Mismatch Repair system protein deficiency as a resistance factor for locally advanced rectal adenocarcinoma patients receiving neoadjuvant chemo-radiotherapy.

BACKGROUND: Available data on Mismatch Repair system (MMR) deficiency are conflicting and derived from small studies. Our study aimed to evaluate the therapeutic implications of MMR status in patients with locally advanced rectal cancer (LARC). METHODS: We retrospectively collected data from 318 patients affected by LARC treated in Italy at the Medical Oncology Units of the University Hospital of Cagliari, Istituto Nazionale dei Tumori Milan, and AOU Ospedali Riuniti Ancona. All patients underwent neoadjuvant chemoradiotherapy. The primary objective was major TRG while secondary objectives were pathological complete response, disease-free survival (DFS) and overall survival (OS). RESULTS: One hundred sixty patients (148 pMMR and 12 dMMR) were included in the exploratory cohort and 158 (146 pMMR and 12 dMMR) were included in the validation cohort. A major TRG has been shown in 42.6% and 43.1% patients with pMMR in exploratory and validation cohort, respectively; while no major TRG have been shown in dMMR patients in both cohorts. Exploratory and validation cohorts showed a statistically significant higher mDFS in pMMR patients compared to dMMR: NR vs. 14 months and NR vs. 17 months, respectively. CONCLUSION: Our results indicated an association between dMMR and poor response to preoperative chemoradiotherapy and they represent a hypothesis-generating data for new neoadjuvant strategies.

Preventive sparing of spinal cord and brain stem in the initial irradiation of locally advanced head and neck cancers.

Since reirradiation in recurrent head and neck patients is limited by previous treatment, a marked reduction of maximum doses to spinal cord and brain stem was investigated in the initial irradiation of stage III/IV head and neck cancers. Eighteen patients were planned by simultaneous integrated boost, prescribing 69.3 Gy to PTV1 and 56.1 Gy to PTV2. Nine 6 MV coplanar photon beams at equispaced gantry angles were chosen for each patient. Step-and-shoot IMRT was calculated by direct machine parameter optimization, with the maximum number of segments limited to 80. In the standard plan, optimization considered organs at risk (OAR), dose conformity, maximum dose < 45 Gy to spinal cord and < 50 Gy to brain stem. In the sparing plans, a marked reduction to spinal cord and brain stem were investigated, with/without changes in dose conformity. In the sparing plans, the maximum doses to spinal cord and brain stem were reduced from the initial values (43.5 ± 2.2 Gy and 36.7 ± 14.0 Gy), without significant changes on the other OARs. A marked difference (-15.9 ± 1.9 Gy and -10.1 ± 5.7 Gy) was obtained at the expense of a small difference (-1.3% ± 0.9%) from initial PTV195% coverage (96.6% ± 0.9%). Similar difference (-15.7 ± 2.2 Gy and -10.2 ± 6.1 Gy) was obtained compromising dose conformity, but unaffecting PTV195% and with negligible decrease in PTV295% (-0.3% ± 0.3% from the initial 98.3% ± 0.8%). A marked spinal cord and brain stem preventive sparing was feasible at the expense of a decrease in dose conformity or slightly compromising target coverage. A sparing should be recommended in highly recurrent tumors, to make potential reirradiation safer.

Treatment Volume, Dose Prescription and Delivery Techniques for Dose-intensification in Rectal Cancer: A National Survey.

BACKGROUND/AIM: The aim of the study was to investigate boost volume definition, doses, and delivery techniques for rectal cancer dose intensification. PATIENTS AND METHODS: An online survey was made on 25 items (characteristics, simulation, imaging, volumes, doses, planning and treatment). RESULTS: Thirty-eight radiation oncologists joined the study. Twenty-one delivered long-course radiotherapy with dose intensification. Boost volume was delineated on diagnostic magnetic resonance imaging (MRI) in 18 centres (85.7%), and computed tomography (CT) and/or positron emission tomography-CT in 9 (42.8%); 16 centres (76.2%) performed co-registration with CT-simulation. Boost dose was delivered on gross tumor volume in 10 centres (47.6%) and on clinical target volume in 11 (52.4%). The most common total dose was 54-55 Gy (71.4%), with moderate hypofractionation (85.7%). Intensity-modulated radiotherapy (IMRT) was used in all centres, with simultaneous integrated boost in 17 (80.8%) and image-guidance in 18 (85.7%). CONCLUSION: A high quality of treatment using dose escalation can be inferred by widespread multidisciplinary discussion, MRI-based treatment volume delineation, and radiation delivery relying on IMRT with accurate image-guided radiation therapy protocols.

Surgery and radiotherapy in the treatment of malignant parotid tumors: a retrospective multicenter study.

AIMS AND BACKGROUND: Major salivary gland cancers are rare, with many histologic types and subtypes. The low incidence and heterogeneity of primary parotid carcinomas makes their outcome difficult to evaluate. Treatment remains primarily surgical, but optimal therapeutic regimens have yet to be fully realized. The present study reviews the experience of three Italian institutions in the treatment of primary parotid carcinomas in order to describe the clinicopathological presentation and treatment options with emphasis on radiotherapy and to analyze the factors influencing survival. METHODS AND STUDY DESIGN: The records of 110 patients with primary parotid neoplastic lesions treated at three Italian institutions from 1993 to 2004 were retrospectively reviewed. Six patients were excluded from the study: 3 received surgery alone and 3 were not assessable, for a total of 104 assessable patients. Acute and late toxicity of radiotherapy was quantified following the recommendations of the RTOG/EORTC. Survival was analyzed by the actuarial Kaplan-Meier product-limit method. The influence of selected factors on 10-year disease-specific survival was analyzed. RESULTS: The 104 assessable patients were treated as follows: 11 patients received radiotherapy as their only treatment (3 with a palliative purpose) and 93 had postoperative radiotherapy. Thirty-two patients underwent neck dissection: neck lymph node metastases were found in all them. Their mean age was 60 years (range, 14-92). According to the UICC/2002 TNM Classification, 8 patients were stage I, 19 stage II, 34 stage III, 25 stage IVA, 5 stage IVB, 3 recurrent and 10 not assessable (Tx). The most frequent histologies were adenoid cystic carcinoma (n = 16), mucoepidermoid carcinoma (n = 15), and acinic cell carcinoma (n = 15). Twenty-three patients had recurrences: 10 had local recurrences, 3 neck recurrences, 9 distant metastases, and 1 patient had both local recurrence and distant metastases. No factors were observed that would negatively influence the prognosis. Actuarial 10-year disease-specific survival was 71% and actuarial 10-year local control 82%. CONCLUSIONS: The treatment of salivary gland malignancies remains primarily surgical. Our study confirms the results of the literature with surgery and adjunctive radiotherapy in patients with advanced-stage disease. No variables were observed to influence the prognosis.

Brain metastases from endometrial carcinoma: report of three cases and review of the literature.

AIMS AND BACKGROUND: Endometrial carcinoma is a rare cause of brain metastases, accounting for less than 1% of all metastatic lesions to the brain. This report aims to review our experience in the treatment of patients with brain metastases from endometrial carcinoma in order to establish the characteristics of these patients and evaluate the results and efficacy of whole-brain radiation therapy as a palliative measure. METHODS: Three cases of brain metastases from endometrial carcinoma treated with radiotherapy were identified in the files of the Division of Radiotherapy at the A. Businco Regional Oncological Hospital of Cagliari between 1999 and 2005. RESULTS: All patients had brain metastases as the only sign of systemic disease (a single lesion in 2 patients and 2 lesions in 1 patient). Two patients were classified as RTOG RPA class I and 1 patient as class III. Radiotherapy to the brain was delivered after surgical resection in the first 2 patients and as the only method of palliation in the third patient. The delivered radiation dose was 3000 cGy in 10 fractions over 2 weeks in the postoperative setting and 2000 cGy in 5 fractions over 1 week to the patient treated with irradiation alone. The 2 surgically treated patients are alive and well after 16 and 64 months, respectively. The patient treated with palliative intent died 2 months after irradiation. CONCLUSIONS: The combination of surgery and postoperative whole-brain irradiation in selected patients with solitary brain metastases from endometrial carcinoma is an effective method of palliation.

Planning hybrid intensity modulated radiation therapy for whole-breast irradiation.

PURPOSE: To test tangential and not-tangential hybrid intensity modulated radiation therapy (IMRT) for whole-breast irradiation. METHODS AND MATERIALS: Seventy-eight (36 right-, 42 left-) breast patients were randomly selected. Hybrid IMRT was performed by direct aperture optimization. A semiautomated method for planning hybrid IMRT was implemented using Pinnacle scripts. A plan optimization volume (POV), defined as the portion of the planning target volume covered by the open beams, was used as the target objective during inverse planning. Treatment goals were to prescribe a minimum dose of 47.5 Gy to greater than 90% of the POV and to minimize the POV and/or normal tissue receiving a dose greater than 107%. When treatment goals were not achieved by using a 4-field technique (2 conventional open plus 2 IMRT tangents), a 6-field technique was applied, adding 2 non tangential (anterior-oblique) IMRT beams. RESULTS: Using scripts, manual procedures were minimized (choice of optimal beam angle, setting monitor units for open tangentials, and POV definition). Treatment goals were achieved by using the 4-field technique in 61 of 78 (78%) patients. The 6-field technique was applied in the remaining 17 of 78 (22%) patients, allowing for significantly better achievement of goals, at the expense of an increase of low-dose (∼5 Gy) distribution in the contralateral tissue, heart, and lungs but with no significant increase of higher doses (∼20 Gy) in heart and lungs. The mean monitor unit contribution to IMRT beams was significantly greater (18.7% vs 9.9%) in the group of patients who required 6-field procedure. CONCLUSIONS: Because hybrid IMRT can be performed semiautomatically, it can be planned for a large number of patients with little impact on human or departmental resources, promoting it as the standard practice for whole-breast irradiation.