Results:

This cohort of 503 patients included 298 patients younger than 70-year-old (59%) and 205 patients older than 70 (41%). Patients older than 70 included 134 patients aged 70-79 (27%), 62 patients aged 80-89 (12%) and 9 patients aged 90-100 (2%). Clinical outcomes of 71 patients aged 80 to 100 years (14 % of the entire cohort, median age 83 y) are reported. The median age of the 90–100-year-old group was 92 y. The median age of the 80–89-year-old group was 82 y. The median prescribed dose in both groups was 60 Gy (range 40-65 Gy). 5 patients out of 71(7%) underwent retreatment after previous CK radiosurgery receiving 45 Gy (2) or 40 Gy (3), all achieved stable pain control.
BNI-PS pre-treatment score was V in 39 patients, IV in 25, III in 7, II and I in 0. No patients had post-treatment BNI-PS scores of V and IV. Scores of III, II, and I have been found, respectively, in 9, 27 and 35 patients.

Pre-treatment VAS score was 7-10 in 64 patients, 4-6 in 7 and < 4 in 0. Post-treatment VAS score was 7-10 in 0, 4-6 in 12 and < 4 in 59.

BNI-NS pre-treatment score was one in 62 patients, II in 9, III and IV in 0. BNI-NS post-treatment score was one in 54, 15 in 9, III in 2 and IV in 0.

In summary, pain disappeared or improved in respectively 59 (83%) and 5 (7%) patients while only 2 out of 71 (3%) developed hypoesthesia associated with bothering paresthesias (grade III BNI-NS).

Results: 

Initial pain relief (BNI I–IIIb) was achieved in 71.4% (10/14) after the first RS and 57.1% (8/14) after the second. At 2 years, 57.1% (8/14) maintained adequate control (BNI I–IIIa). Recurrence occurred in 42.9% (6/14), with a median time to recurrence of 14 months (first-treated side) and 18 months (second-treated side). Patients with MS had lower success rates (40% vs. 66.7% in idiopathic TN; p=0.29) and earlier recurrence (median: 11 vs. 16 months). Facial numbness (BNI IV) developed in 21.4% (3/14) after the first RS and 28.6% (4/14) after the second; one patient (7.1%) experienced bilateral mild numbness. No severe complications (e.g., anesthesia dolorosa, motor deficits) occurred. Higher radiation doses (=80 Gy) correlated with better pain control (p=0.04) but increased numbness risk (p=0.07).

Results: 

90% of patients experienced more than 80% tremor relief, while remaining 10% saw over 50% improvement. The multimodal imaging approach significantly enhanced Vim localization, optimizing stereotactic interventions. Internal capsule-based lateral boundary assessment improved tremor control outcomes, reducing inaccuracies seen with conventional techniques. A frameless robotic radiosurgery system proved to be non-invasive, effective alternative to traditional interventions, achieving durable tremor suppression. Statistical analysis confirms that a frameless robotic radiosurgery system significantly improves tremor severity, validating its efficacy for treating tremor-predominant Parkinson’s disease.

Results:

The most commonly used fractionations were 24 Gy in 3 fractions and 25 Gy in 5 fractions; both used in 9 cases. For the 24 Gy in 3 fr we reached median max doses of 33,61 Gy in hypophysis, 13,8 Gy in optic chiasm; 8 Gy left optic nerve and 10 Gy in right optic nerve. Whereas for the 25 Gy in 5 fractions median max doses were 34,15Gy in hypophysis, 22,79 Gy in optic chiasm; 9,73 Gy left optic nerve and 24 Gy in right optic nerve. The median follow-up was 26 months (7-47 months). We have observed that 40% of the adenomas have decreased in size, and the rest have remained stable without any growth. Two out of six functioning patients have achieved biochemical control.

The tolerance of the treatment was excellent. Only in 10 patients (43,5%) acute toxicity was reported consisting of grade 1-2 transient cephalea. Not chronic toxicity was reported except for a single case of transient diplopia with no visual acuity lost, completely recovered after steroids.

Results:

Out of 30 patients, 22 women and 8 men. Mean age 62 years old (39-87). Most common locations were: pontocerebellar angle (14p), cavernous sinus (6p), optic nerve (4p) and others (6p). 13 patients had undergone previous surgery. 83% (25p) received a total dose of 25-30Gy in 5 fractions, 17% (5p) single fraction (14-18Gy). Mean lesion volume 10cc .For the 5 fractions scheme: mean maximum dose (Dmax) in PTV was 46.04 Gy,, mean Dmax in visual pathway 30.67Gy, pituitary 36.69Gy and brainstem 30.50Gy. For 1 fraction scheme: mean Dmax in PTV was 20.96 Gy, mean Dmax in visual pathway 7.46Gy, pituitary 7.97 Gy and brainstem 9.84 Gy.Mean conformation index of 1.3.With a median follow-up of 24 months (3-59) for 26 p who underwent the first control RMI, 100% patients achieved radiological stability. Acute toxicity was reported in 46% of patients presenting minor grade 2 toxicity, most frequently mild transient headache and asthenia. Chronic toxicity was evaluated for 26p, 26% presented minor grade 2 headache (6), neurological deterioration (1) and tinnitus (1). No cases of stroke or cranial nerve palsy were reported. Radiologic radionecrosis occurred in 1 asymptomatic patient.

Results:

The median follow-up was 157 months, representing one of the longest follow-up periods reported. The mean age was 51.9 years, with 50.9% female patients. The median tumor size was 1.7 cm, with a median target volume of 0.94 cc. Median maximum and prescribed doses were 22.5 Gy and 18 Gy, respectively. NF2 patients received higher doses (P=0.016) and had longer follow-up (P=0.012). NF2-associated tumors more frequently presented with higher Koos grades and required additional interventions (P=0.025). CN V deficits correlated with CN VIII symptom resolution (P=0.002). Notably, smokers (P=0.001) and non-hypertensive patients (P=0.001) had higher symptom resolution rates. Local recurrence was higher in those with prior surgery (P=0.048). Remarkably, local control rates were 100% at 2 years, 98.8% at 5 years, 94.2% at 15 years, and 89.3% at 25 years. Overall survival was 100% at 10 years and remained at 97.1% at 25 years.

Results:

Between December 2019 and July 2023, 22 patients (median age: 55 years; range: 28–70 years) were included. According to RANO criteria, 21 patients exhibited tumor response, with 6 achieving complete response, resulting in an objective response rate of 95.5%. Additionally, one patient maintained stable disease without progression. Median progression-free survival (PFS) was 9.1 months (95% CI, 7.5–24.7), with a 6-month PFS rate of 85.7% (95% CI, 71.9–100.0). Median overall survival was 19.5 months (95% CI, 10.6–46.8). Common adverse events included hand-foot skin reactions (40.9%), hypercholesterolemia (27.3%), and hypertension (22.7%). Four patients experienced grade 3 adverse events, accounting for an 18.2% incidence rate. Therapy discontinuation due to ischemic stroke (grade 3) occurred in one patient. No grade 4 events or treatment-related deaths were reported.

Results: 

51 patients with LACC (M0) have been enrolled. At the time of primary diagnosis all patients had FIGO 2009-2018 stage from IIb to IIIC. Median age was 51 years (range 32-72); 42/51 had histological diagnosis of squamous-cell carcinoma HPV-related and 9/51 had histological diagnosis of adenocarcinoma. During concurrent treatments all patients received weekly Platinum-based chemotherapy (40mg/mq) plus radiotherapy to a total dose on clinical target volume (CTV) of 45-50.4 Gy (1.8 Gy/fraction). All patients have been submitted to SBRT-boost (Gold Fiducial tracking) with a median total dose delivered of 21 Gy/3 fraction (range 12-24Gy) on gross tumor volume (GTV) after restaging with contrast-enhanced MRI and 18-FDG-PET. An isotropic margin of 2mm (PTV) on GTV has been applied. To contour we matched simulation-CT with contrast-enhanced MRI using the software for deformable imaging fusion. G1-G2 toxicities were: 62% dysuria, 50% fatigue G2, 10% anemia, 20% leukopenia, 25% thrombocytopenia, 5% diarrhea, 10% nausea and vomiting. None of the patients showed toxicities = G3. Median FU time 10 months (range 1-45 months). We observed Complete/Partial response (CR and PR, respectively) in 82.4% of the cases, with 30/51 CR (58.9%) and 12/51 (23.5%) PR. Progressive disease was reported in 13 patients (7 local progression, 1 local and systemic, 5 systemic).

Results: 

All 20 patients were treated using the SGRT-h technique. The mean breathhold duration was 22 s. Target coverage goals were met for all plans and did not differ between groups. All OAR constraints were satisfied. There was a statistically significant difference in the mean heart dose (150 cGy and 275 cGy for SGRT-h and RC-c respectively, (p<0.007)) and in the heart V30 (0.4% and 5.5% for SGRT-h and RC-c respectively (p<0.03)). There was a trend towards lower mean LAD dose with SGRT-h (225 cGy compared to 275 cGy), however this failed to reach statistical significance (p<0.20). Similarly, a trend towards lower ipsilateral lung V5 and V20 was observed with SGRT-h (40.2 %and 16.3% respectively) compared to RC-c (50.4%and 21.7%), however this was not statistically significant. The questionnaire revealed that patients found the instructions for SGRT-h easier to understand and the treatment less restrictive.

Results:

The measured respiratory curve closely matched the simulated motion, with amplitude differences under 0.1 mm and cycle variations of 0.1 seconds. Minor artifacts affected gating accuracy by less than 0.7 mm. Gamma pass rates for 2 to 5 mm gating tolerances were ≥ 95%, indicating high system accuracy (Figure 1). Gating thresholds over 5 mm showed decreased but acceptable performance, while non-gated delivery yielded unacceptable gamma pass rates.

Results:

179 patients (15 of whom had bilateral cancer) were treated between 2009 and 2015 with helical tomotherapy for non-metastatic breast cancer. The median age of the patients was 53 years. Of these, 189 were treated for non specific invasive carcinoma, while 5 patients were treated for carcinoma in situ.

85.1% of patients had lymph node irradiation associated with breast or chest wall irradiation. 152 of the 163 irradiated breasts received a boost at the lumpectomy bed. The median duration of treatment was 46 days.

After a median follow-up of 10 years, there were 9 local recurrences, 2 regional lymph node recurrences and 29 patients had metastatic progression. Only 18 patients died at the end of the study, of whom 7 were cancer-related.

At 10 years, local recurrence-free survival was 95.3%, locoregional recurrence-free survival was 94.5%, metastasis free survival was 82.9%, specific survival was 94.3%, and overall survival was 88%. The occurrence of local, regional or distant recurrence correlated neither with HR or HER2 status, nor with grade, nor with the presence of emboli. In terms of molecular subgroups, recurrence-free survival was 86.3%, 90.9% and 76.7% respectively for the triple negative, HER+ and RH+/HER2- subgroups.

In terms of acute skin toxicities, 96 patients presented grade 1 radioepithelitis, 72 grade 2 and 6 grade 3. 40 patients had late skin toxicity at last follow-up. No grade 3 or higher acute or late toxicity and no radiation-induced late pulmonary or cardiac toxicity was reported.

Results:

Fifty-four women (median age 66.5 years, range 51–83) were enrolled from March 2016 to May 2021. Median follow-up of the cohort is 60 months (range 0-100 months). 83.3% of women had IDC while 16.7% had DCIS. 87% were Caucasian, 9.3% African American, 1.9% Asian.

All patients received 30 Gy in 5 fractions. The median treatment duration was 9 days (range 7–14). The median CTV expansion was 10 mm (range 5-10) and PTV expansion was 3 mm (range 2-5 mm). The median PTV volume was 116 cm³ (IQR 69-156), and the median prescription isodose line was 81.5% (IQR 80-83).

There was 1 ipsilateral breast tumor occurrence with no local, regional, or distant failures. 5-year actuarial survival was 87%. No deaths were directly attributed to breast cancer. Two patients withdrew from the protocol. Grade 1 skin toxicity occurred in 5 patients (9.3%) at 1-month follow-up; no grade 2-4 toxicity was observed. Cosmetic outcomes at 5 years were rated excellent in 60% and good in 40%. Neither fat necrosis nor breast pain were reported at last follow-up.

Results: 

From 12/2019 to 5/2024, 14,15 and 15 pts were treated with median follow-up of 35,36,12.6 mo for 30,34 and 38Gy, achieving pCR+nCR rates of 64.3%, 93.3% and 93.3% respectively. For the 30Gy group, MTS post-SPBI was 5.9 mo (range 2.8-11.7) with 35.7% (5/14) achieving pCR and 64.3% (9/14) achieving pCR/nCR. MTS for 34Gy was 7.3mo(range 5.3-12): 7/15 (46.7%) had pCR while 14/15 (93.3%) had pCR/nCR. MTS for 38Gy was 11.4mo (range 8.4–12.9):10/15 (66.7%) pCR, while 14/15(93.3%) had pCR/nCR.

A time-to-surgery cutoff of 277 days best distinguished MP grade 5 (pCR), yielding an AUC of 0.765 (95% CI: 0.617 – 0.912), sensitivity 0.818, specificity 0.727. When evaluating pts who had surgery >270 days post radiation, 100%, 66.7% and 64.3% achieved pCR (p = 0.40) and 100%, 83.3%, and 92.9% achieved pCR/nCR when treated with 30Gy, 34Gy and 38Gy respectively (p = 0.69).

Tumor size >11.5mm (AUC=0.56, 95% CI: 0.37-0.74) is less likely to have a MPS of 5, but only has a sensitivity of 0.67 and +predictive value 0.58, suggesting that tumor size alone is not the best predictor of pCR. Combining MTS + size results in AUC of 0.79(95% CI:0.63-.93), with sensitivity=0.91and specificity=0.64.

Of the 15 pts with a nCR 53.3% had =3mm of residual disease. The mean ki67 was 11.0% at diagnosis and 1.8% at surgery.

There were 59 acute grade 1; 3 acute grade 2 (breast pain and dermatitis); 2 late grade 2 (breast pain and surgical washout), and 1 grade 3 (slow healing wound ulceration in a pt with uncontrolled diabetes in the 30 Gy cohort).

Results:

From 11/2023 to 10/2024, twelve Pca patients with a median age of 76.9 (67.2-81.2) were enrolled. Three were HR, 5 UIR, and 4 favorable intermediate risk. Median initial PSA was 8.68 (2.9-18.15) ng/ml; one patient was ISUP grade 5, two patients 4, one patient 3, and 8 patients 2. Three patients presented grade (G)2 Genito-urinary toxicity, and 7 G1. Six patients presented G1 gastro-intestinal toxicity.

Results:

A total of 18 patients with a median age of 73 years completed treatment, with a median follow-up of 6.43 months. Prostate cancer distribution was as follows: low (n=2, 11%), favorable intermediate (n=10, 56%), and unfavorable intermediate (n=6, 33%). The decipher score distribution was as follows: low (n=8, 44%), intermediate (n=3, 17%), and high (n=7, 39%). Of the entire cohort, median prostate volume was 39.5 cc, 61% (n=11) underwent an intraprostatic micro boost with 5 patients due to an elevated decipher score, and 17% (n=3) received ADT as a component of treatment. With early follow-up, we observed only one instance of acute grade 2 GU and GI toxicity (5.5%) that occurred 9 days after treatment completion and resolved at the 1 month follow up. No instance of severe GU or GI toxicity was reported.

Results: 

There were no differences in age (69 vs 72 p=0.1), PSA (7.8 vs 7.5 p=0.3), or prostate volume (39 v 38 ml p=0.9) in those with or without RS, respectively. Use of RS was associated with more intermediate/high risk (96% v 85% p<0.001), ADT use (52% v 39% p<0.001), more Caucasian patients (63% v 55% p<0.001), and treatment more recently (p<0.001). Baseline EPIC scores were not different (Table). Declines in EPIC scores following SBRT were small with the majority approaching baseline after 6 mo and remaining stable up to 5 yrs. Mean QOL decline met pre-defined thresholds for minimally important difference (MID) only for urinary obstructive, bowel, and hormonal/vitality QOL at 1 mo and then recovered. At no time did any mean meet a threshold for 2x MID. No significant differences were observed in any QOL domain for those who received RS or not (all p>0.1). Sexual function was also not different if limited to those with baseline EPIC >60 and no ADT use (p>0.3).

Results:

Thirty-three patients (median age of 66, 85% Caucasian) completed SBRT. Sixty-seven percent were stage T1c, 84.8% had a Gleason score of 7 and 57.6% were primary grade 4. Median baseline PSA was 6.5, with a median of 42% positive cores. 85% of our patients had unfavorable intermediate risk prostate cancer. The median duration of ADT was 6 months. Seventy nine percent received PI-RADS 4/5 simultaneous integrated focal boost. Median follow-up was 36 months. Toxicity was low with AUA scores peaking at 1 month (median=11, vs. baseline median AUA of 4.5) improving by three months (median=5) and stabilizing at 3-4 from 24 to 60 months. No grade 3-5 RTOG acute or late urinary or bowel toxicity was observed. Among patients with at least 24 months of follow-up (n=23), median PSA was 0 (range 0-0.6). At 36 months (n=18), 48 months (n=13), and 60 months (n=10), median PSA remained 0, with maximum PSA of 0.2, 0.09, and 0.05, respectively.

Results:

Baseline characteristics were similar between the SBRT (584 treated / 607 allocated) and MHRT (608 / 601) groups. Median age was 73.1 vs 72.4 years; intermediate-risk disease (NCCN criteria) was present in 65% vs 63%, and high-risk in 35% vs 37%; median PSA was 8.5 ng/mL vs 8.3 ng/mL. Late toxicity data were available for 584 SBRT and 604 MHRT patients. At two years, RTOG G2+ GU toxicity was higher with SBRT vs MHRT (9% (46/536) vs 3% (14/555), p<0.0001), as was CTCAE G2+ GU toxicity (13% (70/544) vs 4% (20/560), p<0.0001). Cumulative RTOG/CTCAE G2+ GU incidence was 24% (135/583) / 32% (184/583) for SBRT and 10% (57/602) / 13% (77/602) for MHRT. GI toxicity at two years was similar between SBRT and MHRT: RTOG G2+ GI toxicity (2% (9/537) vs 2% (11/557), p=0.71), and CTCAE G2+ GI toxicity (3% (19/544) vs 3% (17/560), p=0.67). Cumulative RTOG/CTCAE G2+ GI incidence was 8% (48/582) /13% (75/582) for SBRT and 6% (33/601) / 10% (60/602) for MHRT. G3+ GI and GU toxicities at two years were <2% for both groups. MCID in UO at two years was significantly higher with SBRT vs MHRT (46% (191/418) vs 27% (120/447), p<0.0001), though no significant difference was seen in UI (32% (144/445) vs 25% (117/470), p=0.012) or bowel function (38% (169/447) vs 32% (147/466), p=0.047).

Results:

Total 153 patients were randomized from 2016 to 2024 (RT = 77, Obs = 76). Overall, 62% patients had pT3-T4 and 41% had pN+ disease, and a variant histology component in 28% patients. Chemotherapy was neoadjuvant for 71% and adjuvant for 20% patients. No patients received immunotherapy. In RT arm, 63 received planned RT and 14 (defaulted/refused RT = 8, pre-RT progression =4, RT deemed unfeasible = 2) were analyzed with the Obs group (n=90).

Over a median follow-up was 23 months (42 months for survivors), 37% patients had recurred, with 18% locoregional recurrences (RT 8% vs Obs 26%, p=0.006). Two-year LRFS was 65.3% (RT) vs 57.4% (Obs) (HR 0.74, 95% CI 0.46-1.19, p=0.22). Two-year DFS was 59.9% vs 52.8% (HR 0.74, 0.47-1.17, p=0.20), and BCSS was 77.6% vs 64.4% (HR 0.57, 0.31-1.07, p=0.07) respectively. RT showed significantly better LRFS (sHR 0.55, 0.31-0.97, p=0.04) and DFS (sHR 0.55, 0.32-0.95, p=0.03) in competing risk analysis. Overall, 45% patients died (31% due to disease, 14% other cause). Two-year OS was 68.1% (RT) vs 57.0% (Obs) (HR 0.80, 0.49-1.30, p=0.4). There were no isolated locoregional recurrences in the RT arm, with 2-year locoregional control 91.2% (RT) vs 76.4% (Obs) (HR 0.27, 0.10-0.71, p=0.004). Subgroup analysis showed significant benefit with RT in T3-T4 (sHR LRFS 0.40, DFS 0.42) and N+ disease (sHR LRFS 0.39, DFS 0.40). Late grade 3+ toxicity was similar (RT 8.5% RT vs Obs 10.5%, p=0.6).

Results:

10 patients died prior to 18 months after treatment or were lost to follow up, with none reporting myelopathy. 109 patients had records from phone clinic, hospital clinic attendance, or GP records where patients were assessed. No cases of myelopathy were recorded. In 49/130 patient treatments, CordPRV dose was above recent tolerance 2022 dose consensus tolerance [1] but below TG101 tolerance [3]. In 109/130 patient treatments, the spinal canal was above 22Gy(0.1cc), and within [1] and [3] 24Gy tolerance.

Results:

Forty-eight lesions in 43 patients (median age: 65; range: 20-78) were reviewed. One patient required separation surgery for severe ESCC (Bilsky grade 3). The median clinical target volume (CTV) was 63.77 cm³, and the median margin dose was 24 Gy. Over a median follow-up of 8 months, local tumor control was 91.1% at 6 months, 87.1% at 1 year, 82.8% at 3 years, and 62.1% at 5 years. Median overall survival was 17 months. Of the 21 lesions exceeding dose constraints, only one patient exhibited clinical myelopathy, which correlated with local tumor recurrence. No radiographic myelopathy or other radiation-induced complications were observed.

Results: 

Sixteen patients were initially accrued from 2018-2023, the trial closed to slow accrual due to COVID-19. 13 patients were treated successfully with SBRT boost following 3DCRT, meeting the primary outcome (0.81, 0.57-0.93). Median baseline motor score was 7 normal (range 2-7), pain score was 5.5 (1-10), and most patients were ambulatory. Most had a solitary spinal site of metastasis (53.3%), and Bilsky 1c or 2 MESCC (66.7%). A majority received 20 Gy/5 fraction 3DCRT (81.3%), and SBRT boost was given a median of 36 days afterwards (33-50.1 IQR). Motor function was maintained in 76.9% and improved by 2 points from baseline in 15.4% of patients at 1-month post-SBRT boost and was subsequently maintained in patients at 3 and 6 months. Ambulatory function improved in 15.4% and was maintained in 69.2% of patients at 1 month, and improved again at 3- and 6-months post SBRT in 18.2% and 12.5% respectively. Pain improved in 23.1%, 18.2% and 37.5% of patients at 1, 3 and 12 months respectively. Only 1 Grade 3 toxicity (chest wall pain) occurred which resolved at 3 months. Median global QoL improved from baseline (69.2), to 76.3, 76.6 and 82.5 at 1,3 and 6 months respectively. BM 22 scores improved in functional and pain domains at 1,3, and 6 months. There were 2 local recurrences (143 and 236 days), and median survival of the entire cohort was 8.9 months (7.8-NR)

Results:

The median follow-up was 21 months (1-60). Local control at 24 months for patients receiving single-fraction SBRT was 92.1% compared to 88% for those treated with fractionated schemes. The median progression-free survival has not been reached. At two years local relapse free survival was 90%.

Median overall survival was 40 months. The two-year overall survival was 65.4%. There was no significant difference in overall survival between the different fractionation regimens.

Regarding tolerance, 89.6% of patients experienced no acute toxicities from SBRT. Seven patients reported acute toxicity, none exceeding grade II. The most common acute side effects included asthenia followed by esophagitis and enteritis.

6 cases of vertebral compression fracture (VCF) have been reported out of 73 lesions treated (8.22%). All cases of VCFs occurred in patients treated with a single fraction. There are no significant differences in the maximum dose in PTV or in the degree of previous SINS related to the VCFs cases.

Results:

In total, 52 patients were included, and 55 online adaptive treatments were performed. An adaptive plan was chosen in 58% of fractions and 78% of patients were treated with at least one adaptive plan. This resulted in a significantly higher given GTV Dmean compared to the planned dose (100.6 BED10 vs. 95 BED10, P< 0.001). The dose to D0.5cc of the gastro-intestinal organs (GIO) was 2.3 Gy EQD2 higher for the SOC plan on the fraction CT compared to the SOC plan on the original planning CT (P=0.009), this finding represents the dosimetric impact of inter-fraction motion without plan adaption. The GIO D0.5cc was also 2.7 Gy EQD2 higher (p=0.01) on the fraction CT with the given plan compared to the SOC plan on the planning CT scan. However, no significant difference in GIO D0.5cc was found between the SOC plan on the fraction CT and the given plan on the fraction CT: this increased dose is not an effect of plan adaption.

Results: 

Between April 2020 and September 2024 a total of 26 oligometastatic lesions located in the peritoneum or in the abdominal wall detected in 20 patients received SBRT with Helical TomoTherapy. All cases have been assessed in multidisciplinary team. Only in three patients out of 20, more than one lesion received SBRT: 2 lesions in 2 patients, and five lesions in a single case of colorectal cancer with ongoing 3rd line systemic treatment. Median total dose was 30 Gy (27-35 Gy) in 5 fractions (3-5). The most frequent primary neoplasm was ovarian cancer in 14/20, endometrial in 2/20, while the remaining were colorectal, vaginal, pancreatic and non-small cell lung cancer. Four lesions were located in the abdominal wall, while the remaining 22 in the peritoneum. Concurrent systemic therapy was administered in 18/20 patients. With a median follow-up of 15 months (range, 6-59), our 1-year LC was 100%, while 1-year DPFS, PMFS, TNTS and OS rates were 54%, 69%, 61% and 83%, respectively. At statistical analysis, abdominal wall lesions were significantly related to improved OS rates (p=0.03), as well as patients who developed a further oligometastatic progression treated with a second course of SBRT (p=0.04). No G=3 adverse events occurred.

Results:

Median follow-up was 36 months. Grade (G)1 and 2 acute toxicity was observed in 8.1% of patients. No G≥3 acute toxicity was observed. Late toxicity was low, only 5% of patients presented a G1 toxicity. Complete response was found in 61.6% of lesions (only 5% of patients did not respond to SBRT). Twelve- month LRFS and DFS were 89.4% and 37%; at 24 and 36 months LRFS and DFS were 87.9% and 19.9%, respectively (Fig. 1). OS was 81.5% at 12 months, 68% at 24 months and 19.9% at 36 months.

The 1- and 2 year actuarial DFS rate were 42% and 23% in patients with complete response versus 23% and 9% in patients with partial response, stable, or progressive disease (p=0.005) (Fig.2).