the PTV expansion for the brachytherapy patients were limited to the chest wall and skin. Normal structures including both ipsilateral lung and breast and heart for left-sided lesions were outlined. The lumpectomy cavity was subtracted from the PTV and normal breast tissue for evaluation. To evaluate dose to the ipsilateral breast and lung, PTV, and heart, a dose-volume histogram (DVH) analysis was performed. All histograms were normalized to the volume of the structure (i.e., expressed as percent volume). RESULTS: The average percentage of the breast receiving 100% and 50% of the prescribed dose (PD) was higher in the 3D-CRT group (24% and 48%, respectively) compared with the MammoSite (5% and 18%, respectively) and interstitial patients (10% and 26%, respectively). Improved coverage of the PTV was noted in the 3D-CRT plans compared with the MammoSite and interstitial HDR plans. With the interstitial HDR technique, 58% of the PTV received 100% of the PD compared with 76% with MammoSite and 100% with 3D-CRT techniques. The percentage of the PTV receiving 90% of the PD was 68%, 91%, and 100% for the interstitial HDR, MammoSite, and 3D-CRT patients, respectively. The ipsilateral lung V20 was slightly higher for 3D-CRT at 5% compared with 0% for both brachytherapy techniques. CONCLUSION: In those treated with 3D-CRT, coverage of the PTV was better with 3D-CRT but varied with the definition used. At the coverage at 90% of the PD, no difference was observed between 3D-CRT and MammoSite (which were both better than interstitial). 3D-CRT resulted in better coverage of the PTV compared with MammoSite or interstitial brachytherapy techniques. Better PTV coverage with 3D-CRT came at the cost of a higher integral dose to the remaining normal breast. Dosimetrically, the best partial breast irradiation technique appears to depend on the clinical situation. Of the brachytherapy techniques, MammoSite appears to be superior in PTV coverage. When comparing MammoSite vs. 3D-CRT PTV coverage at 90% of the PD, the difference was not significantly different.

The validity of surgical clips as a radiographic surrogate for the lumpectomy cavity in image-guided accelerated partial breast irradiation.

PURPOSE: We hypothesize that surgical clips placed in the biopsy cavity during lumpectomy can be used as radiographic markers to facilitate image-guided external beam accelerated partial breast irradiation. METHODS AND MATERIALS: We evaluated 28 patients with surgically placed clips in the lumpectomy cavity and two CT scans on different days. To establish whether the clips remain predictive of the lumpectomy cavity throughout therapy, we analyzed the motion of both cavities with repeat volumetric CT scans. The three-dimensional (3D) locations of each lumpectomy cavity and the associated clips were defined as individual regions of interest (ROIs). A single point of interest (POI) was defined for each ROI. The calculated movements of the lumpectomy cavity POIs between different scans were compared to those of the clip POIs. The second CT data set was then moved in accordance to the calculated clip POI's movement. The volume of the (second) lumpectomy cavity associated with the second scan outside of the (first) cavity of the first scan was measured. In addition, the required amount of a radial margin expansion around the first lumpectomy cavity to ensure coverage of the second lumpectomy cavity both before and after moving the second lumpectomy according to the clip POI movement was calculated. RESULTS: The two CT scans were obtained on average 27 days apart, and the mean lumpectomy size decreased from 35 to 16 cc. The clip and lumpectomy cavity POIs moved a mean of 3 mm along the three principal Cartesian axes. In moving the second lumpectomy cavity according to the clip POI displacement from its original position, the volume of the second lumpectomy cavity outside of the volume of the first decreased from 2.6 cc to 1.0 cc after correction, and the required radial margin on the first lumpectomy cavity to include the second lumpectomy cavity decreased from 5.5 mm vs. 3.8 mm. CONCLUSION: The surgically placed clips after lumpectomy are strong radiographic surrogates for the biopsy cavity. If the clips were used to guide accelerated partial breast irradiation, a planning target volume margin of the order of 5 mm could be used, significantly smaller than the 10-mm margin currently employed.